GB2126801A - Jacket for wrapping around a pipe, cable, or the like - Google Patents

Abstract

A jacket for wrapping around a pipe, cable or the like including a sheet of flexible material 100 which is heat-shrinkable in the direction between first and second edges 101, 102, a first metal clip element 103, being secured on the first edge and a second metal clip element 104 being secured on the second edge, the first and second metal clip elements being inter-engageably contactable with one another to hold the edges in proximity. The first clip element 103 includes a hook formation 108, the second clip element includes a bar 116 having at least a portion 118 extending parallel to the second edge, and this portion can be inserted into inter-engagement with the hook formation 108. A detent 111 is provided to retain the portion 118 in the hook formation. <IMAGE>

Description

SPECIFICATION A jacket for wrapping around a pipe, cable or the like The present invention relates to a jacket for wrapping around a pipe, cable or the like, for example, to seal against the elements a joint within the jacket.

British Patent No 1 155 470 suggests a heat recoverable closure member which includes heatshrinkable material having ridges or protruberances adjacent two opposite edges. The material is arranged with the adjacent edges in abutting relationship, and a fastening clip is slid over the ridges to maintain the edges in this abutting relationship. Heat is then applied and the heat shrinkable material shrinks so that it clamps tightly around the cable, pipe or the like. Material of this type has the advantage that it can be wrapped around existing cables or pipes and does not have to be fed in from one end. This is of great practical importance when one is wishing to seal a joint between conductors in a cable, for example a telephone cable.

This arrangement, however, has the disadvantage that it is necessary to apply the fastening clip from one end of the ridge and this can be difficult in certain circumstances and when the clip has been so applied it can give rise to damage to the sheathing or coating of the adjacent cables and/or pipes.

European Patent Specification No 23 41 8 discloses an improved jacket of this type which is provided on each edge with a metal clip. In one particular construction the clip elements are formed with a body portion attached to the sheet material and hook members which extend in the opposite sense to one another and are inclined towards the body member to hook into one another. A strip of material on one of the clip elements, or on the flexible sheet material, extends under the free edge of one of the hook members to maintain the other hook member in engagement. In another construction the first clip element is provided with spaced apart bridges which are engaged with co-operating spaced apart hooks on the second clip member.Such a structure does have some advantages but it can be difficult to inter-engage a hook element with its complementary hook element or with a bridge particularly if the heat-shrinkable sheet material is rather rigid.

It is now proposed, according to the present invention, to provide a jacket for wrapping around a pipe, cable or the like, comprising a flexible sheet of material which is heat-shrinkable in the direction between first and second opposite edges; a first metal clip element secured on said first edge and the second metal clip element secured on said second edge, the first and second metal clip elements being inter-engageably contactable with one another, to hold said first and second edges in proximity; wherein said first clip element includes a hook formation and wherein said second clip element includes a bar having at least a portion extending parallel to said second edge, which portion can be inserted into interengagement with said hook formation, and means to retain said at least one portion in said hook formation.

With such a construction the two metal clip elements can readily be inter-engaged regardless of the rigidity of the sheet material. Furthermore, the inter-engagement can easily be effected even in a confined space.

The retaining means preferably comprise a detent on said hook formation, the hook formation flexing during insertion of the bar, to allow the bar to pass the detent, the hook formation springing back to enable the detent to retain the bar.

In a preferred construction according to the present invention the first and second clip elements are formed from sheet metal stock, the hook formation being punched out of the stock of the first clip element and the means to hold the bar being punched out of the stock of the second clip element. These means to hold the bar preferably are such that the bar is securely held in the second clip element, but can divot relative to the hook formation of the first clip element. This can be achieved by having the bar formed of a circular cross-section wire.

~Advantageously the bar is bent to form a series of aligned first portions engageable in the hook formations of the first clip element and a series of aligned second portions parallel to and off-set from the first portions, the second portions being secured to the second clip element.

The ability of such a bar structure to pivot relative to the hook formation of the first clip element allows the jacket of the present invention to be easily inserted and it is particularly suitable when used with very small cables, as the design allows the two clip elements to hinge relative to one another through an angle which may, for example, be as much as 900 more.

Each clip element may comprise elongate strips each clamped onto a thickened portion of the flexible sheet material, the two thickened portions extending along the associated edge of the flexible sheet material. The thickened portions may project from one surface of the sheet material only, which surface is intended to form the outer surface of the sheet when it is wrapped around a pipe, cable or the like. Preferably the elongate strip of each clip element is segmented by lines of weakness extending transverse to the associated edge, to enable the strip material to bend more readily to conform to the shape of the joint or the like being wrapped by the jacket.

In order that the present invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawing in which: Figure 1 is a perspective view of one embodiment of jacket according to the invention shown partly in cross-section; Figure 2 is an enlarged cross-section through the edge portions of the jacket showing the interengagement of the first and second clip elements; and Figure 3 is a perspective view of a portion of the bar used in the second clip element.

Referring first to Figure 1 there is illustrated a sheet 100 of heat shrinkable material, such as cross-linked polyolefin, having first and second edges 101,102 which are thickened. The heatshrinkable material is arranged so that, when heated, it will shrink so that the distance, along the sheet material, between the edges 101 and 102 will reduce.

Two elongate strip metal material clip elements 103 and 104 are shown secured to the edges 101 and 102 respectively. The strip material 103 has a body portion 105 provided with a series of parallel slots 106 punched out of the body portion and extending transverse to the edge 101. The body portion is folded over the thickened edge part adjacent the edge 101. The body portion 105 has extending beyond the edge 101 a hook member 108 punched out of the body portion and which can be seen more clearly in Figure 2. The hook member is punched out so that it is connected only at the bottom 109 to the body portion and it has an inclined tongue portion 110 at its free end.

Between the tip of the tongue 110 and the point 109 there is a leftwardly directed (as seen in Figure 3) detent 111.

The clip element 104 is generally similar to the clip element 103 in that it includes a body portion 112 and parallel slots 113 extending transverse to the edge 102. Instead of having a centrally punched out tongue 108, each of the individual clip portions formed between the slots 113 is provided with a pair of clamp members 115, which, as before, are punched out of the stock of the strip material. These clamp members 115 hold a portion 11 6 of a bar indicated by the general reference numeral 117 in Figure 3.The portions 116 are aligned with one another and parallel to further portions 11 8 which are aligned with one another and generally longer than the portions 11 6. In fact, the dimensions of the off-set between the two parallel sets of portions 11 6 and 11 8, and the length of the portions 11 8, are such as to enable the latter portions to be engaged over the tongues 110 of the hook members 108, and they can be pushed down over the detent projections 1 the tongue flexing to the right, as seen in Figure 3 while this happens, and then springing back to retain the portions 11 8 of the bar 11 7 within the hook.

The clamping portions 115 are clamped sufficiently tightly onto the bar portions 11 6 to prevent any relative rotation therebetween.

However, relative rotation can take place between the portions 11 8 of the clip member 104 and the clip member 103, so that the two clip members 104 and 103 can pivot relative to one another by 900 or more.

In use, the sheet material 100 is wrapped around the cable, pipe, joint etc and the two clip elements are inter-engaged simply by pushing the clip member 104 downwardly relative to the clip member 103, so that the bar portion 118 engages over the tongue 110 of the hook member 108 in the manner described above. The detent 111 will prevent the bar from slipping out again. A fly tongue 120 is provided on the sheet material 10 to extend from a location spaced from the edge 101 to a position beyond the two clip elements when they are inter-engaged to seal the pipe wrapping. Thereafter, the material as a whole is heated and the heat-shrinkable sheet 100 shrinks and tightly clasps around the pipe, cable, joint etc.

Hot melt or other adhesives lining may be provided on the inner surface 26 and mastic or other fillers may be introduced.

While the clips can be made of any suitable metal, a material such as plated copper alloy or advantageously stainless steel is preferred.

The tongue is preferably provided with a rigidifying rib which can be seen in Figure 2 of the drawings. The construction of the two clip elements is such that the bulk of their formation can be carried out on the same tool. When the second clip element has been punched out it can then be passed to a further station and the bar 117 locked in place by folding over the clamping portions 115 in a press tool.

It will be appreciated that the construction of the present invention is very easy to use and has great flexibility yet provides a very strong bond between the ends of the heat-shrinkable material.

Claims (10)

1. A jacket for wrapping around a pipe, cable, or the like, comprising a flexible sheet of material which is heat-shrinkable in the direction between first and second opposite edges; a first metal clip element secured on said first edge and a second metal clip element secured on said second edge, the first and second metal clip elements being inter-engageably contactable with one another, to hold said first and second edges in proximity; wherein said first clip element includes a hook formation and wherein said second clip element includes a bar having at least a portion extending parallel to said second edge, which portion can be inserted into inter-engagement with said hook formation, and means to retain said at least one portion in said hook formation.

2. A jacket according to claim 1, wherein said retaining means comprise a detent on said hook formation, the hook formation flexing during insertion of the bar, to allow the bar to pass the detent, the hook formation springing back to enable the detent to retain the bar.

3. A jacket according to claim 1 or 2, wherein the first and second clip elements are formed from sheet metal stock, the hook formation being punched out of the stock of the first clip element and the means to hold the bar being punched out of the stock of the second clip element.

4. A jacket according to claim 3, wherein the means to hold the bar are such that the bar is securely held in the second clip element, but can pivot relative to the hook formation of the first clip element.

5. A jacket according to claim 4, wherein the bar is formed of a circular cross-section wire

6. A jacket according to any preceding claim wherein the bar is bent to form a series of aligned first portions engageable in the hook formations of the first clip element and a series of aligned second portions parallel to and off-set from the first portion, the second portions being secured to the second clip element.

7. A jacket according to any preceding claim, wherein each clip element comprises elongate strips each clamped into a thickened portion of the flexible sheet material, the two thickened portions extending along the associated edge of the flexible sheet material.

8. A jacket according to claim 7, wherein the thickened portions project from one surface of the sheet material only, which surface is intended to form the outer surface of the sheet when it is wrapped around a pipe, cable or the like.

9. A jacket according to claim 8, wherein the elongate strip of each clip element is segmented by lines of weakness extending transverse to the associated edge, to enable the strip material to bend more readily to conform to the shape of the joint or the like, being wrapped by the jacket.

10. A jacket for wrapping around a pipe, cable or the like, said jacket being substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.