FENCING SYSTEM AND METHOD OF ASSEMBLY INVOLVING CONCEALING OF THE FASTENERS BETWEEN THE HORIZONTAL RAIL AND VERTICAL PALES

Related Applications

This application claims priority to Australian Provisional Patent Application

5 No. 2009900714 in the name of Gryffin EPSS Pty Ltd, which was filed on 20

February 2009, entitled "Fencing System and Method of Assembly" and

Australian Provisional Patent Application No. 2009901 156 in the name of Gryffin

EPSS Pty Ltd, which was filed on 17 March 2009, entitled "Fencing System and

Method of Assembly" and the specifications thereof are incorporated herein by0 reference in their entirety.

Field of the Invention

The present invention relates to the field of fencing, particularly manufacture of fences and fence parts for use delineating boundaries or5 providing secure enclosures.

In one form, the invention relates to a system of palisade fencing and a rail suitable for use in the system of palisade fencing.

Background Art 0 It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation and/or the identification of certain related art problems. Moreover, any discussion of material such as documents, devices, acts or5 knowledge in this specification is included to explain the context of the invention and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein. 0 Fences have been used since ancient times as freestanding structures to restrict or prevent movement across boundaries. Myriad forms of fencing have developed over the centuries, including barbed wire, chain link, dry-stone, live (eg hedgerows), wattle, split-rail, wood panel, stake-and-wire, electric, palisade and so forth. Referring specifically to palisade fences these typically comprise a series of pales, such as metal stakes or pickets, held in position by horizontal rails. The rails are typically supported on vertical posts or other structures.

One of the problems associated with palisade fences is that the pales are often attached to the face of the rails using fixing mean such as bolts, security nuts or rivets. Often a palisade fence comprises two horizontal rails fixing a pale at two points. If one fixing means is removed from one point, a pale can be swung to one side to open a gap and allow access through the fence thus defeating the purpose of the fence. Even if the palisade fence has three rails (for example, two rails at close spacing in the lower part of the fence and one rail near the top of the fence) strong blows from a hammer can break both the lower fixing means to open a gap in the fence.

Previous attempts have been made to address the issue of unauthorized pale removal or displacement achieved by cutting one or more of the fasteners that secure a pale to L-shaped cross rails. For example, bolts are often cut by insertion of a chisel into the open space between the rear of the pale and the front face of the cross rail. Previous rail systems have been designed so that any attempt to remove pales tends to cause deformation to the rail which will make it difficult to displace or remove the pale. Furthermore, some systems are designed to leave only a very short portion of the fastener extending between the rail and pale, thus protecting the fastener from attack by a chisel or crowbar or the like. These arrangements typically remove or minimize the need for fasteners and they are principally used to minimize rattling of the pales against the rail. When fasteners are used, only a short portion of the fastener extends between the rail and the pail, or the head is protected, thus protecting the fasteners from attack by a chisel or crowbar or the like.

The problem of pale removal is less apparent in palisade fences constructed by passing each pale through the rails so that strong blows against the side of the pale are unlikely to break the fixing means. Even if the fixing means is broken, the upper fixing means (which is not easy to strike successfully with a hammer or the like) and the rail surrounding the pale can prevent the pale from being removed. One significant drawback of the system where the pale is passed through the rail is that in one version the head end of the pale has to be able to pass through slot in the upper rail, and it has to be of the same cross sectional shape as the rest of the rolled pale. Accordingly, the head of the pale cannot have a flared spike (like a spearhead) which is preferred for higher security palisades, or for decorative purposes.

In another similar system, each pale is lifted above the uppermost rail and kept exactly vertical as it is inserted down through the slots in the rails. The taller the fence, the more difficult this becomes. For manually installed fences this can become a significant occupational health and safety issue. For very tall fences a crane may need to be used to lift and position the pale. Also, in the case of damageable pales, eg pales having a powder coated finish etc, lowering the pale down through the rail can scratch and cause unsightly damage to the pale surface.

Summary of Invention

In a first aspect of the present invention there is provided a rail for palisade fencing comprising a profiled rail section adapted to be fastened to fencing pales using fasteners, wherein, in use, the fasteners are enclosed by the profiled section on at least one side of the fence to prevent tampering of the fasteners.

Preferably, the profiled rail section encloses the fasteners, and the pales at the fasteners, on both sides of the fence.

The profiled rail section may be single piece or may comprise multiple sections including a front section and a rear section. In a preferred embodiment the front section is fastened to a pale and the rear section is fastened to the front section, a pale or posts of the palisade fencing. The front and rear sections can interlock with one another. In another version the front and rear sections have hooked interlocking fingers that are anchored by a pale fastener.

The rail preferably includes a cross rail to provide stability and integrity to the fence. The cross rail may be a separate part to be fastened to the pale or may be defined by a reinforced portion of the profiled rail section.

In another aspect of the invention there is provided a palisade fencing system comprising: fencing pales and support posts; a rail as described above to horizontally space and support the fencing pales on the support posts; and fasteners to fasten the rail to the fencing pales and support posts.

The pales of the palisade are not necessarily hollow section (unlike most other fencing systems) but can be formed from strips of material such as folded or rolled metal, formed into a two-dimensional shape, usually a ¹ W or a deformed ¹ V (known as a D pale). The pales may comprise one part. Alternatively, the pales may comprise a standard shape pale body to which various pale head styles can be attached.

The fastening means may be any convenient fastening means known in the art including, but not limited to, self tapping screws, one way screws or bolts. Preferably the rail is configured to completely enclose both the driving end and the head of the fastener. The rail may be attached to posts by any convenient means.

The rail may be manufactured of a single strip of material, typically a rolled or folded strip of metal. In this conformation, the slot is typically cut in the metal. Alternatively, the rail may be manufactured in sections, typically from two or more strips of material. For example, the sections described above may be formed by the overlap of these strips of metal. In this embodiment, the slot may be cut in the metal, or alternatively the slot may be formed by, or intermediate to, the strips of metal.

The rail may be adapted in other ways to conceal a driving end of the fasteners. For example, the rail may comprise one or more sections that form a shroud that encloses and thus conceal the driving end of the fasteners and/ or the head of the fastener.

In accordance with yet a further aspect of the invention there is provided a shroud for retrofitting along a cross rail on palisade fencing comprising: a front section profiled to enclose part of a pale and a cross rail fixing from a front of the fencing; and a rear section fastenable to the front section so as to together enclose the cross rail and the fixing from a rear of the fencing.

The two parts of the front and rear section may be held together by any convenient means, including interlocking parts and/or secondary fasteners such as self tapping screws or welding. While the shroud is described as incorporated into the rail of an existing palisade fence by retrofitting, it is understood that a new fence may be constructed having a cross rail and the described shroud. By retrofitting the shroud the strength and security of an existing fence can be substantially upgraded without having to disassemble the existing structure or replace or re-engineer existing parts.

In another aspect of the invention there is provided a method of retrofitting the above shroud to a cross rail of a palisade fence including fitting the front section over a pale so as to cover a cross rail fixing on a front of the fence, the front section extending rearwardly to also enclose the cross rail; fitting the rear section over the front section to form an enclosed cross profile between the front and rear sections; and fastening together the front and rear sections.

In one embodiment a method of assembling a palisade fencing system may include: locating a pale in a first rail by sliding in a first direction into a slot in the first rail, locating said pale in a second rail by sliding in a second direction into a slot in the second rail, passing the driving end of a fastener into each rail and the pale, and tightening the fasteners to pull the pale against the rail.

The fencing system of the present invention may be further strengthened, without detriment to the appearance of the fence by the inclusion of reinforcement within the rail. For example, when the rail comprises a shroud the reinforcement may be enclosed therein, for example in the form of a cross rail. Typically the reinforcement includes a cable or bar that is resistant to cutting by a hand tool such as a hacksaw, or mechanised cutting tools such as a circular saw.

Other aspects and preferred forms are disclosed in the specification and/or defined in the appended claims, forming a part of the description of the invention.

Brief Description of the Drawings

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: Figure 1 a is an illustration of a longitudinal cross section of part of a palisade fence made according to one embodiment of the present invention wherein the rail is constructed from a single strip of metal; Figure 1 b is a transverse cross section of the pale shown in Figure 1 a;

Figure 2 is an illustration of a longitudinal cross section of part of a palisade fence made according to another embodiment of the present invention wherein the rail is constructed from a single strip of metal;

Figure 3 is an illustration of a longitudinal cross section of part of a palisade fence made according to yet another embodiment of the present invention wherein the rail is constructed from two strips of metal;

Figure 4 is an illustration of a longitudinal cross section of part of a palisade fence made according to yet another embodiment of the present invention wherein the rail is constructed from three strips of metal; Figure 5 is an illustration of a longitudinal cross section of part of a palisade fence having two-part pales in accordance with yet another embodiment of the present invention.

Figure 6 is an illustration of a longitudinal cross section of part of a palisade fence having a rail comprising a shroud in accordance with yet another embodiment of the present invention.

Figure 7 is an illustration of a blank for manufacturing one part of the shroud of Figure 6.

Figure 8 is a cross sectional view of the shroud of Figure 6 formed from the blank of Figure 7. Figure 9 is an illustration of a longitudinal cross section of part of a palisade fence made according to another embodiment of the present invention wherein the rail is constructed from two interlocking strips of metal.

Figure 10 shows, in longitudinal cross section, a variation of the palisade fence construction of figure 9 where a reinforcement is obviated according to another embodiment of the present invention. Detailed Description

The various embodiments of the rail and shroud depicted in the drawings show the part of the pale with a rail fastener enclosed by a tamper resistant elongated enclosure/shroud/shell. In a preferred embodiment, the enclosure is made of cut and folded steel section manufactured from 1.6mm thick steel. The embodiments depicted prevent access to both the pale and the rail fixings, including the head, nuts and collars, and thereby prevent attacks on the rail to pull apart and gain access through the fence. Figures 1 to 5, 9 and 10 illustrate a rail for use with palisade fencing where the rail has a profiled rail section, that can be a unitary piece or made of multiple sections, whereby when the profiled rail section is fastened to fencing pales the fasteners on the fencing pales are covered or enclosed by the profiled section to prevent access to the fasteners and thereby to prevent tampering. The profiled rail section also provides structural support to the palisade fencing as a cross rail.

Figures 6 to 8 illustrate a variation on this concept whereby a cross rail is provided on the palisade fencing and a shroud 20b, 20c, which is not itself necessarily fixed to the pales, is provided along the length of the cross rail enclosing the cross rail and the fasteners fixing the cross rail to the pales thereby preventing access to the traditional weak spot in the palisade fence system, namely the point of fixing the pale and rail.

Figure 1 a is a longitudinal cross sectional view of part of a palisade fence made according to one embodiment of the present invention. Figure 1 a shows a pale 1 located in an appropriately shaped slot 3 in a rail 5, and a fastener 10. The rail 5 is a profiled rail section formed from a single steel strip that is folded to form an "e"-shaped cross section including a rear face 5a a front face 5b parallel to rear face 5a an upper face 5c joining the rear and front faces and having slots 3 for receiving pales, and a return 5d joined to the front face 5b by a lower horizontal face 5e. The rear face 5a is the 'rear' of the rail and its edge is neatly folded 5g. The fastener 10 is a tamper proof screw which when fastened, cuts its thread into the return 5d of the rail and the head of the fastener 10a is flush with the rear surface 5a of the rail. Tightening the fastener 10 such that the driving end 10b goes further through the return 5d pulls the front face 5b onto the pale 1 and, in turn, the pale is pulled into contact with the slot 3 in the upper face 5c of the rail and the fold 5g. As this embodiment comprises a rail made from a single rolled or folded strip of metal, during assembly, a plastic insert may need to be fitted to the slot 3 to prevent damage to painted pales as they are slid through the slot 3 in the rail 5. As with most palisade fencing, the pales are not hollow section but are typically folded or roll formed to form a two-dimensional shape, usually a 'W or a deformed ¹ V (known as a D pale). Figure 1 b shows a transverse cross sectional view of the pale 1 of Figure 1a.

The embodiment of the rail 5 as shown in Figure 1 a is best adapted for use for fences of low height, or as a lower/bottom rail for taller fences. Because this embodiment of the rail is made of a single strip of metal, each pale must be lifted above the rail and kept exactly vertical in order to slide through the slots in the rail. This becomes increasingly difficult the further the rail is off the ground, hence this embodiment of the rail is best used at low heights. However because this embodiment of the rail is made from a single strip of metal and requires minimal forming, it provides many manufacturing advantages. The embodiment of the rail shown in at least Figures 3 and 4 are better for rails located at greater heights.

Figure 2 is a longitudinal cross sectional view of part of a palisade fence made according to another embodiment of the rail. In this embodiment, the rail 5 is made from a lighter material (as compared to the rail depicted in Figures 1a and 1b) and therefore it is necessary to fold back the end 5f of the return 5d to get sufficient material thickness for the fastener 10 (self tapping screw) to operate correctly and fasten securely.

In this embodiment the rear section 5a includes a recess 15 that is large enough to receive the head of the fastener 10a such that it can be tightened up directly against the pale 1. This draws the pale 1 towards the return 5d and the front section 5a merely provides structural stiffening. Preferably the recess is filled so that it is blocked after the fastener 10 is installed.

As this embodiment comprises a rail made from a single rolled or folded strip of metal, during assembly, a plastic insert may need to be fitted to the slot 3 to prevent damage to painted pales as they are slid through the slot 3 in the rail 5.

Figure 3 is a longitudinal cross sectional view of part of a palisade fence made according to another embodiment of the present rail. In this version the rail 5 is a profiled rail consisting of two sections: rear section 5' and font section 5", although the principles are the same as for the embodiment depicted in Figure 2.

In use rail section 5" is first attached to the fence posts (not shown). Next the pales are vertically placed and fastened to the front rail section 5" as illustrated by way of fastener 10. The rear rail section 5' is then fitted to the rail assembly with one-way screws (not shown) passing through the overlapping surfaces 20 of the rail sections 5' and 5". The slot 3 for the pale 1 needs to be cut through both rail sections 5' and 5". Typically the slot 3 in the upper face 20 of the rail needs to be formed to allow the "W" pale (or whichever shape pale is used) to pivot at the fastener 10 and therefore is larger than the section itself. It is preferable to conform this slot around the pale as snugly as possible to avoid 'finger traps'.

As this embodiment comprises a rail made from two strips of metal, it is not necessary to use a plastic insert fitted to the slot 3 during assembly because the pale is secured directly to rail section 5' prior to rail section 5" being fitted.

The embodiment of the rail 5 as shown in Figure 5 can be used for fences of any height but is particularly useful for the upper/top rails of taller fences. Because this embodiment of the rail is made of two sections of metal 5', 5", there is no need for each pale to be lifted above the rail or kept exactly vertical during installation.

Figure 4 is a longitudinal cross sectional view of part of a palisade fence made according to another embodiment of the present invention. This embodiment is similar to the embodiment depicted in Figure 3 except that the rail 5 is made of a slightly thinner steel section and the return section 5d has been replaced with a thick vertical plate 6 that provides a stronger anchor for the fastener 10. The thick vertical plate 6 replacing the return 5d can be secured by a second fastener 20 near the base to a lip on the lower horizontal face 5e. Any suitable fastener can be used as the second fastener 20, such as for example, screws, rivets or spot welds. As this embodiment comprises a rail made from two strips of metal, it is again not necessary to use a plastic insert fitted to the slot 3 during assembly because the pale is secured directly to rail front 5" prior to rear section 5' being fitted. This embodiment also has the advantage of concealing the head 10a of the fastener 10 and protecting the head from tampering.

The embodiment of the rail 5 as shown in Figure 4 can be used for fences of any height but is particularly useful for the upper/top rails of taller fences. Because this embodiment of the rail is made of two sections of metal 5', 5", there is no need for each pale to be lifted above the rail or kept exactly vertical during installation.

Figure 5 is a longitudinal cross sectional view of part of a palisade fence made according to another embodiment of the present rail. In this embodiment the pale 1 has a flared head 1 a as a separate unit. This has the advantage that various pale head styles can be incorporated into the palisade fence, each adapted to fit to a standard shape pale body 1 b. This embodiment has the additional advantage that the system could be assembled by sliding the plain cut pale body 1 b up into a top rail and then lowering them into a lower rail thus avoiding the occupational health and safety issues associated with lowering them down through both rails. The pale head 1 a can then be installed when all pale bodies 1 b are in place.

In the embodiment illustrated in Figure 5 the pale body 1 b and pale head 1 a overlap inside the body of the rail 5. It will be appreciated that any of the rail embodiments depicted in Figures 1 to 4 could be used with the two-part pales. The two parts of the pales 1 a, 1 b are secured by fastening means 10 passing through pre-punched holes, to the return 5d of the rail. It may also be advantageous to have the 'join', between the pale body 1 b and the pale head 1a situated in the vicinity of the top rail so that the join is obscured from view. This provides optimal aesthetics as well as the illusion to would be attackers that each pale is unitary.

This embodiment particularly suits palisade fencing because unlike most fencing systems, the pales are not hollow section but are folded or roll formed to form a two-dimensional shape, usually a 'W or a deformed 'V (known as a D pale).

Use of a two-part pale having a pale body 1 b and a pale head 1 a is particularly advantageous when the fence is to be constructed on sloping or undulating ground. In a particularly preferred embodiment, the amount of overlap between the pale body 1 b and pale head 1 a can be varied to allow variation of the total pale height. Thus individual pale heights can be adjusted so that the top of the fence has a uniform appearance.

Figure 6 is an illustration of a longitudinal cross section of part of a palisade fence having a rail 20 comprising a shroud 20b, 20c and a body 20a. The rail 20 is secured to a D-shaped pale 22 by a fixing, or fastener 24, having a head 24a and a driving end 24b. The rail body 20a is typically a cross rail which in the embodiment shown is an angled cross rail through which the fastener 24 passes. Shroud 20b, 20c is formed from sheet metal. The shroud has a front section 20c approximately "U" shaped in cross section and configured to wrap around the palisade 22 including the head of a fastener 24a securing the palisade 22 to the rail 20. A rear section 20b of the shroud is also "U" shaped and is configured to enclose the driving end 24b of the fastener 24 and enclose rail body 20a from the rear of the fence by fitting or sliding over the open end, or open mouth of the front section. The two parts of the shroud 20b, 20c are held together by secondary fasteners 26a, 26b comprising self tapping screws or any other suitable fastening means including those mentioned above.

Figure 7 is an illustration of a blank for manufacturing one part, the front section 20c, of the shroud of Figure 6. This particular conformation is suitable for retrofit to an existing palisade fence. The blank is flat, and can be made into a usable conformation as shown in Figure 8, by bending where indicated on the broken lines. When fitted to a palisade fence, the palisades reside in the recesses 28. The head of the fastener securing the palisade to the rail is enclosed within faces 20c' and 20c". Faces 21 ', 21 ", 29' and 29" partially enclose the driving end of the fastener and the cross rail.

Figure 8 is a cross sectional view of the shroud rear section 20c of Figure 8 formed from a sheet metal blank according to Figure 9.

Figure 9 is an illustration of a longitudinal cross section of part of a palisade fence made according to one embodiment of the present invention. In this embodiment the rail is constructed from two interlocking strips of metal - a front section 35a and a rear section 35b. A flat rail 37 is secured to the pale 39 by a fastener 41. Typically the rail 37 comprises a flat bar which has very little resistance to bending in the horizontal plane but it is sufficiently strong in the vertical plane to allow attachment of pales as the palisade fence is assembled. The attachment of the front section 35a and a rear section 35b significantly increases the horizontal and vertical strength of the palisade fence assembly.

In this embodiment the fastener 41 is a self tapping screw, but could alternatively be a bolt, rivet or the like. The front section 35a and rear section 35b of the rail are shaped to include interlocking 'fingers' 43 that are like castellations, and hook over alternate sides of the reinforcement 37. Typically the castellations are 12 to 15 mm in width although this can be varied to suit the width of the pales. The front section is cut to include slots to receive the pales. The front section 35a and rear section 35b are secured by a secondary fastener 45 in the form of an assembly clamping fixing such as a blind rivet or screw.

Figure 10is an illustration of a longitudinal cross section of part of a palisade fence made according to a further embodiment of the rails which is a variation to the embodiment of figure 9. In this embodiment the rail is constructed again from two interlocking strips of metal - a front section 35a' and a rear section 35b'. As opposed to the embodiment of figure 11 there is no flat rail 37 secured to the pale 39'. Again the attachment of the front section 35a' and a rear section 35b' significantly increases the horizontal and vertical strength of the palisade fence assembly. The fastener 41 ' is a self tapping screw, but could alternatively be a bolt, rivet or the like. The front section 35a' and rear section 35b' of the rail are shaped to include interlocking 'fingers' 43' that are like castellations, and hook alternatively over opposite sides of a pale fixing nut 46'. Typically the fingers 43 are 12 to 15 mm in width although this can be varied to suit the width of the pales. The front section 35a' is cut to include slots or voids 47' to receive the pales 39'. The front section 35a' and rear section 35b' are secured by a secondary fastener 45' in the form of an assembly clamping fixing such as a blind rivet or screw.

The embodiment as shown eliminates the reinforcement rail 37 of figure 9 and forms the rear section 35b' into a generally rectangular hollow section or tube. The unit effectively becomes a two piece assembly similar to that shown in figures 3, 5 an 6.

The front section in the various embodiments described herein is profile cut to correspond with the pale section to be installed, generally a 'D' or 'W shaped pale, and then folded to create a void around the fasteners which it encloses. The void is roughly polygon in shape and so provides the rail with strength and structural integrity along the entire length of the fence. The polygon shape of the front section in some of the described embodiments is closed by the rear section. The rear section also provides locking folds for the front section and generally prevents the front section being removed under extreme force. The rear section is secured to the front section with suitable tamper proof fixings such as a variety of screws and blind rivets or even spot welds.

These general characteristics of the front and rear sections apply to the multi-part rails described herein as well as the shroud. Similar characteristics can be found with a single part rail which has its own defined front and rear sections but which has closed slots through which the pales must be inserted. The multipart rails have the advantage of having open slots which can be placed against the pale without having to longitudinally slide the pale into the slot.

In the event of an attempted attack, namely, destruction of the palisade fence by levering a pale, the described palisade fencing system having the rail or shroud would transfer the load of levering directly to the rail which would decrease the load on any individual fixing and thereby eliminate the need for high resistant bolts or rivets. Using special high strength pale fixings on known palisade fencing systems will improve the resistance to levering but eventually the fixings will shear or the head of the fixing will pull through the pale material. Generally, breaking one fixing will weaken the system and make it possible to pull a pale to one side and gain access through the fence. With the present rail and shroud systems, even it is was possible to break one of the fixings, the rail or shroud will keep the relevant pale locked firmly in place. In summary, preferred embodiments of the present invention stem from the realization that the rail can be better configured to permit the pale to pass through the rail without compromising its strength, while better concealing and tamper proofing the fastening means.

Advantages provided by the present rail, shroud and rail system include: • improved security and resistance to tampering,

• the head shape of the pale is not limited by the shape of the slot in the rails, • the angle of the pale head and length of the pale can be adjusted to allow for ground contour,

• the pales are held securely against removal, or rattling due to vibration, • the fasteners are well concealed,

• the rail is configured such that the strength is not compromised by the inclusion of slots for receiving the pales,

• ease of assembly,

• reduction of occupational health and safety issues during installation, particularly when the fence is tall, and

• economy of manufacture from material sheets.

Further scope of applicability of embodiments of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure herein will become apparent to those skilled in the art from this detailed description.

While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth.

As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. The described embodiments are to be considered in all respects as illustrative only and not restrictive.

Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures. For example, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface to secure wooden parts together, in the environment of fastening wooden parts, a nail and a screw are equivalent structures.

"Comprises/comprising" or "includes/including" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof." Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', 'includes', 'including', and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".