GB2178909A - Cable barrier gland - Google Patents

Abstract

A barrier gland assembly includes a non-compressed sealing compound 27 between and/or surrounding the conductor cores 26 of the cable 21 at least in the region of a wall 10. The assembly comprises a tubular entry component 11 having its inner end threadedly secured in an aperture in the wall 10, and a sleeve 12 formed with a cylindrical portion 12B which is insertable into the entry component from its end remote from the enclosure, and which receives the sealing compound. The sleeve is formed with an outwardly extending flange 12A remote from the enclosure, and the sealing compound does not extending appreciably, if at all, beyond said flange. A sealing nut arrangement 13, 15, 17, 19 clamps the cable armour 22 and locates the flange 12A against movement away from the entry component 11. Other gland assemblies include a seal between a nut arrangement and the flange 12A. <IMAGE>

Description

SPECIFICATION Barrier Glands This invention relates to barrier gland assemblies which are arranged to secure cables in enclosure walls.

The present applicant's British Patent No. 2074395 discloses a barrier gland assembly in which a bared conductor core of a cable is sealed and located within a barrier gland assembly by means of a sealing compound. The sealing compound is received within a sleeve member of generally top-hat form i.e. it has a cylindrical section which extends axially within an entry component of the remainder of the barrier gland assembly and is spaced from the cable. On the end of the sleeve which would normally be located within the enclosure there is a short radial flange which abuts the end of the entry component which has passed through and is threadedly secured in the enclosure wall.In this prior arrangement there is an elastomeric seal located within the bore of the entry component and this is compressed on assembly onto the external surface of the cylindrical section of the top-hat sleeve by means ofthreaded engagement between an outer threaded spigot of the entry component and a compression nut having, at its other end, an external tapered seat for armouring of the cable which is clamped to it by an armour clamp nut. The method of assembly of this construction, priorto insertion in the enclosure wall, involves full assembly and clamping up of all the parts prior to the insertion of the sealing compound in the top-hat sleeve.After the sealing compound has been inserted, set and cured, the components of the barrier gland are then partially disassembled in that the armour clamp nut is released from the compression nut to release the armouring, and the compression nut and the entry component are slightly separated to relieve the compression of the elastomeric seal on the top-hat sleeve. Thereafter the entry component and the compression nut can be rotated as a unit in order threadedly to engage the entry component into the enclosure wall, whereafter the compression nut is again tightened onto the entry component to recompress the elastomeric seal onto the top-hat sleeve. Finally, the armour clamp nut can be re-engaged onto the compression nut to complete the assembly.Whilst this arrangement provides that the top-hat sleeve has axial location against outward movement from the enclosure and entry component by virtue of the engagement of its flange with the internal and face of the entry component, there is no location of the sleeve in the reverse direction, i.e. towards the enclosure, and it has been found in certain circumstances that the top-hat sleeve can move slightly with respect to the capable, for example by 2 to 3 mm, as a result of which the integrity of the sealing compound at its inner end with respect to the crotch of the cable cores and the remainder of the cable sheathing is impaired. Naturally, the incorrect sealing of the sealing compound cannot be detected by the fitter, since any such incorrect location of the sealing compound is completely hidden.

Another, independent, problem with certain barrier gland assemblies is that, where the armouring is of braid, rather than individual wires or rods, an axially short compression ring is employed between the compression nut and the braid. In some circumstances it has been found that this ring, which is relatively rigid, can be distorted or even break. This can cause difficulties in the strength and earthing continuity of the coupling of the cable of the assembly.

It is accordingly one of the objects of the present invention to alleviate or overcome the disadvantages outlined above.

According to one aspect of the present invention a barrier gland assembly which is arranged to secure a cable in an enclosure wall with a non-compressed sealing compound between and/or surrounding the conductor cores of the cable at least in the region of the wall, comprises a tubular entry component having one end, hereinafter referred to as the inner end, which is arranged to be threadedly secured in an aperture in the enclosure wall, the entry component having located at least partially within it a sleeve which has a cylindrical portion which is insertable into the entry component from its end remote from the enclosure, and which is arranged to receive said non-compressed sealing compound to seal cable cores extending through the sleeve, the sleeve having an integ rally formed outwardly extending flange on its end remote from the enclosure, and the sealing compound substantially filling said cylindrical portion, but not extending appreciabiy, if at all beyond said flange, and engaging a sheathed part of said cable which terminates in the region of said flange, and said flange being located against movement away from said enclosure by engagement directly or indirectly with either other parts of said gland assembly, or said cable. Preferably said flange is located on a side thereof facing the enclosure by a shoulder formed on the entry component, and the armouring of the cable. The flange may also be located against a resilient seal engaging and axially immovable with respect to the cable, when fully assembled.

Another aspect of the present invention comprises an assembled combination of a cable and a barrier gland assembly located within an aperture in an enclosure wall through which the cable extends, the barrier gland assembly comprising a tubular entry component having one end, hereinafter referred to as the inner end, which is threadedly secured in the aperture in the enclosure wall, the entry component having at least partially within it a sleeve which has a cylindrical portion which is only insertable into the entry component from its end remote from the enclosure, and which has within it, around bared cable cores extending through it, a non-compressed sealing compound to seal the cable cores within the sleeve, with the compound adhering to the bore of the sleeve, the sleeve having an integrally formed outwardly extending flange on its end remote from the enclosure, a portion of that part of the cable sheathing which surrounds the cable cores but which has not been bared therefrom being positioned close to or slightly within that end of the sleeve which has the outwardly extending flange, with the non-compressed sealing compound located against said end and being at least partially prevented from being extruded from that end of the sleeve by said portion of the cable sheathing acting as a plug to that end of the sleeve, the flange being located against movement away from the enclosure by engagement directly or indirectly with either other parts of the gland assembly or the cable.

According to yet another aspect of the present invention a barrier gland assembly which is arranged to secure a cable in an enclosure wall with a non-compressed sealing compound between and/ or surrounding the conductor cores of the cable at least in the region of the wall comprises a tubular entry component having one end, hereinafter referred to as the inner end, which is arranged to be threadedly secured in an aperture in the enclosure wall, the entry component having an intermediate portion a bore of which provides an outwardly tapered seatfacing awayfrom said inner end, the entry component having an outer end on the side of the intermediate portion remote from said inner end, and which outer end is threaded to engage a threaded first end of a tubular compression nut which has on the external surface of its other, second, end, an inwardly directed tapered armour seat for receiving armouring of the cable, a tubular armour clamp nut being engageable with part of the compression nut and having an outwardly inclined face at the end of its bore adjacent the compression nut for clamping the cable armour on to the armour seat, the entry component having located within it, in the region of its inner end and its intermediate portion, a sleeve which has a cylindrical portion aligned with said inner end of the entry component, said cylindrical portion being arranged to receive said sealing compound which adheres to the bore of the sleeve and which seals cable cores extending therethrough without mechanical compression of the sealing compound, and an integral outwardly flared flange of the sleeve being aligned with the outwardly tapered seat of the entry component, a resilient seal being provided which has one face in abutment with the outwardly flared flange of the sleeve on its side remote from the outwardly tapered seat of the entry component, the arrangement being such that, when the compression nut and entry component are engaged, and drawn together, the resilient seal is compressed between the flange of the sleeve and the compression nut, or an intermediate part or parts engaged by the compression nut, and forced into sealing engagement with a portion of the cable within the gland.Preferably there is provided, between the elastomeric seal and the compression nut an earthing washer, which forms the or one of the intermediate parts, and arranged, on assembly, to engage a metallic sheath of the cable and electrically to interconnect it with the compression nut. The earthing washer may have a radial portion extending between the elastomeric seal and the compression nut, and integral petals arranged to extend axially from a bore of the radial portion to overlie the metallic sheath of the cable.

In the above arrangements, the arrangement may be such that, when fully located on a cable, and thereafter release is obtained of the threaded connections between the compression nut and both the entry component and the armour clamp nut, the compression nut is axially located between the elastomeric seal (or said intermediate part(s)) at one end, and the cable armour at the other end, but can rotate with respect to the cable to enable it to be reconnected to the entry component without rotation or either the entry component or the cable.

According to yet another aspect of the present invention a method of locating a cable having a portion thereof extending through an enclosure wall, the cable being of a type having conductor cores surrounded by one or more sheaths, comprises baring a portion of the conductor cores in a region where they will be located in line with the enclosure wall, assembling onto that part of the cable to be located in line with the enclosure wall and immediately exterior thereof a barrier gland assembly which includes an entry component arranged to be threadedly secured to the enclosure wall, and a sleeve having a cylindrical portion thereof located within that part of the entry component to be located in line with the enclosure wali, and, before the entry component is located in the wall, securing to the entry component another component of the barrier gland assembly which is arranged axially to locate and secure the cable with respect to the assembly, inserting into the cylindrical portion ofthe sleeve a sealing compound from the end of the sleeve intended to be located within the enclosure, the sealing compound being manually forced, without mechanical compression, into the sleeve and up to the end of the sheath around the bared conductors, the sleeve having an outwardly directed flange at its end intended to be remote from the enclosure and which, during said insertion of the sealing compound is axially located with respect to both the cable and the gland assembly, allowing the sealing compound to set, separating the entry component from said other component of the gland assembly, whilst leaving the sleeve firmly located on the cable at least partially by means of the sealing compound, securing the entry component in said enclosure wall, inserting said cable, with the sleeve and its compound therein, through the entry component, and resecuring said other component of the gland assembly to the entry component.

Another aspect of the present invention provides a barrier gland assembly which is arranged to secure a cable and in an enclosure wall with a non-compressed sealing compound between and/or surrounding the conductor cores of the cable at least in the region of the wall, in which the assembly comprises a tubular entry component having one end, hereinafter referred to as the inner end, which is arranged to be threadedly secured in an aperture in the enclosure wall, the entry component having a cylindrical bore receiving a sleeve which has a short, outwardly extending, flange at its end remote from the enclosure, and which flange is arranged to abut a shoulder on that end of the entry component to prevent axial movement of the sleeve towards the enclosure, that end of the entry component having on its external surface a tapered armour seat for receiving armouring of the cable such that on assembly the armouring provides location for the flange of the sleeve against axial movement thereof outwardly of the enclosure, and an armour clamp nut arranged to cooperate with the entry component and having an outwardly inclined face at the end of a bore thereof adjacent the entry component for clamping the cable armour onto the armour seat, the arrangement being such that non-compressed sealing compound can be manually inserted into the sleeve around bared cable cores located therein, with the inner end of the non-compressed sealing compound engaging a bared end of sheathing of the cable located adjacent the end of the sleeve in the region of its flange.

Yet another aspect of the present invention provides a barrier gland assembly which is arranged to secure a cable end in an enclosure wall with a non-compressed sealing compound between and/or surrounding the conductor cores of the cable at least in the region of the wall, the assembly comprising a tubular entry component having one end, hereinafter referred to as the inner end, which is arranged to be threadedly secured in an aperture in the enclosure wall, the entry component having an intermediate portion a bore of which provides an outwardly tapered seat facing away from said inner end, the entry component having an outer end on the side of the intermediate portion remote from said inner end, and which outer end is threaded to engage a threaded first end of a tubular compression nut which has, on its internal surface of its other, second, end, a seating for an elastomeric seal arranged to be compressed by engagement with the compression nut of a seal nut to force the elastomeric seal into engagement with the external surface of a cable extending through the gland, the entry component having located within it, in the region of its inner end and its intermediate portion, a sleeve which has a cylindrical portion aligned with said inner end of the entry component, said cylindrical portion being arranged to receive said sealing compound to seal cable cores extending therethrough without mechanical compression of the sealing compound, and an integral, outwardly flared, flange of the sleeve being aligned with the outwardly tapered seat of the entry component, and a further annular member provided between said outwardly flared flange and the compression nut, or an intermediate part or parts engaged by the compression nut, such that engagement of the compression nut and the entry component forces said further annular member into engagement with a portion of the cable within the intermediate portion of the entry component, thereby axially to locate the cable therein. In such an arrangement said further annular member may be an elastomeric seal, and there may be included between the further annular member and the compression nut, an earthing washer which forms the or one of the intermediate parts and which is arranged, on assembly, to engage a metallic sheath of the cable and electrically to interconnect it with the compression nut.In this construction the further annular member may comprise a metallic bonding connector which is arranged, on full securement of the entry component and compression nut, to engage a bared portion of a steel tape armour of the cable both to provide earthing continuity between the steel armour and the compression nut, and also to provide the axial location of the cable within the gland.

According to another aspect of the present invention a barrier gland assembly which is arranged to secure an armoured cable in an enclosure wall includes a first annular member through which an at least partially bared portion of the cable normally extends, the said first member having, on its side normally facing away from the enclosure, an external surface thereof forming a tapered armour seat for locating a bared end portion of the cable armouring, a tubular armour clamp nut being engagablewith said first annular member to secure the armouring to the tapered armour seat with the interposition, between the tubular armour clamp nut and the armouring, of an armour clamp ring having a tapered bore to correspond substantially to the taper of the tapered armour seat, the ring having a discontinuity at one peripheral section thereof to allow the diameter of the ring to vary during assembly and disassembly.

The invention may be carried into practice in various ways but a number of specific embodiments will now be described by way of example with reference to the accompanying drawings in which: Figure lisa sectional side elevation of a barrier gland according to the present invention showing a cable end secured thereby in an enclosure wall; Figure 2 is a similar view of a second embodiment; Figure 2A is a perspective view of an armour clamping ring utilised in the embodiment of Figure 2; and Figure 3 to 6 are sectional side elevations of four further embodiments.

Referring firstly to Figure 1 this illustrates a cable end secured by means of a barrier gland in an enclosure. Part of the enclosure wall is shown at 10, the wall having a threaded aperture 1 OA which receives a corresponding threaded spigot 1 1A of an entry component 11 which is of generaliy tubular form having an internal cylindrical bore 11 B, a flange 1 1C which, when the entry component 11 is assembled in the aperture 1 OA of the enclosure 10, abuts the outer surface of the enclosure wall. If appropriate, the flange 11 C is formed with appropriate flats to enable it to be assembled by means of a spanner.

To the right of the flange 1 1C in Figure 1 the entry component 11 hasafurtherthreadedspigot liD which merges into a tapered or conical region 1 E, the external surface of which is knurled to accept armouring of the cable as will be described.

Arranged to be located within the entry component is a top-hat sleeve 12 the diameter of the exterior of the cylindrical portion 1 2B of which is slightly less than the bore 11 B to provide a radial clearance forming a flame path annulus. At its right hand end the top-hat sleeve is formed with a short radially outwardly directed flange 1 2A for a purpose to be described.

Cooperating with the threaded spigot 11 D of the entry component 11 is an internally threaded portion 13A of an armour clamp nut 13 which, to the right of the threaded portion 13A thereof which engages the spigot 11 D is an internally tapered or conical surface 13B which overlies but is spaced from the knurled conical surface 1 E of the entry component 11 forthe purpose of clamping the armouring of the cable between these parts.

The armour clamp nut 13 is completed by means of a further end spigot 1 3C having an externally threaded end 13D on its external surface and a cylindrical bore 13E to surround the end of the external surface of the cable on assembly.

Cooperating with the threaded spigot 13D is an outer seal nut 15 having an internal thread to cooperate with the threaded end 1 3D and containing within it an elastomeric seal 17 and a taper skid washer 19, the latter being drawn leftwards in Figure 1 on clamping up of the seal nut 15 to compress the elastomeric seal 17 on to the external surface of the cable without undue deformation thereof.

Referring now to the structure of the cable in this embodiment, it has, at its right hand end an outer sheath 21 which protects armour wires 22, an inner insulation layer 24 and spaced cable cores 26.

As will be described, during assembly of the barrier gland, the cable cores have packed between them, and between them and the bore of the top-hat sleeve 12 a sealing material 17 which is located in position without mechanical compression and which comprises a two part epoxy putty, or a mastic with cross linked properties, or a cold cure silicone rubber or similar material.

The assembly of the structure of Figure 1 will now be described. An entire gland nut of the form shown is first partially disassembled in order to separate from one another the entry component 11, the top-hat sleeve 12 and the armour clamp nut 13, ensuring that the outer seal nut 15 is only loosely connected to the armour clamp nut to avoid compression of the elastomeric seal 17.

The armour clamp nut 13 and its associated components are then passed over the end of the cable and, after determining the bared length of conductors which is required to connect to the equipment in the enclosure, the outer sheath 21 of the cable is stripped to uncover the armouring 22, then, using the entry component 11 as a gauge, the armouring 22 is out back to a length equal to the knurled conical section 11 E of the entry component.

The inner insulation 24 over the cores 26 is then stripped to a point which leaves a short length of it, of the order of 3 mm, within the top-hat sleeve 12, thereby to provide a restriction against which the sealing compound will be forced in a manner now to be described.

Sealing material 27 is then packed into the voids (crutch) of the cable and around the cores 26 to a length not less than 12.5 mm and the top-hat sleeve 12 is then slipped over the cable cores 26, and the sealing material 27 so far incorporated to a position at which the flange 1 2A of the top-hat sleeve 12 sits at the root of the flared out armouring 22.

The cable is then passed through the entry component 11, whilst this is loose and unattached to the enclosure. The armour clamp 13 is then fully tightened onto the entry component 11 to secure the armour wires 22, with the armouring butted to the shoulder formed between the end of the knurled section 11 E and the threaded spigot 11 D.

The outer seal nut 15 is then tightened to cause the elastomeric seal 17 to displace onto the cable outer sheath to form a weather proof seal.

The top-hat sleeve 12 is then fully filled with sealing material 27, and the end of the material through which the cores 26 protrude is smoothedoff. This assembly is then left until the sealing material 27 has hardened.

In this way an assembly is produced in which all the critical lengths and relative clamping positions of the parts have been determined prior to the location of the entry component 11 in the wall 10.

To connect the assembly to the wall 10, the elastomeric seal 17 is relaxed by slackening the outer seal nut 15 and the entry component 11 is disconnected from the armour clamp nut 13. The entry component 11 can then be located in the wall 10 and the parts reassembled.

Alternatively, if space within the enclosure permits, once the assembly has been completed as aforementioned up to the stage at which the top-hat sleeve 12 is slipped over the cables, the entry component 11 could be screwed into the wall 10, the cable passed through it, the armour clamp nut fully tightened into the entry component 11 the outer seal nut tightened and the sleeve 12 filled with sealing material 27 from the other side of the wall 10.

It is to be particularly noted from this embodiment that the form of the top-hat sleeve 12 is such that its flange 1 2A on assembly closely engages the inside of the armour wires and also engages round the inner end of the entry component 11 thereby to provide close location in an axial sense for the top-hat sleeve 12 in both directions. This axial location is also augmented by adhesion between the sealing material 27 and the inner surface of the top-hat sleeve 12.

Figures 2 and 2A illustrate a slightly modified construction. Instead of the cable having the armour wires 22 of the first embodiment, the armour wires are substituted by armour braiding 22D. The armour clamp nut 13D of this embodiment, instead of having the tapered inner surface of the first embodiment, has a recess 13E in which is located an armour clamping ring 14 of the form shown in Figure 2A. From the section of Figure 2 it will be seen that the armour clamping ring 14 has a cylindrical external surface 13F and a tapered inner surface 1 3G which clamps the armour braiding 22D against the knurled surface of the entry component.

The armour clamping ring 14 has a split region 14D to provide a slight spring action in the assembled position and to allow for ease of removal.

Turning now to Figure 3, this shows an alternative embodiment which incorporates means for elec trically earthing a metallic inner tubular sheath 125 of the cable and for this purpose, as will be described, the barrier gland incorporates a further intermediate threaded annular member and also a special seal and earthing washer.

Referring now to Figure 3, a complete assembly is shown which is located in an enclosure wall 110 having threaded aperture 11 OA to receive an externally threaded spigot 11 1A of an entry component 111 having a flange 11 1C which may be provided with flats for the use of a spanner. To the right ofthe flange 11 1C is a further tubular spigot portion 111 D which is internally threaded at 111 E for a purpose to be described. It will be noted that the spigot portions 11 1A and 111 Dare at significantly different radii with the internal threads of the spigot portion 111 E displaced outwardly by a tapered or conical seal 111 F.The cone angle of this seat is approximately 40 which serves the purpose of providing location for a tapered flanged end 1 12A of a sleeve 112 which has the same functions as the top-hat sleeve 12 of the first and second embodiments.

The inner or right hand face of the tapered or conical flange 1 12A of the sleeve is arranged to bear on an elastomeric seal 130 which has a tapered or conical face on its left hand side, and a radial face on its right hand side, the latter cooperating with a flange 132Aofa starwasher 132 ofthetype described ih the Applicant's British Patent Specification 1603499. Centrally of the flange 132A the star washer has a number of petals 132B which, in the assembled and clamped up position, engage the external surface of the inner metal sheath 125 of the cable.Positioned to the right of the flange 132A of the star washer 132 is a skid washer 134 which, on assembly, abuts against the star washer 132, forcing it to the left to compress the elastomeric seal 130 and also to provide electrical earthing continuity between the inner metallic sheath 125 of the cable and the barrier gland as a whole.

Cooperating with the threaded bore 111 E is an externally threaded spigot 1 60A of a compression nut 160 having a flange 160B provided, if appro priate, with flats for a spanner, and to the right of the flange 1 60B a further externally threaded portion 160C merging with a tapered or conical end 160D which is knurled to engage armour wires 122 as in the first embodiment. To clamp the armour wires in position the gland is completed by an armour clamp nut 113 and an outer seal nut 115, an elastomeric seal 117 and a taper skid washer 19 of substantially the same form as the corresponding parts in Figure 1.

In this embodiment the gland is arranged to cooperate with a cable having an outer sheath 121 of insulating material which surrounds the armour wires 122. Within the armour wires is a second insulating layer 124 which surrounds the inner metallic sheath 125 previously referred to, which in turn surrounds an inner insulating layer (not shown) that is moulded around the cable cores 126.

The assembly of this gland onto the cable is basically similar in operation to that of the first embodiment with appropriate modifications to enable the accurate location and clamping of the star washer 132 and the elastomeric seal 130.

Accordingly assembly is commenced by separating the various gland components so that the armour clamping nut 113 is separated from the compression nut 160, which in turn is separated from the entry component 111. The elastomeric seal 117 is maintained in a relaxed condition by slight unwinding of the outer seal nut 115.

The armour clamp nut 113 and its associated and attached components are first passed over the cable and left loose on the cable. The conductor length required is determined and the outer sheath 121 of the cable is stripped to uncover the armour wires 122, then using the compression nut 160 as a guide, the armour wires 122 are cut to a length equal to the knurled section 160D plus 6 mm. The insulation 124 over the metallic sheath 125 is then stripped to an appropriate distance.The metallic sheath 125 and inner insulation is stripped from the cores of the cable to approximately 12.5 mm in front of the second insulation layer 124 in order to leave, on assembly, a short portion of the sheath, and its internal insulation lying just inside the cylindrical section of the sleeve 112, in effect providing a 'plug' to prevent axial movement to the right of the sealing compound to any appreciable extent. The skid washer 134, the star washer 132 and the elastomeric seal 130 are then passed over the metallic sheath 125 of the cable. Epoxy putty material 127 is then packed into the voids of the cable and around the cores 128, ensuring that the flange of the star washer 132 faces the elastomeric seal 130.

The cable is then entered, complete with the sleeve 112, into the entry component 111, whilst this is separated from the enclosure wall 110.

The cable is fed inward and the compression nut 160 is then engaged into the threaded bore of the entry component 11 to an extent sufficient to compress the star washer 132 onto the metallic sheath of the cable. The armour wires 122 are splayed around the knurled conical surface 160D of the compression nut, 160 and fully tightened to secure the armour wires, with the armouring butted to the shoulder of the knurled section. The outer seal nut 115 is then clamped up to cause the elastomeric seal 117 to displace onto the outer cable sheath 121.

It is to be appreciated that, at this time, the entry component 111 is not engaged with the wall 110 of the enciosure. The sleeve 112, equivalent to the top-hat sleeve 12 in the first embodiment, is then fully filled with epoxy putty 127 to form an explosion proof and weather proof seal and it is then left to harden.

The entry component 111 is then dismantled from the compression nut 160, and, after relaxing the seal 117, the armour clamp nut 113 is also released from the compression nut 160 and these parts are allowed to slip along the cable to an axial extent which enables the entry component 111 to be engaged in the aperture in the enclosure wall 110 and screwed up tight.

Thereafter, the compression nut 160 can be rotated between the skid washer 134 and the root of the armour wires 122, but cannot be moved axially to any great extent. In this way the compression nut 160 operates in the manner of a running coupling enabling the compression nut 160 to be tightened up in the tubular right hand spigot of the entry component 111 which tightens up the star washer 132 to engage the metallic sheath 125 and also compresses the elastomeric seal 130 to engage the sheath 126, without rotation of the cable.

Subsequently, the armour clamp nut 113 can be secured to the compression nut 160 and fully tightened to secure the armour wires 122. Finally the outer seal nut 115 is reclamped onto the armour clamp nut 113, the compress the seal 117 onto the outer sheath 121 of the cable to form a weatherproof seal.

In this embodiment the intermediate component or compression nut 160, during final assembly, can be initially separated from its two cooperating, components, namely the entry component 111 and the armour clamp nut 113, to enable the entry component 111 first to be rotated with respect to the cable leaving the cable stationary, while the entry component 111 is securely engaged in the threaded opening of the wall 110 of the enclosure. Thereafter the compression nut 160 is capable of being rotated relatively to the cable in the manner of a running coupling to complete the engagement of the star washer 132 onto the cable.

The particular form of the sleeve 112 with its tapered flange 1 12A is of particular significance in this embodiment because it serves not only to locate the sealing material 127 in relation to both the cable and the gland as does the top-hat sleeve 12 in the previus embodiment, but the conical flange 11 2A also provides a compressive reaction member against which the elastomeric seal 130 can react.

Hence, once the gland is assembled and the sealing material 127 hardened (at which time it adheres to the sleeve 112), removal of the entry component 111 does not result in relaxation oftheseal 130 since the adhesion between the cores 126, the sealing material 127 and the sleeve 112 ensures that the seal 130 remains compressed between the sleeve 112 which is adhesively axially located in relation to the cable and the compression nut which is clamped axially in relation to the cable by the armour clamp nut 113 on the armour cores 122. However, once the armour clamp nut 113 is removed, the seal 130 is partially relaxed, but not fully, since the compression nut 160 'backs off' to a position where it abuts the roots of the armour wires 122.

The next embodiment of Figure 4 embodies similar principles of assembly as the embodiment 3 in that it has an entry component 211, an intermediate component or compression nut 260 and an outer seal nut 215 which function basically in a similar manner during assembly, but, in this case, since there is no armouring or metallic sheath to the cable, the engagement of the components 211 and 260 during assembly, with the intermediary of a skid washer 234, serve to clamp up merely an elastomeric seal 230. Also, the omission of armouring means that the outer seal nut 215 can engage directly onto the compression nut 260, with the interposition of an elastomeric seal 217 and a skid washer 219 to form a weather-proof seal.

The embodiment of Figure 5 can be regarded as a hybrid of the embodiments of Figures 3 and 4 in that the cable has a metallic sheath 325 and therefore a star washer 332 is incorporated as in the embodiment of Figure 3, this component being clamped up in exactly the same way as in the embodiment of Figure 3.

However, the embodiment of Figure 5 is designed to cooperate with a cable which has no armouring and therefore, to the right of the star washer 332, the form of the gland is virtually the same as in the embodiment of Figure 4 and similar parts bear similar reference numerals with the substitution of 300 instead of 200.

Finally, the embodiment of Figure 6 is designed to cooperate with a cable which has a steel tape armour 422 which does not necessitate connection by means of an armour clamping nut. Instead a lead bonding connector 450 is incorporated which is somewhat similar to the elastomeric seal 130 of Figure 3,230 of Figure 4 and 330 of Figure 5. The connector 450 is a tapered ring having a number of peripherally spaced axially extending slots 450A extending approximately half-way along its length and open-ended adjacent the flange 412A of the sleeve 412, so enabling the lead ring to distort on clamping up to grip the steel tape armour.

Apart from this, the parts to the right of this connector are very similar to the corresponding parts in Figures 4 and 5 in order to provide a weather proof seal against the external sheath 421 of the cable.

Claims (18)

1. A barrier gland assembly which is arranged to secure a cable in an enclosure wall with a noncompressed sealing compound between and/or surrounding the conductor cores of the cable at least in the region of the wall, the assembly comprising a tubular entry component having one end, hereinafter referred to as the inner end, which is arranged to be threadedly secured in an aperture in the enclosure wall, the entry component having located at least partially within it a sleeve which has a cylindrical portion which is insertable into the entry component from its end remote from the enclosure, and which is arranged to receive said non-compressed sealing compound to seal cable cores extending through the sleeve, the sleeve having an integrally formed outwardly extending flange on its end remote from the enclosure, and the sealing compound substantially filling said cylindrical portion, but not extending appreciably, if at all beyond said flange, and engaging a sheathed part of said cable which terminates in the region of said flange, and said flange being located against movement away from said enclosure by engagement directly or indirectly with either other parts of said gland assembly, or said cable.

2. An assembly as claimed in claim 1 in which said flange is located on a side thereof facing the enclosure by a shoulder formed on the entry component.

3. An assembly as claimed in claim 1 or claim 2 in which said flange is located against a portion of armouring of the cable.

4. An assembly as claimed in any one of claims 1 to 3 in which said flange is located against a resilient seal engaging and axially immovable with respect to the cable, when fully assembled.

5. The assembled combination of a cable and a barrier gland assembly located within an aperture in an enclosure wall through which the cable extends, the barrier gland assembly comprising a tubular entry component having one end, hereinafter referred to as the inner end, which is threadedly secured in the aperture in the enclosure wall, the entry component having located at least partially within it a sleeve which has a cylindrical portion which is only insertable into the entry component from its end remote from the enclosure, and which has within it, around bared cable cores extending through it, a non-compressed sealing compound to seal the cable cores within the sleeve, with the compound adhering to the bore of the sleeve, the sleeve having an integ rally formed outwardly extending flange on its end remote from the enclosure, a portion of that part of the cable sheathing which surrounds the cable cores, but which has not been bared therefrom, being positioned close to or slightly within that end of the sleeve which has the outwardly extending flange, with non-compressed sealing compound located against said end and being at least partially prevented from being extruded from that end of the sleeve by said portion of the cable sheathing acting as a plug to that end of the sleeve, the flange being located against movement away from the enclosure by engagement directly or indirectly with either other parts of the gland assembly or the cable.

6. A barrier gland assembly which is arranged to secure a cable end in an enclosure wall with a non-compressed sealing compound between and/or surrounding the conductor cores of the cable at least in the region of the wall, the assembly comprising a tubular entry component having one end, hereinafter referred to as the inner end, which is arranged to be threadedly secured in an aperture in the enclosure wall, the entry component having an intermediate portion a bore of which provides an outwardly tapered seat facing away from said inner end, the entry component having an outer end on the side of the intermediate portion remote from said inner end, and which outer end is threaded to engage a threaded first end of a tubular compression nut which has on the external surface of its other, second, end, an inwardly directed tapered armour seat for receiving armouring of the cable, a tubular armour clamp nut being engagable with part of the compression nut and having an outwardly inclined face at the end of its bore adjacent the compression nut for clamping the cable armour on to the armour seat, the entry component having located within it, in the region of its inner end and its intermediate portion, a sleeve which has a cylindrical portion aligned with said inner end of the entry component, said cylindrical portion being arranged to receive said sealing compound which adheres to the bore of the sleeve and which seals cable cores extending therethrough without mechanical compression of the sealing compound and an integral outwardly flared flange of the sleeve being aligned with the outwardly tapered seat of the entry component, a resilient seal being provided which has one face in abutment with the outwardly flared flange of the sleeve on its side remote from the outwardly tapered seat of the entry component, the arrangement being such that, when the compression nut and entry component are engaged, and drawn together, the resilient seal is compressed between the flange of the sleeve and the compression nut, or an intermediate part or parts engaged by the compression nut, and forced into sealing engagement with a portion of the cable within the gland.

7. An assembly as claimed in claim 6 including, between the elastomeric seal and the compression nut, an earthing washer, which forms the or one of the intermediate parts, and arranged, an assembly, to engage a metallic sheath of the cable and electrically to interconnect it with the compression nut.

8. An assembly as claimed in claim 7 in which the earthing washer has a radial portion extending between the elastomeric seal and the compression nut, and integral petals arranged to extend axially from a bore of the radial portion to overlie the metallic sheath of the cable.

9. An assembly as claimed in any one of claims 6 to 8 in which, when fully located on a cable, and then after release of the threaded connections between the compression nut and both the entry component and the armour clamp nut, the compression nut is axially located between the elastomeric seal (or said intermediate part(s)) at one end, and the cable armour at the other end, but can rotate with respect to the cable to enable it to be reconnected to the entry component without rotation of either the entry component or the cable.

10. A method of locating a cable having a portion thereof extending through an enclosure wall, the cable being of a type having conductor cores surrounded by one or more sheaths, comprising baring a portion of the conductor cores in a region where they will be located in line with the enclosure wall, assembling onto that part of the cable to be located in line with the enclosure wall and immediately exterior thereof a barrier gland assembly which includes an entry component arranged to be threadedly secured to the enclosure wall, and a sleeve having a cylindrical portion thereof located within that part of the entry component to be located in line with the enclosure wall, and, before the entry component is located in the wall, securing to the entry component another component of the barrier gland assembly which is arranged axially to locate and secure the cable with respect to the assembly, inserting into the cylindrical portion of the sleeve a sealing compound from the end of the sleeve intended to be located within the enclosure, the sealing compound being manually forced, without mechanical compression, into the sleeve and up to the end of the sheath around the bared conductors, the sleeve having an outwardly directed flange at its end intended to be remote from the enclosure and which, during said insertion of the sealing compound is axially located with respect to both the cable and the gland assembly, allowing the sealing compound to set, separating the entry component from said other compression of the gland assembly, whilst leaving the sleeve firmly located on the cable at least partially by means of the sealing compound, securing the entry component in said enclosure wall, inserting said cable, with the sleeve and its compound therein, through the entry component and resecuring said other component of the gland assembly to the entry component.

11. A barrier gland assembly which is arranged to secure a cable end in an enclosure wall with a non-compressed sealing compound between and/or surrounding the conductor cores of the cable at least in the region of the wall, the assembly comprising a tubular entry component having one end, hereinafter referred to as the inner end, which is arranged to be threadedly secured in an aperture in the enclosure wall, the entry component having a cylindrical bore receiving a sleeve which has a short, outwardly extending, flange at its end remote from the enclosure, and which flange is arranged to abut a shoulder on that end of the entry component to prevent axial movement of the sleeve towards the enclosure, that end of the entry component having on its external surface a tapered armour seat for receiving armouring of the cable such that, on assembly, the armouring provides location for the flange of the sleeve against axial movement thereof outwardly of the enclosure, and an armour clamp nut arranged to cooperate with the entry component and having an outwardly inclined face at the end of a bore thereof adjacent the entry component for clamping the cable armour onto the armour seat, the arrangement being such that non-compressed sealing compound can be manually inserted into the sleeve around bared cable cores located therein, with the inner end of the non-compressed sealing compound engaging a bared end of sheathing of the cable located adjacent the end of the sleeve in the region of its flange.

12. An assembly as claimed in claim 11 in which the armour clamp nut engages and clamps the armour onto the entry component with the interposition of an armour clamp ring having a tapered axial cross-sectoin and having a discontinuity at one peripheral section thereof to allow the diameter of the ring to vary during assembly and disassembly.

13. A barrier gland assembly which is arranged to secure a cable end in an enclosure wall with a non-compressed sealing compound between and/or surrounding the conductor cores of the cable at least in the region of the wall, the assembly comprising a tubular entry component having one end, hereinafter referred to as the inner end, which is arranged to be threadedly secured in an aperture in the enclosure wall, the entry component having an intermediate portion a bore of which provides an outwardly tapered seatfacing away from said inner end, the entry component having an outer end on the side of the intermediate portion remote from said inner end, and which outer end is threaded to engage a threaded first end of a tubular compression nut which has, on its internal surface of its other, second, end, a seating for an elastomeric seal arranged to be compressed by engagement with the compression nut of a seal nut to force the elastomeric seal into engagement with the external surface of a cable extending through the gland, the entry component having located within it, in the region of its inner end and its intermediate portion, a sleeve which has a cylindrical portion aligned with said inner end of the entry component, said cylindrical portion being arranged to receive said sealing compound to seal cable cores extending therethrough without mechanical compression of the sealing compound, and an integral, outwardly flared, flange of the sleeve being aligned with the outwardly tapered seat of the entry component, and a further annular member provided between said outwardly flared flange and the compression nut, or an intermediate part or parts engaged by the compression nut, such that engagement of the compression nut and the entry component forces said further annular member into engagement with a portion of the cable within the intermediate portion of the entry component, thereby axially to locate the cable therein.

14. An assembly as claimed in claim 13 in which said further annular member is an elastomeric seal, and, including, between the further annular member and the compression nut, an earthing washer is included which forms the or one of the intermediate parts, and which is arranged, on assembly, to engage a metallic sheath of the cable and electrically to interconnect it with the compression nut.

15. An assembly as claimed in claim 13 in which the further annular member comprises a metallic bonding connector which is arranged, on full securement of the entry component and compression nut, to engage a bared portion of a steel tape armour of the cable both to provide earthing continuity between the steel tape armour and the compression nut, and also to provide the axial location of the cable within the gland.

16. A barrier gland assembly which is arranged to secure an armoured cable in an enclosure wall, the assembly including a first annular member through which an at least partially bared portion of the cable normally extends, the said first member having, on its side normally facing away from the enclosure, an external surface thereof forming a tapered armour seat for locating a bared end portion of the cable armouring, a tubular armour clamp nut being engagablewith said first annular member two secure the armouring to the tapered armour seat with the interposition, between the tubular armour clamp nut and the armouring, of an armour clamp ring having a tapered bore to correspond substantially to the taper of the tapered armour seat, the ring having a discontinuity at one peripheral section thereof to allow the diameter of the ring to vary during assembly and disassembly.

17. A barrier gland assembly substantially as specifically described herein with reference to any one of Figures 1 to 6 of the accompanying drawings.

18. An armour clamp ring substantially as specifically described herein with reference to Figure 2 or 2A of the accompanying drawings.