The invention relates to attachment means and methods for attaching an article to an assembly. In particular, though not exclusively, the invention relates to attachment means and methods for attaching a panel to a railing assembly.

Constructing an assembly from component parts typically requires the careful and accurately-positioned attachment of successive component articles to an assembly in a state of partial construction. Large, unwieldy and/or heavy component articles of the assembly can prove difficult to manage when attempting to attach to the assembly under construction.

An example of this includes large assemblies such as railing assemblies and component articles such as large panel sections to be attached to those railing assemblies.

Existing railing assemblies, which comprise large panel sections, often comprise an upper and a lower rail between which a panel section is secured. Simple one-piece clips of a generally U-shape are employed to secure edges of the panel to an adjacent rail. Initially, the base of one or more U-shaped clips are secured to a base rail and a lower edge of a railing panel is then inserted within the U-shaped clip(s) to secure to the panel in that state. Subsequently, a corresponding upper rail of the rail assembly is then lowered onto the upper edge of the railing panel so as to locate parts of the upper edge within downwardly- facing U-shaped clips attached to the lower edge of the upper rail. In this way, first: the lower edge, and subsequently: the upper edge, of a panel section of a railing assembly are secured to the railing assembly under construction. This sequence of construction is inconvenient, difficult and potentially dangerous especially if the panel section in question is heavy or fragile, such as a glass panel. The U-shaped clips into which a lower edge of the panel is inserted must be strong enough alone to hold the panel upright until the U-shaped clips of the upper rail can be applied to the upper edge of the panel.

The invention aims to provide alternative attachment means and methods for attaching an article to an assembly, being particularly suited to attaching a panel to a railing assembly.

At its most general, the invention concerns an attachment means and methods, employing component parts e.g. of a clip, trim, clasp or grip, fixable together (e.g. separably) to define a channel between them dimensioned to accommodate an edge of a panel such that the channel may be build around the panel edge rather than the panel edge inserted into a pre-constructed channel. Preferably, the two parts are fixable together via a pivoting action of one part relative to the other e.g. to draw/move that part into attachment to the other part to define the channel. Preferably, the attachment means is a two-part structure in which a second part is (e.g. separably) fixable to a first part without the need for additional fixing member such as screws, nails, bolts, etc to enable the two parts to fix together. For example, those two parts may be (e.g. separably) fixable together at an interface between formations in each forming an interference fit, a push-fit or a snap-fit together. Preferably, a first of the two parts of the attachment means provides a docking surface dimentioned and arranged to support a received edge of a panel to permit, most preferably, the weight of the panel to be supported at the docking surface in use. A wall portion or part may preferably be formed adjacent the docking surface to extend generally transversely relative to the docking surface preferably such that peripheral parts of one side of the panel adjacent to the edge of the panel received at the docking surface may reside in parallel, or abut the wall part concurrently in use. In this way, a panel edge may be docked in a first part of the two-piece attachment means and the second part of the attachment means subsequently fixed to the first part to construct a channel around the docked panel edge. This permits upper and lower supporting rails of a railing assembly to be positioned and fixed in the assembly each with a respective first part (including the docking surface) of each of a pair of two-part attachment means fixed to opposing respective edges of the upper and lower rails between which a panel may be docked before subsequently constructing respective channels in the upper and lower rails by fixing respective second parts of the attachment means to each rail to define completed channels each housing and retaining a respective upper or lower edge of the panel in question. Of course, the attachment means may be used other than in such a pairing.

The two parts of the attachment apparatus preferably comprise separate and separable first and second jaw members defining a two-part attachment apparatus. The invention may be a railing assembly attachment means. The two parts may be separable via a pivoting action. The pivoting action described above may be enabled by provision of interface surfaces comprising a convex surface of one part over/against which a concave surface of the other part slides, or moves, as part of the pivoting action of the other part as a whole. This enables simple e.g. hingeless pivoting action in the sense that no hinge pin is required meaning that the two parts remain separate and separable.

In a first of its aspects, the present invention may provide an apparatus or a kit of parts for a railing assembly including attachment means for attaching a panel to the railing assembly comprising a first jaw member defining a first wall part and adapted to be fixable to a component of the railing assembly, a second jaw member defining a second wall part and adapted to be (e.g. separably) fixable to the first jaw member (e.g. via a pivoting action about the first jaw part) to place the second wall part in spaced apposition to the first wall part to define therewith a channel for accommodating an edge of the panel thereby to attach the panel to the railing assembly.

The first jaw member may define a spacer part adjacent the first wall part extending in a direction transverse thereto without extending thereacross wherein the spacer surface is adapted to define a base (or top) of the channel which spaces the second wall part in apposition to the first wall part. In this way, the spacer part may serve as a docking surface to receive an edge of a panel to be attached to a railing assembly before the second jaw member is fixed to the first jaw member to form the channel with the docked panel edge in situ. This is particularly useful when the edge to be received is a lower panel edge and may then support the weight of the panel as the channel is formed. In not extending, preferably to any extent, across the first wall part, the spacer surface does not obstruct movement of an edge of a panel towards the first wall part. This means that the surface parts of a panel adjacent the panel edge may be moved directly transversely (as opposed to obliquely) towards the first wall part without requiring the edge to be obliquely "slotted into position". The spacer surface may be flat. The spacer surface may extend transversely from the first wall part. For example, the first wall part and the spacer surface may join at a right-angle. In alternative embodiments, the spacer surface may extend obliquely across adjacent parts of the first wall part, or may possesses a recess formation adapted, in either case, to receive a panel edge to retain the position of such an edge to prevent slippage. As a lower panel edge is received by a spacer surface, peripheral parts of the face of the panel adjacent the received edge and adjacent an upper edge of the panel, may be pressed by a user against the first wall part of a lower first jaw member fixed to an upper surface of a base rail of a railing assembly, and simultaneously against the first wall part of an upper first jaw member fixed to the underside of an upper rail of the assembly. Thus, the panel may be held in place whilst "stood" on the docking surface provided by the spacer surface of the lower first jaw member before the lower and upper first jaw members are joined with corresponding lower and upper second jaw members to form lower and upper channels respectively.

The second jaw member may be (e.g. separably) fixable to the first jaw member by via an interference fit between (e.g. separably) inter-lockable respective parts thereof. The fit may be a frictional fit, a snap-fit or the like between abutted and opposing parts. This obviates the need for additional fixing components to fix the first and second jaw members together. The inter-lockable parts may be a lug or tongue formation (s) on one of the first and second jaw members, inter-lockable with a socket or groove formation (s) on the other of the first and second jaw members.

A part of the second jaw member may be positionable in interface with a part of the first jaw member to permit the first jaw member to slide, rotate or pivot about the interface to bring parts of the second jaw member into (e.g. reversibly) inter-lockable or inter-locking engagement with parts of the first jaw member. A pivoting or levering action may be permitted/provided to facilitate inter-locking of respective parts of the two jaw members to fix them together to define the channel, and optionally by a reverse movement may be un- lockable, separable or dismountable .

One of the first and second jaw members may define fulcrum means and the other of the first and second jaw members (e.g. the second) may define a second-class lever structured to be pivotable about the fulcrum means to push-fit parts of the second jaw member to parts of the first jaw member to fix the first jaw member and the second jaw member together. In this way, the push-fittable parts of the second jaw member may be suitably positioned upon the second jaw member to permit mechanical advantage provided by lever action to force inter- lockable parts together.

The second jaw member may be pivotable about the fulcrum means to bring parts of the second jaw member into glancing abutment with parts of the first jaw member thereat the second jaw member may be further so pivotable by lever action to force the abutted parts thereof to slide into said push-fit with parts of the second jaw member. The jaw parts so arranged for glancing abutment may be adapted to form an interference fit or friction fit as between abutted parts. The first jaw member may be resiliently deformable to splay by force of said lever action the separation between the fulcrum means and said abutted parts thereof to accommodate parts of the second jaw member push- fitted therebetween in use. The material of the first and/or second jaw member may be a material selected from: metal (e.g. Aluminium, or an alloy); plastic; PVC, or the like.

Parts of the second jaw member may be resiliently deformable by force of said lever action to permit accommodation thereof between the fulcrum means and said abutted parts of the first jaw member when push-fitted therebetween in use.

The second (or first) jaw member may include a tongue formation receivable in a preferably complementarily shaped groove formation in the first (or second) jaw member by a push-fit to fix the first jaw member and the second jaw member together.

The tongue formation may define a projection comprising parallel tongue sides (e.g. flat) joined at the tongue tip by a curved convex surface (e.g. with a constant radius of curvature) . The groove formation may include a complementarily- shaped channel formed so as to terminate at a concave channel base. The complementary shaping may be such as to enable an intimate fit therebetween. The tongue formation may define a projection comprising converging tongue sides. One or each of these tongue sides may be flat and may collectively define a tapered wedge-shaped tongue formation. The tongue tip may be a flat surface. The groove formation may include a complementarily-shaped channel being so shaped with respect to at least one of the tongue sides, preferably each tongue side being a tongue side adapted for glancing abutment to the complementary channel formation in use to form an interference/friction fit therewith.

Preferably, the tongue formation may define a tapered wedge having flat sides converging towards and terminating at a tongue tip part adapted for insertion into the complementary channel formation by a push-fit to engage one or both walls of the complementary channel. The complementary channel may comprise flat channel walls converging towards the channel base. Preferably, the channel wall against to which a tongue wall is adapted to abut in use, by rotation of the second jaw member about the fulcrum means of the first jaw member to fix the two jaw members together, is adapted to obstruct further such a rotation when abutment is achieved to prevent the whole of the tongue formation in question being pushed into the complementary channel. The greatest width of the tapered wedge of the tongue formation preferably exceeds the greatest width of the complementary channel. In this way, complete insertion of the tapered wedge into the channel is prevented.

The second-class lever may be operable to push-fit parts of the tongue formation into parts of the groove formation. The groove formation may define the fulcrum means which includes a fulcrum surface presented generally towards the jaw member within which it is formed (e.g. first jaw member) and the tongue formation may be arranged to engage the fulcrum surface such that parts of the tongue formation between the fulcrum surface and distal parts of the second jaw member are pushable into an interference fit with complementarily shaped groove parts by leverage applied to a said distal part about the fulcrum means.

The groove formation may have an elongate slot which extends along a surface of the first jaw member in a direction parallel to the first wall part or the panel when attached to the railing assembly thereby preferably to be parallel to either in use. The tongue formation may have an elongate edge which extends along a surface of the second jaw member in a direction parallel to the second wall part or the panel when attached to the railing assembly preferably so as to be parallel to either in use.

The attachment means may be a two-piece attachment means comprising the first and second jaw members as said two pieces. The second wall part may include a flat surface (e.g. separably) fixable in parallel spaced opposition to a flat surface of the first wall part to define opposing walls of the channel. The kit of parts may include the panel.

The apparatus or kit of parts may include one or more retaining pins wherein the panel includes one or more through- holes/openings dimensioned to receive a retaining pin therethrough and one or both of the first wall part and the second wall part includes a recess formation (e.g. a socket, slot, slit, groove etc) formed therein and dimensioned to receive an end of a retaining pin when received in a said through-hole thereby to retain the panel in position thereat via the retaining pin. Thus, the retaining pin, with its end(s) docked in a recess formation of one/both of the first and second wall parts, adds longitudinal positional security to the panel along the length of the channel to prevent the panel sliding along the channel. The panel may include a plurality of through-hole adjacent an edge (e.g. an edge uppermost/lowermost, or at a side, in use) . The through-holes may be regularly arrayed. The through-holes are preferably positioned, and/or the height of the first and/or second wall parts dimensioned such that the entirety of one, some or each through-hole is not accessible and/or is fully covered thereby when accommodated in the channel in use such that a retaining pin therein cannot be extracted without disassembling the channel .

Both the first wall part and the second wall part may include a respective said recess formation formed therein to be positionable mutually in register across said channel. Consequently, a recess formation on one wall part may oppose a corresponding recess formation in the other wall part of the attachment means across the channel defined by the wall parts in use. Such a (each) recess formation in a given wall part may be a slot, slit, channel or groove extending in parallel to a corresponding recess formation on the opposing wall part of the channel. A given (e.g. each) recess formation in one of the first and second wall parts may be the mirror image of the corresponding recess formation in the other of the first and second wall parts.

The apparatus or kit of parts for the railing assembly may include a further attachment means, separate from the aforementioned attachment means, for attaching the panel to the railing assembly comprising a third jaw member defining a third wall part and adapted to be fixable to a (e.g. another) component of the railing assembly, a fourth jaw member defining a fourth wall part and adapted to be (e.g. separably) fixable to the third jaw member to place the fourth wall part in spaced apposition to the third wall part to define therewith a channel for accommodating an edge of the panel thereby to attach the panel to the railing assembly. The further attachment means may be identical to the attachment means described above, and the panel may have a further edge adapted in the manner described above to interact with the further attachment means as described above (e.g. through-holes, retaining pins etc) . For example, the two attachment means may accommodate opposite edges of the panel to attach it to opposite parts (e.g. opposing rails, such as the upper side of a base rail and the opposing lower side of an upper/ top rail or hand rail) of the railing assembly. The kit of parts or apparatus for the railing assembly may include a rail or a pair of rails (e.g. a hand rail and a base rail) . The attachment means, or each of the attachment means and the further attachment means may be adapted to attach to one or either of the rail or rails.

The rail(s) may define an abutment channel adapted to abut to the attachment means, with a base surface at least a part of which is shaped to project of extend into the abutment channel. The base surface may be convexly curved in part or in its entirety - e.g at all parts, and optionally uniformly or with a varying curvature. The/each rail may define a single respective abutment channel. The/an attachment means may be dimensioned to abut the rail only at the abutment channel. The first (e.g. and/or third) jaw member may be arranged to connect to the rail via an abutment potion thereof defining a recess shaped to receive the projecting or extending base surface part(s) of the rail such that parts of the abutment portion within the recess abut the received projecting base surface part when the first (e.g. and/or third) jaw member is connected to the rail in use. The abutment portion may be laterally dimensioned to match the width of the base (and/or the walls of) of the abutment channel. Opposite walls of the rail channel may oppose lateral movement of the first (third) jaw member when abutted therein. The opposite walls of the abutment channel may be parallel along the length of the channel. This, and/or the convex nature of the abutment channel base, gives significant lateral structural strength to the assembly when the jaw member is attached/fixed to a rail when abutted in this way, when a panel is being mounted to the part-assembled railing in use and pushed against by the closing action of the second (fourth) jaw member to define a channel accommodating a panel edge as described above. The abutment portion of the first/third jaw member may be concave to correspond to the convexity of the base of the abutment channel. The abutment portion and abutment channel base may be shaped to provide an intimate fit/interface therebetween when abutted (e.g. across the whole of the surface of the abutment portion facing the abutment channel base in use.

The groove formation of the first (third) jaw member preferably extends into the jaw member under those parts of the jaw member which define the base of the channel of the attachment means in use (e.g. the spacer surface) . Preferably, the tongue formation of the second (fourth) jaw member extends under those parts of the first (third) jaw member which define or are adjacent the base of the channel of the attachment means when mated therewith in use. This arrangement prevents detachment of the second (fourth) jaw member from the first (third) jaw member in a direction along the surface of the panel retained therebetween in use (e.g. vertically downward/upwards) . The tongue formation may comprise two tongue parts which diverge. At least a part of at least one of the two tongue parts may point or extend in a direction away from the other. This divergence assists in anchoring or rooting the tongue formation within the groove formation. The tongue formation may possess a lateral dimension (e.g. width) which exceeds the lateral dimension of the opening of the groove formation adapted to receive the tongue formation. A hooking or rotation action may be required to fully insert the tongue formation into the groove formation.

The tongue formation may include a hooked tongue member shaped to define a tongue concavity and may terminate at a lip, and the groove formation may include a fulcrum groove defined between two groove walls of which the outermost groove wall terminates with the fulcrum surface. The fulcrum surface preferably has a convexly curved or rounded (preferably circularly) outer surface over which the tongue concavity of the hooked tongue member is preferably adapted to slidingly move as the second jaw member is rotated or pivoted about the fulcrum surface to push the lip into the fulcrum groove and towards the outermost groove wall. Preferably the tongue concavity of the hooked tongue member and the fulcrum surface are complementarily-shaped. Preferably, the fulcrum surface projects, in part, into and across the fulcrum groove to define with the outermost groove wall a wall concavity adapted to receive the lip of the hooked tongue member when the second jaw member is fully attached to the first jaw member via the tongue and groove formation. This enables more secure retention of the hooked tongue member within the fulcrum groove and the second jaw member to the first jaw member as a result.

The tongue formation and groove formation are preferably elongate and preferably extend linearly along the axial direction of the first and second elongate jaw members respectively.

It is to be understood that the invention may be sold in assembled of unassembled form. In another of its aspects, the invention may provide apparatus for a railing assembly including the components of the kit of parts described anywhere above .

In a second of its aspects, the invention may provide a railing assembled from a kit of parts as described anywhere above.

In a third of its aspects, the invention may provide a railing assembly including a panel and attachment means attaching a panel to the railing assembly comprising a first jaw member defining a first wall part fixed to a component of the railing assembly, a second jaw member defining a second wall part and (e.g. separably) fixed to the first jaw member (e.g. via a pivoting action about the first jaw member) to place the second wall part in spaced apposition to the first wall part to define therewith a channel accommodating an edge of the panel to attach the panel to the component of the railing assembly.

The second jaw member may be (e.g. separably) fixed to the first jaw member by via an interference fit between (e.g. separably) inter-lockable respective parts thereof.

The second jaw member may include a tongue formation received in a complementarily shaped groove formation in the first jaw member by a push-fit to fix the first jaw member and the second jaw member together.

The groove formation may have an elongate slot which extends along a surface of the first jaw member in a direction parallel to the panel .

The tongue formation may have an elongate edge which extends along a surface of the second jaw member in a direction parallel to the panel.

The attachment means may be a two-piece attachment means comprising the first and second jaw members as said two pieces.

The second wall part may include a flat surface (e.g. separably) fixed in parallel spaced opposition to a flat surface of the first wall part to define opposing walls of the channel .

The first jaw member may define a spacer part adjacent the first wall part extending in a direction transverse thereto without extending thereacross to define the base of the channel .

The spacer surface may extend transversely from the first wall part . The railing assembly may include one or more retaining pins wherein the panel includes one or more through-holes with a retaining pin extending therethrough and one or both of the first wall part and the second wall part includes a recess formed therein and containing an end of a retaining pin to retain the panel in position thereat.

Both the first wall part and the second wall part may include a respective said recess mutually in register across said channel .

In a third of its aspects, the invention may provide a kit of parts for a hand rail assembly according to the first aspect of the invention including a rail to which the first jaw member is adapted to be fixable.

In a fourth of its aspects, the invention may provide a hand rail assembly including the railing assembly of the invention in its second aspect, and a rail to which the first jaw part is fixed. In another aspect the invention may include an attachment means, or a hand rail assembly, or a kit of parts therefore, as described above and further include a panel having a peripheral panel edge dimensioned to fit within the channel formable by the attachment means . The channel formable by the attachment means may be dimensioned to be greater in length than the length of the peripheral panel edge it is adapted to receive in use. For example, the peripheral edge in question may be the whole of one straight edge, such that the whole of that straight edge, between other edges deviating from it, is receivable within the channel of the attachment means in use. The invention may include multiple attachment means adapted to be positionable such that respective channels formable thereby are arranged in longitudinal alignment so that one panel edge may bridge adjacent attachment means. The multiple attachment may be end-abutted in succession to form one effectively continuous channel. The effectively continuous channel formable by the plurality of attachment means may be dimensioned to be greater in length than the length of the peripheral panel edge it is adapted to receive in use.

Thus, it will be appreciated that the apparatus, kit of parts or assembly described anywhere above realises a corresponding method for attaching assembling a railing assembly, and such methods are encompassed by the invention.

In a fifth of its aspects, the invention may provide a method for assembling a railing assembly including attaching a panel to a railing assembly comprising fixing to a component of the railing assembly a first jaw member defining a first wall part, receiving an edge of the panel at the first wall part, fixing (e.g. separably) to the first jaw member a second jaw member defining a second wall part (e.g. via a pivoting action about the first jaw member) to place the second wall part in spaced apposition to the first wall part to define therewith a channel containing the edge of the panel thereby to attach the panel to the railing assembly.

The method may include (e.g. separably) fixing the second jaw member to the first jaw member by via an interference fit between (e .g. separably) inter-lockable respective parts thereof .

The method may include pivoting the second jaw member as a second-class lever about a fulcrum on the first jaw member to push-fit parts of the second jaw member to parts of the first jaw member to fix the first jaw member and the second jaw member together.

The method may include pivoting the second jaw member is about the fulcrum to bring parts of the second jaw member into glancing abutment with parts of the first jaw member and thereat further so pivoting the second jaw member by lever action to force the abutted parts thereof to slide into said push-fit with parts of the second jaw member.

The method may include resiliently deforming the first jaw member to splay by said lever action the separation between the fulcrum means and said abutted parts thereof to accommodate parts of the second jaw member to be push-fitted therebetween.

The method may include resiliently deforming parts of the second jaw member by said lever action to permit accommodation thereof between the fulcrum and said abutted parts of the first jaw member to be push-fitted therebetween.

The method may include receiving a tongue formation of the second jaw member in a complementarily shaped groove formation in the first jaw member by a push-fit to fix the first jaw member and the second jaw member together.

The method may include using the second jaw member as a second- class lever against the first jaw member to push-fit parts of the tongue formation into parts of the groove formation.

The method may include receiving a retaining pin into a through-hole in the panel and inserting an end of the received retaining pin into a recess formed in the first wall part and/or the second wall part thereby to retain the panel in position thereat via the retaining pin.

There now follow illustrative, but non-limiting, examples of embodiments of the invention with reference to the accompanying drawings in which:

Figure 1 illustrates an end view of a first jaw member of an attachment means for attaching a panel to the rail of a railing assembly; Figure 2 illustrates a perspective view of the first jaw member of Figure 1 ;

Figure 3 illustrates another perspective view of the first jaw member of Figure 1 ; Figure 4 illustrates an end view of a second jaw member of an attachment means for attaching a panel to the rail of a railing assembly;

Figure 5 illustrates a perspective view of the first jaw member of Figure 4 ; Figure 6 illustrates another perspective view of the first jaw member of Figure 4 ;

Figures 7A, 7B, 7C, and 7D illustrate successive positions of the first jaw member of Figure 1 pivoted about the second jaw member of Figure 4. Figure 7D illustrates the first and second jaw members separably fixed together to define a channel therebetween for receiving or accommodating a panel edge;

Figure 8 illustrates an end view of a first and second jaw members fixed together to form an attachment means for attaching a panel to the rail of a railing assembly; Figure 9 illustrates a perspective view of a retaining pin;

Figure 10 illustrates an end view of the attachment means of Figure 7D and Figure 8 containing within its channel a glass panel edge and a retaining pin passing across the channel and through the panel from the first jaw member to the second jaw member;

Figures 11, 12A and 12B show views of an end cap;

Figures 13, 14 and 15 show views of an end region of the attachment means including an end cap of Figures 11, 12A and 12B; Figures 16 and 17 show views of a railing assembly including a glass panel attached to upper and lower parallel rails via respective upper and lower attachments means;

Figures 18 and 19 show views of a channel cover strip;

Figures 2OA to 2OD illustrate successive positions of another embodiment of the first jaw member pivoted about the second jaw member. Figure 7D illustrates the first and second jaw members separably fixed together to define a channel therebetween for receiving or accommodating a panel edge;

Figures 21, 22, 23 and 24 illustrate four different views of a further embodiment of the first jaw member; Figures 25, 26, 27 and 28 illustrate four different views of a further embodiment of the second jaw member adapted to cooperate with the first jaw member of figures 21 to 24;

Figures 29 and 30 schematically illustrate operation of the lock groove and lock tongue of the first and second jaw members of figures 2OA to 2OD, and 21 to 28.

In the drawings, like articles are assigned like reference symbols .

Figure 1 illustrates an end view of a first jaw part (1) comprising an abutment portion (2A) on one side of which is formed a concave abutment surface (9) structured and arranged for abutment against a complimentarily convex surface of a rail length of a handrail assembly (figures 16, 17) . From a side of the abutment part (2A) opposite to that possessing the abutment surface (9) is formed a flat spacer surface (4) the plane surface of which is disposed to be substantially parallel to a tangent at the middle of the concave abutment surface (9) . From one terminal edge of the flat spacer surface (4) extends a first wall part (2B) in a direction generally perpendicular to the plane of the spacer surface (4) . A substantially flat surface region (3) of the first wall part (2B) joins the flat spacer surface (4) at a right-angle. Within the flat surface region (3) of the first wall part (2B) is formed a first recess formation in the form of a re-entrant slot (10) possessing a substantially rectangular cross-sectional profile with parallel flat slot walls and a flat slot base which is substantially parallel to the flat surface part (3) of the first wall part

(2B) . The width of the re-entrant slot, defined by the separation of the parallel side walls thereof, is dimensioned to receive an end of a retaining pin (see figure 9, 10) . A second recess formation (11) is formed as a wedge-shaped groove located between the first recess (10) and the terminal end of the first wall part (2B) . The second recess formation is adapted to receive a complementarily shaped angled ridge ( (340, Figure 19) of a cover strip such as is illustrated in figures 16 and 17.

Adjacent the terminal edge of the flat spacer surface (4) opposite that from which the first wall part (2B) extends, there is formed a groove formation (5) comprising a substantially semi-circularly profiled lock groove (6) adjacent the flat spacer surface (4), and a fulcrum groove (7) located between the lock groove (6) and a fulcrum edge (8) presenting outwardly and to the fulcrum groove a surface having a substantially circular profile in cross section. The locking groove (6) and the fulcrum groove (7) are separated by an intermediate ridge.

Figures 2 and 3 illustrate different perspective views of the first jaw member (1) and illustrate the extruded longitudinal elongation of the profile of the first jaw member illustrated in Figure 1. It is to be noted that the perspective views illustrated in figures 2 and 3 show end portions of the first jaw member in perspective, and that the profile illustrated in Figure 1 persists along substantially the entire length of the jaw member, which may be any length, but in preferred embodiments is a length not exceeding 2.1 metres.

Accordingly, as figures 2 and 3 illustrate, the flat wall surface (3) of the first wall part (2B) , and the flat spacer surface (4) are each longitudinally elongated. Similarly the first (10) and second (11) recesses formations formed in the first wall part are longitudinally elongated to define a slot or a groove running parallel to the axis of extrusion of the first jaw member. Furthermore, the locking groove (6) , fulcrum groove (7) and fulcrum edge (8) of the groove formation (5) also extends longitudinally in parallel along the extrusion axis of the first jaw member to define elongated formations running along the entire length of the first jaw member (1) .

A counter-sunk screw hole (13) is formed in the flat spacer surface (4) and extends through the abutment portion (2A) of the first jaw member (1) to an opening (12) in the centre of the concave abutment surface (9) . The counter-sunk screw hole (13, 12) is structured and arranged to accept a fixing screw (not shown) for fixing the first jaw member (9) to a rail of a railing assembly with the abutment surface (9) abutted against a complimentarily shaped convex abutment surface of the rail.

Figure 4 illustrates an end view of a second jaw member which shows its cross-sectional profile.

The second jaw member is an extruded elongated structure as illustrated in figures 5 and 6 possessing along its length the cross-sectional profile as illustrated in figure 4, except for those parts possessing a counter-sunk key hole (22, 23 of the figures 5 and 6) . One side of the second jaw member presents a substantially flat wall surface (15) having a first recess formation (20) defining a re-entrant slot presenting a substantially flat slot base defined between a pair of opposing slot walls. The re-entrant slot extends along the flat surface (15) of the second wall part in parallel with the longitudinal extrusion axis of the second jaw member (14) . A second wedge- shaped recess formation (21) is formed in the flat surface of the second wall part (15) in between the re-entrant slot and a terminal end of the second jaw member. The re-entrant slot (20) of the second wall part is adapted to receive an end of a retaining pin (figure 9, 10) and the wedge-shaped second recess formation of the second wall part is structured and arranged to receive a complementarily shaped angled ridge ((330, Figure 19) of a cover strip such as is illustrated in figures 16 and 17. From an edge of the second jaw member projects a tongue formation (16, 17, 18, 19) including a lock tongue (16) disposed within the tongue formation nearmost the flat surface (15) of the second wall part, and spaced by a recess (19) from a pivot tongue formation (17) which presents a concave pivot surface (18) on the side of the pivot tongue (17) opposite to that side of the pivot tongue nearmost the lock tongue (16) and the second wall part (15) .

Figures 5 and 6 illustrate different perspective views of the jaw member and show the elongated extruded nature of the second jaw member which may be of any length and is preferably the same length as the first jaw member and preferably no longer than 2.1 metres in length. It is to be noted that the prescriptive use of figures 5 and 6 show only one end of a length. The cross-sectional profile of the second jaw member illustrated in figure 4 persists substantially along the entirety or at least the majority of the elongated length of the second jaw member such that the first and second recess formations (re-entrant slot 20, angled groove 21) define elongated channels extending along the flat surface (15) of the second wall part. The lock tongue (16) , the pivot tongue (17) and the pivot surface (18) present projections (16, 17) and concave recessed surface (18) respectively, which are each longitudinally elongated.

As shown in figure 5, in a surface of the second jaw member outwardly presented in use, is formed a counter-sunk screw hole (22) which extends through the body of the second jaw member to an opening (23) in the flat surface (15) of the second wall part and is structured and arranged to receive a locking bolt or screw (not shown) .

It will be understood that the shape and dimensions of the tongue formation (16, 17, 18, 19) of the second jaw member (14) are complimentary to the shape and dimensions of the groove formation (6, 7, 8) of the first jaw member (1) . Consequently, the second jaw member is seperably fixable to the first jaw member via the interlockable tongue and groove formations .

The sequence of figures 7A, 7B, 7C and 7D illustrate a second- class lever action via which the second jaw member (14) may be pivoted about the first jaw member (1) to push-fit the tongue formation into the groove formation to fix the first jaw member and the second jaw member together with the first wall part (3) and the second wall part (15) in spaced apposition to define between them a channel for receiving an edge of a panel of the railing assembly illustrated in figures 16 and 17.

Referring to figure 7A, the concave pivot surface (18) of the second jaw member is abutted along its length against the complimentarily convex surface of the fulcrum edge (8) on the first jaw member (1) . The second jaw member, in this position, is freely pivotable about the fulcrum edge (8) of the first jaw member by a sliding action of the pivot surface (18) across the complimentarily-shaped surface of the fulcrum edge (8) . By application of a pivoting force (F), the second jaw member may be pivoted in this way towards the first jaw member about the fulcrum edge (8) thereby to bring the lock tongue (16) into closer proximity with the complimentarily-shaped lock groove (6) and, concurrently, to bring the pivot tongue (17) into increasing proximity to the complimentarily-shaped fulcrum groove (7) . Figures 7A, 7B and 7C show successive stages of rotation in this manner, in which the second jaw member (14) is pivoted into increasing proximity to the first jaw member (1) such that the elements of the tongue formation (16, 17) are brought into increasing proximity with complimentarily-shaped elements of the groove formation (6, 7) .

Referring to figure 7C, there is illustrated a position of the second jaw member relative to the first jaw member immediately prior to a glancing abutment between a surface portion of (100) of the lock tongue (16) with an immediately opposing surface portion (101) of the lock groove (6) located at the periphery of the opening of the lock groove (6) immediately adjacent a terminal edge of the spacer surface (4) of the first jaw member. Subsequent rotation or pivoting of the second jaw member (14) into and beyond the position of abutment indicated in figure 7C, is achieved via a second-class lever action implemented by the second jaw member against the first jaw member as follows.

As a turning force (F) is applied to the second jaw member at parts of the second jaw member distant from both the fulcrum edge (8) of the first jaw member, and the lock tongue (16) of the first jaw member, to bring the opposing parts of the lock groove and lock tongue into abutment. A reactive force (not shown) is generated at the abutted surface area (101) of the lock groove in a direction generally converse to the direction of the turning force (F) so as to resist subsequent turning of the second jaw member about the fulcrum edge. Subsequent application of the turning force (F) causes the recessed pivot surface (18) of the fulcrum tongue (17) to urge against the opposing surface of the fulcrum edge (8) in the first jaw member. The fulcrum tongue (17) acts against the fulcrum edge (8) which serves as a fulcrum applied at one end of the lever defined by the second jaw member in this circumstance.

The applied force (F) , urging a subsequent turning of the second jaw member, causes the abutted surface (100) of the lock tongue (16) to urge against the opposing surface parts (101) of the lock groove thereat to generate a load force upon the lever defined by the second jaw member. Accordingly, with the load force positioned in between the fulcrum and the applied force (F) the second jaw member functions as a second-class lever to overcome the load force generated at the lock tongue (16) and to urge the lock tongue into an interference fit with the complimentarily-shaped lock groove (6) of the first jaw member as illustrated in figure 7D. Reversing the sequence of rotation by applying an opposite rotating force (-F) separates the second jaw from the first in the sequence Fig.7D to Fig.7A.

The second jaw member and/or the first jaw member are formed from materials, such as metal (e.g. aluminium) , alloy, plastic, PVC, possessing a sufficient degree of resilient deformability to permit parts of one or both of the tongue formation onto the groove formation to resiliently deform to permit the lock tongue (16) to slide across abutted opposing surface parts of the lock groove (6) and into a fully docked or fully mated interference fit in which the tongue formations are fully mated with complimentarily-shaped groove formations.

In preferred embodiments, the tongue and groove formations are dimensioned such that the tongue formation may at least partially resiliently re-form (e.g. expand or return to, or towards, its un-deformed state) when in the fully inter-locked position with the groove formations. In this way, the tongue formations may be snap-fitted into the groove formations.

It is to be noted that in the fully attached state illustrated in figure 7D, the first wall part (3) of the first jaw member opposes the second wall part (15) of the second jaw member. The first recess formation (re-entrant slot 10) and second recess formation (groove 11) of the first jaw member are opposed to, and in register with, the first recess formation (re-entrant slot 20) and second recess formation (groove 21) respectively, of the second jaw part. Accordingly, each of the re-entrant slots of the first and second jaw members may concurrently receive an end of the same pin positionable to extend across the channel (25) formed by the opposing first and second wall parts, as illustrated in figure 10. Figure 8 shows in greater detail the cross-sectional structure of the attachment means comprising the first and second jaw members seperably fixed together as described above. It is to be noted that the surface portion of the lock tongue (100) most radial distant from the centre of rotation (50) about which the second jaw member pivots in use, is greater than such radial distance of the surface portion (101) of the lock groove against which the lock tongue initially abuts when the second jaw member is pivoted towards fitment with the first jaw member as described above. However, inner parts of the lock groove against which the aforementioned radially distanced parts (100) of the lock tongue are arranged to abut in the fully mated, or fully inter-locked, position illustrated in figure 8, are more radially distant from the centre of rotation (50) and may be as equally distant therefrom as is the afore-mentioned most radially distant part (100) of the locking tongue.

The re-entrant slot (20) formed in the flat surface of the second wall part has a flat slot wall nearmost the tongue formation which meets the re-entrant slot base surface to form therewith an obtuse angle. This disposition is provided to permit the slot wall surface in question to be moved over an edge of a cylindrical retaining pin (60, figure 9) as the second jaw member is pivoted to position the re-entrant slot over the pin end to receive the pin end.

Figure 9 illustrates a perspective view of the retaining pin

(60) and Figure 10 illustrates the position of the retaining pin in use. Opposite ends of the retaining pin are accommodated in respective re-entrant slots of the first and second jaw members. The pin passes through a through-hole (65) formed through a panel (66) , an edge (67) of which is retained within the channel (25) formed by the first and second jaw members between the retaining pin (60) and the spacer surface (4) of the first jaw member (1) . In this way, the first and second jaw members may not only enable a retaining channel (25) to be constructed around a panel edge (67) in the construction of a railing assembly, but they may also permit additional securing of the retained panel via the use of one or more retaining pins (60. Of course, in this arrangement, the through-hole (65) formed in the panel (66) is preferably spaced from the panel edge (67) by a distance no greater than that between the spacer surface (4) of the first jaw member and the edge of the re-entrant slot (10) of the first wall part nearmost of the spacer surface (as illustrated in figure 10 for example) .

It is to be noted that a plurality of such through-holes (65) may be formed appropriately along the panel (66) adjacent the edge (67) thereof to be retained in the channel defined by the first and second jaw members in use. A screw or bolt (not shown) may be inserted through the counter-sunk screw hole (22) in the second jaw member through a through-hole in the panel (66) and into a correspondingly registered threaded screw hole in the first jaw member. This enables the first and second jaw members to be screwed firmly in a clamping position against opposite sides of the retained panel adjacent to the retained panel edge.

Figure 11 shows a perspective view of an end cap (145) to be positioned at a terminal end of the assembled attachment means

(1, 14) comprising the first and second jaw members fitted together. The end cap comprises an abutment surface (150) the periphery of which is dimensioned to match the periphery of the terminal end of the assembled attachment means to which it is inttended to abut in use. The outer surface of the end cap, visibly presented outwardly in use, projects from peripheral edges of the abutment surface in the manner of a sleeve into which a terminal end of the attachment means may be inserted in an interference fit. Figures 12A and 12B illustrate additional top and front views of the end cap illustrated in perspective in figure 11. Figures 13, 14 and 15 illustrate an end view and two different perspective views of the end cap attached to the attachment means in use. It is to be noted that the end cap possesses a channel of the same shape and form as the channel defined by the first and second jaw members (1, 14) , and also possesses a concave abutment surface (90) of the same shape and form as the abutment surface (9) defined by the first jaw member and positionable in adjacency to the abutment surface of the first jaw member to serve as a continuation thereof when the end cap is attached to the attachment means in use.

Figures 16 and 17 show a perspective view and a side view respectively, of a railing assembly (200) . The railing assembly includes an upper rail (210) , a lower rail (220) and a plurality of glass panels (230) secured between the upper rail and lower rail via an upper attachment means (250) and a lower attachment means (240) of the type discussed above.

Parts of each channel unoccupied by a panel edge are covered by a channel cover strip (300) comprising a cover part 305 with a gently convex surface (outwardly presented in use) , and dimensioned to extend transversely across the opening to the channel formed between the terminal edges of opposing first and second wall parts. The cover part also extends longitudinally along those parts/lengths of the opening to a channel which are unoccupied by a panel edge. This applies to both the channel of the attachment means fixed to the upper rail 210 of the railing assembly, and the channel of the attachment means fixed to the lower rail 220 thereof.

A pair or separate resiliently deformable strip walls (310,

320) project in parallel from a flat surface of the cover part (305) opposite the convex surface thereof, and extend along the longitudinal axis of the cover strip. Each strip wall meets the cover part at a respective region of the flat surface between the central region of the flat surface and a respective one of the two long strip edges. The two strip walls are separated along their lengths by a uniform distance dimensioned to permit both walls concurrently to be inserted into the channel opening to engage concurrently a part of a respective one of the first and second channel wall parts. An angled ridge projects from a surface of each strip wall being positioned and dimensioned to engage a second recess formation (11, 21) in a respective one of the first and second wall parts of the channel when the wall parts are fully inserted. Each angled ridge is shaped to complement the angled shape of a given second recess formation, the resilient deformability of the wall parts enabling the angled ridge each possesses to snap-fit into a corresponding second recess formation as the ridge is pushed into register with the recess formation when the cover strip is push-fitted to the channel of the attachment means in use .

Figure 2OA illustrates an end view of a first jaw part (360) comprising an abutment portion (360A) on one side of which is formed a concave abutment surface (9) structured and arranged for abutment against a complimentarily convex surface of a rail length of a handrail assembly (figures 16, 17) . From a side of the abutment part (360A) opposite to that possessing the abutment surface (9) is formed a spacer surface (405) the surface of which is disposed to be substantially parallel to a tangent at the middle of the concave abutment surface (9) . From one terminal edge of the spacer surface (405) extends a first wall part (360B) in a direction generally perpendicular to the spacer surface (405) . A substantially flat surface region (403) of the first wall part (360B) joins the flat spacer surface (405) at a right-angle. Within the flat surface region (403) of the first wall part (360B) is formed a recess formation in the form of a re-entrant slot (10) possessing a substantially rectangular cross-sectional profile with parallel flat slot walls and a flat slot base which is substantially parallel to the flat surface part (403) of the first wall part (360B) . The width of the re-entrant slot, defined by the separation of the parallel side walls thereof, is dimensioned to receive an end of a retaining pin (a shortened version of the pin of figure 9) .

Adjacent the terminal edge of the spacer surface (405) opposite that from which the first wall part (360B) extends, there is formed a groove formation comprising a narrowing tapered lock groove (410) adjacent the spacer surface (405) , and a fulcrum groove (7) located between the lock groove (410) and a fulcrum edge (8) presenting outwardly and to the fulcrum groove a surface having a substantially circular profile in cross section. The locking groove (410) and the fulcrum groove (7) are separated by an intermediate ridge.

The first jaw member is elongate and an extruded longitudinal elongation of the profile of the first jaw member illustrated in Figure 2OA.

Accordingly, the flat wall surface (403) of the first wall part (360B), and the spacer surface (405) are each longitudinally elongated. Similarly the recess formation (10) formed in the first wall part is longitudinally elongated to define a slot or a groove running parallel to the axis of extrusion of the first jaw member. Furthermore, the locking groove (410) , fulcrum groove (7) and fulcrum edge (8) of the groove formation also extends longitudinally in parallel along the extrusion axis of the first jaw member to define elongated formations running along the entire length of the first jaw member (360) .

A counter-sunk screw hole (not shown) may be formed in the spacer surface (405) to extend through the abutment portion (360A) of the first jaw member to an opening (not shown) in the centre of the concave abutment surface (9) . The counter-sunk screw hole may be structured and arranged to accept a fixing screw (not shown) for fixing the first jaw member to a rail of a railing assembly with the abutment surface (9) abutted against a complimentarily shaped convex abutment surface of the rail.

Figure 2OA also illustrates an end view of a second jaw member (350) which shows its cross-sectional profile.

The second jaw member (350) is an extruded elongated structure possessing along its length the cross-sectional profile as illustrated in figure 2OA, except for those parts optionally possessing a counter-sunk screw hole (not shown) . One side of the second jaw member presents a substantially flat wall surface (15) adapted to oppose the re-entrant slot (10) in the of the first jaw member when the second and first jaw members are fixed together (see Figure 20D) optionally to abut an end of a retaining pin (a shortened version of the pin shown in figure 9) the opposite end if which may be housed within the re-entrant slot (10) in the opposing wall of the first jaw member .

From an edge of the second jaw member projects a tongue formation (17, 400) including a lock tongue (400) disposed within the tongue formation nearmost the flat surface (15) of the second wall part, and spaced by a recess from a pivot tongue formation (17) which presents a concave pivot surface on the side of the pivot tongue (17) opposite to that side of the pivot tongue nearmost the lock tongue (400) and the second wall part (15) .

The second jaw member has an elongated extruded structure in a direction perpendicular to the cross-sectional view shown, and may be of any length. It is preferably the same length as the first jaw member and preferably no longer than 2.1 metres in length. It is to be noted that the perspective views of figures 20A to 2OD show only one end of a length. The cross-sectional profile of the second jaw member as illustrated persists substantially along the entirety or at least the majority of the elongated length of the second jaw member. The lock tongue (400), the pivot tongue (17) and the pivot surface present projections (400, 17) and a concave recessed surface respectively, which are each longitudinally elongated.

In a surface of the second jaw member outwardly presented in use, is formed an outer re-entrant slot (370) shaped to extend linearly along the outwardly-presented surface of the second jaw member in parallel to the axis of the channel formed between the two jaw members when assembled together. The outer re-entrant slot is defined by two parallel and flat slot walls which oppose each other across a flat slot base separating the two. The flat slot base is positioned to be parallel and adjacent the flat wall (15) of the second jaw member.

A counter-sunk screw hole (not shown) extends through the flat slot base to an opening (not shown) in the flat surface (15) of the second wall part and is structured and arranged to receive a locking bolt or screw (not shown) . A screw hole (not shown) is formed in the base of the re-entrant slot (10) of the first jaw member and is adapted to receive and engage an end of the locking bolt or screw extending through the second jaw member and across the channel (25) formed between them when assembled in use. In this way, the screw holes in the re-entrant slots of the second and first jaw members are positioned t be brought into register when the two jaw members are assembled to gether to define the channel (25) .

Two relatively narrower retaining grooves (380, 390) extend into the outwardly-presented surface of the second jaw member each in parallel adjacency to a respective one of the two parallel edges defining the opening of the re-entrant slot in the outward surface of the second jaw member. These are adapted to receive and retain a respective one of two complementarily-shaped parallel, folded peripheral long edges of an elongate cover strip (375) providing a cover surface bounded by the long edges. This serves to removably cover the outward re-entrant slot of the second jaw member and any screw or bolt housed therein.

It will be understood that the shape and dimensions of the tongue formation (400, 17) of the second jaw member (350) are complimentary to the shape and dimensions of the groove formation (410, 7, 8) of the first jaw member (360) . Consequently, the second jaw member is seperably fixable to the first jaw member via the interlockable tongue and groove formations .

The sequence of figures 2OA, 2OB, 2OC and 2OD illustrate this second embodiment of the invention in use in a sequence of successive positions. A second-class lever action is shown via which the second jaw member (350) may be pivoted about the first jaw member (360) to push-fit the tongue formation into the groove formation to fix the first jaw member and the second jaw member together with the first wall part (403) and the second wall part (15) in spaced apposition to define between them a channel for receiving an edge of a panel of the railing assembly illustrated in figures 16 and 17.

Referring to figure 21B, the concave pivot surface of the second jaw member is abutted along its length against the complimentarily convex surface of the fulcrum edge (8) on the first jaw member (350) . The second jaw member, in this position, is freely pivotable about the fulcrum edge (8) of the first jaw member by a sliding action of the pivot surface across the complimentarily-shaped surface of the fulcrum edge

(8) . By application of a pivoting force (F) , the second jaw member may be pivoted in this way towards the first jaw member about the fulcrum edge (8) thereby to bring the lock tongue (400) into closer proximity with the complimentarily-shaped lock groove (410) and, concurrently, to bring the pivot tongue (17) into increasing proximity to the complimentarily-shaped fulcrum groove (7) . Figure 2OC shows a successive stage of rotation in this manner, in which the second jaw member (350) is pivoted into increasing proximity to the first jaw member (350) such that the elements of the tongue formation (400, 17) are brought into increasing proximity with complimentarily- shaped elements of the groove formation (410, 7) .

Subsequent rotation or pivoting of the second jaw member into a position of abutment, indicated in figure 21D, is achieved via a second-class lever action implemented by the second jaw member against the first jaw member as follows.

As a turning force (F) is applied to the second jaw member at parts of the second jaw member distant from both the fulcrum edge (8) of the first jaw member, and the lock tongue (400) of the first jaw member, to bring the opposing parts of the lock groove and lock tongue into abutment. A reactive force (not shown) is generated at the abutted surface area (500, figure 29) of the lock groove in a direction generally converse to the direction of the turning force (F) so as to resist subsequent turning of the second jaw member about the fulcrum edge. Subsequent application of the turning force (F) causes the recessed pivot surface of the fulcrum tongue (17) to urge against the opposing surface of the fulcrum edge (8) in the first jaw member. The fulcrum tongue (17) acts against the fulcrum edge (8) which serves as a fulcrum applied at one end of the lever defined by the second jaw member in this circumstance .

The applied force (F) , urging a subsequent turning of the second jaw member, causes the abutted surface (510) of the lock tongue (400) to urge against the opposing surface parts (500) of the lock groove thereat to generate a load force upon the lever defined by the second jaw member. Accordingly, with the load force positioned in between the fulcrum and the applied force (F) the second jaw member functions as a second-class lever to overcome the load force generated at the lock tongue (400) and to urge the lock tongue into an interference fit with the complimentarily-shaped lock groove (410) of the first jaw member as illustrated in figure 21D. Reversing the sequence of rotation by applying an opposite rotating force (-F) separates the second jaw from the first in the sequence Fig.21D to Fig.21A.

It is to be noted that in the fully attached state illustrated in figure 21D, the first wall part (403) of the first jaw member opposes the second wall part (15) of the second jaw member.

Figures 21, 22, 23 and 24 illustrate four different views of a further embodiment of the first jaw member, and figures 25, 26, 27 and 28 illustrate four different views of a further embodiment of the second jaw member adapted to cooperate with the first jaw member of figures 21 to 24.

A first jaw member (480) and second jaw member (520) each possesses features, properties and functions of the first jaw member (360) and second jaw member (350) respectively described above with reference to figures 2OA to 2OD. The additional function of the further embodiment is to serve as a bridging or interface assembly to be located between the opposing ends of two successive and axially in-line elongate attachment means of the type described with reference to figures 2OA to 2OD to serve to align in register the opposing ends (and the channels they present) and to cover the outwardly visible space or discontinuity therebetween.

Like items are assigned like reference numerals symbols accordingly. The first and second jaw members of the further embodiment are adapted for attachment to, for use as an endplate to, the first and second jaw members described above with reference to figures 2OA to 2OD.

The body of the bridging assembly comprises fist and second jaw members in the form of first and second abutment plates. It is not elongate as is the elongate attachment means of earlier embodiments. Peripheral edges of the first and second abutment plates of the bridging assembly follow, match or conform to aspects of the cross-sectional profile (across the elongate axis) of the first and second jaw members, respectively, of the elongate attachment means (figures 2OA to 20D) and match the shape and dimensions of the wall surfaces (15, 403 - excluding the re-entrant slot (10) thereof) , the spacer surface (405), the groove formation (410, 7, 8) comprising the lock groove fulcrum groove and fulcrum edge, the abutment surface (9) and the tongue formation (400, 17) of that elongate attachment means .

A first retaining lip (480, 490) extends along the parts of the peripheral edge of the first abutment plate other than those parts adapted to interface with another component (e.g. second abutment plate, rail surface) or define the channel for receiving a panel edge. That is to say, other than those parts defining the wall surface (403), the spacer surface (405), the groove formation or the concave abutment surface (9) . A second retaining lip (520) extends along the parts of the peripheral edge of the second abutment plate other than those parts adapted to interface with another component (e.g. first abutment plate) or define the channel for receiving a panel edge. That is to say, other than those parts defining the wall surface (15) or the tongue formation (400, 17) .

Each of the first and second retaining lips, and the tips collectively, defines the peripheral edge of a respective abutment plate outwardly presented in use of the bridging assembly. Along its length, each retaining lip projects transversely from each of the opposite plate surfaces of the respective abutment plate to form an over-hang shaped and adapted to extend over and embrace peripheral parts of the outer (e.g. outwardly presented) surface of the opposing terminal ends of two elongate attachment means when the abutment plates of the bridging assembly are abutted to those terminal ends in register therewith as part of the bridging assembly.

First and second locating lugs (500, 510) project transversely from a first side of the first abutment plate and third and fourth locating lugs (540, 550) project transversely from a first side of the second abutment plate adapted to be parallel to, and in-plane with, the first side of the first abutment plate when assembled together in use. Each one of the first to fourth locating lugs is positioned relative the others, and relative to the retaining lip (480, 520) , to align in register with a respective one of a first to fourth alignment openings (1000, 1010, 1020, 1030) formed in the terminal end of each of the first and second jaw members (360, 350) of an elongate attachment means (figures 20a to 2Od) and to intimately fit within the respective alignment opening when the bridging assembly is abutted thereto in use.

Fifth and sixth locating lugs (460, 470) project transversely from a second side of the first abutment plate and a second side (530) of the second abutment plate is substantially wholly flat and without locating lugs. The second side of the second plate is adapted to be parallel to, and in-plane with, the second side of the first abutment plate when assembled together in use. Each one of the fifth and sixth locating lugs is positioned relative the other, and relative to the retaining lip (480, 520) , to align in register with a respective one of a first and second alignment openings (1000, 1010) formed in the terminal end of a first jaw member (360) of an elongate attachment means (figures 20a to 2Od) and to intimately fit within the respective alignment opening when the bridging assembly is abutted thereto in use. The absence of locating lugs at the second surface (530) of the second abutment plate allows that the second abutment plate may be attached (via locating lugs 540 and 550) to a terminal end of a second jaw member (350) and the combination fitted by a rotation illustrated in figures 2OA to 2OD, to a first jaw member (360) to which is attached the first abutment plate (480) via locating lugs (500, 510) extending from the first abutment plate in parallel to those extending from the second abutment plate. The fifth and sixth locating lugs (460, 470) extending from the opposite side of the first abutment plate may be inserted (e.g. previously) into the first and second alignment openings (1000, 1010) of a terminal end of another first jaw member arranged in-line with that to which the first abutment plate is also attached to provide a continuity with the first jaw member between which the first abutment plate is so sandwiched. A further second jaw member may be attached (e.g. previously) to the further first jaw member to define a channel from which the first and second members may add by collectively defining a continuation of that channel when the second jaw member carrying the second abutment plate, is fixed by said rotation, to the first jaw member such that the entire bridging assembly is sandwiched between two end-to-end attachment means.

Figures 29 and 30 schematically illustrate operation of the lock groove and lock tongue of the first and second jaw members of figures 2OA to 2OD, and 21 to 28. These figures 29 and 30 schematically illustrate the benefits gained by the tapering configuration of the fixing tongue (400) and fixing groove (410) of the invention in preferred embodiments.

The second jaw member, and/or the first jaw member may be produced by extruding a material (e.g. metal, plastic etc) through an extrusion dye adapted and arranged to define the profile of the jaw member in cross section (transverse to the long axis of the member) . Repeated use of the dye has been found to result in a wearing of the dye to such an extent that the dimensions of the lock tongue (400) of the second jaw member and/or the lock groove (410) change. Alternatively, the structure of the dye for one jaw member may not be as accurate as desired in practical use such that intended lock tongue and lock groove structures are not quite as intended when manufactured in practice.

These practical inaccuracies could affect the nature or existence of an interface between surfaces of the lock tongue and groove necessary to form an abutting interference fit to fix the tongue formation to the groove formation in use were it not for the beneficial configuration of those formations in a preferred embodiment as illustrated on figures 20A-20D, 29 and 30.

Referring to figure 29, the lock tongue comprises a projection (400) comprising converging tongue sides (510) . Each of these tongue sides is flat and they collectively define a tapered wedge-shaped tongue formation. The tongue tip is a flat surface. The lock groove (410) includes a complementarily- shaped channel with opposite channel walls (500) each being so shaped with respect to a respective one of the two tongue sides

(510) for glancing abutment therewith in use to form an interference/friction fit as shown.

In this way, the tongue formation defines a tapered wedge having flat sides converging towards and terminating at a tongue tip part adapted for insertion into the complementary channel formation by a push-fit to engage one or both walls of the complementary channel. The complementary channel comprises flat channel walls (500) converging towards the channel base. The channel walls against to which a tongue wall is adapted to abut in use, are thus adapted to obstruct further rotation of the second jaw member (350) towards the first jaw member (360) when abutment is achieved to prevent the whole of the tongue formation in question being pushed into the complementary channel .

The greatest width (X ₁ ) of the tapered wedge of the tongue formation exceeds the greatest width (Y ₁ ) of the complementary channel. In this way, complete insertion of the tapered wedge into the channel is prevented. A separation (Z ₁ ) between the tongue tip and the opposing channel base is ensured by providing that the lock tongue extends/projects by an amount no more than the depth of the lock groove.

Figure 30 schematically illustrates the coupling illustrated in figure 29 when the greatest width of the lock tongue X ₁ is reduced (e.g. through extrusion dye wear or other error in the manufacture of either/both the first and second jaw members) to a value X ₂ such that X ₂ < X ₁ or the greatest width of the lock groove Y ₁ is increased (e.g. through extrusion dye wear or other error) to a value Y ₂ such that Y ₂ > Y ₁ , or a combination of both circumstances .

The result of this change in lateral dimension of the lock tongue and/or groove is that the wall surfaces (510) of the lock tongue at the wider part of the tapering lock tongue are permitted to fit into the lock groove to an the interference fit with the channel walls (500) of the lock groove. Those parts of the lock tongue which formed the interference fit when lateral dimensions of the tongue and/or groove were greater now continue to form such a fit but with parts of the lock groove walls located deeper within the lock groove previously unemployed for this purpose. As a result the separation between the tip of the lock tongue and the base of the lock groove (Z ₂ ) is reduced as more of the tongue may enter the groove since the tongue is thinner and/or the groove is wider than was the case as illustrated in figure 29.

In this way, the lock tongue and lock groove formations are made robust to deviations in the dimensions of either and permit continued interlocking interference fitting between the two formations. Of course, the converse of the deviations as described above may occur, such that the tongue formation is wider or the groove formation narrower, or both, than intended. The tapering nature of the formations is able to permit an interface between the two formations regardless. The result would be that the tongue and groove would fit together with the tongue being inserted to a lesser extent than illustrated intended (Z increases) . The embodiments described above are intended to be illustrative and non-limiting such that variants and modifications thereof, such as would be readily apparent to the skilled person, are intended to be encompassed by the scope of the invention, such as defined by the claims.