GB2046030A - Sleeve assembly for sealing a joint between two cable ends - Google Patents

Abstract

A sleeve assembly for sealing the joint between two cable ends comprises a sleeve 10 surrounding the joint and housings 11 detachably and sealingly 13 mounted one at each end of the sleeve. Each housing 11 has an annular portion 12 engageable on the sleeve and an end wall 14 closing the end of the sleeve and having an opening(s) 15, 16 for the passage of a cable(s) 40, 41 to be jointed. Two cap-shaped liners 20 each have an annular wall 24 engaged with the annular portion of the associated housing. An end wall 21 of each liner has a cable-receiving opening(s) 22, 23 aligned with the opening(s) 15, 16. A resin material such as epoxy resin or polyurethane resin is introduced through an aperture 28 in each liner to seal the cable onto the end housing. The sleeve 10 is then slid over the housings 11 to complete the seal. <IMAGE>

Description

SPECIFICATION A method and a joint closure for sealing a joint between two cable ends The present invention relates to a method and to a joint closure for sealing a joint between two cable ends.

When one wishes to seal two cable ends, for example two telephone cable ends, the insulation is stripped back and each individual conductor is bared. A suitable connector is then applied to the conductor of each cable which is to be joined to a conductor of the other cable and an electrical connection is thus effected.

Once this has been completed, for all the conductors of the cable, it is necessary to provide a seal around the whole assembly to prevent moisture from entering the joint, which clearly could give rise to unsatisfactory breakdown of the insulation which will be particularly troublesome in a telephone cable. Various proposals have been made but none of them has been entirely satisfactory from a point of view of economy and ease of assembly as well as effectiveness in the end product.

It is now proposed, according to the present invention, to provide a joint closure for sealing a joint between two cable ends, said closure comprising a sleeve, first and second end housings detachably and sealingly mounted one at each end of the sleeve, the end housing having an angular portion engageable on the sleeve and an end wall closing the end of the sleeve, and located axially outwardly of the annular portion, at least one cable receiving opening in the end wall of each end housing, two cap shaped liners, each having an annular wall engaged with the annular portion of one of said end housings and an end wall at the inner axial end to the liner, each liner end wall having a cable receiving opening or openings corresponding to the opening or openings of the associated end housing, each liner further being provided with an aperture for the introduction of resin to fill the liner and associated end housing.

Such a structure can be manufactured reasonably inexpensively and can be assembled easily by the man making the joint between the two cable ends. Having passed the sleeve over the exterior of one of the cable ends, he can then pass that cable through the opening or one of the openings of one of the end housings and its associated liner. Resin material, such as an epoxy resin or polyurethane resin can be introduced through the aperture into the liner completely to fill the space within the liner and associated housing and to form a bond with the outer insulator of the cable. If more than one cable is introduced at one end and is to be connected to one or more cables at the other end, then all of the cables are introduced through the openings in the housing and liner before the resin is injected.Thus a firm bond is formed between the housing, its liner and the cable or cables passing therethrough.

This operation is effected at each end and one can then carry out the electrical connections.

The sleeve can then be slid back to cover both end portions and the electrical connections between the conductors of each cable.

Preferably a sealing ring is provided between each housing and the sleeve, this may, for example, be an O-ring positioned in a recess in the annular wall of the associated end housing. The sleeve can be locked on to the end wall by means of a clamp for example a screw clamp.

Tie rods are advantageously provided between the end housings, these may be located in recesses in the liners and locked in place by the resin. These tie rods then take up the axial loading between the two cables.

Sometimes it is desired to add a cable at a later stage. For example one can consider a situation in which one cable is to be connected initially to another cable with some of the conductors of the one cable left un-connected, and another cable is then introduced at a later date and is connected to the free unused conductors of the one cable.

If this is the case, then a tube may be provided within the liner and may pass from one of the openings of the liner to a corrresponding opening of the associated end housing. This tube is preferably closed at each end. When the resin material is introduced, it will surround this tube but will leave its interior free. Preferably the inner end of the tube extends axially inwardly of the end wall of the liner and this is advantageously tapered, so that it can be cut off, when the extra cable is to be introduced, at an appropriate axial position of the cone to give the desired diameter for that of a new cable. Further resin material may then be introduced firmly to seal the cable to the tube.

Gromits may be provided on the or each opening and these gromits will become filled with the resin material.

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 drawings, in which: Fig. 1 is an axial section through one end of one embodiment or joint closure according to the present invention shown with two cable ends inserted therein; Fig. 2 is an end elevation of the other end of the joint closure of Fig. 1; and Fig. 3 is a section taken along the line ZZ of Fig.

2.

Referring first to Figure 1 of the drawings there is shown therein one embodiment of joint closure according to the invention, this comprising a sleeve 10 of plastics material, for example PVC.

This has located therein an end cap 11 which has an annular portion 12 which can be engaged within the sleeve 10 this portion 12 having an 0 ring 13 located in a recess on its outer surface to engage the ;nner surface of the sleeve 1 0. Again the end housing will be formed of PVC.

An end wall 14 of the housing is provided with two openings 1 5 and 1 6 each provided with a gromit 1 7 and 1 8 respectively.

A polycarbonate liner 20 has an end wall 21 provided with apertures 22 and 23 corresponding to the apertures 1 5 and 16 and it also has an axially extending wall 24 the outer diameter of which corresponds to the inner diameter of a recessed portion 25 of the annular portion 12 of the end cap 11.

The end cap 11 a illustrated in Figures 2 and 3 is substantially similar in construction except that its end wall 1 4a only has a single aperture 1 5a with a corresponding gromit 17a. As can be seen more clearly from this figure, the liner 20a has two recesses 30 and 31. Similar recesses are provided in the liner 20 but these cannot be seen in Figure 1.

Located in these recesses are end portions 32 and 33 of tie bars 34 and 35. The end portions have radially inwardly turned parts 36 and 37 respectively. These end parts may be provided with apertures as indicated in phantom in Figure 3.

Ciamping bolts 38 are provided between the tie rods 34, 35 and their end portions 32, 33 and these may provide adjustment of the length of the tie bar or may be inserted in selected ones of holes in this tie bar.

An aperture 28 is formed in each liner at a location axially inwardly of the associated housing annular wall 12.

Figures 1 to 3 show the connection of two cables 40 and 41 to a further cable 42. First of all one passes the sleeve 10 over the cable or cables at one end. For example one passes the sleeve 10 over the two cables 40 and 41. The cable 40 is then passed through the gromit 17, and thus through the opening 1 5 and then through the opening 22 in the liner. Similarly the cable 41 is passed through the gromit 18 the opening 1 6 and the opening 23.

The other cable 42 is passed through its gromit 1 7a and the opening 1 5a as well as through an opening 22a in the liner. By loosening the bolts 38, the tie rods 34 and 35 are removed. The cables are stripped and their conductors connected in the perfectly conventional manner.

These are then preferably wrapped with a suitable insulating tape.

A soft sealing material such as putty is then introduced around the conductors as at 43 and a resin material 50 such as an expoxy resin or polyurethane resin is introduced through the aperture 28 and is allowed to cure. The resin material extends in to the gromits and firmly bonds the outer surface of the insulating material of the cables to the housings and to the liners in a fluid tight and firm manner. Once the resin is cured, it is possible then to connect up the tie rods 34, 35 to their respective end portions to take up any axial strain between the cables.

The sleeve 10 is then passed back so that it engages over both of the O-rings 13, 1 3a and the assembly is then clamped up by suitable clamps 51, 52 so that the sleeve is fully engaged against the end housings and against the O-rings 13, 1 3a.

It will be appreciated that this structure is completely water tight and a very firm bond is provided between the two cables from a mechanical point of view also.

Should one wish to introduce a subsequent cable at a later date, it is possible for an extra opening to be provided in the housing and for a corresponding opening to be provided in the liner and for a tube to extend between these two openings. This tube will be closed at each end and a blind gromit will be provided at the outer end.

Advantageously the inner end of the tube extends inwardly of the liner end wall and is tapered preferably in a conical manner so that it is closed in this way. When the new cable is to be introduced, having removed the sleeve, an appropriate amount of the cone is cut off to suit the diameter of the new cable to be introduced.

This cable is then introduced and is connected up as before. Resin is then injected between the tube and the outer surface of the cable to effect the seal therebetween.

Claims (14)

1. A joint closure for sealing a joint between two cable ends, said closure comprising a sleeve, first and second end housings detachably and sealaby mounted one at each end of the sleeve, the end housing having an annular portion engageable on the sleeve and an end wall closing the end of the sleeve and located axially outwardly of the annular portion, at least one cable receiving opening in the end wall of each end housing, two cap-shaped liners each having an annular wall engaged with the annular portion of one of said housings, and an end wall at the inner axial end of the liner, each liner end wall having a cablereceiving opening or openings corresponding to the opening or openings of the associated end housing, each liner further being provided with an aperture for the introduction of resin to fill the liner and associated housing.

2. A closure according to claim 1, wherein a sealing ring is provided between each end housing and the sleeve.

3. A closure according to claim 1 or 2, wherein a radially compressible clamp is provided to clamp the sleeve onto each end housing.

4. A closure according to claim 1,2 or 3, wherein the annular wall of the liner is dimensioned to be inserted within the annular portion of the associated end cap.

5. A closure according to any preceding claim, wherein at least one axially adjustable tie rod is provided to extend between the two liners.

6. A closure according to claim 5, wherein the tie rod or rods are provided with radially bent portions, each engaged within a recess in each liner and embedded in the resin.

7. A closure according to any preceding claim, wherein the openings in the end wall of each housing are each provided with a gromit.

8. A closure according to any preceding claim, wherein at least one of the end housings and associated liner are each formed with at least two cable-receiving openings, and at least one of the openings in each of the end cap and liner are interconnected by a tube enabling a cable subsequently to be passed through the tube.

9. A closure according to claim 8, wherein the tube is closed at each axial end.

10. A closure according to claim 9, wherein the closure is closed at the inner axial end, adjacent the opening in the liner, by a tapered portion.

11. A closure according to any preceding claim, wherein the liner is formed of polycarbonate plastics material.

12. A joint closure for sealing a joint between two cable ends substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

13. A method of jointing two cable ends, comprising removing the sleeve from a joint closure according to any one of the preceding claims, passing one of the cables through the sleeve and then through an opening in one end housing and the associated liner, passing the other cable end through an opening in the other end cap and its associated liner, effecting the joint between the conductors of the cable, passing a resin material through the aperture in the liner to fill the liner and housing and to bond onto the exterior of the cable and then moving the sleeve axially so that it sealingly covers both of the end housings.

14. A method of jointing two cable ends, according to claim 1 3 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.