GB2291902A - Modular fencing without posts between top and bottom rails - Google Patents

Abstract

A guard rail module (120; 121) comprises a top rail (122) and a bottom rail (124) mutually joined solely by bars (126). Posts (128) depend from the bottom rails for insertion into the ground (99). The posts forming part of a given module do not extend above the bottom rail. The bars are preferably staggered to provide areas of enhanced visibility through the module at shallow angles of view. The absence of posts between top and bottom rails helps visibility and significantly reduces manufacturing costs. An end-post (140) may be present. Ports (128) may be joined by nuts and bolts (130, 132); rails 122 are joined by connection fitted inside the hollow rails and tightened by screws, e.g. using an Allen key. <IMAGE>

Description

GUARD RAIL MODULES AND CONNECTORS SUITABLE THEREFOR This invention relates to guard rail modules and to connectors suitable therefor. This invention relates more particularly but not exclusively to modules that can be assembled to form guard rails for controlling pedestrians in the vicinity of road traffic, and to connectors suitable for interconnecting such guard rail modules or other articles utilising similar structural elements.

In this specification, references to alignments and directions are based on the assumption that the guard rail module has its principal plane substantially vertical, the upper edge of the module above the lower edge of the module and at least the lower edge of the module substantially parallel to substantially horizontal ground in which the module is, or is to be, installed. In the event that a guard rail module in accordance with the invention is otherwise aligned, references to alignments and directions should be translated and construed accordingly.

According to a first aspect of the present invention there is provided a guard rail module comprising a top rail and a bottom rail mutually interconnected by a plurality of bars each extending in a substantially vertical direction, and at least one post integral with and depending from the bottom rail for insertion into ground or other medium to support the module in use thereof, the or each such post not extending above the bottom rail whereby the top and bottom rails are mutually interconnected within the module solely by means of said bars.

Either, or preferably both, of the top and bottom rails may be substantially horizontal and may be formed of hollow tubular material, preferably RHS (rectangular hollow section).

The module may have a post depending from each end of the bottom rail whereby the module is self-supporting in use, independently of any other part of a guard rail comprising the module.

Adjacent ones of the bars preferably have mutually different lateral displacements from the mid-plane of the module whereby to increase resistance of the top rail to displacement relative to the bottom rail. More preferably the bars are located with respect to the mid-plane of the module as to provide one or more areas of enhanced visibility through the module between the top and bottom rails, at a substantially horizontal line of sight making a shallow angle with respect to the mid-plane.

According to a second aspect of the present invention there is provided a connector for mutually interconnecting a pair of tubular members in substantially end-to-end relationship, such tubular members including but not being restricted to respective top or bottom rails of a pair of guard rail modules according to a preferred form of the first aspect of the present invention, the connector comprising two opposite ends individually insertable into the bore of a respective one of a pair of tubular members to be mutually interconnected in substantially end-to-end relationship by the connector, each of the two opposite ends of the connector being individually selectively clampable against an internal surface of the respective tubular member such that when both ends of the connector are so clamped, the pair of tubular members are mutually interconnected in substantially end-to-end relationship by the connector.

The clamping of each end of the connector may be by means of a respective screw disposed to be rotatable from a location outside the respective tubular member.

Each end of the connector is preferably constructed or adapted to be expanded by rotation of the respective screw in a direction to cause clamping of the respective end, such expansion preferably being such as to cause parts of the respective end of the connector to bear against opposite sides of the bore of the respective tubular member. Expansion of each end of the connector may be by unfolding of an initially folded portion of the connector, or by wedging action on end parts mutually separable by such wedging action.

According to a third aspect of the invention there is provided a guard rail comprising a plurality of guard rail modules according to the first aspect of the present invention, respective top rails and/or bottom rails of adjacent modules being formed of hollow tubular material and mutually interconnected by a respective connector according to the second aspect of the present invention.

The guard rail may further comprise an end post linking the top rail and the bottom rail of a module located at one end of the guard rail.

Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings wherein: Fig. 1 is an elevation of a guard rail module; Fig. 2 is a vertical transverse section of a guard rail module under side load; Fig. 3 is a horizontal section through part of the guard rail module of Fig. 2; Fig. 4 is a horizontal section through part of an alternative form of guard rail module; Fig. 5 is a perspective view of a fragment of the alternative form of guard rail module of Fig. 4; Fig. 6 is a vertical transverse section of the alternative form of guard rail module of Figs. 4 and 5 under side load; Fig. 7 is a horizontal section through part of a further alternative form of guard rail module; Fig. 8 is a perspective view of a fragment of the further alternative form of guard rail module of Fig.

7; Fig. 9 is a horizontal section through part of a still further alternative form of guard rail module; Fig. 10 is an elevation of one end of a guard rail; Fig. 11 is a horizontal section through part of a preferred form of the guard rail of Fig. 10; Fig. 12 is an elevation of one end of another form of guard rail; Fig. 13 is a vertical longitudinal section, to an enlarged scale, taken through an inter-module top rail joint of the guard rail of Fig. 12; Fig. 14 is a fragmentary elevation, to an enlarged scale, of one of the joints shown in Fig. 12; Fig. 15 is a fragmentary elevation, to an enlarged scale, of another one of the joints shown in Fig. 12; Fig. 16 is a sectional view taken in a horizontal plane, to an enlarged scale, of an alternative form of the joint shown in Fig. 13;; Fig. 17 is a view corresponding to the view of Fig. 16, but in which the adjacent guard rail modules are mutually angled to fit a generally curving rail path; Fig. 18 is a vertical transverse section, to a much enlarged scale, of an alternative form of the joint shown in Fig. 13; Fig. 19 is a vertical transverse section, to a much enlarged scale, of another alternative form of the joint shown in Fig. 13; Fig. 20 is a perspective view of another form of connector; Figs. 21 and 22 are respectively longitudinal and transverse vertical sections of the connector of Fig.

20, in use in circumstances analogous to those illustrated in Fig. 13; Fig. 23 is a horizontal section of the connector of Fig. 20, in use in circumstances similar to those illustrated in Figs. 21 and 22, but where adjacent guard rail modules are mutually angled to fit a generally curving rail path; Fig. 24 illustrates a modified version of the arrangement of Fig. 22; Fig. 25 generally corresponds to Fig. 22 but shows a further form of connector; Fig. 26 is a perspective view of a still further form of connector; Fig. 27 is a transverse vertical section of the connector of Fig. 26, in use in circumstances analogous to those illustrated in Fig. 13; Fig. 28 is a vertical transverse section of an alternative form of connector in use in circumstances analogous to those illustrated in Fig. 13; Fig. 29 is a perspective view of another alternative form of connector; ; Figs. 30 and 31 are respectively longitudinal and transverse vertical sections of the connector of Fig.

29, in use in circumstances analogous to those illustrated in Fig. 13; Fig. 32 is a horizontal section taken on the line A-A in Fig. 30; Fig. 33 is a horizontal section taken on the line B-B in Fig. 30; Fig. 34 is a perspective view of a further alternative form of connector; Fig. 35 is a fragmentary view, to a slightly enlarged scale, of the connector of Fig. 34; and Fig. 36 is a perspective view of a still further alternative form of connector.

Referring first to Fig. 1, a guard rail module 100 comprises a horizontal top rail 102 and a horizontal bottom rail 104 mutually joined by an array of regularly spaced vertical bars 106. Three posts 108 depend from the bottom rail 104 for embedment in ground or pavement 99 on which the module 100 is installed.

The tops of the posts 108 are welded to the bottom edge of the bottom rail 104 to be integral therewith. In the module 100, no part of the posts 108 extends above the bottom rail 104.

The components of the guard rail module 100 are conveniently formed of mild steel and welded together to form a unitary entity which is preferably galvanised and/or painted to impart corrosion resistance to suit outdoor use in a damp climate. It is particularly preferred that the top and bottom rails 102 and 104 be formed of RHS (rectangular hollow section).

Fig. 2 is an exaggerated illustration of the deformation of an installed guard rail module 100 under the influence of lateral loading on the top rail 102 when the bars 106 are installed in a conventional single row as shown in Fig. 3. However, if the bars 106 are staggered alternately to one side and the other of the longitudinal mid-plane of the guard rail module 100, as shown in Figs. 4 and 5, the deformation performance of the module 100 is improved as illustrated in Fig. 6 (again, with exaggeration).

While the bars 106 in a single row (Fig. 3) might be simply made thicker to reduce susceptibility to deformation of the kind shown in Fig. 2, staggering of the bars 106 to either side of the mid-plane, eg. as shown in Figs. 4 and 5, is preferred for increasing deformation resistance in compensation for the absence of posts joining the top and bottom rails 102 and 104.

Another advantage of the Fig. 4 arrangement of bars 106 over the Fig. 3 arrangement is the improved ability to see through the module 100 at shallow angles, arising from the lateral displacement of the bars 106 from a single plane. Such improved "see through" ability greatly increases the safety of pedestrians and road traffic by allowing easier sighting of hazards.

Figs. 7 and 8 show a further alternative arrangement of the bars 106 for increased through visibility in which successive groups of four bars are disposed on shallow diagonals across the plane of the module 100, effectively to form windows through the module 100 at shallow angles (as particularly shown in Fig. 8).

Fig. 9 shows a still further alternative arrangement of the bars 106 for increased through visibility at particularly shallow angles to the plane of the guard rail module, in which successive groups of eight bars are disposed on very low-angle diagonals across the plane of the module 100, thereby to enhance the effect demonstrated in Figs. 7 and 8.

Fig. 10 illustrates an assembled guard rail incorporating an alternative form of guard rail module 120 comprising a top rail 122 and a bottom rail 124 mutually joined by an array of regularly spaced vertical bars 126. A short post 128 depends from each end of the bottom rail 124 for embedment in the ground or pavement 99. The tops of the two posts 128 are welded to the bottom rail 124, one at each end, such that the posts 128 become integral with the bottom rail 124 and the rest of the guard rail module 120.

The materials, fabrication techniques, surface treatment and arrangement of the bars 126 in the module 120 can be as previously described in respect of any of the variants of the guard rail module 100.

Immediately to the left of the module 120 (as viewed in Fig. 10) is an adjoining further guard rail module 121, which is preferably identical in all respects to the module 120.

The modules 120 and 121 are mutually connected at their lower ends by a bolt 130 extending transversely through adjacent posts 128 and secured by a nut 132. The modules 120 and 121 are mutually connected at their upper ends by a connector which is lodged entirely within the ends of the RHS forming the respective top rails, and is therefore not visible in Fig. 10.

Various alternative forms of RHS rail connector will be described below.

The bars 126 in the guard rail module 120 are preferably arranged as previously described with reference to Fig. 7, i.e. in diagonals of four. More preferably, the bars 126 are arranged with diagonal groups starting and finishing at the ends of the module such that the end bars in each module have a maximum offset from the mid-plane of the module, as shown in Fig. 11. Thereby, two adjacent bars in a guard rail comprising mutually connected modules will have a maximum mutual transverse separation on either side of the inter-module joins and thus improve deformation resistance of the assembled guard rail.

As shown in Fig. 10, the guard rail continues indefinitely to the left (and out of the Figure), but terminates on the right. To provide adequate strength at the free end of the guard rail, an end post 140 is provided. The end post 140 is fabricated of mutually welded pieces of the same RHS as is used to form the top and bottom rails 122 and 124 in the guard rail module 120.

The end post 140 has a short horizontal top section 142 and a short horizontal bottom section 144 mutually joined by a vertical section 146. At the foot of the end post 140 is a ground-engaging mounting post 148 corresponding to the posts 128 in the module 120. The end post 140 is dimensionally compatible with the guard rail module 120.

The end post 140 is joined to the rest of the guard rail, and specifically to the right end of the module 120, by means of a bolt and nut 130, 132 through the adjoining posts 148 and 128, and a connector (not shown) inside the contiguous ends of the end post top section 142 and the module top rail 122. Connection of the end post 140 to the adjacent module 120 by means identical to those used for module-to-module connections minimises the inventory of parts and maximises constructional flexibility.

Fig. 12 illustrates another form of assembled guard rail incorporating another alterative form of guard rail module 160 comprising a top rail 162 and a bottom rail 164 mutually joined by an array of regularly spaced vertical bars 166. A short post 168 depends from one end of the bottom rail 164 for embedment in ground or pavement (not depicted in Fig. 12).

The top of the single post 168 is welded to one end of the bottom rail 164 such that the post 168 becomes integral with the bottom rail 164 and the rest of the guard rail module 160.

The materials, fabrication techniques, surface treatment, and arrangement of the bars 166 in the module 160 can be as previously discussed in respect of any of the variants of the guard rail module 100.

Immediately to the left of the module 160 (as viewed in Fig. 12) is an adjoining further guard rail module 161, which may either be exactly identical to the module 160, or be identical to the module 160 except for the addition of a second post corresponding to the post 168.

The modules 160 and 161 are mutually connected by the same means as previously described with reference to Fig. 10.

Immediately to the right of the module 160 (as viewed in Fig. 12) is an end post 170 whose function is analogous to that of the previously described end post 140 (Fig. 10), the end post 170 additionally serving as a mounting post for the adjacent end of the guard rail module 160 (whose single mounting post 168 is at the other end of the module).

The end post 170 is much simpler than the end post 140, being essentially one straight length of RHS, plus two connectors 190 and 200 (detailed below with reference to Figs. 14 and 15). (As an alternative to the use of the connectors 190 and 200 to attach the end post 170 to the module 160, the end post may be welded to the module to form a non-standard "end module".) Suitable dimensions for the guard rail of Fig. 12 are as follows: length (parallel to ground) of module 160:- 2 metres; height (between top and bottom rails):- 90 centimetres; thickness of top and bottom rails 162, 164 and of end post 170 (at right angles to plane of Fig. 12):- 50 millimetres or 70 millimetres; depth of top and bottom rails 162, 164 and breadth of end post 170 (in the plane of Fig. 12):- 30 millimetres; transverse dimensions of bars 166:- 12 x 12 millimetres (alternatively, the bars 166 may be transversely circular, with a diameter of 12 millimetres).

A suitable form of top rail connector for the guard rail of Fig. 12 is schematically illustrated in Fig.

13. The connector 180 comprises an elongate member 182 whose transverse dimensions are sufficiently large (in conjunction with the material of the connector 180) to provide adequate strength but sufficiently small as to allow the member 182 to fit within the hollow interiors of the top rails of the adjacent guard rail modules 160 and 161 (denoted as location A&commat;t in in Fig. 12). A suitably dimensioned hole in the underside of each top rail, near the ends to be mutually connected, allows insertion of a respective screw 184 into previously drilled and tapped holes 186 in each end of the member 182. Tightening of each screw 184 clamps the member 182 against the bottom surfaces of the interiors of the top rails and thereby simultaneously mutually connects and mutually aligns these top rails.

Components of the top rail connector 180 may be formed of any suitable material, for example a metal or a plastics material.

Fig.14 illustrates a form of connector suitable for mutually connecting the top rail 162 and the top end of the end post 170 (denoted as location "B" in Fig. 12).

The connector 190 comprises an elbow member 192 having one end 194 secured in the upper end of the length of RHS principally constituting the end post 170. The other end 196 of the member 192 has a transverse crosssection dimensioned to fit within the hollow interior of the top rail 162 of the guard rail module 160 (compare with the member 182 in the connector 180 of Fig. 13). An internally threaded transverse hole 198 in the end 196 allows the connector 190 to be clamped against an inner surface of the top rail 162 by means of a screw (not shown in Fig. 14) in a manner similar to the connector 180 of Fig.13.

The transition in the elbow member 192 between the vertical end 194 and the horizontal end 196 is suitably shaped (eg curved as shown in Fig.14) and suitably finished (eg smoothed to avoid injury to pedestrians).

The elbow member 192 may be formed as a casting of a suitable metal or alloy.

Fig. 15 illustrates a form of connector suitable for mutually connecting the bottom rail 164 and a lower post of the end post 170 (denoted as location "C" in Fig.12). The connector 200 comprises a member 202 welded to the side of the end post 170 as a horizontal projection therefrom. The member 202 is essentially the same as the horizontal arm 196 of the connector 190 (see Fig.l4), ie the member 202 has a cross-section to fit within the hollow interior of the bottom rail 164 (formed of the same size of RHS as the top rail 162) and has a threaded hole 204 for screw clamping of the member 202 to the bottom rail 164.

The connector member 182 of Fig.13 conveniently has a cross-section which is uniform along the length of the member (excepting the holes 186); Fig.l6 and 17 illustrate a non-uniform variant of the top rail connector. In Fig.16, a top rail connector 210 comprises a connector member 212 whose transverse cross-section is substantially rectangular at any point but whose width diminishes from the mid-length towards either end such that in plan, the member 212 tapers in both directions. The member 212 has a constant thickness throughout, and internally threaded holes 214 for screw clamping of the member 212 to the top rails 162 in the same manner as the connector 180 of Fig.13.

The connector member 212 may be formed of any suitable material, eg nylon or steel.

As used in the manner illustrated in Fig.16, the connector 210 mutually connects the top rails 162 in substantially co-linear end-to-end alignment, just as in Figs. 12 and 13. However, the lateral double taper of the connector member 212 allows the connected top rails 162 to be at an angle from one to the other as shown in Fig.17. This facility permits guard rails to be installed around curves, or along a zig-zag path.

If the holes 169 in the underside of the top rails 162 for passage of the connector clamping screws (not shown) are suitably enlarged with respect to the diameter of the screws per se, no other modification is necessary to allow for variation in the angle between adjacent guard rail modules, up to the limit permitted by the taper of the connector member 212 (as shown in Fig.17).

Fig.18 shows a top rail connector 220 which obviates the projection of any connector part beyond the profile of the top rail. In the connector 220, an elongate double-ended connector member 222 (similar to the connector member 182 of Fig.13) has two internally screw-threaded holes 224 (only one being visible in Fig.l8) for cooperation with respective clamping screws 226 (only one being visible in Fig.18). The screws 226 are countersunk Allen screws each having a hexagonal socket 228 centrally located in a head 230 whose outside diameter is substantially greater than the diameter of the clearance hole 232 necessary in the top rail 162 for passage of an Allen key (not shown) to rotate the screw 226 in its threaded hole 224. Thus by unscrewing the screw 226 from the hole 224 in the connector member 222, the screw head 230 is forced against one side of the interior of the top rail 162, around the hole 232, and the member 222 is forced against the opposite side of the interior of the rail 162. Thus all parts of the connector 220 remain inside the top rails, whereas by way of contrast, the heads of the clamping screws 184 in the connector 180 (Fig.13) remain on the outside of the rail.

Fig.19 shows a variant 240 of the connector 220 of Fig.18, wherein the connector member 222 is substituted by a member 242 of compliant or elastic material. The member 242 is transversely bowed such as to be concave on the face which is ultimately forced against the interior of the top rail opposite the key hole 232.

The dotted outline in Fig.19 shows the member 242 before clamping, and the full lines depict the member 242 after clamping. By suitably selecting the transverse dimensions of the member 242, it can be arranged for the member 242 to deform under the load imposed by the clamping screws such as to move laterally into forceful contact with the sides of the top rail, thereby to increase the rigidity of the madeup connection (compare Fig.l9 with Fig.18).

Fig 20-23 show another connector 250 comprising a folded metal plate 252 having elastic spring-like properties. The apex 254 of the plate 252 (Fig.20) is formed with two holes 256 for reception of clamping screws 258. The holes 256 may be pre-threaded, or the screws 258 may be self-tapping to form threads in initially untapped holes 256. Fig.21 shows the connector 250 in use to mutually interconnect two adjacent rails 162 (each rail 162 having been preformed with a hole for insertion of the respective screw 258). Fig.22 illustrates the deformation of the plate 252 from its initial high-angle shape (shown in dashed outline) to its final relatively flattened shape (shown in full lines) under the forces developed by tightening of the clamping screws 258.Friction between edges 257 of the relatively flattened plate 252 and the walls of the tubular rails 162 locks the plate 252 relative to the rails 162, so that the connector 250 acts structurally as a flange to permit lateral shear forces to be transferred between the interconnected rails 162. The plate edges 257 may be provided with serrations (not shown) to improve the performance of the connector 250. Fig.23 shows how an edge 257 of the plate 252 can deform to accommodate a non-colinear alignment of the two rails 162 being interconnected.

Fig.24 shows a connector 260 which is a variant of the connector 250, the screws 258 being replaced by Allen grub screws 262. Although located entirely within the hollow tubular rails 162, each Allen grub screw 262 can be turned by means of a hexagonal key (not shown) inserted through the hole 264 in the wall of the rail 162 and into a hexagonal socket 266 in the end of the screw 262. Instead of the plate 252 (unchanged from the connector 250) being pulled against the wall of the rail 162 by the screw 258, it is now pushed against the wall by the screw 262 pushing against the opposite wall (compare Fig.24 with Fig.22).

A further connector 270 shown in Fig.25 is a derivative of the folded-plate connector 250 of Fig.20. In the connector 270 a folded metal plate 272 having elastic spring-like properties has an initial cross-section which is W-shaped and shown in Fig.27 in dashed outline. This generally resembles the plate 252 with additional integral wings of the same material and oppositely folded. By suitably selecting the dimensions of the plate 272 in relation to the internal dimensions of the rails 162 in which the connector 270 is to be used for their interconnection, then upon suitably tightening clamping screws 274 (only one being shown in Fig.25), the plate 272 deforms to the position shown in full lines in Fig.25, in which the plate 272 is wedged into all four internal corners of the RHS of which the rail 162 is constituted.The fully installed connector 270 thus acts structurally as horizontal and vertical flanges between the two interconnected rails 162.

Another connector 280 as shown in Fig.26 and 27 comprises an elongate block 282 of constant thickness and double-tapered width which converges from midlength towards both ends. Each end of the block 282 is provided with a through hole 284 which is cylindrical at the face not visible in Fig.26 and transforms to a conically expanding hole towards the visible face, as shown by the transverse cross-section through one of the holes 284 illustrated in Fig.27. Each end of the block 282 is divided by a longitudinal vertical slit 286 contiguous at its inboard end with a transverse vertical slit 288. Each slit 286 symmetrically intersects a respective one of the holes 284. The block 282 is suitably formed of a thermoplastics material.

Other components of the connector 280 comprise a pair of clamping screws 290 each fitted with a nut 292 which is externally conical. Fig.27 shows one of the screws 290 and its nut 292, with the connector 280 in place but not yet tightened. As each screw 290 is tightened, it draws its nut 292 into the conical part of the respective hole 284 and thereby expands that end of the block 282, by opening up the slit 286 and, to a lesser extent, the slit 288. Ultimately both ends of the block 282 will be expanded against the sides of the respective rail 162 as well as being clamped against the rail face through which the screw 290 passes. The double taper of the block 282 allows the interconnected rail to be mutually collinear (as in Fig.16) or at an angle (as in Fig.17).

A connector 300 shown in section in Fig.28 is a development of the connector 280 of Figs 26 and 27. In the connector block 302 horizontal slits 304 divide each end of the block 302 into a lower portion 306 and as an upper portion 308. Each end of the upper portion 308 is divided by a vertical slit 310, part of which is opened up as a conical recess 312. The lower portion 306 is undivided by any vertical slit, and each end of the block 302 has an internally threaded through hole 314 axially aligned with the conical recess 312. With the connector block 302 located inside a hollow tubular rail 162 as shown in Fig.28, insertion of a screw 316 into the threaded hole 314 clamps the lower portion 306 against the inner face of the rail 162 and extends into the conical recess 312, forcing apart the sides of the upper portion 308 on either side of the slit 310. By suitably selecting the cone angle of the recess 312, the two sides of the upper portion 308 can be forced both sideways and upwards by the screw 316, until bedded in the upper internal corners of the rail 162.

This gives the fully installed connection rigidity both horizontally and vertically.

Figs 29-33 show a connector 320 which is very similar to the connector 300 of Fig.28. Referring to Fig.29, the connector block 322 is substantially the same as the block 302, save that the conical recess 312 of Fig.28 is now extended as a full-length tapered slit 330. As before, the block 322 is divided at each end by a horizontal slit 324 into a lower portion 326 and an upper portion 328. The lower portion 326 at each end of the block 322 is provided with an internally threaded through hole 334 for the reception of a screw (not shown in Figs 29-33).

Fig.30 shows a longitudinal vertical section through the installed connector 320 (minus clamping screws), and a transverse vertical section is shown in Fig.31 (which corresponds to Fig.28). Fig.32 shows a horizontal section (taken on the line A-A in Fig.30) through the lower portion 326 of the connector block 322. Fig.33 whose a horizontal section (taken on the line B-B in Fig.30) through the upper portion 328 of the connector block 322.

Fig.34 shows an alternative connector 340 which is a variation of the connector 320, with the vertical slit extended through the lower portion to provide the clamping screw (not shown) with a self-tapping facility (shown in enlarged fragmentary perspective in Fig.35).

Fig. 36 shows another self-tapping connector 350 which is another variation of the connector 320. In Fig. 36, the internal structure is shown in the nearer half of the connector block as though formed in transparent material.

The connectors described above as exemplary embodiments of the present invention have been principally depicted as interconnecting the top rails of guard rail modules in accordance with the present invention, but these connectors may also be utilised for interconnecting the bottom rails of such modules where the bottom rails are formed with open ends in the same manner as the top rails. The connectors may also be utilised for interconnecting hollow tubular items (whether formed of RHS or not) that are not parts of guard rail modules.

Other modifications and variations of the above described exemplary embodiments can be adopted without departing from the scope of the invention as defined in the appended claims.

Claims (18)

CAIMS

1. A guard rail module comprising a top rail and a bottom rail mutually interconnected by a plurality of bars extending in a substantially vertical direction, and at least one post integral with and depending from the bottom rail for insertion into ground or other medium to support the module in use thereof, the or each such post not extending above the bottom rail whereby the top and bottom rails are mutually interconnected within the module solely by means of said bars.

2. A guard rail module according to Claim 1 wherein either or both of the top and bottom rails are substantially horizontal.

3. A guard rail module according to Claim 1 or Claim 2 wherein either or both of the top and bottom rails are formed of a hollow tubular material.

4. A guard rail module according to any preceding claim, comprising a post depending from each end of the bottom rail whereby the module is self supporting in use, independently of any other part of a guard rail incorporating the module.

5. A guard rail module according to any preceding claim wherein adjacent ones of the bars have mutually different lateral displacement from the mid-plane of the module whereby to increase resistance of the top rail to displacement relative to the bottom rail.

6. A guard rail module according of Claim 5 wherein the bars are so located with respect to the mid plane of the module as to provide one or more areas of enhanced visibility through the module between the top and bottom rails, at a substantially horizontal line of sight making a shallow angle with respect to the mid-plane.

7. A connector for mutually interconnecting a pair of tubular members in substantially end-to-end relationship, the connector comprising two opposite ends individually insertable into the bore of a respective one of a pair of tubular members to be mutually interconnected in substantially end-to-end relationship by the connector, each of the two opposite ends of the connector being individually selectively clampable against an internal surface of the respective tubular member such that when both ends of the connector are so clamped, the pair of tubular members are mutually interconnected in substantially end-to-end relationship by the connector.

8. A connector according to Claim 7 wherein the clamping of each end of the connector is by means of a respective screw disposed to be rotatable from a location outside the respective tubular member.

9. A connector according to Claim 8 wherein each end of the connector is constructed or adapted to be expanded by rotation of the respective screw in a direction to cause clamping of the respective end.

10. A connector according to Claim 9 wherein the expansion of each end of the connector is such as to cause parts of the respective end of the connector to bear against opposite sides of the bore of the respective tubular member.

11. A connector according to Claim 9 or Claim 10 wherein the expansion of each end of the connector is by unfolding of an initially folded portion of the connector.

12. A connector according to Claim 9 or Claim 10 wherein the expansion of each end of the connector is by wedging action on end parts mutually separable by such wedging action.

13. A connector according to any of Claims 7 to 12, wherein the tubular members are the respective top or bottom rails of a pair of guard rail modules according to any of Claims 1 to 6.

14. A guard rail comprising a plurality of guard rail modules according to any of Claims 1 to 6, respective top rails and/or bottom rails of adjacent modules being formed of hollow tubular material and mutually interconnected by a respective connector according to any of Claims 7 to 12.

15. A guard rail according to Claim 14 and further comprising an end post linking the top rail and the bottom rail of a module located at one end of the guard rail.

16. A guard rail module substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

17. A connector for mutually interconnecting a pair of tubular members in substantially end-to-end relationship, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

18. A guard rail substantially as hereinbefore described with reference to and as shown in the accompanying drawings.