GB2100940A - Arrangement for sealing cables - Google Patents

Abstract

An arrangement for sealing cables has a main member or wall which is of uniform thickness, with a number of openings into which can be inserted a respective cable inlet (1) which has two abutment collars (3, 4) at its insertion end (2) to lie against opposite faces of the main member. The region between the abutment collars and the other end region (6) of each cable inlet are heat-shrinkable. Each opening has recesses in its edge with which projections (5) of the collar (3) cooperate to provide a bayonet-type connection. Then the cable inlet is fixed to the main member by healing the cable inlet. An adhesive (7) is applied externally between the collars and internally at region (6). The invention is applicable for example, to pot sleeves, sleeves with cable inlets at both ends, and so-called distributing sleeve covers. <IMAGE>

Description

SPECIFICATION Arrangement for sealing cables The invention relates to an arrangement for seal ing cables with respect to a main member through which the cables pass and which may be arranged at the mouth end of a cable sleeve, for example.

In the arrangements which are referred to as cup or pot sleeves, sealing in the cable inlet region bet ween the main member and each cable is effected by means of casting resin, which is expensive and complicated on site and also liable to give trouble, while also requiring prolonged setting periods (see the Egertonx prospectus 'Ready Access Jointing Sleeves').

In the arrangements which are referred to as distributing sleeve covers, a cover of that kind is provided with a plurality of connecting members or stubs which are formed thereon and through each of which a respective cable can be introduced, wherein the sealing effect is produced by a tube portion of heat-shrinkable material, which has been previously pushed on to the end of the respective cable. The tube portion is pushed on to the associated connecting member and then subjected to the effect of heat to cause it to shrink on to the connecting member and the cable casing. This construction requires distributing sleeve covers which are of a complicated configuration and in particular requires all connecting members which are not being utilised to be closed off (see the Rose Prospectus 'Distributing Sleeve Covers').

It is also known, both in the case of cable sleeves out of which cables are taken at both ends and also in the case of cup or pot sleeves, to use sleeve heads comprising moulded portions, with a plurality of cable inlets, wherein sealing is effected either by shrinking the cable inlets on to the cable casings or by a welding operation.

When all the cable inlets are not fully utilised, that method is also relatively expensive and gives rise to difficulties in regard to sealing cable inlets which are not being used (see DAS No. 2655548 and Siemens Prospectus Cup sleeve type 80 T).

The problem of the present invention is to provide an arrangement which, while generally being very simple in design and fitting, is versatile in use, that is to say, can be used both for cup or pot sleeves and also for sleeves with cable inlets at both ends, and also for so-called distributing sleeve covers, and the like.

According to the present invention, this problem is solved by an arrangement for sealing cables with respect to a main member through which the cables pass in which the member is of equal thickness substantially throughout and is provided with a number of openings into each of which a respective cable inlet can be fitted, each cable inlet having at its insertion end two abutment collars, the spacing of which in the inserted condition approximately corresponds to the thickness of the main member which lies b('t- ween them, the region between the abutment collars being heat-shrinkable substantially in the axial direction and the other end region remote from the inser tion end of each cable inlet being heat-shrinkable substantially in a radial direction, and each opening having recesses in its edge and each cable inlet hav ing one of its end abutment collars formed to provide projections such that each cable inlet can be inserted into its associated opening in the manner of a bayonet-type connection and can be firmly braced to the main member by subsequent heating in an abutment collar region.

First of all, that construction provides that the seal ing components required are of a very simple configuration, while also giving an uncomplicated and extremely secure assembly, while a consideration of particular advantage is that in each case it is only necessary to provide the number of cable inlets which is actually required in each situation.

An improvement in the sealing effect can also be achieved in that each cable inlet is provided with an adhesive layer between the two abutment collars and on the sides of the abutment collars which are towards the main member, and in the interior of its other end region.

In order to simplify sealing ofthe openings which, although provided in a main member, are not required in a situation of use, it is desirable for the arrangement to be such that each opening in the main body has a predetermined-rupture pressure or desired-rupture pressure closure means, which remains closed when the opening in question is not required. Obviously, openings which are not required could also be closed off by closure plugs which are to be fitted subsequently, instead of using the above-mentioned closure means. As will be described in greater detail hereinafter, the invention permits in particular versatile use for dealing with widely varying problems in regard to cable inlets.

The invention is described in greater detail with reference to examples thereof shown in the accompanying drawings, in which: Figure 1 shows a side view of a cable inlet; Figure 2 shows an end view of the cable inlet shown in Figure 1; Figure 3 shows a plan view of a main or basic member for receiving cable inlets; Figure 4 shows a sectional elevation taken along line Ill-Ill in Figure 3; Figure 5 shows a partly sectional side view of a pot or cup sleeve with an assembly comprising a basic member carrying cable inlets; Figure 6 shows a partly sectional side view of an end of a cable sleeve having end assemblies comprising basic members carrying cable inlets; and Figure 7 shows a side view of part of a simple distributing sleeve cover carrying cable inlets.

A cable inlet as illustrated in Figures 1 and 2, which is generally indicated by reference numeral 1, comprises a conventional heat shrinkable plastics material and, at its insertion end, has an end abutment collar 3 having four projections 5 and, at a spacing therefrom, a further abutment collar4 of larger diameter. The region between the abutments collars 3 and 4, and the other end region 6 of the cable inlet 1, are heat-shrinkable, that is to say, those regions are pre-stressed in such a way that when heat is subsequently applied, the region between the abut ment collars shrinks substantially in the axial direc tion, that is to say, experiences a reduction in length, while the other end region shrinks substantially in a radial direction, that is to say, the diameter thereof is reduced.

Each cable inlet is provided with an adhesive coat ing or layer 7 between the two abutment collars 3 and 4 and on the facing sides thereof, and also in the interior of the other end region 6.

A main or basic member 8 as shown in Figures 3 and 4 is in the form of a circular disc which is of equal thickness substantially throughout, and may also comprise plastics material or another material of such high strength and thermal resistance that it can withstand the shrinkage forces and temperatures which are applied by the abutment collars 3 and 4 ofthe above-described cable inlet 1 when it is shrunk on to the main member 8.

As shown in Figure 3, the main member 8 has a number of substantially circular openings 9, each of which has four recesses 10 in the edge portion thereof, such that the configuration of the openings corresponds to the outside contour of the end abutment collar 3 so that, with the four projections 5 and recesses 10 as illustrated, a respective cable inlet 1 is held in position in the manner of a bayonet-type connection, by being inserted into its associated opening 9 and subsequently rotated through for example 45", while when heat is subsequently applied to the respective end 2 of the cable inlet, the cable inlet is firmly braced to the main or basic member 8. The adhesive 7 provides a gas-tight and liquid-tight connection between the cable inlet and the main member 8, in particular in the region of the abutment collar 4.

A cable which is inserted into the cable inlet can then also be shrink-connected in a gas-tight and fluid-tight manner to the respective cable inlet, by shrinking the other end region 6 thereof to the cable casing, the layer 7 of adhesive also contributing to a sealed connection in this case. As shown in Figure 4, a closure means 11 which ruptures at a predetermined pressure differential may be provided in each opening 9, the closure means 11 remaining closed when the respective opening is not required for the insertion of a cable end, while if that is not the case, the respective closure means is simply removed.

In the embodiment of a cup or pot sleeve as shown in Figure 5, a cylindrical main member 8 ofthe above-described kind, with cables 12 passing thereinto, is sealed by means of cable inlets 1 in the above-described manner, and the splice (not shown) in the interior of the cable is gas-tightly and liquidtightly sealed to the main member 8 by a cup 13 in known manner by means of a clamping ring 14, with an interposed sealing ring 15.

In the embodiment shown in Figure 6, a substantially circular main or basic member 8a is provided at each end of a cable sleeve to provide for cable inlets at both ends of the sleeve. For the purposes of enhancing the gas sealing effect, the illustrated cable inlet 1 is shrink fitted to a cable 12 with its other end region 6 in the interior of the cable sleeve. In this arrangement, each main member 8a is also provided at its end with an annular groove 16, and edge por tions 17, which are flanged over at a right angle of two conventional semicylindrical support casing members 18 of aluminium or other suitable material are fitted into the annular groove 16. A shrink tube member 19 is then shrunk in conventional manner over the members 18 and the main members 8a at both ends.

In the embodiment shown in Figure 7, a main or basic member 8b which is basically of a configuration in accordance with the invention is in the form of a distributing sleeve cover, as referred to above, and is provided with a corresponding numberof openings of the above-described kind, into which respective cable inlets 1 of the above-described kind can then be inserted, from one side or the other, for sealing off cables 12 which correspondinglytermi- nate threat It wiz1 be appreciated that the above-described embodiments may be modified in many ways without thereby departing from the basic concept of the invention. Thus for example more or less than four projections and recesses may be provided at the end abutment collars of the cable inlets and the openings in the main members. In addition, recesses in the form of annular shoulders may be formed in the main members, in the regions thereof adjacent the abutment collars, so that, after the end abutment collar has been inserted into and turned in the associated opening, the surfaces of the end abutment collar and the main member are aligned with each other, and so on.

Claims (6)

1. An arrangement for sealing cables with respect to a main memberthrough which the cables pass in which the member is of equal thickness substantially throughout and is provided with a number of openings into each of which a respective cable inlet can be fitted, each cable inlet having at its insertion end two abutment collars, the spacing of which in the inserted condition approximately corresponds to the thickness of the main member which lies between them, the region between the abutment collars being heat-shrinkable substantially in the axial direction and the other end region remote from the insertion end of each cable inlet being heat-shrinkable substantially in a radial direction, and each opening having recesses in its edge and each cable inlet having one of its end abutment collars formed to provide projections such that each cable inlet can be inserted into its associated opening in the manner of a bayonet-type connection and can be firmly braced to the main member by subsequent heating in an abutment collar region.

2. An arrangement according to claim 1, in which each cable inlet is provided with an adhesive layer between the two abutment collars and on the sides of the abutment collars which face the main member, and in the interior of the said other end region.

3. An arrangement according to claim 1 or claim 2, in which each opening in the main member has a closure means which ruptures at a predetermined pressure differential and which is removed when a cable inlet is to be inserted into the opening.

4. An arrangement for sealing cables to a main member substantially as hereinbefore described with reference to Figures 1 to 4 and 7 of the accompanying drawings.

5. An arrangement for sealing cables to a main member substantially as hereinbefore described with reference to Figure 5 of the accompanying drawings.

6. An arrangement for sealing cables to a main member substantially as hereinbefore described with reference to Figure 6 of the accompanying drawings.