GB2314216A

GB2314216A - Cable tray bend

Info

Publication number: GB2314216A
Application number: GB9712187A
Authority: GB
Inventors: Arne Gya
Original assignee: Oglaend System AS
Current assignee: Oglaend System AS
Priority date: 1996-06-14
Filing date: 1997-06-10
Publication date: 1997-12-17
Anticipated expiration: 2017-06-10
Also published as: NO962518L; MY128976A; NO962518D0; NO302262B1; GB9712187D0; GB2314216B

Abstract

A bend 18 which can serve as an internal or external bend when joining cable trays or ladders, comprises two parallel side elements 20 which are connected by at least one transverse member 40 connected to the elements 20 by means of bolts 30, 32, 34. The member 40 can be fixed so that its flat portion is near the outer (longer) edge 36 of the bend thus providing an internal bend, or near the inner (shorter) edge 38 so providing an external bend (Figure 4). The member 40 may be moved from one position to another by loosening the securing bolts and rotating it about 180{; the bolts slide in an elongate hole (44 Figures 1 and 2) in the elements 20 to bring the flat portion near the edge of the elements. In another embodiment (Figures 5 and 6) three transverse members (40') are used.

Description

BEND FOR A CABLE TRAY/LADDER TYPE CABLE TRAY The present invention relates to a bend for respectively a cable tray and a ladder type cable tray consisting of straight lengths of joined elongated sections and interposed connecting bends, which cable tray or ladder type cable tray sections individually comprise two parallel side elements with an interposed continuous plate-shaped step, in the case of a cable tray, or a greater number of steps distributed along the length of the ladder type cable tray sections in the form of "ladder rungs", and in which said bend has corresponding side elements and at least one step connecting them, and a connecting portion - for example in the form of mounting holes - at each end, for connection to adjacent ends of a first cable tray/ladder type cable tray length, extending in one direction, and to a second cable tray/ladder type cable tray length, extending in another direction and at an angle to said first direction, for example of 900, the direction of the first cable tray/ladder type cable tray, the two directions being essentially in one common plane.

Said second cable tray/ladder type cable tray length, which will normally comprise several joined length sections of respectively said cable tray and ladder type cable tray, which serve for the safe and protecting reception and possibly fixed mounting of for example cables, hoses, hydraulic piping/hoses, instrument tubing etc. laid for protected suspension between the two parallel side elements of the cable tray/ladder type cable tray, and bearing supportedly against respectively a plate-shaped continuous stepportion (cable tray) and mutually spaced individual rungs (ladder type cable tray) and, as requires, fixed to respectively the tray shaped step and the ladderrung-like step of the ladder type cable tray. For securing the cables to the cable tray/ladder type cable tray may be used clamps, known in themselves, or other fasteners which are anchored in holes formed in the step-portion and possibly in the side elements. Cable tray/ladder type cable tray sections are joined to each other and to interposed bends by means of for example screw bolts, each having a fixed bolt head at the one end and a threaded portion for a tightening nut at the opposite end.

When, for example, a horizontally running cable tray/ladder type cable tray length, which may comprise a number of longitudinal, joined cable tray/ladder type cable tray sections, at an outer, free end is to be continued (after a bend) by a, for instance, vertically upward cable tray length or ladder type cable tray length, which shall, likewise, comprise a number of longitudinal, joined ladder type cable tray sections, this means application of a so-called internal bend which is connected to said outer, free end of the horizontal cable traylladder type cable tray length by means of screw bolts.

By such a bend a cable, for example, which is to be mounted between the side elements of the cable tray/ladder type cable tray and of the bend, and possibly be anchored to the step portion, is placed, as if it were placed inside the corner section of a rectangular picture frame.

On the other hand. if a vertically running cable tray length or ladder type cable tray length is to be continued by for example a horizontal cable tray/ladder type cable tray length, a so-called external bend will be necessary between the adjacent ends of the two at 900 angled cable tray lengths/ladder type cable tray lengths. Compared to an internal bend in which one or more steps are close to the larger dimension of the mid-portion of the bend, the step(s) of an external bend will be close to the shorter dimension of the midportion of the bend.

A conventional internal bend may not be used for an external bend, and a conventional external bend may in the same manner not be used for an internal bend. This means, among other things, more extensive stockkeeping.

From EP 0 521 536 Al publication is known a bend for a cable tray/ladder type cable tray in which the same bend, in a manner known in itself, may be used both as an external bend and as an internal bend. By this known bend this is enabled by the fact that the side edges of a base plate are to be folded over parallel side elements of the bend. The base plate may, therefore, be mounted on that side of the curve of the bend side elements, which is necessary to create the necessary bend. This EP publication thus represents a somewhat different technique than the one disclosed in the preceding description. The known bend is not, as presupposed by the present invention, configured of at least one transverse step between parallel, arc shaped/angled side elements.

A combined external bend/internal bend for a cable tray/ladder type cable tray according to the invention distinguishes itself compared to the known and conventional technique by the fact that the step or each step is rotatably supported about an axis which is preferably eccentric to the longitudinal line of symmetry of the linear portion of the step, the step being fixable to at least one bend side element in at least two different positions achieved through rotation.

By combined bends, which may be converted into internal or external bends, according to the present invention, the side elements of the bends - as in other known and conventional bends of the general type in question are held together by means of the step or the steps.

If it is known, according to plans or drawings, that more internal bends than external bends are used, the combined bend may in its not mounted state be screwed together as internal bends having the step/steps positioned at the longest side element edges. If, then, an external bend is needed, the tightening nut is loosened so much at each bend step, that the latter may be rotated 1800 about the flush longitudinal axes of the screw bolts transverse to the bend. When the 1800 rotation of the bend step in question has taken place, the two external tightening nuts on the screw bolts are tightened, and the conversion from internal bend into -external bend is finished.

A non-limiting example of a presently preferred embodiment is explained in detail in the following description with reference to the accompanying drawings, in which Fig. 1 shows a perspective view, seen at an angle from above, of a cable tray bend, in which the mounting ends of the step are located at the shorter side edges of the bend side element, corresponding to an external bend; Fig. 2 shows a perspective view, seen at an angle from above, of the same cable tray bend as in Fig. 1, but 0 here the bend step has been rotated 180 compared with the step position in Fig. 1, so that here the step is located close to the longer side edges of the bend, corresponding to an internal bend; Fig. 3 shows a perspective view of a joined corner section of a cable tray, having a horizontal length, which by way of an internal bend passes into an upward vertical length; Fig. 4 shows a perspective view of a joined corner section of the cable tray in Fig. 3, in which a vertically upward cable tray length via an external bend passes into a horizontal cable tray length; Fig. 5 shows a perspective view of a corner section of a horizontal ladder type cable tray length, which by way of an internal bend formed in accordance with the invention, is continued by a vertical upward ladder type cable tray length; Fig. 6 shows the same embodiment of a ladder type cable tray as that in Fig. 5, but here the upward, vertical ladder type cable tray length by way of an external bend passes into a horizontal ladder type cable tray length.

In Figs. 3 - 6 are included an elongated tubular element 10 which may constitute an electric cable, a hydraulic hose, an instrument tubing or similar whichis protectedly placed between side elements 12/12' of the cable tray/ladder type cable tray and bear against a step plate 14 of the cable tray or individual steps 16 of the ladder type cable tray, which steps 16 are fixed to the side elements 12 or 12'. The electric cable 10 etc. is secured to the step plate 14 of the cable tray or the steps 16 of the ladder type cable tray in a known manner.

On studying the paths of the cable 10 respectively at the corners of the cable trays in Figs. 3 and 4 and at the corners of the ladder type cable trays in Figs. 5 and 6, it will be apparent why the respective bends, generally designated by the reference numeral 18 in Figs. 1 - 4 and by 18' in Figs. 5 and 6, are called respectively "internal bends" (Figs. 2, 3 and 5) and "external bends" (Figs. 1, 4 and 6). From Figs. 3 and 5 it will appear that the cable 10 extends on the inside of the corner, while the cable 10 at the bend portions according to Figs. 4 and 6 extends along the outside of said frame corner, hence the expressions internal bend (Figs. 2, 3 and 5) and external bend (Figs. 1, 4 and 6).

Each bend 18 for cable trays, Figs. 1 - 4, has two parallel, mutually spaced bend side elements 20 which are symmetrically identical, mirrored about an imaginary interposed vertical central plane. It appears from the figures in the drawings that the bend side elements 20 are mutually opposed, having narrow flanges 22 directed towards each other, running along both the upper as well as the lower bend edges.

Each bend side element 20 consists of a mid-portion 24, of inclined position in application, and an angled mounting portion 26, 26' at each end. In the shown embodiment the two mounting portions 26, 26' at the ends of the bend side elements are at 900 to each other, but bends of greater or smaller angles may of course be produced.

Each bend side element 20 is in a known manner formed with holes 28 for mounting to an adjacent end portion of a cable tray length. For the securing, by utilization of the corresponding holes in the side elements of the bend and of the cable tray, are used screw bolts 30, having a fixed head 32 at the one end and a threaded portion at the other end for a tightening nut 34.

As any other bend 18, this one has an outer edge 36 of a greater longitudinal extension than the opposite inner edge 38, see for example Figs. 1 and 2.

The shown embodiment of a cable tray bend 18, Figs. 1 4, has one transverse step 40 holding the side elements 20 together. Within the scope of the invention more transverse steps 40 may be used. For a ladder type cable tray bend 18' in Figs. 5 and 6, three such steps 40' have been used. These steps 40, 40' are preferably formed with holes to be used in fixing for example the cable 10 by means of not shown clamps or any other suitable fasteners.

An important feature of these side-element-connecting transverse steps 40, 40' is that they have angled mounting portions 42, one at each end of the step 40, 40'. These mounting portions 42 have a mounting hole (not visible in any figure as it is covered by the head of a screw bolt) each, which is brought to correspond with a groove 44 in the adjacent bend side element, which groove enables an eccentric support of the intermediate step body. It should readily be obvious that if the nuts 34 are loosened so much that the fixing/mounting portion 42 of the step 40, 40' on each side is no longer anchoringly pressed against the adjacent inner side of the respective bend side element, the step 40, 40 may be rotated, via the hole in each angled mounting portion 42, about an axis of rotation A, Fig. 2, which longitudinal but eccentric to the step body itself.

It is a 1800 eccentric rotation of the step 40 which is necessary to convert for example an external cable tray bend 18 according to Fig. 1 into an internal cable tray bend according to Fig. 2. After a possible rotation of the step 40, the nuts 34 are tightened, so that the step 40 braces the bend.

Ladder type cable trays and their bends do not deviate from the principles of the embodiment described above.

The ladder type cable tray bend 18' does not have angled side elements as the side elements 20' extend in a 900 circularly shaped curvature. The bend side -elements 20' are mutually connected by means of three transverse steps 40' which are formed and are mountable, eccentrically rotatable etc. in the same way as in the embodiment according to Figs. 1 - 4. The end portions of the side elements of the ladder type cable tray bends have four holes each for anchoring bolts 34, see Fig. 6.

Fig. 5 shows the application of an internal bend 18', while Fig. 6 shows the application of an external bend 18' corresponding to the internal bend, except that the steps 40' in the external bend have been rotated 1800 eccentrically compared with the steps 40' of the internal bend, Fig. 5.

Claims

CLAIMS:

1. A bend for a cable tray/ladder type cable tray, comprising two parallel, mutually spaced bend side elements which are connected by at least one transverse step, and whose outer, free ends individually are formed for connection to an adjacent end portion of a cable tray/ladder type cable tray length, which cable tray/ladder type cable tray lengths longitudinally are to extend in an angled relationship of for example 90 , in which the step or each step is rotatably supported about an axis (A) which is preferably eccentric to the longitudinal line of symmetry of the linear portion of the step, the step being fixable to at least one bend side element in at least two different positions achieved through rotation.

2. A bend according to claim 1, in which the or each step has an angled mounting portion at each end, which mounting portions are parallel with their free, outer ends pointed in the same direction, each step being rotatably supported at the adjacent bend side element, and being fixable to the respective bend side element in at least two positions achieved through rotation.

3. A bend according to claim 2, in which each angled step end portion is provided with a hole for receiving the axle of a screw bolt which has a fixed head at one end and a threaded portion for a tightening nut at the opposite end, the screw bolt, the fixed bolt head and the nut forming one of said fasteners, so that the common axis of the two axles of the screw bolts form said eccentric axis of rotation (A).

4. A cable tray comprising a bend according to any one of the preceding claims.

5. A bend for a cable tray/ladder type cable tray substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.