WO1996013876A1

WO1996013876A1 - Split ring

Info

Publication number: WO1996013876A1
Application number: PCT/GB1994/002394
Authority: WO
Inventors: Brian Henry Birkett
Original assignee: Birkett Electric Ltd
Priority date: 1993-03-03
Filing date: 1994-11-01
Publication date: 1996-05-09

Abstract

A split ring cable protector for use in forming a cable joint in the form of two collar half sections which are joined together along a structural zone of weakness with their free ends in separation. The split ring performs its function by the user simply squeezing the two half collar sections together about the zone of weakness so that, as well as being effective, it is extremely easy to handle in contrast to the existing arrangements.

Description

SPLIT RING

FIELD OF THE INVENTION

The present invention relates to a mechanical device in the form of a split ring for use in forming a cable joint.

BACKGROUND OF THE INVENTION

Various types of cable joint are known, used typically to join cables with one or more inner insulated conducting cores and one or more outer insulating or protecting sheaths.

To protect the inner cables, a surrounding layer of stiff metal wires, known as an armour sheath, is arranged between the outer sheath of the cable and the insulated conductor cores.

The armour sheath also acts as an earthing wire, being bridged between cables to be connected, by a connecting piece of insulated conductor wire and secured to the armour sheath of the cables by a jubilee clip or other suitable clamping means.

It will be appreciated that as the jubilee clip is tightened around the armour sheath, the latter will be pressed directly against the insulation of the conductor cores causing possible damage which could lead to shorting of the system.

Some form of protection is thus necessary between the armour sheath and the insulated conductor cores and this typically takes the form of metal tubes of various designs interposed between d e insulated conducting cores and d e armour and around which a clamp such as a jubilee clip may be arranged so that the earth wire is securely held between the metal tube and die jubilee clip and damage to the insulated cores is avoided. Two examples of d e prior art include a prefabricated metal tube in die form of a split ring and a metal tube formed of two separable constituent parts having interengagable lugs such mat me protective tube is rendered whole and structurally stable by fitting die two interconnecting pieces togemer between the armour sheath and me insulated cores of me cables.

As regards me prefabricated split ring, diis lacks versatility and a wide range of sizes has to be manufactured to suit differing cable dimensions.

The device comprised of interlocking constituent pieces is a relatively complicated arrangement and expensive to manufacture. It is furthermore not easy to use in practice, consequendy being inefficient in terms of loss of valuable working time during installation.

SUMMARY OF THE INVENTION

An object of the invention accordingly is to provide a mechanical device of the type described above for use in cable joints which combines ease of use with full protection for me insulated conductor cores of the cables of me joint, thus obviating the disadvantages of me prior art.

According to the invention there is provided a cable protector for use in forming a cable joint comprising two collar half sections interconnected in disposed apart relationship along a structural zone of weakness such mat upon the application of pressure the half sections may be brought togemer around a cable to be protected to form a split protective ring.

Preferably the interconnected collar half sections are formed out of extruded aluminium.

BRIEF DESCRIPTION OF THE DRAWINGS

Otiier features and advantages of me invention will now be described by way of example wim reference to the accompanying drawings wherein; Fig 1 shows a schematic view of a cable joint to which the present invention is particularly useful;

Fig 2 shows a cross-section of a cable protector; and

Fig 3 shows a schematic view of me cable protector of Fig 1

A typical known clear cable joint 1 for joining together two cables 2, 3 is illustrated in Fig 1.

PREFERRED EMBODIMENTS OF THE INVENTION

The cables 2 and 3 have an outer cover 4 and an inner armour sheath to reveal individual insulated conducting cores 6. Both the outer cover 4 and sheatii 5 have been removed. The individual insulated conductors 6 are joined togetiier using cable connectors 7 and an earth connection E is made between the sheaths 5 of respective cables 2 and 3.

As seen in Fig 1 the earth connector E is clamped to the sheaths 5 using a jubilee clip 8 and it is to obviate damage to the conducting cores 6 when the clamp 8 is tightened mat a cable protector (not shown in Fig 1) is required, being interposed between me outer protective sheatii 5 and die inner insulated conducting cores 6 wim the earth connector E securely fastened to die sheatii 5 between d e clamp 8 and the cable protector.

A cable protector 9 according to one embodiment of the invention for use with e cable joint in Fig 1 is shown in Figs 2 and 3.

The cable protector 9 is formed of two collar half sections 10 and 11 joined along perimeter edges thereof witii an indented longitudinal groove 12 formed along me join between the sections 10, 11, forming a line or zone of weakness in the structure.

When used in die cable joint of Fig 1 the sheath 5 is drawn back over the outer cover 4 whereupon the still open cable protector 9 is placed around me inner insulated conducting cores 6. Pressure is then applied by die installer electrician, for example, to the two half collars 10 and 11, tiius causing them to pivot around die line of weakness occasioned by die groove 12, forcing the two halves 10, 11 together to form a split ring enclosing me inner insulated conducting cores 6.

The sheatii 5 is returned to its original position and die clamp 8 tightened d ereabout, thus securely clamping the earth connection E to the sheath 5 whilst simultaneously obviating any damage to die insulated cores 6 caused by me clamping, and effecting a solid earth connection between d e cables 2 and 3.

In a preferred embodiment, the half collar section 10 and 11 may be, but are not limited to being, semi-circular. Similarly, a preferred, although not limiting, material out of which to construct the device of Fig 2 is metal, such as extruded aluminium.

Although the invention has been described wim reference to its use in a cable joint it has wider application as a general mechanical device for use in other fields where split rings may be employed for whatever purpose.

Claims

1. A cable protector for use in forming a cable joint comprising two collar half sections interconnected in disposed apart relationship along a structural zone of weakness such mat upon the application of pressure the half sections may be brought together around a cable to be protected to form a split protective ring.

2. A cable protector as claimed in claim 1 wherein the half collar sections are semi-circular in cross section.

3. A cable protector as claimed in claims 1 or 2 wherein the half collar sections are constructed out of extruded aluminium.

4. A cable joint comprising portions of one or more insulated conducting cores, means for forming a joint between the portions of me conducting cores, a protective earthed sheatii arranged as to enclose die conducting cores either side of the joint, a split ring arranged between d e conducting core and d e protective sheath eitiier side of die joint as to enclose the conducting core, an earth connection between die protective earth sheatiis and clamping means tightened around each of die protective sheaths to allow secure clamping of the earthed connection to die earthed sheatiis against the split ring without damage to the conducting cores characterised in that me split ring is in the form of two collar half sections interconnected along a structural zone of weakness which has allowed d e collar sections to be disposed between die conducting core and die protective sheatii by die application of pressure to die half sections when in an initial disposed apart relationship.

5. A cable joint as claimed in claim 4 wherein the split ring is made out of extruded aluminium.

6. A method of forming a cable joint between cables consisting of portions of one or more insulated conducting cores enclosed by portions of a protective earthed sheatii comprising joining the portions of die conducting cores, drawing back die portions of die protective sheatii enclosing the conducting cores eitiier side of me joint, placing a split ring in the form of two collar half sections interconnected in disposed apart relationship along a structural zone of weakness around die conducting cores either side of die joint, applying pressure such that the half sections are brought togetiier to form split rings enclosing the conducting cores, returning the portions of die protective earthed sheath over the split rings, connecting together both portions of the protective earthed sheatii by an earth connection and tightening clamping means around portions of die protective sheatii engaging with the earth connection and corresponding wim the split rings as to allow secure clamping of the earth connection to a portion of me protective earthed sheatii against the split rings without damage to the conducting cores.

7. A method of forming a cable joint as claimed in claim 6 wherein the split rings are in the form of extruded aluminium.

8. A split ring cable protector for use in forming a cable joint, substantially as hereinbefore described witii reference to and as illustrated in the accompanying drawings.

9. A cable joint and method for forming same substantially as hereinbefore described with reference to and as illustrated in the accompanying drawmgs.