GB1581552A

GB1581552A - Support structure

Info

Publication number: GB1581552A
Application number: GB3586176A
Authority: GB
Original assignee: N Greening Ltd
Current assignee: N Greening Ltd
Priority date: 1977-07-04
Filing date: 1977-07-04
Publication date: 1980-12-17

Description

(54) SUPPORT STRUCTURE (71) We, N. GREENING LIMITED, a British Company of Bewsey Road, Warrington, Cheshire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: The invention relates to supporting structures or systems, particularly for flexible elongated members such as electric wires or cables.

So-called cable trays in the general form of trough sections, usually shallow, jointed or otherwise coupled together have been widely used for supporting electric cables.

One example of such cable trays and systems can be found in our patent specification No. 959206. In general, there are side members of each tray or support section that have extending between them a perforated or apertured cable supporting platform. Such systems offer substantially continuous support for flexible cables and so are frequently preferred to ladder-type structures. In general, however, cable trays are relatively heavy structures and it is an object of this invention to provide a lighter structure that has, at least potentially, similar or comparable strength and supporting capability.

According to the invention there is provided a support structure comprising a pair of spaced side members interconnected and located in spaced relation by a mesh structure including two crossing sets of substantially parallel elements secured together at crossing positions, the side members being of substantial height compared with the thickness of the mesh structure to present a channel or tray form for the support structure, wherein at least some of the side member interconnecting mesh elements that are secured to the crossing mesh elements have additional elements also secured to the crossing elements at crossing positions and spaced from their corresponding interconnecting elements by said crossing elements.

Such a structure has beam-like support characteristics with a total "beam" thickness including the spacing between the interconnecting and corresponding additional elements.

It is preferred that, at least for support structures with parallel side members, one set of mesh elements lie parallel with the side members with only the other set interconnecting those said side members. At least some of such other mesh elements may differ in shape and/or cross-section from said one elements in being adapted to give a desired rigidity to the support structure as a whole. This may be achieved by having those said other elements, or all of them, present a greater dimension at least in the depth of the tray or channel than the crossing mesh elements.

A suitable mesh structure comprises a welded wire mesh with substantially orthogonal crossing sets of wire elements welded together at all crossing positions, though it is emphasised that some degree of benefit of the preferred embodiments of this invention may be achieved if the crossing mesh elements are not secured to each other at every crossing position and/or if one set of elements does not always overlie the other, say in a woven or part woven mesh.

Suitable additional elements may have any desired size and cross section, but are conveniently embodied as lengths of wire of the same gauge as said interconnecting elements of a welded wire mesh.

It is convenient for the side members to have a flange with the side member intercoupling mesh elements secured, typically by welding, to one side of the flange and the additional elements secured, also typically by welding to the other side of the flange so as effectively to grip the flange between them in the manner of a mortice joint, thereby providing substantial resistance to deformation of the support structure by tipping of the side members towards each other above the position of the mesh supporting flanges thereof, particularly where successive sections of such a support structure are rigidly secured together end-to-end by way of their side members, for example using fish-plate bolted couplings, taper interfittings, double wall type socketed couplings as in our above mentioned specification, or other suitable intercoupling means.

The side members may be of simple channel construction, or may have their upper, that is non-mesh coupling part, rolled over to form a bead, or may have an oppositely directed flange at the non-mesh supporting part, preferably with mutual inclination of the side members so as to allow nesting of support structures during storage and/or for their end-to-end coupling when the mesh need not extend fully to the ends of each support structure.

A further alternative arrangement of a mesh structure and additional supporting element may have end portions of the side member interconnecting elements of the mesh adjacent the side members turned towards the flange then inwards to engage the flange with the additional elements running from or adjacent to the flange engaging edges at least at selected side member interconnecting elements of the mesh. Where the return side bends of the mesh structure produce a spacing that is greater than the thickness of crossing elements of the mesh, the additional support elements may conveniently be bowed or bent upwardly to engage at least some of those crossing elements.

Specific implemcntation of the invention will now be described, by way of example, with preference to the drawings accompanying the Provisional Specification, in which: Figure 1 is a perspective view of one cable tray end embodying this invention; Figure 2 is a sectional view of a part of the tray of Figure 1; Figure 3 shows a modification of a cable tray side member; Figure 4 is a sectional view generally similar to Figure 2 but including another modified side member Figure 5 is a sectional view through a further modified side member; Figure 6 is a sectional view through another embodiment of the invention; and Figure 6a is a detail of ;he embodiment of Figure 6.

In Figure 1 of the drawings, a cable tray 1() is shown as comprising a pair of side members 11 and 12 of simple channel section with upper and lower flanges sub s ripted A and B, respectively. These side members 11 and 12 are shown as lying substantially parallel with each other at a desired spacing with their flanges in mutually opposing relation. The lower flanges 11B and 1 2B are shown as being interconnected by a welded wire mesh 14 having two sets of wire elements arranged orthogonally and welded together at their crossing points 15. One set of wire elements of the mesh extends parallel with the side members 11 and 12 and the other set extends perpendicularly between those side members with free ends 16 that are welded to the interior surfaces of the flanges 11B and 12B for interconnecting purposes. As shown, the set of side member interconnecting mesh wires lie above the other set of wires which may conveniently correspond with the thickness of the flanges liB and 12B.

At each of positions corresponding to alternate ones of the side member interconnecting mesh wires an additional wire 17 is shown welded to the exterior surfaces of the flanges 11B and 12B and also to the other wire elements of the mesh at the corresponding crossing points 15. The positions of the welds is best seen from Figure 2 at 18 for connection to the flange 12B and at 15 to the crossing points. For an appropriately close pitch of wire mesh the side member interconnecting wires and the additional wires 17 approach a beam-like stiffness of a total depth including the spacing between them which is equal to the gauge of the other wire elements of the mesh and is conveniently also equal to the thickness of the flanges 11B and 12B.

It will be appreciated that the locations of the wire mesh 14 and the additional support wires 17 may be transposed so that the ends 16 of the mesh are welded to the exterior surface of the flanges 11B and 12B and the support wires 17 are welded to the internal surfaces of those flanges.

It should further be appreciated that the support wires 17 could be replaced by bars or plates of any desired width, thickness or cross-section whether disposed within or externally of the side member flanges. It should also be appreciated that the spacing of and number of both sets of wire mesh elements may be different from that shown as desired or required for particular implementations of the invention. Also, the additional wire 17 or other reinforcing element may be provided otherwise than at alternate ones of the interconnecting mesh wires, say at every one, at two out of every three, at every third one or otherwise as desired. The beam-like stiffening properties could be sacrificed at least partially if the additional wires or reinforcing elements were offset from the interconnecting mesh wires and this might be acceptable in some applications. It is, however, pointed out that if two closely spaced additional wire ele ments are offset on opposite sides of a corresponding wire mesh element an even greater stiffness might be imparted on welding each adjacent to crossing points 15.

It is realised that the stiffening effect of the additional support wires or other elements 17 could be at least approximated by utilising a much heavier gauge for at least the side member interconnecting wire elements of the mesh albeit with some loss of rigidity resulting from the illustrated effective gripping of the flange is a mortice jointlike fashion, though this may at least to some extent be compensated for by heavier welding or preformed accommodating deformation of the flanges.

In order to ease handling problems, say where the cable trays are pulled across joists, the supporting wires 17 or other elements may be recessed to be flush with or below the lower surfaces of the sides of the side members 11 and 12. As shown in Figure 3, this is readily achieved by kinking or grooving the flanges 1 1B and 12B to accommodate the supporting wires 17.

Another way to achieve this is shown in Figure 4 where a member 22 is shown having its flange 22B stepped at 24 to accommodate the supporting wire elements 17.

Figure 4 also shows the side member 22 formed with an inwardly rolled upper edge 25 as an alternative to the upper flanges 11A and 12A of Figure 1. If desired, the upper side member edge could be rolled outwardly as is shown in Figure 6 to be described, and it may be desired to have the side walls of the side members diverge slightly away from their lower flanges as shown in Figure 5, and so allow stacking of the cable trays one within another for storage purposes.

Another possible embodiment ensuring that the reinforcing members do not project externally of the side members is shown in Figure 6. In that Figure, side members 31 and 32 having externally rolled upper edges 31A and 32A are also shown with inwardly directed lower flanges 31B and 32B. The welded wire mesh 14 is shown as having its ends doubled back on themselves and welded to the lower flanges 31B and 32B on the internal surfaces thereof with a spacing of the supporting part of the mesh 14 from those flanges that is greater than the gauge of the wire used in the mesh. The additional supporting wires are referenced 67 and are shown, see particularly Figure 6A, as being welded to the interior surfaces of the flanges 31B and 32B alongside the turned over ends of the mesh 14 and are bowed upwardly and welded only to the central one of the crossing points 15. Clearly, the reinforcing wire 67 could be bent or otherwise formed so as to be welded to the upper two welded mesh intersection positions 15 if desired. Also, the ends of the reinforcing wires and the ends of the side member interconnecting wire elements of the mesh could be aligned and welded with butting ends on the lower flanges or the wires could be flattened and superposed for welding together and to the flange one above the other. Furthermore, the doubling over of the mesh sides could result in an effective spacing equal to the gauge of the crossing mesh wires, particularly for the superposed welding alternative.

No specific provision has been shown for interconnecting the illustrated cable trays end to end in a cable supporting system, but it is to be understood that provision will normally be made for doing so. This may be by way of fish-plate members, preferably fitting internally of the side members with appropriate registering bolt holes through both the fish-plates and the side member walls. Alternatively, the side members of the cable tray may, at one end, be stepped away from each other or flared (or at least one of them so formed), or be stepped towards each other or tapered (or at least one of them so formed) so as to accommodate or fit within, respectively, the unmodified end of a similar cable tray. If desired, a socketed intercoupling may be provided for by making the side walls either of double form as in our above mentioned patent specification, or at least formed with return lips for retention purposes.

It is also to be understood that a side member and interconnecting mesh construction is suitable for special cable tray sections, such as slow or right angle bends, T-pieces, bridging or crossover pieces, riser pieces, or taper pieces for interconnecting cable trays of different width. In the construction of bends, T-pieces or crossovers, it is particularly convenient for the mesh to have a similar gauge for each set of wires and for reinforcement by additional wires to be in correspondence with different sets of the constituent wires at different positions of the piece concerned, together, if necessary, with reinforcing or bracing wires or other elements extending non-parallel with, typically diagonally across, the mesh at a central part corresponding to direction changes within the piece of fitting.

WHAT WE CLAIM IS: 1. A support structure comprising a pair of spaced side members interconnected and located in spaced relation by a mesh structure including two crossing sets of substantially parallel elements secured together at crossing positions, the side members being of substantial height compared with the thickness of the mesh structure to present a channel or tray form for the support structure, wherein at least some of the side member interconnecting mesh elements that are secured to the crossing mesh elements

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ments are offset on opposite sides of a corresponding wire mesh element an even greater stiffness might be imparted on welding each adjacent to crossing points 15. It is realised that the stiffening effect of the additional support wires or other elements 17 could be at least approximated by utilising a much heavier gauge for at least the side member interconnecting wire elements of the mesh albeit with some loss of rigidity resulting from the illustrated effective gripping of the flange is a mortice jointlike fashion, though this may at least to some extent be compensated for by heavier welding or preformed accommodating deformation of the flanges. In order to ease handling problems, say where the cable trays are pulled across joists, the supporting wires 17 or other elements may be recessed to be flush with or below the lower surfaces of the sides of the side members 11 and 12. As shown in Figure 3, this is readily achieved by kinking or grooving the flanges 1 1B and 12B to accommodate the supporting wires 17. Another way to achieve this is shown in Figure 4 where a member 22 is shown having its flange 22B stepped at 24 to accommodate the supporting wire elements 17. Figure 4 also shows the side member 22 formed with an inwardly rolled upper edge 25 as an alternative to the upper flanges 11A and 12A of Figure 1. If desired, the upper side member edge could be rolled outwardly as is shown in Figure 6 to be described, and it may be desired to have the side walls of the side members diverge slightly away from their lower flanges as shown in Figure 5, and so allow stacking of the cable trays one within another for storage purposes. Another possible embodiment ensuring that the reinforcing members do not project externally of the side members is shown in Figure 6. In that Figure, side members 31 and 32 having externally rolled upper edges 31A and 32A are also shown with inwardly directed lower flanges 31B and 32B. The welded wire mesh 14 is shown as having its ends doubled back on themselves and welded to the lower flanges 31B and 32B on the internal surfaces thereof with a spacing of the supporting part of the mesh 14 from those flanges that is greater than the gauge of the wire used in the mesh. The additional supporting wires are referenced 67 and are shown, see particularly Figure 6A, as being welded to the interior surfaces of the flanges 31B and 32B alongside the turned over ends of the mesh 14 and are bowed upwardly and welded only to the central one of the crossing points 15. Clearly, the reinforcing wire 67 could be bent or otherwise formed so as to be welded to the upper two welded mesh intersection positions 15 if desired. Also, the ends of the reinforcing wires and the ends of the side member interconnecting wire elements of the mesh could be aligned and welded with butting ends on the lower flanges or the wires could be flattened and superposed for welding together and to the flange one above the other. Furthermore, the doubling over of the mesh sides could result in an effective spacing equal to the gauge of the crossing mesh wires, particularly for the superposed welding alternative. No specific provision has been shown for interconnecting the illustrated cable trays end to end in a cable supporting system, but it is to be understood that provision will normally be made for doing so. This may be by way of fish-plate members, preferably fitting internally of the side members with appropriate registering bolt holes through both the fish-plates and the side member walls. Alternatively, the side members of the cable tray may, at one end, be stepped away from each other or flared (or at least one of them so formed), or be stepped towards each other or tapered (or at least one of them so formed) so as to accommodate or fit within, respectively, the unmodified end of a similar cable tray. If desired, a socketed intercoupling may be provided for by making the side walls either of double form as in our above mentioned patent specification, or at least formed with return lips for retention purposes. It is also to be understood that a side member and interconnecting mesh construction is suitable for special cable tray sections, such as slow or right angle bends, T-pieces, bridging or crossover pieces, riser pieces, or taper pieces for interconnecting cable trays of different width. In the construction of bends, T-pieces or crossovers, it is particularly convenient for the mesh to have a similar gauge for each set of wires and for reinforcement by additional wires to be in correspondence with different sets of the constituent wires at different positions of the piece concerned, together, if necessary, with reinforcing or bracing wires or other elements extending non-parallel with, typically diagonally across, the mesh at a central part corresponding to direction changes within the piece of fitting. WHAT WE CLAIM IS:

1. A support structure comprising a pair of spaced side members interconnected and located in spaced relation by a mesh structure including two crossing sets of substantially parallel elements secured together at crossing positions, the side members being of substantial height compared with the thickness of the mesh structure to present a channel or tray form for the support structure, wherein at least some of the side member interconnecting mesh elements that are secured to the crossing mesh elements

have additional elements also secured to the crossing elements at crossing positions and spaced from their corresponding interconnecting elements by said crossing elements.

2. A support structure as claimed in claim 1, wherein only one set of elements interconnect the side members.

3. A support structure as claimed in claim 2, wherein the side members are parallel to each other and to one set of elements.

4. A support structure as claimed in any preceding claim, wherein the crossing sets of elements are secured together at all crossing positions.

5. A support structure as claimed in any preceding claim wherein the additional elements and corresponding interconnecting elements are secured at the same crossing positions.

6. A support structure as claimed in any preceding claim wherein the additional elements are secured to a flange of each side member.

7. A support structure as claimed in any preceding claim, wherein the side member interconnecting mesh elements are secured to a flange of each side member.

8. A support structure as claimed in claim 7 as appendent to claim 6, wherein the side member interconnecting mesh elements are secured to one side of the flange and the additional elements are secured to the other side of the flange.

9. A support structure as claimed in any preceding claim, wherein end portions of side member interconnecting elements turn transversely and inwards to engage a flange of the side member.

10. A support structure as claimed in claim 9, wherein the additional elements run from adjacent to the flange engaging end portions at least of selected side member interconnecting elements of the mesh.

11. A support structure as claimed in claim 10, wherein the turned side portions of the mesh structure space the mesh interconnecting elements from the flange by a distance that is greater than the thickness of the crossing elements and the additional support elements bow upwardly to engage at least some of those crossing elements.

12. A support structure as claimed in any preceding claim, wherein the mesh structure comprises a welded wire mesh with substantially orthogonal sets of wire elements welded together at at least some crossing positions.

13. A support structure as claimed in claim 12, wherein the mesh structure comprises at least partly a woven mesh

14. A support structure as claimed in claim 12 or 13, wherein the additional elements comprise wire of the same gauge as the interconnecting elements of the welded wire mesh.

15. A support structure as claimed in any one of claims 1 to 13, wherein at least some of the elements of one set are of a different cross-section and/or shape from elements not of that set.

16. A support structure as claimed in any preceding claim wherein at least some elements present a greater dimension at least in the depth of the channel or tray than the crossing mesh elements.

17. A support structure as claimed in any preceding claim wherein the side members have outwardly directed flanges at their non-mesh supporting part.

18. A support structure as claimed in any preceding claim, wherein the side members are mutually inclined so as to allow nesting of similar support structures.

19. A support structure as claimed in any one of claims 1 to 16 wherein the side members are of channel shape.

20. A support structure as claimed in any one of claims 1 to 16 wherein the side members have their upper or non-mesh coupling part rolled over to form a bead.

21. A support structure as claimed in claim 18 or 19 or 20, wherein the mesh structure does not extend fully to the ends of the side members.

22. A support structure as claimed in any preceding claim, including means for intercoupling the structure in end-to-end relationship with another support structure.

23. A support structure substantially as herein described with reference to and as shown in Figures 1 and 2 or Figure 3 or Figure 4 or Figure 5 or Figure 6 of the drawings accompanying the Provisional specification.