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Title:
A CLIP FOR USE IN A PANEL ASSEMBLY SYSTEM, AND A PANEL ASSEMBLY SYSTEM UTILISING SUCH A CLIP
Document Type and Number:
WIPO Patent Application WO/2019/145106
Kind Code:
A1
Abstract:
A clip for a panel assembly system, a panel assembly system, and a method of assembling such a panel assembly system are disclosed. The clip is a mechanically intermediate component by means of which functional or decorative spars or planks of the system are secured to supporting and in most cases underlying framework members. The clip itself comprises a body portion whose cross- sectional shape comprises a web portion and a pair of spaced apart flanges both being provided on a first front side of the web portion and projecting upwardly therefrom away from the web portion. Each of said flanges is provided at their remote ends with nib formations which project from the ends of said flanges in a direction substantially parallel with the web portion such that together, the web portion, the flanges and the nibs define at least a pair of spaced apart essentially parallel channels extending over at least a portion of the width or height of said clip. On the second, rear side of the web portion of the clip, there is further provided one or more elongate ribs which are of a cross-sectional shape such that said one or more ribs defines at least a corresponding number of grooves with the rear side of said web portion. Each framework member of the system is provided with formations which are complementary to the shape of the elongate ribs so that any clip can be slidingly connected to any framework member. I n preferred embodiments, the elongate ribs of the clips and the complementary formations provided on the framework members are dovetail-like in configuration, with corresponding formations of the framework members being received within the grooves defined by and behind the elongate ribs of the clips. Most advantageously, the clip is further provided with one or more elongate projections extending beyond at least one end of the web portion and generally parallel with the one or more elongate ribs such that when first and second identical clips are connected to any sing le framework member one after another, the remote free ends of the one or more elongate projections of the second clip ultimately abut the first clip thereby ensuring that the web portions of respective first and second clips are spaced apart by a distance substantially equal to the length of the one or more elongate projections. The cross-sectional shape of the spars, at least behind their functional or decorative surface, is further complementary with the flange and nib formations provided on the clips such that spars can be manually push- or snap-fitted between two or more appropriately positioned clips having already been connected to the framework members.

Inventors:
GILMARTIN, Lionel (13 Tithebarn Road, Hale Barns, Altrincham Greater Manchester WA15 0HR, WA15 0HR, GB)
Application Number:
EP2018/086367
Publication Date:
August 01, 2019
Filing Date:
December 20, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
CLIPFIT LIMITED (Regency House, 45-51 Chorley New Rd, Bolton Lancashire BL1 4QR, BL1 4QR, GB)
International Classes:
E04F13/08; E04F15/02
Domestic Patent References:
WO2010004539A12010-01-14
WO2015170205A12015-11-12
Foreign References:
AU2015202234A12016-11-17
US7010894B12006-03-14
Attorney, Agent or Firm:
OPUS IP LIMITED (Orchard House, 41 Altrincham Road, Wilmslow Cheshire SK9 5NG, SK9 5NG, GB)
Download PDF:
Claims:
CLAI MS

1. A clip for a panel assembly system including at least one framework member with which said clip is to be connected, said clip having a body portion whose cross-sectional shape comprises a web portion and a pair of spaced apart flanges both being disposed to a first and the same side, being a front side of said web portion and projecting therefrom, each of said flanges being provided at their remote ends with nib formations which project from the ends of said flanges in a direction su bstantially parallel with the web portion such that together, the web portion, the flanges and the nibs define at least a pair of spaced apart essentially parallel channels extending over at least a portion of the width or height of said clip which is further provided, on a second, rear side thereof, with one or more elongate ribs which are of a cross-sectional shape such that said one or more ribs defines at least a corresponding number of grooves with the rear side of said web portion such that when said one or more ribs are slidingly received within or disposed arou nd complementarily shaped formations provided on or proximate at least one su rface of said at least one framework member, said complementary formations are received in said grooves interlocking fashion whereby said clip is essentially connected to said framework member,

characterised in that

the web portion is provided with one or more elongate projections extending beyond at least one end of the web portion and generally parallel with the one or more elongate ribs such that when first and second identical clips are con nected to said framework member one after another, the remote free ends of the one or more elongate projections of the second clip u ltimately abut corresponding areas of the first clip thereby ensuring that the web portions of respective first and second clips are spaced apart by a distance substantially equal to the length of the one or more elongate projections.

2. A clip according to claim 1 wherein the one or more elongate ribs extend across one su rface of the web portion of the clip in a direction which is generally perpendicu lar to that along which the chan nels extend, said channels being partially defined by the opposite su rface of said web portion on which said one or more elongate ribs is provided.

3. A clip according to any preceding claim wherein the one or more elongate projections extend from, and form part of, the one or more elongate ribs.

4. A clip according to any preceding claim wherein the interlocking connection between said clip and the framework member to which it is con nected is dovetail-like in configuration, with respective complementary formations of suitable shape being provided on both clip and framework member.

5. A clip according to any preceding claim wherein the nib formations are provided with one or more of:

- a first profiled surface along a front side thereof, said first su rface terminating at or proximate the free ends of said nib formations,

- a second profiled surface along a rear side thereof, said second surface also terminating at or proximate the free ends of said nib formations.

6. A clip according to any preceding claim wherein the length of each of the pair of nib formations provided at the ends of the flange portions, said length being measu red in the direction that said nib formations project towards or away from one another, is one of: identical, and different.

7. A clip according to claim 3 and any claim dependent thereon wherein the ends of the one or more elongate ribs of the clip opposite the remote free ends of the elongate projections are disposed substantially behind the rear surface of the web portion of said clip.

8. A clip according to claim 3, and a ny of claims 4-6 when dependent on claim 3 wherein the ends of the one or more elongate ribs of the clip opposite the remote free ends of the elongate projections project beyond the rear surface of the web portion of said clip.

9. A clip according to either of claims 7 or 8 wherein one or both of the remote free ends of the one or more elongate projections, and the opposite ends of the elongate ribs, are inclined relative to the longitudinal axis of the one or more elongate ribs, and at the same ang le of inclination.

10. A clip according to any of claims 7-9 wherein the ends of the one or more elongate ribs of the clip, and the opposite remote free ends of the elongate projections are provided with complementary formations which are capable of being interlocked to at least some extent and whereby adjacent clips may be at least partially connected to one another by means of such interlock.

1 1. A clip according to any preceding claim, wherein the clip is provided with a pair of spaced apart elongate ribs, symmetrically and laterally on either side of a central axis of the web portion of the clip which, together with the su rface of the web portion on which said ribs are provided, define shallow channel therebetween.

12. A clip according to any of claims 1 - 10 wherein the clip is provided with a single elongate rib formation disposed substantially centra lly of the web portion of the clip.

13. A clip according to any preceding claim wherein the total width of the one or more elongate ribs is one of: 0.7-0.8, 0.6-0.7, 0.5-0.6, 0.4-0.5, and 0.3-0.4 times the total width of the web portion of the clip.

14. A clip according to any preceding claim wherein the total length of any one elongate rib and a corresponding elongate projection, whether forming part of said elongate rib or not as the case may be, is one of; 1.2- 1.6, or 1.2 - 2, or 1.5-2.5 times the total depth of web portion of the clip.

15. A clip according to any preceding claim wherein in the clip is injection mou lded and constituted su bstantially of a plastics material having an inherent resiliency.

16. A clip according to any preceding claim wherein the clip is made of one of: Acrylonitrile butadiene styrene, and nylon.

17. A clip according to any preceding claim, and further provided with one or more of: one or more countersu nk apertu res through the web portion of the clip body, and one or more apertures provided in at least one of the two spaced apart flanges which project outwardly from the front side of the web portion of the clip.

18. A clip according to claim 1 1 and any claim dependent thereon wherein at least one of the flanges of the clip projecting from the front su rface of the web portion is discontinuous in that it consist of two separate, spaced apart flange portions which together define an opening therebetween which is at least partially coincident with the shallow cha nnel defined between the two elongate ribs provided on the opposite side of the clip web portion.

19.. A clip according to claim 18 fu rther provided, on the rear surface of the web portion on which the elongate ribs are disposed, with at least one indentation adapted to receive therein a formation provided at a free end of an appropriately shaped and sized locking clip, and whereby such a locking clip can be releasably connected with said clip.

20. A panel assembly system comprising a panel assembly system comprising at least two spaced apart framework members arranged su bstantially parallel with one another, at least one spar adapted to be connected to said framework members so as to be orientated substantially perpendicu lar relative to each thereof, and at least a pair of clips according to any of claims 1 -19, a first one of said clips being slidingly connected to a first of said framework members, and a second one of said clips being slidingly connected to a second of said framework members, such that a spar may be connected to both said clips and thus to each post and automatically assume the desired orientation with respect to each, each of said framework members being provided, in or on at least one surface thereof, with formations which are complementary in shape and dimension to the one or more elongate ribs provided on said clips such that the latter may be slidingly received within or disposed around the former, and whereby a rear side of one clip may be connected to its respective framework member, and wherein the spar cross-section is one of: generally H -shaped and lipped C-shaped, such that a pair of channels is defined along the length of said spar and adapted to receive the corresponding nib formations of the said clips when connected thereto.

21. A panel assembly system according to claim 20 wherein the cross section of the spa rs is H - shaped having first and second flanges separated by a web portion, and the flanges provided on any clip of the system are spaced apart from one another by a distance which is at least as large as the length of the maximum distance between the free ends of one flange of the spar such that said one spar flange can be accommodated between said clip flanges with the free ends of said one spar flange being received within the chan nels of the clip which are defined by said clip flanges, the clip web portion, and the nib formations which project from the ends of said clip flanges.

22. A panel assembly system according to claim 20 wherein the cross section of the spars is essentially a lipped C-shape having first and second lipped flanges separated by a central web portion, and the flanges provided on any clip of the system are spaced apart from one another by a distance which is the same or less than length of the distance between the free ends of the lipped flanges of the spar such that at least the lips of the spar flanges can be received within those chan nels provided by the clip and which are defined by said clip flanges, the cli p web portion, and the nib formations which project from the ends of said clip flanges.

23. A panel assembly system according to any of claims 20-22 wherein the rear most free ends of the spar rear flange or lips as the case may be, are at least profiled arou nd one or more of: their rearmost edges, and their foremost edges, such profiling being generally complementary to the profiling provided on the nib formations of any clip to which the spar is con nected.

24. A panel assembly system according to any of claims 20-23 wherein the framework member is multi-faceted and at least one face thereof is provided with formations which are complementary to the one or more elongate ribs provided on any clip of the system to allow sliding connection thereof to said framework member on a front side of said face.

25. A panel assembly system according to claim 24 wherein the formations provided on the framework member and the one or more elongate ribs provided on any clip of the system are dovetail-like in configuration.

26. A panel assembly system according to any of claims 24-25 wherein the framework member is provided, on a rear side of that face thereof which is provided with formations which permit connection of any clip of the system, with one or more pairs of engagement flanges which project substantially perpendicularly rearwardly of said face, such when one or more fixing screws is screwed into and through the clip and subsequently into the framework member to fixedly secure said clip to said framework member, the shank of said screw passes through said face and the screw threads thereof progressively bite into the engagement flanges on either side of said screw shank.

27. A panel assembly system according to any of claims 20-26 which comprises multiple framework members, multiple spars, and a plurality of clips, wherein the number of clips of the system is the order of SP x (P/(P- Ί)), where SP is the total number of spars extending between the number of framework members P.

28. A panel assembly system according to any of claims 20-27 and including a plurality of specifically according to claims 18 or 19, and further including one or more locking clips having an essentially U-shaped cross section comprising a pair of flanges and an interconnecting web.

29. A method of assembling a panel assembly system according to any of claims 20-27, comprising the following steps:

(a) securing a plurality of framework members to a sub-structure in spaced apart relationship,

(b) slidingly connecting a first set of clips to said framework members, each clip of said first set of clips being slidingly connected to each framework member and fixedly secured thereto in substantially the same position on each framework member,

(c) connecting one or more spars between two or more framework members, each spar being of a length which is at least the same as the distance between any two framework members and having a cross-section which is one of H-shaped and lipped C-shaped, such connection being achieved by at least one of the following: I nserting one free end of the rearmost flange portion or lip of the spar into one of the chan nels defined behind the nib formations of each of the clips in the set such that the spar and thus also the flange portion or lip is inclined at an acute ang le to web portions of the clips, and then applying a normal connecting force to a front surface of the spar such that the nib formations which partially define the other chan nels of the clips is deflected outwardly or inwardly as the case may, allowing the other spar flange portion or lip to pass beyond the nib formation and into said channel, whereupon that nib formation resiliently "snaps" back into place,

Disposing the rearmost flange portions or lips of a spar directly above and in contacting relationship with respective opposed nib formations of the clips in the set such that the free ends of said spar flange portion or lips are approximately symmetrically disposed with respect to the nib formations and the spar flange portion or lips are essentially parallel with the web portions of the clips, and then applying a normal con nection force to the spar such that either:

- the nib formations of the clips are simulatenously deflected outwardly or inward ly as the case may be to substantially the same extent and by being so deflected, allow the free ends of the spar flange portion or lips to pass between or around the nib formations and into the channels of the clip behind said nib formations, or

- one of the nib formations of each clip in the first set is deflected outwardly or inwardly as the case may be to a greater extent than the other, but in any case the nib formation deflections are such that the free ends of the spar flange portion or lips can pass between or around the deflected nib formations of the clips and into the channels behind them,

(d) sliding ly connecting one or more subsequent sets of clips to said framework members, each clip of said subsequent set of clips being slidingly connected to each framework member and slid therealong u ntil the one or more elongate projections provided on any clip in the su bsequent set of clips abuts the corresponding clip, or a part thereof, of the first or any previous set of clips, and

(e) connecting one or more fu rther spars between the framework members as prescribed in step (c) using the clips of the one or more su bsequent sets.

30. A method according to claim 29, wherein the clips utilised in the method as are specified in claims 18 or 19 or any dependent thereon, and fu rther including the step, for any one or more of the first or su bsequent sets of clips used in the method, of con necting one or more locking clips to one or more of the clips in any set.

Description:
A Clip for use in a Panel Assembly System, and a Panel Assembly System utilising such a

Clip

Field of the Invention

The present invention relates to a clip for use in a panel assembly system, and a panel assembly system incorporating such a clip. More specifically, although not necessarily exclusively, the present invention relates to a domestic, industrial or commercial fencing, decking, wall or ceiling cladding system, or a similar system adapted for rapid and predominantly manual erection and which, when erected, provides a functional surface which may also be capable of bearing a load and beneath, behind or above which is disposed an array or fra mework of support members to which various spars or planks, which together constitute the fu nctional surface of the panel, are connected by means of the said clip. I n most cases, the fu nctional surface will be purely aesthetic or decorative, or it may provide a cladding or support surface function, but in any event, the particu lar function performed by the fu nctional surface shou ld not be considered as limiting the present invention. I ndeed, although the following description is provided with almost exclusive reference to fencing and decking systems, it should be understood that the clip of the present invention, and the panel assembly system in which it is used, although ideally suited to the provision of a rapid assembly fencing system, may equally be employed to provide a means of creating a horizontal, vertical or inclined functional panel having a wide variety of possible applications. Fu rthermore, although fencing and decking are in general most commonly installed in domestic gardens, the panel assembly system of the present invention may be installed in any interior or exterior location where a functional, decorative or aesthetic su rface is required, and neither the reason for installation nor its location should be considered as limiting the present invention.

Background to the Invention

Domestic fencing, decking and wall and ceiling cladding systems are already well known and widely available, and can take various different forms. I n terms of fencing, the very simplest arrangement is that of the common picket fence which consists of multiple spaced apart su pporting or mounting colu mnar pickets which may be manually driven, e.g. with a sledge-hammer, into the earth at appropriate spaced apart locations, and thereafter a corresponding number of individual fence panels is simply suitably secured, e.g. with nails or screws at either end to a respective pair of pickets. The fence panels themselves usually consist of a plurality of spaced apart vertical balusters each being nailed in appropriate locations to two or three lateral (i.e. horizontal) rails about being 1 -2m in length and arranged behind the fence balusters and in generally perpendicular orientation therewith such that the whole panel assembly may be easily manually lifted and positioned between or in front of the pickets to which said panel is to be secured to complete one section of the fence. In purely decorative fencing, being one which is not required to function as a screen for what may lie to one or other side of the fence, the balusters may be spaced apart to a relatively large extent and thus gaps will exist between adjacent balusters, whereas if some degree of screening is required, then naturally adjacent balusters will be disposed relatively much closer to one another or they may be arranged contiguously or imbricated such that there is very little if any light penetration through the panel from one side to the other.

A corresponding basic decking system is analogous to the simple picket fence described above in many ways, except that of course a deck is generally horizontal whereas a fence is vertical, and the deck, when complete, will generally be capable of bearing a non-negligible load. Briefly, a simple decking system consists of a horizontal framework of joists and/or beams on top of which a plurality of decking planks is commonly arranged and suitably secured, again (in the simplest decking installations) using nails or screws. Naturally, in the case of decking, there is the additional requirement that the functional decking surface be load bearing as well as being decorative and generally aesthetically pleasing, and therefore in practically all decking installations, the predomination of decking planks will be disposed in parallel relationship and relatively very close to one another, i.e. only a few mm apart. Generally, decking planks are not installed directly adjacent one another in contiguous or imbricated relationship because for decking, there is the requirement that the deck be completely flat, and additionally some allowance must be made for thermal expansion and contraction of the planks and to allow rainwater to dissipate and/or permeate through the deck. This is particularly true for decking structures in which (at least) the planks are made of composite materials such as wood-plastic composite (hereinafter "WPC", made of wood fibre/wood flour and thermoplastic(s) such as polyethylene, PE, polyprolylene PP, polyvinylchloride PVC etc.), because such composite materials can expand and contract significantly over the course of a year, particularly in temperate climates. More recently, extensive use of WPC materials is being made in fencing and decking systems alike, due to the increased moisture resistance and general longevity of such materials as compared with traditional timber. Furthermore, planks of WPC materials can be moulded or extruded relatively inexpensively, and such manufacturing processes allow for planks to be manufactured with any desired cross-sectional profile and with suitable surface patterning on their substantially planar top-most or front-most surfaces, such as for example with a wood grain-like pattern, so as to render at least those surfaces very similar in appearance to conventional timber planks. Additionally, pigmentation of WPC materials is relatively easily achieved, and therefore WPC materials can be manufactured with a wide variety of both colours and finishes as may be required.

The facility for creating decorative WPC planks having both highly uniform, planar timber-like surfaces and precisely designed, configured and shaped cross-sectional profiles has recently promoted the use of such materials in the field of decking systems. For example, W02015170205A1 in the name of "i Deck s rl" describes a decking system sold by that company under the trade name "EasyClick"™. Also of relevance to the present invention is the "EasyChange"™ decking system also available from that company, and both of these systems are briefly described below.

In the EasyChange™ decking system, an aluminium substructure is erected to the desired height and is comprised of an interconnected framework of joist-like and beam-like aluminium rails, said framework being supported at various locations underneath the framework by aluminium struts which will generally have feet which rest directly on the underlying supporting surface above which the deck is to be installed and which will ultimately bear the load of both the deck itself and anything it supports. To account for any unevenness in the level of the underlying supporting surface, the aluminium struts which support the framework may be adjustable so as to be of variable length, but regardless of how the aluminium substructure is erected, it is generally a fundamental requirement that the interconnected framework is level over its entire area. Each of the aluminium rails of which the said framework is constituted is provided with a plurality of pre-fixed, uniformly spaced apart rotating nylon cams having first and second operative positions, each of which can be rotated between said positions by means of a suitable tool having an elongate shank and an inverted T-shaped formation at the free end thereof. Both the shank and T-shaped formation of the tool are of a thickness which allows for insertion of said parts of the tool into and through the gap defined between an adjacent pair of decking planks suitably positioned on the framework on either side of the cam. The said cams have an elongate cross-section and are provided with lugs at either longitudinal end such that in a first position, wherein the elongate axis of the cam lies perpendicular to the alu minium rail to which it is con nected, a pair of decking planks may be laid on the framework adjacent the cam and on either side thereof. The planks are provided with a suitable cross-sectional profile which is substantially uniform along the entire length of the plan k and includes, on either side, a cha nnel formation defined on one side by the u nderside of the pla nk surface and on the other by a suitable projection, said chan nel formation being of a depth marginally greater than the thickness of the cam lugs so as to be capable of receiving them. In order for adjacent sides of a respective pair of adjacent planks to be secu red to the framework, it is simple matter to insert the tool th rough the gap between respective adjacent edges of the two plan ks and into a suitably shaped recess provided in the uppermost surface of the cam, and then to rotate the tool and thus the cam such that each of the oppositely disposed lugs thereof is rotated into a chan nel formation provided in a respective one or other of said planks, thus effectively secu ring respective edges of the two adjacent plan ks to the u nderlying supporting framework at the cam location. To completely secure a sing le plank to the u nderlying framework along a single edge, the process is repeated for each and every cam provided on each of the beam-like or joist-like rails the plank straddles. Depending on the length of the plank, between 2-8 cams may be required to be rotated into position such that their lugs are fully received and engaged within the cha nnel formations provided on each of a respective pair of adjacent plan ks.

Although the EasyChange™ decking system is much more straightforward and quick to install than a conventional timber deck, it is considerably more expensive due to the cost of manufacturing the aluminiu m rails with pre-spaced, rotateably mou nted cams thereon. There are also a number of other disadvantages. Firstly, for decking systems, it is to be noted that the plan ks, at least compared to fencing systems, are relatively wide (e.g. 12-30cm), and therefore, in the EasyChange™ system at least, in order for each plan k to be most firmly, securely and robustly connected to the framework, it is required to be secured at a plurality of locations on either side of the plank by a corresponding nu mber of separate and distinct cams as described above. Once secu red in this man ner, it is practica lly impossible to remove the plank without either destroying the plank itself or the cams which secure it to the framework, un less of cou rse the cam tool is used to rotate all the cams securing any particular plan k from their fu lly engaged position into a fully disengaged position. This particu lar system does not lend itself particularly well to fencing, because the ease of installation of the deck and the various planks which constitute it relies on the fact that the deck is horizontal and plan ks disposed on it prior to connection to the underlying framework are held, albeit loosely, in place under gravity. I n a corresponding fencing system, not only wou ld it be much more difficult to manipulate the relatively heavy planks and thus position them on a suitable vertically orientated framework, but then in order to connect each plank to such a framework, it would be necessary to secure both edges of each plank by two separate actions because each and every cam only secures one edge of any plank, whether this be an upper or lower edge (if the plank is to be horizontally orientated), or a right or a left edge (if the plank is to be vertically orientated). This particular problem would be further exacerbated in a fencing system because, although the EasyChange™ system allows for individual planks to be removed from an assembled deck by rotating all the various cams which secure all the edges, and thus the plank itself, to the framework, the rotating of the said cams necessarily, automatically and unavoidably also releases one edge of each of the planks lying on either side of the plank which is to be removed, and such planks are therefore much more prone to working loose because they are then only secured to the framework along one edge. As will be understood by the skilled reader, this propensity to work loose is further exacerbated if gravitational forces are acting in the general direction in which any particular plank might work itself loose, as would almost certainly be the case if the plank were orientated horizontally in a corresponding fencing system. In a decking system by contrast, gravity acts more positively to retrain each and every plank in position.

Turning now to WO2015170205A1 and the EasyClick™ decking system of "i Deck sri" described therein, this system is similar to the EasyChange™ decking system described above in that each and every decking plank is secured along either edge to an underlying framework consisting of a plurality of Aluminium rails by means of respective pairs of p re-spaced, pre-installed and pre mounted nylon clips. The fundamental differences between the EasyClick™ system and the EasyChange™ system described above are firstly that in the former, the planks are effectively permanently secured to the aluminium rails of the underlying framework, and secondly, in the latter system, instead of requiring a tool, the planks can simply be press-fittingly connected to the framework by manual force, such as may be easily exerted by a human foot. Again however, although the ease and speed of installation is increased as compared to the EasyChange™ system, the EasyClick™ decking system also does not lend itself particularly well to fencing, firstly because the wide planks commonly used in decking are heavy and unwieldy and manually positioning them against a vertically orientated framework as would be required is not straightforward. Secondly, the amount of force which can be exerted by a human foot, i.e. equivalent to the majority of the weight of a human above it, is significantly greater than that which can be exerted through a human hand, and fencing in general is structurally far less substantial than a decking framework by design because there is little if any requirement for fencing to be load bearing. Therefore, on the one hand it may be far more difficult to manually connect planks of the EasyClick™ system to the nylon clips provided on the various rails of a vertically orientated framework (as would be required for a fence), and on the other hand, applying the significant force which may be required to achieve such connection may instead deform, destabilise, or otherwise displace the vertically orientated framework before any such connection is achieved. Finally, the fact that the planks are essentially permanently secured to the underlying framework after their edges are secured within respective pairs of nylon clips renders this particular decking system a somewhat inflexible, not to mention excessively costly, proposition as regards being converted to or adapted for a corresponding fencing solution.

A yet further disadvantage of both the EasyClick™ and the EasyChange™ decking systems described above is that both systems are preconfigured for planks of a specific width, and most notably, the clips or cams are mounted on and thus secured to the aluminium rails which constitute the underlying framework at pre-spaced locations corresponding to the width of the planks to be used. Therefore, although such systems may be relatively straightforward and simple to install, they cannot be adapted or modified to receive planks of a different, or differing, widths. In short, the spacing of the clips or cams on the rails must precisely match the width of the planks, and the simplicity of both systems lies in the presumption that each and every plank will be of the exactly same width - from a manufacturing perspective at least, it would be impractical and/or far too costly to provide rails with a plurality of clips or cams mounted thereto at variable spacings.

Thus it is a first object of the present invention to provide a rapidly and easily erectable fencing system which overcomes the abovementioned disadvantages, or at least such of those disadvantages which would be immediately apparent if the abovementioned systems were employed directly as fencing systems.

It is a further object of the invention to provide a fencing, decking, wall or ceiling cladding system or other such system which is simpler, quicker and less costly to manufacture and assemble than corresponding prior art systems. It is a yet further more general object of the invention to provide a rapidly and simply erectable panel assembly system which, in some embodiments at least, not only allows for individual or multiple spars (which term is to be considered herein as encompassing planks, balusters, spars and the like of which the overall panel is substantially constituted) within the assembly to be easily removed and replaced manually without the need for specific or specialised tools, but also permits for such removal without compromising the integrity of the remainder of the panel assembly.

I n certain other embodiments, it is a yet fu rther object of the present invention to provide a rapidly and simply erectable panel assembly system wherein the spars or planks within the assembly are essentially locked in place on the supporting, underlying or suspending (in the case of a ceiling system) framework members so as to be incapable of being easily removed, except destructively.

Summary of the Invention

According to the present invention there is provided a clip for a panel assembly system, said clip having a body portion whose cross-sectional shape comprises a web portion and a pair of spaced apart flanges both being disposed to a first and the same side, being a front side of said web portion and projecting therefrom, each of said flanges being provided at their remote ends with nib formations which project from the ends of said flanges in a direction substantially parallel with the web portion such that together, the web portion, the flanges and the nibs define at least a pair of spaced apart essentially para llel chan nels extending over at least a portion of the width or height of said clip which is further provided, on a second, rear side of said web portion, with one or more elongate ribs with first and second ends and which extend in a direction which is perpendicu lar to that along which said channels extend and which are formed so as to define at least a corresponding nu mber of grooves with the rear side of said web portion,

Characterised in that

the web portion is provided with one or more elongate projections extending beyond at least one end of the web portion parallel with the one or more elongate ribs, optionally being extensions thereof, and having at least first free ends remote from said web portion, such that when first and second identical clips are mounted adjacently on a suitable su pporting post, consecutively and in identical orientation by means of their one or more elongate ribs being slidingly received within or disposed around complementary formations provided on said post, the first free ends of the projections of one of the first and second clip abut corresponding areas of the other clip and thereby provide a spacing function whereby the web portions of respective first and second clips are spaced apart by a distance su bstantially equal to the length of the one or more projections. I n a most preferred arrangement, the one or more elongate projections extend directly from, and are integrally formed with, the one or more elongate ribs, and are thus extensions thereof having identical cross sectional shape such that those portions of the one or more elongate ribs which project beyond the web portion of the clip to provide the spacing function therefor are also sliding ly received within or disposed around complementa ry formations provided on a post to which said clip is thereby affixed. I n this particular preferred arrangement, the elongate ribs effectively function both as a means of spacing one particular clip from an adjacent one, and as a means of affixing the clip to the post or other suitable member. That such dua l functions are achieved both effectively simultaneously and in the same general (mathematical) plane is advantageous in many respects, not least of which are the overall ease, speed, and simplicity with which the clips may be consecutively affixed to the said post. Thus, mu ltiple identical clips each as described above, can be very quickly con nected to a su pporting post by simply sliding the one or more elongate ribs on any particular clip into or around suitable complementary formations provided on the post. Fu rthermore, although the clips can, initially at least, slide u p and down, or along the length of the post and are therefore somewhat free to move axially along (or u p and down) the length of the post, they are nevertheless robustly connected to it in on account of the interlocking between clip and post which is achieved as a result of the chan nel formations provided on the post being received within the grooves defined between the elongate ribs and the rear side of the web portion of each and every clip.

Most preferably and advantageously, such interlocking is dovetail-like in configuration with appropriate formations being provided on the post which are capable of receiving or otherwise complementarily engaging with the one or more elongate rib formations provided on the clip.

Most advantageously, the length of the elongate ribs provided on the clips, or more precisely the distance between their most remote first and second ends (if, for instance, they are discontinuous), is longer than the dimension of the web portion of the clip measu red in the direction of said ribs, thus ensuring that the clip is not only securely con nected to the post, but also that the web portions of the clips (by means of which decorative and/or load bearing spars may be con nected thereto, and thus to the underlying posts) a re automatically spaced apart by a desired amount, which will of cou rse depend, to some extent at least, on the width of said spars. The type of cli p to which the present invention is directed is therefore also capable of being produced with one or more elongate ribs of differing lengths to very easily allow for the erection of a panel assembly in which the individual spars may be of different widths, provided of course that cli ps having elongate ribs of corresponding ly different lengths are used so as to provide appropriate spacings between the web portions of the clips, each spacing corresponding to that of each spar of different width, as will become apparent from the fu rther description of the invention provided below. Finally, in the most common arrangements, particu larly for conventional fencing, decking, and wall and ceiling cladding systems, where all the decorative and/or load bearing spars are of identical width, the clips of the present invention enable very rapid erection of the entire fence, deck, wall or ceiling because the su pporting posts (or joists, beams, or other framework members, as the case may be) can be provided in simple lengths corresponding to the width of the deck or the heig ht of the fence without requiring clips to be individua lly mou nted thereon and connected thereto at pre-spaced lengths. Erection and/or assembly is therefore extremely simple in that a set of individual clips is simply slid, one after another, into or arou nd the chan nel formations provided on the post, and the position and spacing of each clip is dictated only and automatically by the position of the previous clip which it is slid into abutti ng relationship with. Naturally, there may be a requirement to fixed ly mount the fi rst cli p in any set to the post, for example by screw, nail, adhesive, or the like, in order to ensure a horizontal or vertical level or other desired orientation or align ment, but after that, all the remaining clips may simply disposed one after another on top of the first clip, or to one or other side of it. Of course, during assembly of an entire panel, any single spar forming pa rt thereof will generally be connected between at least two posts, beams, joists or the like in which a respective pair of clips is provided at an identical vertical, lateral or other disposition, said spar being thus connected to the posts by means of (at least) the said pair of clips.

Preferably the nib formations are provided with at least a first chamfered, radiused or otherwise profiled su rface along a front side thereof, said first su rface terminating at or proximate the free ends of said nib formations, and also preferably with a second chamfered, radiused or otherwise profiled surface along a rear side thereof, said second surface also terminating at or proximate the free ends of said nib formations, said first and second surfaces being provided to facilitate the con nection, and preferably also the disconnection, of a spar to said clip, said spar being generally H-shaped or lipped C-shaped in cross section, such that a pair of channels is defined within and along any length of spar so as to be capable of receiving the nib formations or a clip, the rear most free ends of the flange or lips being at least chamfered, radiused or otherwise profiled around at least their rearmost edges, and preferably also their foremost edges, and preferably in complementary fashion to the profiling provided on the nib formations of the clip. I n the most preferred arrangement wherein the spar cross-section is essentially H -shaped, the rearmost flange is slightly longer than the distance between the free ends of the nib formations of the clip such that when the rear web portion of the spar is fo reed against the nib formations, respective chamfered, radiused or otherwise profiled su rfaces of each component come into contact with one another and a component of a normally applied force of connection will be directed outwardly through the contacting surfaces of both the rear flange portion of the spar and the nib formations of the clip, and will thus act to resiliently outward ly deflect said nib formations, eventually to such an extent that the distance between the free ends of the nib formations becomes sufficient to allow the flange portion of the spar to pass beyond said nib formations, and thus be received in the chan nel formations of the clip defined behind them with the web portion of the clip body, said nib formations being simultaneously received in the chan nel formations defined within and along the spar in interlocking fashion.

I n the case where the rear surfaces of the nib formations and corresponding foremost su rfaces of the rear flange portion of spar are similarly chamfered, radiused or otherwise profiled (or even when they are not), disconnection of the spar from the clip, or more precisely the release of the spar rear flange portion from the position in which its ends are retained behind and within respective nib formations of the clip, is similarly facilitated, as a component of the discon necting force is directed throug h the contacting surfaces of both panel rear web portion and the nib formations and the said nib formations are again directed outwardly, u ltimately to such an extent that the ends of rear web portion of the spar are released from their position within the chan nels of the clip defined between the nib formations and the web portion of said clip.

The skilled person will also immediately appreciate a nd u nderstand that a mechanical inversion of the above described arrangement is equally possible and should be considered as being within the scope of the present invention. For instance, the spar may have a lipped C-shaped cross-sectional shape, and the flanges provided on said clip may be disposed relatively proximate one another as opposed to be disposed more towards the distal ends of the web portion, and the nib formations provided thereon may extend away from one another instead of toward one another. I n this case, the spar wou ld be con nected to the clip by virtue of the rearmost (optionally radiused, chamfered or otherwise profiled) li ps coming into contact with, and then inwardly deflecting, and u ltimately passing beyond the relatively proximately disposed nib formations provided on the clip behind and with which the rearmost lips of the panel would ultimately interlock. Such mechanical inversion may also equally apply to later described embodiments of the present invention, and the scope of this application should also therefore be considered as extending to such mechanical inversions, even if such are not specifically described herein.

The length of each of the pair of nib formations provided at the ends of the flange portions of any clip, said length being measu red in the direction that said nib formations project towards or away from one another, is preferably identical, but in some alternative embodiments, the length of the nib formations may be different. As the length of the nib formations essentially dictates the depth of each of the pair of spaced apart parallel chan nels provided on the clip which facilitate the con nection of a spar with suitable cross-sectional shape, the provision of channels which are the same depth allows for the connection of a spar to the clip to be orientationally ag nostic in that the force required to deflect (outwardly or inwardly) one nib formation is the same as that to similarly deflect the other. This means that the spar can be con nected to the clip in any of the following ways:

I nserting one free end of the (appropriately dimensioned) rearmost flange portion of the spar into one (and importantly, either) of the channels of the clip such that the spar (and the flange portion thereof) is inclined at an acute angle to web portion of the clip, and then applying a normal connecting force to the front surface of the spar such that the nib formation which partially defines the other, opposite (and at that time, empty) chan nel is deflected outwardly allowing the other spa r flange portion free end to pass beyond the nib formation and into said channel, whereupon that nib formation resiliently "snaps" back into place, or

Disposing the (appropriately dimensioned) rearmost flange portion of a spar on top of respective opposed nib formations of a clip such that the free ends of said spa r fla nge portion are approximately symmetrically disposed with respect to the nib formations and the spar flange portion is essentially parallel with the web portion of the clip, and then applying a normal connection force to the spar such that either:

- both of the nib formations are simulatenously deflected outwardly and to the same extent and by being so deflected, allow the free ends of the spar flange portion to pass between the nib formations a nd into the channels, or

one of the nib formations is deflected outwardly to a g reater extent than the other, but in any case the nib formation deflections are such that the free ends of the spar flange portion can pass between the deflected nib formations and into the chan nels of the clip behind them.

However, in the case where the nib formations of the clip are of different lengths, and the cha nnels are thus not the same depth, the resistance of one nib formation to deflection can be significantly greater than that of the other, and furthermore, depending on the physical dimensions of the said nib formations, the connection (and discon nection, for that matter) of the spar can be rendered either very difficult or impossible un less (for connection) a free edge of the flange portion of any spar is firstly inserted into the relatively much deeper channel defined by the relatively much longer nib formation before the normal con nection force is applied to said spar. This, in this particular embodiment, the length of the nib formations becomes and an important and in some cases critical and determining factor in the connection (and discon nection) of any spar to any clip. For instances, in terms of disconnection, it may be very difficult or impossible (without destruction) to apply sufficient torque to a spar such that the flange portion thereof contacts, and then sufficiently outwardly deflects, one of the nib formations of the clip behind which the relevant edge of the flange portion is retained, but it may be relatively much easier to apply torque in an opposite direction such that the alternate free end of the spar flange portion deflects the relatively much shorter nib formation out of the way, and whereby the said spar flange portion is effectively released from the respective chan nel. The skilled person will i mmediately appreciate that, in certain circu mstances, such directional bias, as far as panel connection and discon nection are concerned, can be advantageous. For instance, the construction of a complete fence panel, deck, wall or ceiling, may be facilitated and simplified by ensuring a nd/or instructing the user to firstly insert clips into any pair of spaced apart posts in the same orientation, and then to attach each individual spar by inserting one free edge of the rear flange of that spar into the lower or u pper chan nel (depending on which nib formation is longer) before then applying a normal connection force to the front of the spar to "snap" the other flange free edge into the other chan nel of the clip. Clips that are directionally biased as regards con nection of spars thereto may be particularly useful if, for example, all the spars in any complete panel assembly system are required to be affixed between posts, beams, joists or the like in one predetermined and particu lar orientation. This can be particu larly advantageous if the front-most surfaces are provided with some decorative pattern or other whose aesthetic effect depends on the particular orientation of the spars. Of cou rse, in other embodiments where the nib formations provided on the clip are the same length, there generally wou ld be no such orientation requirement for connecting the panels.

I n one preferred embodiment, the second ends of the one or more elongate ribs of the clip, are disposed behind the rear su rface of the web portion of said clip so as to be substantially or completely concealed thereby, and such that when first and second clips are mounted adjacently on a suitable su pporting post, one after another and in identical orientation by means of their elongate ribs being slidingly received within or disposed around complementary formations provided on said post, for example in dovetail fashion, the first, exposed ends of the elongate ribs (or the elongate projections forming part thereof) of the first clip abut the second ends of the one or more elongate ribs of the second clip along an abutment surface which is corresponding ly su bstantially or completely concealed behind the rear surface of the web portion of said second clip. I n some preferred arrangements, the first and second ends of the one or more elongate ribs of the clip are provided with complementary abutment su rfaces, one being essentially the mirror image of the other such that at least some portion of the abutment su rface of an end of an elongate rib of the first clip is disposed below and beyond an uppermost edge of the corresponding abutment su rface of the elongate rib of the second clip. I n a most preferred arrangement, the abutment su rfaces of the first and second ends of the one or more elongate ribs are su bstantially or predominantly planar, parallel and inclined relative to the longitudinal axis of the ribs. Other abutment su rface profiles are of course possible, for example stepped or undulating profiles, or it is even possible, in some advanced embodiments, to provide complementary inter-connectable formations over some or all of the abutment surfaces provided by the first and second ends of the one or more elongate ribs, such that adjacent clips may be, preferably releasably, connected to one another in, along and/or within the abutment surfaces, for example in push-fit manner.

I n the embodiment where the elongate projections are not merely extensions of the elongate ribs, the clip may be formed or otherwise provided with suitable complementary abutment su rfaces which project from the rear surface of the web portion of the clip at a suitable location such that abutment surfaces provided at the free ends of the elongate projections come into mating contact therewith when multiple clips are consecutively sliding ly received in the post, one after another, in the same orientation. Regardless of the profile of the abutment surfaces, one particularly desirable aspect of the abutting contact between respective abutment surfaces of the elongate ribs of two adjacent clips, particularly on a vertically orientatated supporting post, is that a substantial part of the abutting contact surface is disposed behind the rear of the web portion of the lower of the two clips, and vertically beneath an upper end of said web portion. In this arrangement, when multiple clips are consecutively slidingly mounted to a supporting post, each and every abutment surface between any two adjacent clips will be similarly disposed, that is substantially behind the rear of the web portion of the lower of the two clips, and lying substantially or completely beneath the upper end of said web portion. There is good reason for this arrangement - with the abutment, or in some preferred arrangements, the connection, between respective ends of the elongate ribs of adjacent clips being disposed behind the rear of the web portion of one of those clips, that web portion, and in turn any spar connected to it on the front side thereof, essentially ensures that the otherwise free exposed ends of the first clip are prevented from being displaced outwardly away from the post, because they are at least partially disposed behind the second clip.

A fu rther advantage will be apparent to the skilled reader when it is considered how a completed fencing panel might assembled using clips of the present invention. For example, between a pair of vertical posts between which fencing is to be provided, a number of (usually identical) clips are consecutively slid into each post in the same orientation in the slots or grooves or other formations (e.g. dovetail or dovetail-like) provided therein, such number corresponding to the number of decorative spars which are to be horizontally affixed at either end to two clips, one in each post and being disposed at substantially the same height. The orientation of the clips, that is whether they are inserted into the posts with free, exposed ends of the elongate ribs orientated downwardly towards the base of the post, or alternatively orientated with their free, exposed ends upwardly disposed towards the uppermost free end of the post is irrelevant, as long as the clips are all slid into and thus connected to both posts with identical orientations. Provided such arrangement is achieved, each and every individual abutting contact between the respective first and second ends of the elongate ribs of each pair of adjacently disposed clips on any particular post effectively both provides support for, and carries and transfers the weight of clips and spars connected to the and disposed above any particular clip both downwardly and (especially where the abutment surfaces are inclined) at least slightly normally relative to the vertical axis of the post. Therefore, and especially where the abutment surfaces are inclined, at least some component part of the weight borne by the clips (except the top-most clip in any post) is directed normally instead of vertically downwardly, and regardless of the direction of such force, it will tend to increase the frictional engagement between the elongate ribs and the complementary and corresponding su rfaces of the formations provided in the posts which retain the clips in place. Thus with every additional pair of clips vertically disposed above those beneath and on each of the two posts, and with every additional spar con nected between those pairs of clips, the overall weight borne by each and every pair of clips beneath naturally increases, but so also does the normal/frictional forces acting on each pair of clips below, and therefore the tendency of the clips below for displacement is increasingly reduced and each and every clip below is more firmly held. The result is a more solid fence or other type of panel construction.

Preferably, the clip is provided with a pair of spaced apart elongate ribs, most preferably disposed laterally to either side of the vertical axis of symmetry of the clip body portion. I n a n alternative arrangement, the clip is preferably provided with a single elongate rib formation disposed su bstantially centrally of the clip body portion and being of a width which is preferably less than 0.8, further preferably less than 0.7, and most preferably about 0.6 times the total width of the clip body portion. I n either case, it is preferable that the elongate projections (or projection, where there is on ly one elongate rib) are merely extensions of the elongate ribs or rib as the case may be. Most preferably, the length of the one or more elongate ribs, including the elongate projection thereof is of in the range of 1.2-1.6, or 1.2 - 2, or 1.5-2.5 times the total depth of web portion of the clip body portion. Preferably, one or more of the clip, the post, and the spars is injection moulded or extruded, fu rther preferably in a plastics materia l such as ABS (Acrylonitrile butadiene styrene) or nylon.

I n a most preferred embodiment, the clip is provided with one or both of: one or more cou ntersun k apertures th roug h the web portion of the clip body to permit one or more screws, rivets or other fixing means to pass through said web portion and engage with and optionally penetrate a substantially planar surface of the post, said surface being part of a suitable formation within or arou nd which the one or more elongate ribs thereof are to be sliding ly received or disposed, and

one or more apertu res provided in the u pper of the two spaced apart flanges which project outwardly from the front side of the web portion, said apertures being adapted to receive appropriate gru b screws and whereby the rearmost web portion of the cross-sectional shape of a plan k or spar may be locked in place after having been press-fittingly connected to the clip.

I n case where cou ntersu nk apertures are provided in the web portion of the clip capable of receiving screws by means of which the clip may be rigidly secured to the post at any desired position, it is yet fu rther preferable that the surface of post which is penetrated by said one or more screws is provided, on a rear side thereof and disposed internally of the post, with pairs of engagement flanges which project internally of the post and substantially perpendicu larly away from the said su rface, said engagement flanges being spaced apart by a suitable distance, for example being anything from 0.1 -5mm less than the maximum diametral dimensions of the screw shan k including th reads provided thereon, such that when such a screw is screwed into the su rface of the post, the threads provided on the screw shank progressively bite into the engagement flanges on the inside of the post and thereby provide an exceedingly robust and secu re connection between the screw, and thus the clip, and the post.

I n certain particularly preferred embodiments, the clip is provided with a pair of spaced apart elongate ribs on the rear su rface of its web portion and between which is thus defined a shallow chan nel over the rear surface of said web portion, and at least one or both of the flanges of the clip projecting from the front surface of the web portion thereof comprise at least 2 separate, spaced apart flange portions so as to define an opening therebetween which is at least partially coincident with said shallow channel to thus reveal and make accessible an intermediate section of a free edge of the flange portion of the spar which is otherwise received i n and retained within the channels of the clip defined on either side of the opening by said flange portions and the respective nib formations provided thereon. A clip having this particu lar configuration is especially advantaged because it permits a secondary locking clip, having an essentially U-shaped cross section comprising a pair of flanges and an interconnecting web, to be con nected to the clip with one flange being received behind the clip and within the shallow chan nel defined between the elongate ribs thereof, and with the other flange being disposed within the opening between said flange portions of the clip and extending over the free edge of the flange portion of the spar otherwise retained within the chan nels extended away from said opening and on either side thereof and defined by said flange portions and the nib formations provided thereon. Thus, the locking clip effectively defines a further channel which can receive and lockingly retain the free edge of the flange portion of the spar against the rear web portion of the (primary) clip in very similar fashion to the chan nels defined on the clip itself, but importa ntly, the clip can be removed if required or desired. I n most preferred embodiments, the respective parts of the locking clip are appropriately dimensioned, one or more of the following arrangements being possible:

The width is marginally less than either or both of the width of the shallow channel and/or the opening, or width of the coinciding parts thereof such that the respective flanges of said locking clip can be received thereby

The length of one or both flanges of the locking clip is less than the length of the elongate projections of the clip to enable that or those flanges to pass between a respective adjacent pair of clips disposed on and affixed to a post,

The material thickness of any of the flanges or the web of the locking clip is greater than that the material thickness of any or all of the web portion, the flanges or flange portions or the nib formations provided on the clip,

The material thickness of one, other or both of the flange portions of the locking clip is one of: essentially the same, marginally greater, or lesser than the materia l thickness of the elongate ribs between said shallow channel is defined and the depth of which is further defined by the said material thickness of said elongate ribs; in the case where the thickness of the a locking clip flange portion is slightly g reater than the thickness of the elongate ribs, this can (advantageously) require that the clip be slightly resiliently deformed before such a flange portion of the locking clip is disposed behind the clip when i n situ on a post; alternatively, a flange portion of the locking clip whose thickness is less than that of the elongate ribs between which it is to be disposed may advantageously be very easily located without requirement for additional force or tools;

The length of at least one of the locking clip flanges is such that, when the locking clip is in situ and providing a locking fu nction for the spar con nected to the primary clip, the free edge of said locking clip flange extends at least as far as the nib formations of the clip, and the relevant flange of the locking clip thus provides a similar degree of resistance to forced or accidental removal of the spar from the primary clip as the respective nib formations of said primary clip disposed adjacently the locking clip and on either side thereof; more preferably, and particu larly where the primary clip is provided with nib formations which are of different lengths, and the locking clip is in situ between the flange portions of the primary clip having shorter nib formations, the length of that flange of the locking clip disposed in the opening between the primary clip flange portions is such that its free edge extends beyond the free edges of the nib formations of the primary clip adjacent thereto, thereby providing a resistance to forced or accidental spar disconnection which is marked ly greater than that provided by either of the nib formations on either side of the locking clip, either individually or in combination; in any event, the length of this one flange of the locking clip is selected such that, when in situ, its free edge either abuts, or is in close proximate relationship with, the web of the spar cross-sectional shape which effectively determines the maximum extent of travel of the locking clip.

Most preferably, the free end of at least one flange of the locking clip is provided with a lip, barb, or other suitable formation, which may optionally including a chamfered, inclined or otherwise profiled leading surface to facilitate insertion of that flange behind the primary clip, and further preferably, the rear surface of the web portion of said primary clip is provided with a corresponding indentation, recess, or other complementary formation, at a predetermined distance from the edge of said primary clip web portion exposed between respective flange portions over and arou nd which said locking clip is adapted to be disposed, such that as the relevant locking clip flange is slid behind the primary clip, the lip, barb or other formation thereof is received in the indentation, recess or other formation of the primary clip with a clearly audible, positive "click" to indicate that the locking clip is secured to the primary clip and providing its locking function for the spar con nected therein and thereto.

I n certain preferred embodiments, any spar connected to and within any clip may be additionally secured to that clip by the use of a pair of locking clips, one being provided on either side (e.g. top and bottom) of the clip and between respective pairs of flange portions provided a long those sides.

It shou ld immediately be understood from the foregoing that the locking clip may regarded as an independently claimable aspect of the present invention either in its own rig ht or in combination with a primary clip, as well as forming a useful and inventive part of the wider panel assembly system as fu rther separately claimed herein.

I n a second and further aspect of the present invention, there is provided a panel assembly system comprising at least two spaced apart posts arranged pa rallel with one another, at least one spar adapted to be connected to said posts so as to be orientated su bsta ntially perpendicular relative to each of two posts, and at least a pair of clips as herein before described, a first one of said clips being sliding ly con nected to and disposed in position on a first of said posts, and a second one of said clips being slidingly con nected to and disposed in a similar position on a second of said posts such that a spar may be connected to both said clips and thus to each post and automatically be perpendicu larly orientated with respect to each, each of said posts being provided, in at least one su rface thereof, with formations which are complementa ry in shape and dimension to the one or more elongate ribs provided on said clips such that the latter may be slidingly received within or disposed around the former, for example in dovetail fashion, and whereby a rear side of one clip may be sliding ly connected that post, and wherein the spar is generally H -shaped or lipped C- shaped in cross section such that a pair of channels is defined along the length of said spar to receive corresponding formations of the said clips, the con nection of the said spar to both said clips being achieved by resilient deformation of one, or both of the respective formations provided on the clip and or on the spar such that the formations of one component pass over the formations of the other, and into respective channels defined in both such that both respective formations are eventually interlocked, and the spar is thus connected to each of the clips.

Preferably, the panel assembly system further includes one or more locking clips as herein before, and further herein below described.

I n a most preferred arrangement, the cross section of the spars is H -shaped, and the overall length of the rear web portion of said clips is slightly longer than the distance between the free ends of the nib formations provided on the front-facing flanges of the clip, the dimension of the rear flange portion of the spar being such that, prior to being con nected to a clip, one or both free ends of said flange portion contacts a respective nib formation of the clip, and as a result of a connecting force applied directly and substantially normally to the front web portion of the spar, a component of that force tends to resiliently deflect that nib formation outwardly to such an extent that the relevant end of the rear web portion can pass beyond said nib formation and subsequently be received in the channel formation behind it and defined partially thereby, said nib formations being simultaneously received in corresponding chan nels provided in and along the length of said spar between respective parallel flange portions thereof.

Preferably, the rear most free ends of the spar rear flange (or lips, in the case of the spars having a cross-section which is lipped C-shape) are at least chamfered, radiused or otherwise profiled around at least their rearmost edges, and preferably also their foremost edges, and preferably in complementary fashion to the profiling provided on the nib formations of the clip. Preferably, the posts will be extruded, preferably in Aluminium, which is most preferably anodised.

In most preferred arrangements, the formations provided in a post and by means of which clips can be slidingly connected thereto will be in the form of a slot provided in at least one, and further preferably all, otherwise substantially planar surfaces if the post cross-sectional shape is a polygon with at least 3 sides, said slot having an increase width portion beneath the outermost post surface in which it is provided such that wider portions of the one or more elongate rib formation provided on a clip can be received and slide relatively freely within said slot increased width portions in dovetail fashion, and yet be prevented from normally escaping from said slot by a narrower width portion thereof disposed more proximately the post surface in which said slot is provided.

In most preferred embodiments of course, the panel assembly system described above will comprise multiple posts, a plurality of spars and a plurality of clips as herein befo re described, the number of clips being required being of the order of SP x (P/(P- Ί)), where SP is the total number of spars extending between the required number of posts P.

In yet further aspects of the invention, there is provided a method of assembly of a panel assembly system, and a spar adapted for use in such a panel assembly system. Furthermore, the skilled reader will appreciate from the foregoing and the following specific description that there are various aspects of both the individual components, and the methods of connecting them together that may be regarded as both features of the components themselves, and features of the panel assembly system to which this application also relates. It should be understood therefore that feature of any particular component may form part of, and thus be claimed as part of, the panel assembly system, as well as being a dependently claimable feature of the component per se.

As the skilled reader will appreciate from the above, the present invention is particularly useful for providing a panel assembly systems which can be very rapidly assembled and wherein the spars or planks are connected between the underlying posts or other framework members in generally orthogonal relationship therewith. However, the skilled reader will also immediately understand that the orientation of the spars or plan ks relative to their underlying su pporting posts or framework members to which they are connected is dictated entirely by the clips which con nect the two components together. It is therefore certainly feasible and within the scope of the present invention to provide modified clips which con nect the spars or pla nks to the posts or framework members is other, non-orthogonal orientations. For example, the spars or planks may be diagonally orientated, as is common in some conventional wooden fences.

All the aspects of the invention will be better understood, a nd fu rther preferred embodiments will become apparent from the following specific description, provided with reference to the following drawings in which:

Brief Description of the Drawings

Figures 1 , 2, 3, 4 shows show respectively plan, perspective, front elevation and end elevation views of a clip according to the present invention,

Figure 5 shows an en larged perspective view of the clip of Figu res 1 -4,

Figure 5 A shows a schematic sectional elevation of the clip of Figures 1 -5 and an adjacent spar with appropriate cross-sectional shape immediately prior to being press-fitting ly connected to the clip,

Figures 6, 7, 8, 9 show respectively perspective views of a post and a covering cap (Figures 7, 8) for the u pper otherwise open end thereof and for use in a panel assembly system according to the present invention,

Figure 10 shows an end perspective view of the clip of Figures 1 -5 having been slidingly inserted into a front-facing slot provided in one of the posts of Figures 6, 7, 9 and a spar after having been press-fittingly connected to and within said clip and thus secu red to said post, Figure 1 1 shows a top perspective view of the arrangement illustrated in Figu re 10,

Figure 12 shows a front perspective view of the post of Figu res 6, 7, 9 in which th ree identical clips of the type shown in Figures 1 -5 have been slid consecutively into a front-facing slot provided in said post and being uniformly spaced apart by virtue of the abutting interacting of the elongate ribs of said clips, and as prescribed by the present invention.

Figure 13 shows a schematic perspective view of a post with alternate crops-sectional shape to those of Figures 6, 7, and 9, together with a modified clip according to a preferred embodiment of the invention,

Figure 14 provides a perspective view of the clip of Figu re 13, together with a pair of locking clips as provided for in yet further preferred aspects of the present invention, illustrating the manner in which said locking clips can be connected to the primary clip to provide their locking fu nction, and

Figures 15, 16, 17 provide schematic sectional elevations of a clip and a spar in various different stages of con nection to said clip.

Detailed Description

Referring firstly to Figu res 1 -4, there is shown a clip 2 according to the present invention. Said clip has a body portion 4 to the rear of which are disposed two spaced apart elongate ribs 6 generally symmetrically arranged on either side of a first axis of symmetry 8 of the body portion. The body portion consists of a web portion 10 which essentially defines the heig ht of the clip body portion 4 and a pair of generally para llel flanges 12 which project forwardly from and relatively perpendicu larly to a front side of said web portion, and each of said flanges is provided with nib formations 14A, 14B respectively which are orientated generally parallel with the web portion 10 and extend in the same direction as said web portion from the respective flange of which it forms part so as to define, together with said web portion and said flanges, a pair of channels 16A, 16B disposed to the front side of the web portion 10 and behind said nib formations. As will become apparent from the following description, the specific clip illustrated and described herein is on ly one of many possible configu rations whereby the clip may be provided with a pair of channels forwardly disposed of the web portion of the clip. The skilled reader will of course immediately understand that alternate arrangements are possible, and instead of being generally inwardly disposed of the clip and towards the extremities of the uppermost and lowermost ends of the web portion, the channels may be defined, together with said web portion, by flange portions which are much more proximate one another and, for example on either side of a horizontal axis of symmetry 9 of said web portion, and nib formations which extend from such alternate flange portions in an opposite direction to that illustrated. I n this latter case, the channels so defined wou ld be orientated generally outwardly of the flange portions, as opposed to the arrangement illustrated in which they are disposed generally inward ly of flanges 12.

The elongate ribs 6 are specifically profiled according to the present invention, and on the one hand they are provided with chamfered abutment surfaces 20, 22 at either end of their length. Although a simple chamfer is illustrated, it is to be understood that the particular configuration and shape of the abutment surfaces is important only in that they should be complementary. For instance, in the Figures, the chamfer angle of the abutment surfaces is identical, and the chamfer orientation for both and either end of each of the elongate ribs such that the abutment surfaces are substantially parallel and capa ble of mating with the corresponding abutment surfaces of an adjacent, identical clip disposed immediately above or below any pa rticular clip, as will be more fully described hereinbelow. Furthermore, althoug h the simple planar abutment surfaces will be most common and most easily provided, it is contemplated that other profiles are possible, and i n a particularly preferred (but not illustrated embodiment), said abutment surfaces may be formed with complementary interlocking formations such that, instead of a simple mating engagement between abutment surfaces of adjacently disposed clips, such clips may be more physically con nected together by means of a more physical engagement between the complementary formations provided on the abutment su rfaces at respective ends of the elongate ribs of adjacent clips. The elongate ribs 6 are important in the context of the present invention in a number of other aspects. Firstly, their cross-sectional shape over substantially their entire length, as can be clearly seen in Figures 1 and 3, is non-u niform, and in this particula r embodiment, trapeziu m-like, and the cross-sectiona l sha pe of one elongate rib is effectively a mirror image of that of the other disposed on the alternate side of the axis of symmetry 8 of the clip. Althoug h various different cross-sectional shapes are possible, it is important that each elongate rib, or at least one ang led or inclined su rface 6A- 1 , 6A-2 extending along the length thereof, defines a groove, referenced at 6 A, 6B for each elongate rib 6, together with the rear side of the web portion 10. I n the embodiment illustrated, each g roove is disposed generally outwardly relative to the body of the elongate rib, but of course the skilled reader will appareciate that an inverse arrangement is equally possible in which the grooves may be disposed generally inwardly of each or one respective elongate rib, that is the groove may be on the inside of the rib and lie more proximate the axis 8 of the clip body. I n any event, such grooves, however orientated and provided on the rear side of the web portion 10, extend in a direction which is generally perpendicular to the direction in which the channels 16A, 16B extend on the front side of the web portion. Furthermore, providing the elongate ribs with different, asymmetric or mirror-image cross-sectional shapes as shown enables the elongate ribs of any clip to be slidingly received in a suitably and corresponding ly cross-sectioned elongate slot, the slot and elongate ribs cooperating in a man ner which allows the clip to be slid up and down within the slot, but prevents the clip from escaping from within the slot in a direction perpendicular to the sliding direction, as will be more fully explained below.

Finally, a yet further important aspect of said elongate ribs 6 is their length. As can be seen very clearly in Figu res 3, 4, the overall length of each elongate rib is identical, and in the embodiment shown, each elongate rib extends from a point at their topmost ends (abutment surface 20) which coincides with the topmost end of the web portion 10. In other, not illustrated, embodiments, the topmost edge or surface of the and each rib may be disposed some distance below the topmost end of the web portion, or in in yet fu rther embodiments, even above the topmost end of the web portion, althoug h in this particu lar lattermost embodiment, certain other advantages, in particu lar the rigidity of construction, may be obviated. From their topmost end (abutment su rface 20), the and each rib extends downward ly, eventually terminating in abutment surface 22 which is disposed some way beyond the lowermost end of the web portion 10. Thus the elongate ribs 6, each being of a length which is greater than the total length (i.e the height) of the web portion 10, can provide a spacing fu nction for adjacently disposed clips which will be automatically spaced from one another by virtue of the engagement of the respective abutment surfaces provided at either end of the elongate ribs of adjacent clips, as will be more fully described below. In terms of the rapidity and ease of assembly of a panel system, this is of great advantage.

Turning now to Figure 5, there is shown an enlarged perspective view of the clip 2, reference numerals from earlier Figures being retained where appropriate, and in which shape and configuration of the nib formations 14 A, 14B can be more clearly seen. In particular, nib formations 14 A, 14B are shown having their front and rear edges chamfered as referenced at 14A-1 , 14A-2, 14B-1 and 14B-2, the front surfaces 14A-1, 14B-1 being rearwardly chamfered towards the clip body 4 and the rear surfaces 14A-2, 14B-2 being chamfered forwardly away from the clip body 4 respectively. This chamfering is important, as will be explained with particular reference to Figure 5A, in which a spar 50 is sectionally illustrated adjacent clip 4. In particular, spar 50 comprises a front-facing usually decorative (or load-bearing, in the case of decking) surface 52, and behind the front surface 52 and to the rear thereof, the cross-sectional shape is specifically designed and dimensioned so as to capable of being press-, snap- or push-fitted into the clip. Yet further specifically, the spar cross-sectional shape includes spaced apart web portions 54, 56 joined by flange portions 58, one, other or both of such portions being provided to their outer edges or surfaces with rib formations 60. In terms of the relative dimensions of the various parts of the clip and spar cross-sections, it is important to note that:

The width of the rib formations 60 provided on the spar is approximately the same as, or marginally less than the width of the channels 16A, 16B defined behind the nibs 14 A, 14B, and as such can therefore be snugly received therein

The total distance between the exterior surfaces of opposite rib formations 60 is (a) marginally greater than the gap defined between the free ends of the nib formations 14A, 14B of the clip, and (b) slightly less than the distance between the inner (planar) surfaces of the flanges 12 which partially define said channels 16A, 16 B; with such dimensions, not only are the rib formations 60 prevented from passing unhindered by the nib formations 14 A, 14B into the area of the clip lying generally behind said nib formations, but also the rib formations, after having been forcibly inserted into that area, they are comfortably received in the channels 16A, 16B such that a small gap exists between the topmost and bottommost surfaces of the rib formations 60 and the interior surfaces of the flanges 12. (Reference should be had to Figure 10 which more clearly illustrates the post-connection arrangement of spar and clip). Two additional features of the clip can also clearly be seen in Figure 5. Firstly, in the upper flange 12 there are provided a pair of grub screw apertures 12A, which may be tapped and into which suitably sized grub screws may be screwed to enable any spar connected to and within the clip (as more fully described below) to be somewhat more permanently locked in place, should this be desired. Also, a pair of countersunk screw holes 10A is also provided through the web portion 10, in this embodiment, asymmetrically of the axis 8, such that the clip can be screwed in position after having been slidingly received in a slot (see description below in relation to Figures 10, 1 1, 12).

In the pre-connection position of spar and clip shown in Figure 5A, it can be seen that rearward facing surfaces of the rib formations 60 abut the chamfered surfaces 14A-1, 14B-1 of nib formations 14B. Importantly, this ensures that when a push-fitting force F is applied in a normal direction to the surface 52 of the spar, a component of this force will be directed through the tangential (or in some embodiments, planar) mating interface of the rib formations 60 and said chamfered surfaces, and necessarily act to outwardly splay both the nib formations 14A, 14B, and the flanges 12 on which they are provided as shown by arrows 62. As the push-fit connection force F increases, so too does the extent to which the nibs/flanges splay outwardly, until eventually the distance between the outwardly splayed nibs is sufficient equal to the maximum distance between the exterior surfaces of the rib formations 60. At this point, the rib formations 60 can pass beyond the outwardly splayed nib formations 14 A, 14B until fo rwa rd motion of spar is arrested when (a) the rearmost web portion 56 of the spar abuts the web portion 10 of the clip, and (b) the rib formations 60 of the spar are completely snugly received in the clip channels 16A, 16B, as clearly shown in Figure 10. To disconnect the spar from the clip, the connection process simply occurs in reverse, and to facilitate the outward splaying of the nib formations 14A, 14B of the clip, the rib formations of the spar cross- section similarly engage with the rear chamfered surfaces 14A-2, 14B-2 of the nib formations, and thus application of a disconnection force acting in generally opposite direction to Force "F" will achieve the same result, ie. Outward splaying of the clip nibs to such an extent that the spar rib formation can pass between them.

Of course, in order for the nib formations, and the flanges of any clip to be deflected outwardly by a connection force, the clips themselves or at least appropriate parts thereof, must be manufactured of a material capable of being elastically deformed under a manually applicable load. Suitable materials are thermoplastics material, ABS, and (most preferably) Nylon ®. It is desirable that the nib formations and flanges be only elastically (as opposed to plastically) deformed, because otherwise the nib formations and flanges would not recover fully, and the spar could become loose or even escape from the clip. Of course, it is most preferable that the spars be capable of being connected to the clips with an audible resilient "snap" once the connection has been achieved, and although this sound be achieved in part by the resilient recovery of both nib formations and flanges after having been outwardly splayed, it is achieved much more reliably by virtue of the slapping interaction between the essentially straight, planar rearmost web portion 56 of the spar, and the similarly planar web portion 10 of the clip which audibly "slap" together when the connection is achieved. Again, both clip and spar are advantageously and preferably suitably dimensioned and shaped to achieve this interaction once the connection between them is completed.

Referring briefly to Figures 6, 7, 8, 9, there is shown an elongate post 80, being most preferably an Aluminium extrusion, ideally anodised after or befo re the extrusion process. The cross-sectional shape of the post is essentially square, but other shapes are of course possible, the only requirement being that at least one side of whatever cross-sectional shape is selected is provided with a slot as will be further described below. Of course with a square cross-section, it is simple matter to extrude sections of tube with slots in each of the 4 sides so that post orientation becomes irrelevant. Ideally, as part of the panel assembly system, in particular for a fencing or cladding system, the lower end of the post will usually either be concealed from view, for example by being buried, or be well below eye level such that it will be invisible in common use, and the upper free end of the post, a decorative cap 84 may be used to conceal the free, visible egdes of the extruded post. Referring specifically to Figure 9, in which the overall cross-sectional shape of the post can be seen, and the nature of the extrusion is more clearly visible, the post interior is provided with buttresses 86 which provide rigidity along lengthier sections of the post, and fu rthermore each side of the post is provided with a generally trapezium-shaped slot extending along the entire length of the post, but wherein the shorter of the two parallel sides of the trapezium is absent. The slot cross-section shape can of course be varied, but as with any slot, it should include a pair of lips or leading, front edges 82A behind which the slot extends to provided recessed regions behind said leading edges, and within which suitably shaped and dimensioned formations of another component can be slidingly received while simultaneously being prevented from escaping from slot.

In the context of the present invention, it will be immediately understood that for the elongate ribs of the clip to be slidingly received in the slot 82, they must be both spaced apart by the required predetermined amount such that their inclined surfaces 6A-1, 6A-2 are substantially disposed within the slot behind and to the lips 82A thereof and in the recessed areas defined behind them, and also of a depth which corresponds to, or is marginally less than the overall depth of the slot. If such an arrangement is achieved, then it is a simple matter to slide clips, or more precisely the elongate ribs thereof, one after another and in the same orientation, into the slots in the process of assembling a panel. Naturally, a number of spaced-apart posts will be required before any panel can be assembled because each spar must be secured to at least a respective pair of clips disposed on two separate, spaced apart posts, as will be immediately u nderstood by the skilled reader. I n most cases however, and particu lar if the present invention is employed in/as a decking system, the spars may be sig nificantly longer than the spacing between any two adjacent spars (or rails, joist- lie, or beam-like members in decking systems), and will therefore be connected to mu ltiple posts by means of a corresponding mu ltiple nu mber of clips provided in said posts.

Referring now to Figu res 10 and 1 1 , and latterly Figure 12, a clip 4, in particular the elongate ribs 6 thereof, is shown having been sliding ly inserted into the slot 82 towards an upper free end thereof. Thus, the arrangements being shown in Figures 10, 1 1 , and to a lesser extent, Figure 12 are rather hypothetical because as the skilled reader will understand, the clips can slide realtively unimpeded within the slots 82 and u nder normal circumstances, gravity wou ld tend to act on both clip and the spar con nected thereto, absent any further clip/spar combinations disposed that illustrated. Despite this, the Figures provide a good indication of, for the present invention, exactly how (a) the spar is to be connected to the clips, and (b) exactly how the elongate ribs 6 of clips are received in the post slots 82 such that the clips can slide therein and without escaping therefrom (except if slid out of the slot at any free open end thereof).

Referring in particu lar to Figure 1 1 , only the u pper abutment surfaces 20 of elongate ribs 6 can be seen, with the remaining lengths of said ribs being slidingly engaged within the slot 82 beneath said abutment surfaces 20. From the Figure, the relative dimensioning and shaping of both slot 82 and elongate ribs 6 can be seen, and it will be immediately u nderstood that both slot and ribs essentially cooperate to some deg ree with one another to provide the desired functionality, namely that of being relatively free to slide up and down within the slot, but being robustly prevented from being released from the slot, except either by the application of a destructive force, or of course being slid from a slot throug h an open end thereof. Also in Figu re 1 1 , it can be understood how g rub screws (not shown) screwingly inserted into g rub screw holes will, if of a sufficient length, eventually impinge on and bite into the rib formations 60 provided on the spar, which can thus be locked i n place in any particular clip as desired.

Finally referring to Figure 12, a set of three clips 4-1 , 4-2, 4-3 is shown vertically arranged one above the other in the position they would adopt if the entire length, or most of it, of slot 82 were filled with clips. I ndeed, in order to assemble and erect a panel of a fence (or a deck, if the post were disposed horizontally in a framework as opposed to vertically), each post wou ld first be sledge- hammered or pile driven into the g rou nd or, more common ly, posts such as described and illustrated may be first screwed, nailed ad hered or otherwise affixed either to existing but dilapidated fence posts, so that each post in the construction wou ld be laterally spaced apart by a suitable distance (obviously less than the length of the spars to be affixed between them). Thereafter, a first clip (i.e. the elongate ribs thereof) would be slid into the post at the top, open end of the slid and slid vertically downward ly towards its lower base end, and then screwing ly fixed into the desired vertical position on the post by means of screws (not shown) screwed into and throug h the cou ntersu nk screw holes 10A and into the alu minium extrusion itself. Once the lowest clip is screwed in place, subsequent clips can be slid into the slot, one after another, and either be allowed to fall under g ravity or be forcibly slid u ntil the lower abutment surfaces of the elongate ribs of any particula r clip come i nto contact with the upper abutment surfaces of the elongate ribs of the clip installed immediately previously. This arrangement of clips is partially illustrated in Figu re 12 in which it can be u nderstood that clip 4-1 will have been slid into slot 82 first, followed immediately thereafter by clip 4-2 and finally clip 4-3 will be slid into position above clip 4-2. It is also to be noted from the Figure that (a) the clips are uniformly spaced, and (b) the engagement of the lower abutment su rfaces of the elongate ribs of clips 4-3, 4-2 with the upper ubutment su rfaces of the elongate ribs of clips 4-2, 4-1 respectively occu rs essentially behind and to the rea r of the web portions of those latter clips.

Thus not on ly do the lengths of the elongate ribs of any clip determine the relative spacing of that particular clip from a clip previously inserted into the slot of a post, but also the fact that the abutment surfaces of the elongate ribs of an upper and a lower clip both are mutually and identically inclined relative to the vertical direction of the post ensures that the load carried by any clip will be transferred to the clip immediately beneath it th rough an interface which is similarly inclined, and therefore there will exist at least some component of force which will tend to force the lower clip outwardly of the slot, and thus into increased frictional engagement with both the lips 82 which define the slot, and the interior surfaces of the slot behind them. In this manner, the overall resistance to sliding movement of the clips within the slot increases due to the increased frictional forces as they are forced against the interior surfaces of the slot as the load carried by and above any particular clip increases. Thus the overall structural rigidity and robustness of a panel assembled as described can be accordingly increased.

Referring now to Figure 13, there is shown a modified clip 200 which is, for the most part, identical to the clip 2 of Figure 2, except that the uppermost nib formations 14A-1, 14A-2 are longer, that is they projects downward ly from respective spaced apart flange portions 12A-2, 12B-2, which together constitute the uppermost flange 12-2 of the clip, to a greater extent that the extent to which lowermost nib formations 16A-1 , 16A-2 project upwardly from respective spaced apart flange portions 12C-2, 12D-2, which together constitute the lowermost flange 12-2 at the opposite side of the web portion 4-2 of the clip. In the illustrated configuration of the clip 200, said spaced apart flange portions 12A-2, 12B-2, and 12C-2, 12D-2 thus define openings 120, 122, the purpose of which will be further explicitly explained below.

Also shown in Figure 13 is a post 800 having a modified cross-sectional shape as compared to the post of Figs. 6, 7, 9 but which nevertheless still defines, in a front surface of said post, a dovetail like slot 82-2, the front edges of which are referenced at 82A-2, and into which, in dovetail-like fashion, the free ends of elongate ribs 6-2 of the clip 200 can be slid, as generally indicated by the dotted lines 130 whereby, except for the capability of the clip to slide within said slot, said clip is affixed to the post. In order that the clip may be robustly and finally secured to the post after having been inserted as described previously and above, a pair of screws 132, 134 may be used, such being inserted through a pair of countersunk screw apertures 10A-2 provided in the clip 200 when the clip is disposed in a desired position within the slot 82-2 and then screwed into those surfaces of the post against by which the rearmost surface of the elongate ribs of the clip are supported and over which, but for the screws, said elongate ribs can slide. To further increase the efficacy of such a screwed connection of the clip to the post, the rear of said surface of said post is provided with pairs of engagement flanges 802, 804 which project internally of the post and substantially perpendicularly away from the said surface. Ideally, said engagement flanges 802, 804 are spaced apart by a suitable distance, for example being anything from 0.1 -5mm less than the maximum diametral dimensions of the shank of said screws 132, 134, including threads provided thereon, such that when such a screw is screwed into the surface of the post, the threads provided on the screw shan k progressively bite into the engagement flanges on the inside of the post. I n this particular configuration, instead of the con nection of the clip to the post being secured on ly by virtue of the engagement of the threads of the screws with a relatively thin section of the post immediately behind the surface thereof which su pports the elongate ribs of the clip, the connection is made more secure by virtue of the fact that the threads of the screw not on ly engage with this relatively thin section of the post immediately behind the clip elongate ribs, but also with a sig nificant length of the engagement flanges provided behind it, as more clearly illustrated in Fig. 13 A.

Referring now to Figure 14, clip 200 is illustrated together with a pair of identical locking clips 300, 302 shown above and below said clip in exploded arra ngement. Although in the Figu re a pair of locking clips is shown, in most preferred arrangements, only a single locking will common ly be used, being the lowermost illustrated of the two, because it is this locking clip which effectively increases the resistance to removal of a spar from within the channel defined behind the shorter (16A-1 , 16A-2) of the two pairs of nib formations of the clip, as will be further described below.

I n any event, and regardless of whether a single or both locking clips are used, each locking clip 300 is essentially of U-shaped in cross-section, with a pair of end flanges 302, 304 being disposed at either end of, and projecting in the same (generally perpendicular) direction away from a central web portion 306. I n preferred configuration, the flanges 302, 304 are of different lengths, with front flange 302 being appreciably shorter than the rear flange 304, the latter being provided with a lip barb or hook-type formation 308 capable of being received within a complementarily shaped recess provided in an appropriate location on the rear su rface of the web portion (shown at 210 in dotted line). I n some preferred arrangements, one or both of the leading edges of the flanges 302, 304, and the hook formation 308 provided on the latter, may be chamfered to some extent back towards the web portion 306 so as to provide surfaces 310, 312 respectively which facilitate the insertion of the clip into its desired position in order that it locks the spar to the clip as described further below.

As can be seen in Fig. 14, the clip 200 has a pair of spaced apart elongate ribs on the rear su rface of its web portion 4-2 between which is thus defined a shallow channel over the rear surface of said web portion and the flanges of the clip projecting from the front surface of the web portion comprise 2 separate, spaced apart flange portions 12A-2, 12B-2, and 12c-2, 12D-2 respectively, so as to define openings 120, 122 therebetween which are substantially the same width as, and coincident with said shallow channel. Although said openings and said shallow channel need not necessarily be the same width, they must be at least partially coincident, as will become apparent. Openings 120, 122 achieve two important functions: firstly, they provide the means whereby respective flanges 302, 304 of the locking clip can be received therein so that said flanges are disposed intermediate the adjacent nib formations 16A-1, 16A-2 on either side thereof, and secondly, when a spar is connected to the clip (as will be descrbied below with reference to Figures 15-17), said openings reveal and make accessible the rearmost flange of the spar which is otherwise retained in place behind the said nib formations.

As the skilled person can appreciate from Figure 14, locking clips 300 are shown remote from the clip for clarity - in use, one or both of said clips will be connected to the clip by firstly disposing the clip rear flange 304 between any two respective adjacent clips already having been connected to a post as described above (see Fig. 12) and between the elongate ribs of one such clip before slidingly said flange behind the web portion of a respective one of the said clips, of course still between the elongate ribs which extend over the rear surface of said web portion, until its hook formation 308 is snap-fittingly received in the correspondingly shaped recess 210 provided on the rear surface of said clip web portion. As the locking clip is slidingly connected to the primary clip in this manner, the frontmost flange 302 moves into the opening 122 and between nib formations 16A-1, 16A-2 which define it. Importantly, if an effective locking function is to be achieved, the length of flange 302 is preferably longer than the adjacent nib formations so as to providea significantly greater retaining force for the rear flange of a spar connected to the clip as further explained below.

Thus, the locking clip 300 effectively defines a further channel 314 which can receive and lockingly retain the free edge of the flange portion of the spar in very similar fashion to the channels defined on the clip itself, but importantly, the clip can be removed if required or desired.

Referring finally to Figures 15, 16, 17, a spar 400, having slightly modified cross-sectional shape to the spar 50 shown in Figures 5 A, 10, 1 1, is shown in various stages of connection to clip 200. For clarity, the post to and within which clip 200 will be connected has been omitted, but it is to be understood that clip 200 will have been firmly and robustly secured to a post as previously described befo re the con nection of the spar to the clip can be reliably achieved.

The cross-section of spar 400 is essentially H-shaped, and comprises front and rear flanges 402, 404 respectively joined together by intervening web portions 406A, 406B, all of which together provide the spar with generally parallel channels 408, 410 between the remote ends of the flange portions 402, 404, and which, ultimately after con nection to the clip is complete, receive the nib formations of the clip to which said spar is con nected. I n the embodiment shown, the spar is both hollow and has a cross-sectional shape which laterally symmetrical, i.e. it is symmetrical about a line joining the mid points of the parallel flanges. I n the particu lar case of con nection to a clip 200 which has upper nib formations 14A-1 , 14A-2 which are longer than opposite lower nib formations 16A-1 , 16A-2, connection of spar 400 can practically, and preferably only, be achieved by firstly inserting one free end 404A of a rear flange 404 into and within the channel of the clip defined by the uppermost nib formation 14A-2, the u ppermost flange portion 12B-2, and the relevant portion of the rear web portion 4-2, as shown in the Figure. One the rear flange 404 of the spar is in this position, with one free end 404A within the clip and disposed behind the nib formation 14A-2, and the other free end 404B outside the clip but directly in front of the lower nib formation 16A-2, the spar can be rotated counter-clockwise as shown at arrow 420, into the position shown in Fig. 16, wherein the u ppermost free edge 404A is forced yet further into the channel defined behind nib formation 14A-2, and the front surface of the free end 404 B, which is preferably radiused or otherwise profiled as previously described, comes into contact with the correspondingly radiused or profiled surface of the lower nib formation which, with increased torque or other force of con nection applied to the spar, is caused to be deflected downwardly as shown by arrow 422 in such as manner as to widen the effective gap between the free ends of the nib formations 14A-2, 16A-2, eventually to such an extent that the flange free end 404B can pass beyond the nib formation 16A-2 and into the channel behind it and which it partially defines together with flange portion 12D-2 and the relevant portion of the clip web portion 4-2. Once this occu rs, the nib formation 16A-2 elastically recovers, and the flange free end 404B is then moderately securely retained behind it, as shown in Fig. 17. Althoug h not specifically illustrated, the skilled person will understand that (a) during con nection, for instance at the point shown in Figure 16, there may additionally be some resilient deflection in the opposite direction, albeit to a possibly lesser extent, of the nib formation 14A-2 as the flange 404 is essentially levered into the position shown in Figure 17, and (b) that the con nection of the spar to the clip occurs along over the entire width of the clip, despite the above description specifically referring to parts of the clip on one side thereof (12B-2, 12D-2, 14A-2, 16A-

2).

After the spar has been connected to the clip, either as shown in Figure 17, and possibly also as shown in Figure 10 depending on dimensions of the spar flange 56 as compared to the distance between the flanges 12 of the clip which receive it, said spar flange 56 or 404 may be additionally locked in position by using a locking clip 300 as previously described. I n the case of Figure 17, is important to note firstly that the there is an appreciable gap between lower nib formation 16A-2 and the lower web portion 406B of the spar, whereas no such ga p exists between upper nib formation 14A-2 and corresponding web portion 406A. The locking clip 300 effectively closes this gap (of course in the region of the locking clip only) after insertion of the locking clip is complete. I n particu lar, insertion of the locking 300 is achieved by firstly inserting the free end of the rear flange 304 behind web portion 4-2 of the clip within the shallow chan nel defined between the elongate ribs (seen more clearly in Figure 14), and then sliding the said locking clip u pward ly u ntil the hook formation is eventually received within complementary recess 210 provided on the rear su rface of the clip web portion 4-2. As the locking clip 300 is slip into this position, the frontmost flange 302 automatically and simultaneously enters into the opening 122 (not shown in Figs. 15- 17) defined between respective nib formations 16A-1 , 16A-2, and becomes disposed in front of the free end 404B of spar rear flange 404 thus either preventing it, at least easily or without destruction of some form, from becoming freed from the clip, for example in the reverse of the man ner in which it was connected thereto as shown in Figs. 15, 16 and 17. Thus, when in position, the free end of front flange 302 of the locking clip is disposed above and beyond the free edges of the adjacent nib formations of the clip, and it is by reason of this heig ht differential that an adequate locking function can be achieved for the spar.