GB2256672A

GB2256672A - Cable cleats

Info

Publication number: GB2256672A
Application number: GB9112813A
Authority: GB
Inventors: Christopher John Calvert
Original assignee: Walkern Victoria Ind Ltd
Current assignee: Walkern Victoria Ind Ltd
Priority date: 1991-06-14
Filing date: 1991-06-14
Publication date: 1992-12-16
Anticipated expiration: 2011-06-14
Also published as: GB2256672B; GB9112813D0

Abstract

A cable cleat 1 comprises three elongate members 2, 3, 4 including a base member 2 for connecting to a wall and two side members 3, 4. The members 2, 3, 4 are connectable in use to form a polygonal structure which can be expanded or contracted around one or more cables. Locking means 25, 26, 27, 28, which in one embodiment comprise rows of opposing teeth 25, 28 biased towards each other by means of bolts 27, 28, are provided between the base member 2 and each side member 3, 4. The connection between the ends of the side members 3, 4 remote from the base member 2 is formed by a bolt 18 extending in the direction of expansion and/or contraction of that connection. At least one of the locking means 25, 26, 27, 28 is releasable to permit one side member 3, 4 to be pivoted about the bolt 18 whilst the other side member 3, 4 remains rigidly connected to the base member 2. <IMAGE>

Description

Cable Cleats This invention relates to cable cleats for mounting one or more cables or the like to a support, and particularly to cleats of the type formed of three elongate members or limbs interconnected in a generally triangular configuration for cleating cables in trefoil or singly.

One known form of trefoil cleat comprises a base member mountable to a support and two side members which are bolted to the ends of the base member and to each other at the apex of the triangle. A disadvantage with this type of cleat is that, generally, to allow insertion of a cable or the like into the cleat one of the side members must first be removed. Another known form of trefoil cleat avoids this disadvantage by having the two side members hingedly connected to the ends of the base member, so that the side members, can be pivoted outwardly in the plane of the cleat for insertion of a cable.

Traditionally, such cable cleats have suffered from the disadvantage that each cleat can only accommodate one size of cable. In our international patent application PCT/GB91/00045 it has been suggested to provide a cleat which can mount cables or the like having a range of diameters, wherein the connections between the elongate members allow for relative movement therebetween, so that the cleat can expand or contract whilst maintaining the same shape. Fixed hinged connections of the type traditionally provided are not suitable for such cleats because they do not have the capacity to allow the connections to expand or contract.

In one of the arrangements illustrated in international patent application PCT/GB91/00045, the elongate members are connected by locking bolts which extend perpendicular to the direction of sliding engagement between the end portions of the members. One of the side members is adapted to be pivoted out of the plane of the cleat about the locking bolt forming the connection with the base member, so as not to obstruct the insertion of a cable or cables. However, the arrangement is rather complex and can be awkward to use in certain circumstances.

According to the present invention there is provided a cleat for mounting one or more cables or the like to a support, comprising three elongate members including a base member mountable to a support and two side members, connectable in use to form a planar polygonal structure encircling said one or more cables or the like, the connections being such as to permit said polygonal structure to expand or contract in the plane of said cleat about said one or more cables or the like whilst maintaining the same shape, there being locking means for locking the respective connections between the base member and the adjacent side members at a selected relative expanded position in said plane, wherein the connection between the ends of the side members remote from said base member is formed by a bolt which extends in said plane through opposed apertures formed in the side members in the direction of expansion or contraction of the connection, wherein, to facilitate insertion or removal of a cable or the like into or from the cleat, the locking means between one side member and the base member is releasable to permit such side member to be pivoted about the bolt out of the plane of the cleat whilst the other side member is maintained fixedly connected at a selected relative expanded position to the base member by the locking means arranged therebetween.

Preferably, either side member may be released and pivoted as aforesaid with the other remaining fixedly connected to the base member so that a cable may be inserted or removed from each side.

There is thus provided a cable cleat which can expand or contract to accommodate a range of cable or the like diameters and wherein at least one of the side members can be pivoted out of the plane of the cleat for insertion of a cable or the like, which has a relatively simple structure and is convenient to use and economic to manufacture.

It is particularly convenient that the side members are pivotal about a connection remote from the base member and the support structure to which the base member is mounted. One reason for this is that the pivotal movement of the side member will not be limited by the support. Since the bolt forming the pivotal connection between the side members extends in the direction of expansion and contraction, it can form the sole means of connecting the ends of said two side members remote from the base member, the connection being expanded or contracted by moving the side members along the bolt until they are spaced apart by a selected distance.The bolt could be threadedly engaged with one of the side members, but preferably it is engaged with a nut adjacent and on the outside of one of the side members, so that tightening of the bolt contracts the connection and loosening the bolt allows the connection to expand. This bolt can therefore act as a means of tensioning the cleat around the cable or cables.

Preferably the bolt forming said pivoted connection is additionally provided with two locking nuts located between the respective apertures in the side members, to provide means of locking the adjacent side members rigidly in a selected relative position of expansion or contraction. Such locking nuts could also be used to lock a side member which is rotated out of the plane of the cleat at any convenient angle of rotation where it causes least obstruction to the insertion or removal of cables.

It is also particularly convenient that the locking means can rigidly lock the base member/side member connections both when the cleat is closed and when it is open. The rigid locking together of the base member and one side member in the plane of the cleat to form a rigid structure when the other side member is pivoted out of the plane of the cleat makes the cleat easy to handle for insertion of one or more cables or the like.

In a trefoil cleat for example, the base member mounted to a support and one side member can form a rigid V shaped structure into which the cables or the like can be placed, whilst the remaining side member is kept out of the way of the cables. When the cleat is closed and tightened about the one or more cables or the like, the rigid locking of preferably all of the connections against relative rotation or translational movement provides a secure structure which is well able to withstand loads such as large repulsive forces between high voltage electric cables tending to expand the cleat, which may occur under short circuit conditions.

The locking means between the base and side members can take any convenient form, and some possible locking means are described in PCT/GB91/00045. For example, the locking means could comprise a pair of bolts at each connection extending perpendicular to the direction of expansion and/or contraction of that connection and extending through apertures formed in one member and one or more elongate slots formed in the adjacent member.

Such would lock adjacent members against relative sliding or rotation. However, in a preferred arrangement said locking means comprise opposing rows of teeth formed in the respective members which are biased towards each other by means of bolts extending between the members perpendicular to the direction of expansion and/or contraction, each said bolt extending through an aperture in one member and an elongate slot in the adjacent member. The resistance of the opposing teeth to sliding over each other provides a particularly rigid locking means.

The cleat preferably has a generally triangular form. The base member is provided with means for mounting to a support, for example one or more apertures to receive a bolt or bolts. The base member may be spaced in use from the support by a spacer. The ends of the base member are preferably angled inwardly, each by the same angle relative to a central portion of the base member which is adapted to be mounted to a support.

Preferably the ends of the side members adjacent the base member are also angled inwardly at equal angles, with the base member lying outwardly of one side member at one end and inwardly of the other side member at the other end. The opposite ends of the side members remote from the base member are preferably directed outwardly such that they lie in a parallel configuration, perpendicular to the direction of expansion and contraction of that connection and to said bolt which extends in that direction through opposed apertures formed in said side members.

A cable cleat according to this invention may be adapted to mount any number of cables or the like to a support, for example one or three. The cleat may be provided with pads mounted to each elongate member, whose inwardly directed faces are shaped as appropriate to engage said one or more cables or the like.

Preferably these pads are removable so that different pads can be mounted to the elongate members depending on the application and the number and type of cables or the like which are to be accommodated.

The cleats may be formed of any suitable material, such as steel, aluminium, moulded glass reinforced nylon, or other metal or plastics materials. Metals are particularly well suited to applications where greater strength and/or flame resistance is important, whereas plastics materials can be more lightweight. In one metal embodiment which is particularly suited for mounting high voltage electric cables the bolt extending in the direction of expansion and contraction of the connection between the side members can be formed of a non-conducting material to reduce eddy currents in the rest of the cleat which is formed of a conducting material.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: Fig. 1 is a view of the illustrated embodiment from one end; and Fig. 2 is a side view of the embodiment of Fig. 1.

The illustrated cable cleat 1 comprises three elongate steel limbs including a base member 2 and two side members 3,4, which are connected end to end in a generally triangular configuration. The base member 2 has a central portion 5 provided with apertures 6,7 to receive bolts (shown dotted) for mounting to a support (not shown). Two end portions 8,9 at either end of the central portion 5 are angled inwardly away from the support. The two side limbs 3,4 each have a central portion 10,13, an inwardly angled end portion 11,14 adjacent the base member 2 and an outwardly angled end portion 12,15 at the end remote from the base member.

The outwardly angled portions 12,15 of the two side limbs are parallel in use and are each provided with an aperture 16,17 which receives a bolt 18 having a head 19 and engaging with a nut 20 spaced from the outwardly facing side of end portion 15 by a washer 21. The connection formed between side limbs 3 and 4 can be expanded by loosening the bolt 18 and sliding the limb 4 therealong, and contracted by tightening the bolt 18 against the nut 20. This bolt 18 can also be used to tension the cleat about the cables 22 therein. Locking nuts 23,24 are engaged with the bolt 18 between the inner faces of the end portions 12,15 of the two side limbs 3,4. These locking nuts 23,24 can be tightened against the inner faces of the end portions 23,24 to prevent contraction of the connection and to lock the connection rigidly at a selected expanded position.

The end portions 8,9 of the base member overlie the other end portions 11,14 of the two side limbs, to the outside of the side limb 3 at one end 8 and the inside of the side limb 4 at the opposite end 9. The opposing faces of the end portions 8,9,11,14 are provided with rows of interlocking teeth 25,26 which are biased towards each other by means of locking bolts 27,28 which extend through elongate slots 29,30 formed in the outermost of the end portions 8,14 and threaded apertures 31,32 formed in the innermost of the end portions 9,11. When the locking bolts 27,28 are tightened, the connections formed between the base limb 2 and the side limbs 3,4 are rigidly locked against relative rotational or translation movement.Once the locking bolts 27,28 are loosened the opposing rows of teeth can be slid over each other, tooth by tooth whilst maintaining a captive interconnection, to expand or contract connections as desired. These connections can then be tightened in a new selected position as desired.

The base member 2 is spaced from the support (not shown) by means of a spacer 33 and removable pads 34 are clipped to the elongate members to engage the three cables 22. Pads having a different contour can be used to replace pads 34 as appropriate for different numbers or sizes of cables and different applications. The pads are formed of a flame resistant plastics material.

In use, in order to open the cleat 1 for insertion of a cable 22 or the like, the bolt 28 is first undone and removed and the side limb 4 is rotated about bolt 18 out of the plane of the cleat. The side limb 4 can be rotated through any convenient angle, say 1800, until it is out of the way of cables 22 being inserted into the cleat. Bolt 18 can be loosened if necessary. At this stage, the adjoining end portions 8,11 at the other end of the base limb 2 are advantageously kept fixedly connected by means of the locking bolt 27 biasing the opposing rows of interlocking teeth 25 into tightly clamped engagement. Thus, the rigidly locked connection prevents slipping in the direction of expansion and contraction and in a lateral direction and also prevents relative rotation between the two end portions 8,11.

The base member 2 can be bolted to a support such that the two rigidly connected limbs 2,3 form a planar Vshaped bracket into which a cable or cables can be inserted.

Once the cables have been inserted into the cleat, side limb 4 is rotated about bolt 18 back into the plane of the remaining two limbs 2,3. It may be necessary to loosen the bolt 18 and/or the locking nut 24 at this stage. Furthermore, the aperture 17 in the end portion 15 which receives the bolt 18 may be of slightly larger diameter than the bolt 18 so as to allow some play between the limb 4 and the bolt 18, to assist in closing the cleat. Once the limb 4 is in the plane of the cleat, locking bolt 28 is replaced and the cleat is contracted around the cables 22 whilst maintaining the same shape, to a size appropriate for the number and diameter of the cables. The locking bolts 27,28 and the locking nuts 23,24 will be loosened at this stage so that the connections with the base member 2 can be contracted by sliding the respective end portions over each other tooth by tooth, and the remaining end portions 12,15 of the side limbs at the connection remote from the base member 2 can be slid towards each other along the bolt 18. When the cleat is contracted to a desired size the locking bolts 27,28 are tightened to rigidly lock the connections at either end of the base member. Finally, the bolt 18 can be tightened further to tension the cleat about the cables and the locking nuts 23,24 are tightened to rigidly lock the remaining connection. The rigid structure so formed is well adapted to withstand stresses including stresses due to repulsive forces between high voltage electric cables under short circuit conditions.

Alternatively, instead of opening the cleat by rotating said limb 4 out of the plane of the cleat, the other side limb 3 could be rotated out of the plane of the cleat whilst base limb 2 and side limb 4 are maintained rigidly connected.

Although the invention has been specifically described in relation to the mounting of electric cables, it should be clearly understood that it could be applied to the mounting of like elongate articles such as, for example, ducts, pipes, rods, tubes or ropes.

Claims

CLAIMS:

1. A cleat for mounting one or more cables or the like to a support, comprising three elongate members including a base member mountable to a support and two side members, connectable in use to form a planar polygonal structure encircling said one or more cables or the like, the connections being such as to permit said polygonal structure to expand or contract in the plane of said cleat about said one or more cables or the like whilst maintaining the same shape, there being locking means for locking the respective connections between the base member and the adjacent side members at a selected relative expanded position in said plane, wherein the connection between the ends of the side members remote from said base member is formed by a bolt which extends in said plane through opposed apertures formed in the side members in the direction of expansion or contraction of the connection, wherein, to facilitate insertion or removal of a cable or the like into or from the cleat, the locking means between one side member and the base member is releasable to permit such side member to be pivoted about the bolt out of the plane of the cleat whilst the other side member is maintained fixedly connected at a selected relative expanded position to the base member by the locking means arranged therebetween.

2. A cleat as claimed in claim 1, wherein the locking means between the base member and each of said side members is releasable to permit either one of said side members to be pivoted about the bolt out of the plane of the cleat whilst the other side member remains fixedly connected to the base member.

3. A cleat as claimed in claim 1 or 2, wherein the ends of the side members remote from the base member are connected in use solely by said bolt.

4. A cleat as claimed in any preceding claim, wherein said bolt is arranged to provide a means of tensioning the cleat around said one or more cables.

5. A cleat as claimed in any preceding claim, wherein said bolt is threadedly engaged in use with a nut adjacent and to the outside of one of the side members.

6. A cleat as claimed in any preceding claim, wherein locking means are provided for locking the connection between the ends of the side members remote from the base member at a selected relative position of expansion or contraction.

7. A cleat as claimed in claim 6, wherein said locking means for locking the connection between the ends of the side members remote from the base member comprises a pair of locking nuts located in use between the side members.

8. A cleat as claimed in any preceding claim, wherein the locking means for locking the respective connections between the base member and the adjacent side members at a selected relative expanded position comprise a bolt at each said connection which extends in use perpendicular to the direction of expansion and/or contraction of that connection through an aperture formed in one member and an elongate slot formed in the adjacent member.

9. A cleat as claimed in claim 8, wherein said locking means at each connection between the base member and a side member further includes opposing rows of teeth formed in the respective members which are arranged to be biased towards each other by means of said bolts extending perpendicular to the direction of expansion and/or contraction.

10. A cleat as claimed in any preceding claim, having a generally triangular form.

11. A cleat as claimed in any preceding claim, wherein the ends of the base member and the ends of the side members adjacent the base member are angled inwardly.

12. A cleat as claimed in any preceding claim, wherein the ends of the side members remote from the base member are angled outwardly so as to lie parallel to each other in use.

13. A cleat as claimed in any preceding claim, wherein the bolt extending between the ends of the side members remote from the base member is formed of a nonconducting material.

14. A cleat substantially as hereinbefore described with reference to the accompanying drawings.