GB2114820A

GB2114820A - Cable ladder

Info

Publication number: GB2114820A
Application number: GB08302366A
Authority: GB
Inventors: Milton Arthur Rowe
Original assignee: GKN Australia Ltd
Current assignee: GKN Australia Ltd
Priority date: 1982-02-08
Filing date: 1983-01-28
Publication date: 1983-08-24
Also published as: GB8302366D0

Abstract

A cable ladder comprises two parallel side-plates 4 with rungs 6. Side-plates 4 are spliced together by means of a fishplate 7 resting on a locator flange 11 and having an upper edge located between the side wall 8 or the side-plate and a retainer rib 12 provided on the undersurface of the top flange 9. Channel shaped rungs 6 are secured to the side plates 4 with screws 15 which are threaded into grooves 13 (fig 2, not shown). The ladder is supported by cantilever 19 and clamp 20 having longitudinally slidable bolts 21. An alternative cantilever support is in fig 3, not shown. <IMAGE>

Description

SPECIFICATION Cable ladder This invention relates to cable ladders. Such ladders consist of a trough-like tray which extends along a workshop wall, a factory wall, or like structural support, as a holder for electricai cables, telephone wires, compressed air hoses and other elongated, frequently flexible, service items.

Cable ladders are much in use, and they generally consist of a pair of side-plates, a plurality of rungs supported ladder-like on and between the side-plates, and fish plate or like splicer means whereby the meeting ends of side-plate lengths are joined together. Side-plate splicing is almost invariably necessary because the required overall length of a cable ladder is usually much greater than is the stock length of side-plate material readily available.

Cable ladders are usually supported on a series of spaced apart cantilever arms whereof the fixed end of each is rigidly secured to a wall, post, column or other rigid support.

The existing cable ladders have proved satisfactory insofar as the mere support of cables (and the like) is concerned, but they are less satisfactory in a number of respects, such as inconvenience of installation, unsightly appearance due to knob-like protruberences such as those constituted by the ends of rung-holding through-bolts and the relatively large nuts applied to those ends, the amount of on-site work required in erection and the equipment necessary therefor, and a number of other adverse features which, each in itself, could be regarded as minor, but which in sum amount to a substantial shortcoming.

The object of this invention is to overcome or ameliorate that shortcoming in a simple but effective manner.

In accordance with the invention there is provided a cable ladder comprising a pair of parallel side-plates, the or each of which includes at least one division formed by the co-linear meeting ends of two side-plate portions; a series of spaced apart rungs whereof the ends are respectively joined to and between said sideplates and splicer means joining said portions together across one of said divisions characterised in that each of said side-plates comprises a channel having an upright web with top and bottom flanges directed into the spaced between said side-plates and a retainer rib on the underside of said top flange disposed parallel to and spaced from said web; the ends of said rungs abut said webs above said bottom flange and said 'splicer means comprises a fish-plate which bridges across one of said divisions, is secured to said web on either side of said division and is supported on the associated side-plate between said web and said rib.

Preferably a locatorflange is provided on each said side-plate extending from the web thereof in the same direction as the top and bottom flanges thereof, said locator flange being disposed parallel to said bottom flange but closer thereto than it is to said top flange; the ends of said rungs abutting said webs between said bottom flange and said locator flange and a said fish-plate being supported on said locator flange.

Each fish-plate may include a bead formation extending along its upper edge and directed inwardly of the associated side-plate web and may also include at least one stiffening flange extending therealong at or adjacent its lower edge and directed inwardly of the associated side-plate web.

Each said rung is conveniently of inverted channel section having a fastener-receiving groove at the edge of each limb of the channel; the ends of each rung abutting a respective side plate web and being secured thereto by at least one fastener extending through the web and into said fastener-receiving groove.

An example of the invention is illustrated in the drawings herewith, wherein: Figure 1 is a perspective view of a portion of a cable ladder with parts broken away, Figure 2 is an end view showing the side-plate and rung arrangement already shown in Figure 1, and Figure 3 is a fragmentary perspective view showing an alternative form of ladder-cantilever attachment.

Referring to Figures 1 and 2, two parallel sideplates 4 are provided, at least one of which has a division in it as indicated at 5. A plurality of rungs 6 are secured by their ends to the side-plates. A splicer fish-plate 7 bridges across division 5.

Each side-plate consists of a web 8, top flange 9 and a bottom flange 10. Web 8 carries a locator flange 11, and top flange 9 carries a retainer rib 12.

The rungs 6 are preferably of the inverted channel form shown, in which the free edge margins of the rung flanges are formed as screwreceiving grooves 1 3. The rungs, or one or more of them, may be furnished with a series of holes 14 to facilitate attachment to the rungs of cableholding ties or straps. The rungs are secured to the side-plates by screws 1 5 passing through holes in web 8 and threading into grooves 1 3.

Fish-plate 7 preferably has a top bead 1 6 and a pair of stiffening flanges 1 7, and is secured to the web portions by screws indicated at 1 8.

An advantage due to the fish-plate arrangement shown, is that the fish-plate can be applied to the side-plate laterally instead of longitudinally. In doing this, the side-plate ends are lined up and, with the fish-plate tilted, the bead 1 6 is entered into the space between rib 12 and web 4. When this is done the fish-plate may be swung to lie flatly against the web and the splice becomes fully effective merely by application of two fastenings such as screws 1 8.

A cable ladder support cantilever is indicated at 1 9. It is preferably of the known channel form shown so that it may accommodate longitudinally slidable but laterally captive nuts (not shown). The ladder is held by clamping plates 20 and screws 21 able to thread into the mentioned nuts.

The only difference introduced by Figures 3 is in the manner of holding the cable ladder to the cantilever support 1 9A. In this instance, instead of using a clamping plate (such as that marked 1 9 in Figure 1) a holding plate 22 is employed. This plate has a hooked formation 23 which merely embraces flange 1 OA so to permit the ladder some degree of longitudinal movement relative to support 1 9A.

Claims

1. A cable ladder comprising a pair of parallel side-plates, the or each of which includes at least one division formed by the co-linear meeting ends of two side-plate portions; a series of spaced apart rungs whereof the ends are respectively joined to and between said side-plates and splicer means joining said portions together across one of said divisions characterised in that each of said sideplates comprises a channel having an upright web with top and bottom flanges directed into the space between said side-plates and a retainer rib on the underside of said top flange disposed parallel to and spaced from said web; the ends of said rungs abut said webs above said bottom flange and said splicer means comprises a fishplate which bridges across one of said divisions, is secured to said web on either side of said division and is supported on the associated side-plate between said web and said rib.

2. A cable ladder as claimed in claim 1 wherein a locator flange is provided on each said side-plate extending from the web thereof in the same direction as the top and bottom flanges thereof, said locator flange being disposed parallel to said bottom flange but closer thereto than it is to said top flange; the ends of said rungs abutting said webs between said bottom flange and said locator flange and a said fish-plate being supported on said locator flange.

3. A cable ladder as claimed in either one of claims 1 or 2 wherein each said fish-plate includes a bead formation extending along its upper edge and directed inwardly of the associated side-plate web.

4. A cable ladder as claimed in any one of claims 1 to 3 wherein each said fish-plate includes at least one stiffening flange extending therealong at or adjacent its lower edge and directed inwardly of the associated side-plate web.

5. A cable ladder as claimed in any one of the preceding claims wherein each said fish-plate is secured to the adjacent web by a fastener passing through said web and engaging within an aperture in said fish-plate.

6. A cable ladder as claimed in any one of the preceeding claims wherein each said rung is of inverted channel section having a fastenerreceiving groove at the edge of each limb of the channel; the ends of each rung abutting a respective side-plate web and being secured thereto by at least one fastener extending through the web and into said fastener-receiving groove.

7. A cable ladder constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.