GB2469833A

GB2469833A - Cable clamp having a hinged arm and an expandable locking bar

Info

Publication number: GB2469833A
Application number: GB0907348A
Authority: GB
Inventors: Peter Sinclair; Scott Horner
Original assignee: LUCY AND CO Ltd W
Current assignee: LUCY AND CO Ltd W
Priority date: 2009-04-29
Filing date: 2009-04-29
Publication date: 2010-11-03
Also published as: GB0907348D0

Abstract

A cable clamp comprises a U-shaped receptacle comprising a pair of arms 16 & 18 extending from a base 14, a locking bar 20 hinged to one arm 16 of the base and rotateable into engagement with the other arm 18, the bar 20 being expandable toward the base 14. The bar 20 can comprise a cross-member hinged to an arm 16 of the base and rotateable into engagement with the other arm 18, a cable grip 36, and a threaded drive 32 connected to the cross-member and the cable grip thereby to allow the cable grip to be driven toward the base, thereby expanding the bar 20. The cable grip can then comprise at least one rearwardly extending skirt section 28 which sits alongside the cross-member. Preferably, the threaded drive comprises a bolt thereby providing a bolt head via which it can be driven. The cable grip can have a recess into which extends a ridge formed on an arm of the U-shaped receptacle when the cable grip is not fully withdrawn, thereby to prevent rotation of the bar as the grip is advanced. The other arm 18 of the U-shaped receptacle can comprise a recess 24 into which the bar can extend, thereby to prevent rearward movement of the bar when a force is exerted on a clamped cable. The locking bar can be hinged 22 so as to rotate in a plane transverse to the plane defined by the arms of the U-shaped receptacle. The invention further relates to a combination of a cable clamp as defined above and an electrical cable comprising a single conductor surrounded by an insulating sleeve, the cable being located within the U-shaped receptacle.

Description

Cable Clamp S...

: FIELD OF THE INVENTION * S *5IS

The present invention relates to a cable clamp suitable for retaining *S..

: electrical distribution cables.

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BACKGROUND ART S... * . *..S

* Cable clamps are commonplace in equipment intended for domestic voltage applications. They assist in the safe retention and organisation of cables, which keeps the equipment safe, reliable and maintainable.

Electrical distribution equipment, such as for electrical distribution, do not generally use cable clamps per Se, for the simple reason that the cables are very much more substantial than domestic cables. Typically, solid aluminium or copper conductors are used, with a cross-sectional area of up to 300mm2 and an insulating polymeric sheath. These will be much more resistant to bending and generally take smoother paths than low voltage cables. There are however situations in which the cable needs to be held in place, and to date wooden battens are usually used for this purpose.

SUMMARY OF THE INVENTION

The present invention therefore provides a cable clamp comprising a U-shaped receptacle comprising a pair of arms extending from a base, a locking bar hinged to one arm of the base and rotateable into engagement with the other arm, the bar being expandable toward the base.

The bar can comprise a cross-member hinged to an arm of the base and rotateable into engagement with the other arm, a cable grip, and a threaded drive connected to the cross-member and the cable grip thereby to allow the cable grip to be driven toward the base, thereby expanding the bar. The cable grip can then comprise at least one rearwardly extending skirt section which sits alongside the cross-member. The threaded drive can be rotateably attached to the cable grip, and can be connected to the cross-member via an internally threaded bore through which the threaded drive passes. Ideally, the threaded drive comprises a bolt thereby providing a bolt head via which it can be driven.

The cable grip can have a recess into which extends a ridge formed on an arm of the U-shaped receptacle when the cable grip is not fully withdrawn, : thereby to prevent rotation of the bar as the grip is advanced.

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The other arm of the U-shaped receptacle can comprise a recess into which the bar can extend, thereby to prevent rearward movement of the bar : when a force is exerted on a clamped cable.

The locking bar can be hinged so as to rotate in a plane transverse to the plane defined by the arms of the U-shaped receptacle.

The invention further relates to a combination of a cable clamp as defined above and an electrical cable comprising a single conductor surrounded by an insulating sleeve, the cable being located within the U-shaped receptacle.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described by way of example, with reference to the accompanying figures in which; Figure 1 shows an isometric view of the cable clamp of the present invention, closed and clamped Figure 2 shows an isometric view of the cable clamp of the present invention, open and ready to accept a cable; Figure 3 shows a view of the cable clamp from above Figure 4 shows a view of the cable clamp from above, closed; Figure 5 shows a view of the cable clamp from above, closed and clamped; Figure 6 shows a view of the cable clamp from one end, open; Figure 7 shows a view of the cable clamp from one end, closed; Figure 8 shows an isometric view of the cable clamp, exploded; and *...

Figure 9 shows a view of the cable clamp from one end, exploded.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Figures 1-9 illustrate a cable clamp according to the present invention.

*:::* Referring to Figure 1, this shows the clamp in a closed and clamped state. It .". consists generally of a U-shaped receptacle 12 which includes a base section 14 and two extending arms 16, 18. The base 14 can be secured to a back plate or an internal wall of electrical distribution equipment (not shown) and the extending arms 16, 18 will thereby define a small enclosed space into which an electrical distribution power cable can be guided. The cable (not shown) is then urged against the base 14 and clamped into place by a locking bar 20. This is attached to distal portions 22, 24 of the extending arms 16, 18 and expands towards the base 14 so as to force the cable into a clamped position in which it is held by friction between the base 14 and the locking bar 20.

Figure 2 shows the clamp 10 in an open state prior to (or immediately after) insertion of the cable. The locking bar is attached to the first extending arm 16 at 22 via a hinge pin which extends generally parallel to the extending bar 16. The hinge pin can be seen more clearly in the exploded figures 8 and 9, described later. This allows the locking bar 20 to rotate up and out of the plane of the U-shaped receptacle 12, thereby clearing the way for insertion of the cable. However, the locking bar 20 remains attached to the remainder of the clamp 10, thus meaning that there are no removable parts which might fall and become lost. When the locking bar 20 is rotated back into the plane of the U-shaped receptacle 12, a lug 26 opposite the hinge pin engages within the recess 24 and is thus secured against rearward movement of the locking bar 20 relative to the second extending arm 18 as the clamping force is increased. The recess 24 has a flat base 28 against which the lug 26 also abuts when the locking bar is closed, thereby providing positive assurance that the locking bar is closed into the correct position.

The locking bar consists of three main parts. The first is a cross-member which carries the hinge pin and, at its opposite end, the lug 26. This is **** fixedly attached via the hinge pin to the U-shaped receptacle and moves between the closed position shown in figure 1 and the open position shown in : figure 2. It has a centrally located bore which is internally threaded to accept a bolt 32 whose head extends away from the base 14 and is accessible from the exterior of the clamp 10. A suitable spanner or socket drive attached to the bolt head allows the boft 32 to be driven through cross-member 30 and towards the : base 14. The tip of the bolt is attached to a cable grip 34 which is thereby driven forward by rotation of the bolt 32 towards the base 14, to clamp a cable between the cable grip 34 and the base 14. The forward hinge of the cable grip 34 is profiled with an arcuate front face 36 to allow a more even contact with a cable, thereby increasing frictional forces that prevent slippage of the cable through the cable clamp 10.

A pair of skirt sections 38, 40 extend rearwardly from the cable grip 36 and sit either side of the cross-member 30. As the cable grip 36 advances forwards, these slide over the cross-member 30 and prevent the cable grip 36 from rotating under the influence of the bolt 32 as it is advanced. Recesses 42 on the edges of the cable grip 36 are also provided. As the cable grip 36 moves forward, these meet and slide over ridges 44 extending inwardly from each lateral arm 16, 18, further preventing rotation of the cable grip 36.

Figures 3-5 show sequential steps in clamping a cable. Figure 3 shows the cable clamp 10 in the open position, in which the U-shaped formation 12 is open-ended, allowing a cable to be inserted. Figure 4 shows the locking bar rotated into position, with the lug 26 engaged within the recess 24 and the ridges 44 not yet engaged with the recess 42. From the position shown in figure 4, the bolt 32 is tightened into the cross-member 30, driving the cable grip 36 forward towards the base 14 and clamping a cable in place. Initially, the skirt sections 38, 40 prevent rotation of the cable grip 36; after the cable grip has moved a short distance the ridges 44 engage with the recesses 42 and further prevent rotation of the cable grip 36.

Figures 6 and 7 show the cable grip 10 from one end, figure 6 clearly showing the ridges 44.

Figure 8 shows the cable grip in an exploded form, illustrating all of the necessary to construct The U-shaped receptacle is made of an upper section 12a and a lower section 12b, each which carries half of the relevant ridge e:. 44a, 44b respectively. The cross-member 30, is integrally moulded with the hinge pin sections 46, 48 extending therefrom and is placed within a correspondingly shaped recess 50 within the lower section 12b of the U-shaped * receptacle. The bolt 32 and the cable grip 36 can then be fitted onto the locking bar 30, and the upper section 12a placed in position over the lower section 12b, enclosing the hinge pins 46, 48. Bolts 52, 54, 56 and 58 can then be fitted to retain the upper and lower sections 12a, 12b. In this way, a clamp is provided which, whilst assembled, has no user-removable parts. They can be undone to a position where the clamp can be rotated to allow a cable to be inserted (or removed). The cable is then pushed into the clamp body, the clamp is rotated to the closed position and the screw is tightened in order to clamp the cable. Such a clamp is automatically range-taking and can thus deal with different sized cables. It is of a robust construction which is capable of fully supporting a cable and carrying the weight of such a cable. It is thus eminently suitable for electrical power cables for use in electrical distribution.

It will of course be understood that many variations may be made to the above-described embodiment without departing from the scope of the present invention. * * S S. S S... * S *5SS * S...

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Claims

CLAIMS1. A cable clamp comprising a U-shaped receptacle comprising a pair of arms extending from a base, a locking bar hinged to one arm of the base and moveable into engagement with the other arm, the bar being expandable toward the base.

2. A cable clamp according to claim 1 in which the bar comprises a cross-member hinged to an arm of the base and moveable into engagement with the other arm, a cable grip, and a threaded drive connected to the cross-member and the cable grip thereby to allow the cable grip to be driven toward the base, thereby expanding the bar.

3. A cable clamp according to claim 2 in which the cable grip comprises at least one rearwardly extending skirt section which sits alongside the cross-member.

A cable clamp according to claim 2 or claim 3 in which the threaded drive is rotateably attached to the cable grip. *.es

**.: 5. A cable clamp according to any one of claims 2 to 4 in which the threaded drive is connected to the cross-member via an internally threaded bore through which the threaded drive passes.

6. A cable clamp according to any one of claims 2 to 5 in which the threaded drive comprises a bolt.

7. A cable clamp according to any one of claims 2 to 6 in which the cable grip has a recess into which extends a ridge formed on an arm of the U-shaped receptacle when the cable grip is not fully withdrawn, thereby to prevent rotation of the bar.

8. A cable clamp according to any one of the preceding claims in which the other arm of the U-shaped receptacle comprises a recess into which the bar can extend thereby to prevent rearward movement of the bar.

9. A cable clamp according to any one of the preceding claims in which the locking bar is hinged so as to rotate in a plane transverse to the plane defined by the arms of the U-shaped receptacle.

10. The combination of a cable clamp according to any one of the preceding claims, and an electrical cable comprising a single conductor surrounded by an insulating sleeve, the cable being located within the U-shaped receptacle.

11. A cable clamp substantially as herein described with reference to the accompanying figures. S... * . S *..* * . ***. *..*S aSS, * S.. *.* * * S... S. * * * S * S