Cable Coupling

Abstract

An improved cable coupler for portable lengths of high-voltage cable includes first and second housings, each of which sealably receives at one open end the end of a length of cable. The individual conductors of the cable received by one housing are operably connected by means to plug terminals and the individual conductors of the cable received by the other housing are operably connected by similar means to socket terminals. These means include heat shrinkable elastomeric sleeve means forming both an insulating sleeve and a stress cone. Each plug terminal is adapted to be received by a socket terminal for an electrical connection therebetween and the other open ends of the housings concentric about the terminals are adapted to be co-axially interconnected with a seal member interposed therebetween to sealably enclose the connected terminals. Connecting means move the housings axially during the coupling and uncoupling thereof.

Description

This invention relates to a cable coupler for portable lengths of high-voltage cable and more particularly relates to a cable coupler having a housing with plug terminals and a housing with socket terminals which are adapted to be interconnected to provide a sealably enclosed electrical connection between the ends of two cable lengths.

In transmission of high-voltage three-phase electrical currents it is sometimes necessary to use portable flexible cable lengths to service portable machinery or equipment, as for example mining equipment. The cable lengths can be joined together by splicing, but preferably a coupling device or coupler is used to enable workmen to plug the lengths of cable together in a manner similar to connecting several common extension cords together.

Since these cable lengths and couplers are typically used in mining operations or the like where the terrain is rough and moisture is present, the cable lengths and couplers are required to be extremely rugged and durable. For example, the cable lengths may be 2 or 3 inches in diameter, 500 feet in length, and weigh more than 2,000 pounds, and the couplers may weigh as much as 150 pounds. As a result both the cable lengths and couplers are difficult to maneuver and position.

A further requirement of these couplers is to provide an electrical connection which will remain sound when exposed to the moist or wet conditions typically present. It is therefore necessary to sealably enclose the electrically connected ends of the cable lengths.

In certain cable couplers heretofore used it has been conventional to include mating housings, each of which receives at one end a length of cable and includes at the other end a tubular extension. The tubular extensions of the mating housings are adapted to telescope one within the other and a peripheral seal member is interposed therebetween. The individual conductors of the cable length received by one housing are operably connected to plug terminals with the mating ends thereof positioned co-axially within the tubular extension and the individual conductors of the cable length received by the other housing are operably connected to socket terminals with the mating ends thereof positioned co-axially with the tubular extension. Insulated cap members extend concentrically about the socket terminals and telescopically fit with insulated cap members concentric about the plug terminals.

In the past various problems have arose in connecting and disconnecting the housings of these heretofore used couplers. Because of the weight of the coupler two men are normally required for the connecting or disconnecting operation. Even when two men are employed often damage occurs to the insulated cap members during a connection or disconnection of the housings. For example, one of the means previously employed to attach the housings involves the use of a large diameter nut which is attached to one housing and mates with external threads on the female tubular extension of the other housing. During a disconnection of the housings, the nut is de-torqued against shoulders to drive the housing apart. It is necessary to turn this nut several revolutions and it is generally difficult to determine when the threads end. Therefore, the relatively heavy housings lose oftentimes their alignment support while the insulated, generally plastic, cap members are still in a telescoped condition. As a result, the weight of one housing will cause it to drop or become misaligned with the other housing upon this sudden unexpected disconnection of the threads thereby breaking the female cap members. Such a break can cause electrical failures because it shorts the voltage or tracking path to ground or from phase.

Moreover, during a connection of the two housings the seal member interposed between the telescoped tubular extensions is compressed by torquing the large diameter nut. Since the seal member is completely enclosed during this operation it is difficult to determine when the seal member has been properly compressed. As a result, the seal member is oftentimes not sufficiently compressed or is damaged by torquing the nut to tightly thereby effecting an improper seal. In addition, this nut arrangement requires special equipment which must be used for such a connection or disconnection of the housings. Furthermore, it is obvious that the threads of such a nut arrangement can easily become damaged or otherwise inoperable in view of the surrounding conditions to which the coupler is typically exposed.

Aside from these above mentioned problems relating to the connection and disconnection of the housings, there are various other problems associated with couplers previously used. The most common problem involves a failure as a result of moisture leaking into the coupler because of insufficient seals at the mating and cable receiving ends.

Accordingly, the present invention is directed to a cable coupler for portable lengths of high-voltage cable with improved means for connection and disconnection of the coupler housings and with improved seal means. Briefly, the cable coupler of the present invention comprises mating housings with tubular extensions adapted to be telescoped together and a seal member interposed between the tubular extensions adapted to provide a primary seal at the mating ends of the housings. The coupler also includes socket and plug terminals encircled by mating insulated cap members and each cap member is provided with seal means to provide a secondary seal at the mating ends of the housings. The other ends of the housings are also provided with primary and secondary seals. The coupler also includes a connecting clamp assembly which moves the housings axially without rotation together during a connection and apart during a disconnection with the degree of movement controlled within predetermined limits to avoid damage to the insulated cap members during a disconnection and to the seal member interposed between the tubular extensions during a connection.

This invention also relates to an internal connection between terminals and individual cable conductors for a co-axial cable assembly used in high-voltage service. In conventional apparatus of this type, a "stress cone" of dielectric material and conductive or semi-conductive material is used which carries an electrical ground connection from the cylindrical braided metallic sheath of the cable assembly to a larger diameter. This stress cone is placed around the dielectric insulation of the cable assembly and tapers from that diameter to a considerably larger diameter allowing a gradient of electrical stress. It has been proposed to make the dielectric sleeve of this stress cone of a heat-shrinkable material, but the difficulty in such a proposed construction is the problem of simultaneously heating a thick section and a thin section which result from the tapering diameter. Not only is there a problem in the amount of thermal energy and time required to heat the thick section, but the danger of trapping air between the heat-shrinkable dielectric sleeve and the cable assembly is even a greater problem, because it is difficult to prevent the tapered portions from shrinking down first. The entrapment of air at the interface between the dielectric sleeve of the cable assembly and the stress cone can cause serious electrical problems.

In accordance with the present invention, these problems are avoided by using an assembly of an elastomeric or rubber sleeve of low modulus with an externally tapered cone on one end, which is held in an expanded condition and which, in its relaxed condition, has an internal diameter slightly smaller than the diameter of the cable dielectric joint which the sleeve covers. The elastomeric sleeve is bonded, at its outer surface, to a heat-recoverable sleeve which retains the elastomeric sleeve in its expanded condition. Recovery of the heat-recoverable sleeve allows the elastomeric sleeve to contract onto the joint and also forces the elastomeric sleeve toward the cable dielectric and joint. A heat-shrinkable electrically conductive or semi-conductive tubing which tightly encloses a portion of the metallic sheath of the cable and the conical portion of the dielectric rubber sleeve may also be employed. This sleeve also may tend to compress the elastomeric low modulus sleeve tightly against the dielectric sleeve of the cable assembly, without entrapment of air at the interface to avoid electrical stress concentration at the point where the stress cone first contacts the cable.

Other objects and advantages of the present invention will be made readily apparent from the following detailed description and the accompanying drawings, wherein;

FIG. 1 is a top plan view of the cable coupler with the housings thereof connected together;

FIG. 2 is a side view partly in section illustrating the telescoped fit of the tubular extensions of the mating ends of the housings;

FIG. 3 is a side sectional view taken substantially along the lines 3--3 of FIG. 1 and illustrating the internal components of the cable coupler;

FIG. 4 is a sectional end view taken substantially along the lines 4--4 of FIG. 3;

FIG. 5 is a top fragmentary view partly in section taken substantially along the lines 5--5 of FIG. 2 and illustrating the connecting clamp assembly;

FIG. 6 is a side fragmentary view partly in section further illustrating the connecting clamp assembly;

FIG. 7 is a side sectional view illustrating the internal components of an alternative embodiment;

FIG. 8 is a side fragmentary view illustrating the connecting clamp assembly;

FIG. 9 is a sectional end view taken substantially along the lines 9--9 of FIG. 3.

Referring now in detail to the drawings, the cable coupler, generally designated 10, comprises first and second housings 12 and 14. Each housing includes a cylindrical, bell-shaped section 16 having open ends 18 and 20. The reduced open end 20 receives the three individual cables A of a high-voltage, three-phase, cable length 24.

The end of the cable length 24 is secured to the housing by a clamp and seal arrangement, generally designated 26. This clamp and seal arrangement 26 includes a heat-recoverable tubing or sleeve 28 which encircles and tightly grips the insulated covering 29 of the cable length 24 and the end of the exterior surface of the bell-shaped section 16 which is reduced at 30 to receive the sleeve 28.

Preferably, the heat-recoverable sleeve 28 contains an inner coating of an adhesive which adheres the sleeve to the cable length insulated covering on jacket 29 and the end of the bell-shaped section 16 when the sleeve is shrunk downwardly thereon. Any desired adhesive may be employed. The choice of a specific adhesive will depend in part on the composition of the sleeve 28, jacket 29, and bell-shaped section. Suitable adhesives include polyesters, polyurethenes, epoxies, nitrile rubber, hot melt adhesives such as polyamides, and rubber based adhesives such as silicone, nitrile, and neoprene adhesive. A polyamide adhesive is especially suitable.

The heat-recoverable tubing 28 may be fabricated from any desired crystalline polymer. Examples of desirable thermoplastic polymers which have been crosslinked or which inherently possess the property of heat recoverability are polyolefins, such as polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer or other ethylene copolymers, polyvinylidene diflouride, polyvinyl chloride, etc. Also, elastomeric thermoplastic materials such as those described in U.S. Pat. No. 3,507,372, the disclosure of which is incorporated herein by reference, may be used.

Additional compounds which may be used are various thermoplastic elastomers known as elastoplastics such as thermoplastic polyurethanes, polymers marketed by Shell under the mark KRATON which are styrene-butadiene-styrene and styrene-isoprene-styrene block copolymers, polyester-polyether copolymers, silicone-carbonate and silicone-styrene block copolymers, etc.

Additionally, other flexible polymers possessing necessary crystallinity such as ethylene-propylenediene terpolymers, trans-polybutadiene and trans-polyisoprene may be used. In addition, various commercially available elastomer-thermoplastic blends such as nitrile rubber-PVC and nitrile rubber-ABS may be employed.

This heat-recoverable sleeve 28 provides one seal between the cable length 24 and the housing at 31. Another seal is provided by a heat-recoverable cable transition member 31a which fits co-axially at one end between the sleeve 28 and the cable length covering 29 and which tightly grips the insulated covering 29. The other end of the cable transition member 31a includes three tubular extensions 32a which encircle and tightly grip the individual cables A. The cable transition member 31a thus provides a secondary seal which prevents moisture from entering the housing should the insulated covering 29 be punctured or become otherwise impaired to permit moisture to enter into the interior of the cable length 24. Preferably, the cable transition member 31a includes an inner coating of adhesive of the type heretofore described with respect to the sleeve 28 and is formed of the same materials as heretofore described with respect to the sleeve 28. Transition member 31a is primarily a seal but can provide additional strain relief when extended sufficiently under clamps 50 and 52.

A clamp assembly, generally designated 32, fits co-axially over the cable length 24, and the small end of the bell-shaped section 16, and the heat-recoverable sleeve 28. The clamp assembly 32 includes a cylindrical clamp housing 34 consisting of two sections 36 and 38 substantially semi-circular in cross-section which are secured to the end of the ball-shaped section 16 by key-way means 40 and bolted together at 42 and 44. Each section includes an integral flange 46 which extends axially beyond the open end 48 of the section and to which a pair of bell-mouthed clamp members 50 and 52 on either side thereof attach. The clamp members 50 and 52 define a funnel shaped bore 54 which extends co-axially about the cable length 24 and sleeve 28 and tapers inwardly toward the bell-shaped section 16. The clamp members are bolted to the flanges at 56 and 58 and a tightening of the bolts causes the clamp members 50 and 52 to clamp down on the heat-recoverable sleeve 28, the cable transition member 31a, and the cable length 24, and thus secure the cable length 24 to the housing and provide a strain relief therebetween.

Referring to FIG. 3, the shielded power cable generally designated A, is of conventional form and includes a central conductor B enclosed within a dielectric layer C, which layer is in turn enclosed within a braided metallic sheet D. An end of the cable A is prepared so that the central conductor B projects from the end of the dielectric layer C, and the layer projects from the end E of the metallic sheet D. Conductor B is joined to metallic contact piece F by crimp connector 109 and the resulting joint is insulated by insulating means generally designated 100. In accordance with this invention, an elastomeric, low modulus, rubbery sleeve 103 of good dielectric properties has a central opening 106 which receives the dielectric layer C of the cable assembly A. The sleeve 103 also covers the crimp connector. In its expanded condition, the sleeve 103 easily slides over the crimp connector and layer C. In its relaxed condition the sleeve 103 fits tightly against the crimp connector and layer C which have a slightly larger diameter than the inside diameter of sleeve 103 when it is relaxed. This elastomeric sleeve 103 has one end which comprises an external conical surface 107 which extends from the opening 106 and merges with the cylindrical surface 108 of the sleeve 103. The sleeve 103 may be selected from any elastomeric material well known to those skilled in the art. Indeed, it may advantageously be of the same material as the cable insulation. Examples of suitable insulating materials are natural rubber, ethylene-propylene rubber, silicone rubber, butyl rubber, styrene-butadiene rubber, etc. In addition, highly plasticized thermoplastic materials such as PVC Plastisol may be used.

In FIG. 3, a layer of semi-conductive material 104 adjacent to crimp connector 109 is shown. Use of such a layer is not necessary, but it may be desirable to prevent corona formation. When crimp connector 109 is crimped, sharp edges may be formed resulting in voids in the elastomeric layer 103. The semi-conductive layer 104 aids in preventing corona formation at these voids. The semi-conductive layer 104 may be the same as or different from the material used for elastomeric layer 103. In general, any elastomeric material containing conductive particles to make it semi-conductive may be used for layer 104. For example, ethylene-propylene rubber with carbon black dispersed therein may be used.

A heat-recoverable tubing 101 encircles and tightly grips the outer surface of elastomeric sleeve 103. Tubing 101 may be electrically conductive, particularly in the case of shielded cable. However, if the outer layer of the cable is non-conducting or semi-conducting, the tubing 101 may be non-conducting. Preferably, the heat-recoverable sleeve 101 is bonded to elastomeric sleeve 103. The two sleeves may simply be welded or fused together. They may be crosslinked at their interface by introducing crosslinking agents such as peroxides at the interface. Various adhesives may also be employed. The choice of a specific adhesive will depend in part on the composition of sleeves 101 and 103. Suitable adhesives include polyesters, polyurethanes, epoxies, nitrile rubber, hot melt adhesives such as polyamides, and rubber based adhesives such as silicone, uitrile and neoprene adhesives.

The heat-recoverable tubing 101 may be fabricated from any desired crystalline polymer. The polymer is made conductive, as desired, by incorporation of conductive particles such as carbon black. Examples of desirable thermoplastic polymers which have been crosslinked or which inherently possess the property of heat recoverability are polyolefins, such as polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer or other thylene copolymers, polyvinylidene diflouride, polyvinyl chloride, etc. Also, elastomeric thermoplastic materials such as thos described in U.S. Pat. No. 3,597,372, the disclosure of which is incorporated herein by reference, may be used.

Additional compounds which may be used are various thermoplastic elastomers known as elastoplastics such as thermoplastic polyurethanes, polymers marketed by Shell under the mark KRATON which are styrene-butadiene-styrene and styrene-isoprene-styrene block copolymers, polyester-polyether copolymers, silicone-carbonate and silicone-styrene block copolymers, etc.

Additionally, other flexible polymers possessing necessary crystallinity such as ethylene-propylene-diene terpolymers, trans-polybutadiene and trans-polyisoprene may be used. In addition, various commercially available elastomer-thermoplastic blends such as nitrile rubber-PVC and nitrile rubber -ABS may be employed.

A second heat-recoverable sleeve 105 covers the conical portion 107 of sleeve 103 and also extends so that it covers cable shielding D. This second sleeve 105 is electrically conducting or semi-conductive. If desired, a conductive adhesive may be used at 110 to fill in any voids that might develop and to aid in bonding sleeve 105 to the cable. The adhesive may also be used to bond sleeve 105 and may be formed of any suitable material. Although heat-recoverable materials are preferred, the sleeve may be formed of other conductive materials such as a metal, e.g., copper or aluminum. If desired, a conductive paint such as silver paint may be used. The preferred material for the sleeve is a heat-recoverable material of the type used for sleeve 101, having a conductive material such as carbon or metal particles dispersed within it. An ethylene-vinyl acetate copolymer made conductive by incorporation of conductive particles is preferred.

As previously indicated, sleeve 103, in the relaxed condition, contracts against layer C and crimp 109. Further, hoop tension forces in sleeves 101 and 105 compress the elastomeric sleeve 103 into tight engagement with the dielectric layer C of the cable assembly A without entrapping air bubbles. The partially relaxed compressed rubber sleeve 103 also tightly grips the metallic crimp connector 109 which is positioned within the bore 106 of the rubber sleeve 103 and which serves to connect the central conductor D to the metallic contact piece F. This contact piece F is mounted within a conventional connector body G formed of insulating material.

Preferred fabrication and installation of insulating means 100 are accomplished as follows. The low modulus elastomeric sleeve 103 is formed by molding ethylene-propylene-diene monomer terpolymer (EPDM) into a soft rubber cone or sleeve. This sleeve has an internal diameter slightly smaller than the outer diameter of the crimp connector when the sleeve is in the relaxed state. An outer sleeve, 101, of low-density polyethylene dna anothe sleeve 105 of low-density polyethylene are separately molded. These sleeves 101 and 105 preferably have a slightly smaller internal diameter than the molded outside diameter of sleeve 103. Sleeve 105, in some cases, could be considerably smaller, eg., the portion of sleeve 105 which grips the cable. The polyethylene sleeves are then expanded using a heated mandrel. The inner surface of the heat-recoverable sleeves and the outer surface of the elastomeric sleeves are then cleaned and if desired abraded. An adhesive comprising 47.5 percent ethylene-vinyl acetate-carboxylic acid terpolymer sold under the trade name of ELVAX 260 and 47.5 percent of ethylene-ethyl acrylate copolymer sold under the trade name of DPD 6169 and 5 percent reinforcing carbon black is used to bond the two sleeves. The heat-recoverable sleeve is placed over the elastomeric sleeve and shrunk around the elastomeric sleeve at about 175.degree. applied for five minutes. Finally, the laminate structure is expanded immediately after shrinkage and while still hot with a mandrel to give the desired inner diameter of the elastomeric sleeve. After cooling to room temperature the mandrel is removed. The heat recoverable sleeve remains distended and, by means of the bonding adhesive, holds the elastomeric sleeve distended. The distended condition lasts indefinitely until sufficient heat is applied to the outer, heat recoverable, portion to allow relaxation. In application the laminate is placed over the cable along with heat-recoverable sleeve 105 prior to making the crimp connection. After the crimp connection is made, the laminate of sleeve 101 and 103 is placed over the crimp connection in the desired position and heat is applied to shrink it over the crimp connection, dielectric layer C and a connector body or insulated bulkhead G. Sleeve 105, a heat-recoverable sleeve of semi-conductive ethylene-vinyl acetate copolymer is then placed in the desired position and heat is applied to recover it over the conical section of sleeve 103, dielectric layer C and braided jacket D.

The bulkhead G is contained within the enlarged bore section 150 of each housing. Each bulkhead is identical and therefore the description thereof will primarily be made in reference only to the housing 14 to avoid repetition. The bulkhead G comprises a cylindrical plate 154 which fits co-axially within a cylindrical flange 156 extending about the open end 18 of the bell-shaped section 16. The bulkhead G includes three triangularly spaced openings 158 which extend axially therethrough and is provided with cylindrical flanges 160 and 161 on either side thereof which extend co-axially about the openings 158. A fourth axially extending opening 162 is also provided in the plate 154 proximate its outer peripheral edge 164.

In housing 14 the bulkhead G supports three plug terminals 166, which extend axially through the openings 158 of the plate 154, and a ground plug terminal 168, which extends axially through the opening 162.

One end of each terminal plug 166 comprises the metallic contact piece F and the other end thereof comprises a split male mating pin 170. Each terminal plug 166 is secured to the bulkhead G by a ring member 172 which fits in a peripheral recess 174 in the terminal plug after the plug is extended through the opening 158 and abuts the end of the flange 160.

In housing 12 the bulkhead G supports three socket terminals 176 and a ground socket terminal 178. One end of each terminal socket 176 comprises the metallic contact piece F and the other end thereof comprises the female mate 178 for a male pin 170. The socket terminals 178 are secured to the bulkhead G in the same manner as the plug terminals 166.

The plug and socket terminals are enclosed with female and male caps, respectively. The female cap is indicated at 120 and the male cap at 121. The caps both insulate and seal the contacts formed by the plugs and sockets. The caps are formed of an elastomeric compound which is quite flexible and is preferably non-tracking. A preferred composition for the caps is an ethylene-propylene oil extended rubber containing iron oxide and hydrated alumina. In general any elastomeric material having a durometer hardness of about 60 may be used.

Each insulated female cap 120 is provided with an internal bore 184 which tapers radially inward from the open end 186 of the cap. A plurality of wipers or seal members 123 protrude radially inward from the interior sidewall 190 of the cap 120 and extend circumferentially thereabouts. The male caps 121 secured to the bulkhead G in housing 12 each include an exterior sidewall 194 which tapers radially outward from the open end 196 thereof. Extending circumferentially about the exterior sidewall 194 are radially extending wipers or seal members 122.

The male pins of the plug terminals 166 are in matched alignment with the female ends of the socket terminals 176, and are adapted to extend therein. The female caps 120 are also in matched alignment with the male caps 121 and the taper of the internal sidewall 190 of each female cap is complimentary to the taper of the exterior sidewall 194 of each male cap to provide a snug fit therebetween. Moreover, the wipers 122 of each male cap are adapted to engage the interior sidewall 190 of a female cap and the wipers 123 of each female cap member are adapted to engage the exterior sidewall 194 of a male cap. Thus, the wipers serve the dual purpose of providing a secondary seal at the mating ends of the housings and cleaning critical surfaces on the caps 120 and 121.

An alternate method of forming the insulating means and caps is illustrated in FIG. 7. This method may be preferred when protection against moisture penetration is particularly important. Referring to FIG. 7, wherein reference numerals corresponding to FIG. 3 are used, it can be seen that central conductor B is connected to terminal plug 300 which comprises conductor receiving end 301 and terminal plug 302.

Around conductor B, tape or other filler material 303 is placed. If desired the filler material may be semi-conductive. Insulating means 304 covers the conductor joint with the terminal plug. If desired the insulating means may include semi-conductive layer 305. An elastomeric layer 306 and a heat recovered layer 307, similar to layers 103 and 101 form the insulating sleeve. The cone end of the sleeve is covered by sleeve 105 in the manner previously described.

The insulating means differs from that shown in FIG. 3 in that the cap 308 for terminal plub 302 forms a continuous sleeve with insulating means 304. As illustrated cap 308 is the same material suitable for both applications is used such a construction is satisfactory. Generally, however, different materials will be preferred for cap 308 and layer 306. Thus, the cap will normally be bonded to the elastomeric layer by molding the elastomeric layer onto the previously molded cap, or by simultaneously molding the two materials in the same mold. Alternatively, the cap may be adhesively bonded to the elastomeric layer using suitable adhesives including those of the type previously described.

Th insulating means 304 is applied in the manner previously described. Either prior to or after application if insulating means 304, cap 308 is inserted through the opening 309 in bulkhead G after split spacer ring 310 having sections 311 and 312 has been placed over sleeve portion 313. The sections are secured by a bolt 314. After the ring 310 is in place, it is held in place by inserting elastomeric retaining ring 315 in groove 316.

The ground plug terminal 168 includes an enlarged head 200 at one end and the other end 202 thereof comprises a split male mating pin. The ground plug terminal 168 extends through the opening 162 with the head 200 on one side of the bulkhead G engaging a conductive member 204 interposed between the head and the bulkhead. A cap member 206 having a central opening 208 fits coaxially over the mating pin 202 and is threadably received by external threads 210 on the ground plug terminal. The cap member 206 is tightened on the threads 210 to draw the head 200 into tight contact with the conductive member 204 which extends to the peripheral edge 164 of the bulkhead G and contacts the housing 14. A seal ring 212 concentric about the ground terminal plug is compressed between the cap member 206 and the bulkhead G.

The ground terminal socket 178 is similarly secured to the bulkhead G in the housing 12, with a head 214 thereof on one side of the bulkhead G being drawn tightly against a conductive member 216, which is in contact with the housing 12, by a cap member 218. A seal ring 220 is compressed between the cap member 218 and the bulkhead G. A mating end 222 of the ground terminal socket 178 is aligned with the male pin 202 and adapted to receive the male pin.

An axially extending cylindrical sleeve or tubular extension 224 having a radially extending flange 226 at one end thereof which is secured to the flange 156 of the bell-shaped section 16 by fasteners such as bolts 228 forms a male end of the housing 14. Interposed between the flange 226 of the tubular extension 224 and the flange 156 of the bell-shaped section 16 is the bulkhead G. The bulkhead G is provided with a circular groove 230 on one side which is adjacent to the peripheral edge 164 and receives a seal ring 232 for preventing leakage between the plate 154 and the tubular extension 224.

The housing 12 is provided with an axially extending cylindrical sleeve or tubular extension 234 which includes at one end a radially extending flance 236 connected by fasteners 238 to the flange about the open end 18 of the bell-shaped section 16. The tubular extension 234 forms a female end of the housing 12 which is adapted to receive the male end of the housing 14 during the coupling thereof. A peripheral seal member 240 on the exterior surface of the tubular extension 224 adjacent the flange 226 is adapted to receive the open end of the tubular extension 234 and thereby form a primary seal between the mating male and female ends of the two housings.

Coupling is accomplished through a clamp connecting assembly generally designated 250. The clamp connecting assembly 250 generally comprises a lever arm 252 pivotally secured to the housing 12, latch members 254 connected to the housing 14, connecting links 255 slidably mounted on the housing 12 and each operably connected to a latch member 254, and tensioning means 256 interconnecting the lever arm 252 and the connecting links 255. The lever arm 252 comprises an axially extending handle section 258, a bi-furcated section 260 which extends circumferentially to each side of the housing 12, and a pair of side arms 262, each which extend from an end of the bi-furcated section 260 to a pivot connection 264. The pivot connections 264 include radially outwardly extending pivot pins 266 carried by support brackets 268 secured to each side of the housing 12 at the flange 156. The support brackets 268 each include an axially extending slide 270 with side flanges 272 to support and guide a connecting link 255 mounted thereon.

Each connecting link 255 includes an axially extending elongated slot 274 through which a pivot pin 266 extends and an aperature 276 at one end thereof. The latch members 254 each comprise a bracket 278 secured to the side of the housing 14 at the flange 156 with an axially extending slide 280 in alignment with a slide 170. The slide 280 is adapted to receive one end of a connecting link 255 and also includes side flanges 282 for supporting and guiding the end of the connecting line 255 with an inclined latch 284 therebetween adapted to receive the aperature 276 of a connecting link 255. The incline of latch 284 begins at the end 286 closest to the housing 12 whereby the other radially protruding end 288 thereof prevents axial movement of the connecting link 255 in a direction away from the housing 14. Axial movement of the connecting link 255 in the other direction is prevented by an end flange 290 of the slide 280 which abuts the end of the connection link.

The tensioning means 256 comprises a pair of substantially straight spring members 292, each pivotally secured at one end to a connecting link at 294 between the elongated slot 274 and the aperature 276 and pivotally secured at the other end to a side arm 262 at 296.

In a coupling or connection operation the housings 12 and 14 are moved into axial alignment with the connecting links 255 slidably mounted in the slides 270 and 280 to maintain this position. The lever arm 252 is raised as shown in FIG. 6 with the connecting links 255 in their forward most position, but attached to the latches 284. The lever arm 252 is then pivoted downwardly toward the housing 12 whereby the spring members 292 cause the connecting links to slide rearwardly which in turn causes the housings 12 and 14 to move a predetermined distance axially together until they reach the closed position as shown in FIG. 5. Once closed, the end of the lever arm 252 is secured by means such as a connecting pin 298 to the housing 12 to maintain the closed positon. In the closed position the spring members 292 are in tension and act through the housings to properly compress the seal member 240.

When disconnecting the housings 12 and 14, the lever arm 252 is disconnected from the housing 12 and raised to release the tension of the spring members 292. This pivotal movement of the lower arm also causes the connecting links to move forwardly to push the housings axially apart. However, the connecting links remain in the slides 270 and 280 with the connecting clamp assembly providing support for the housings thereby avoiding sudden misalignment thereof and damage to the caps.

Having fully described our invention, it is to be understood that we do not wish to be limited to the details herein set forth, but our invention is of the full scope of the appended claims.

Claims

We claim:

1. A cable coupler for portable high-voltage cable lengths, comprising:

first and second housings, one of said housings including a female end and said other housing including a male end adapted to co-axially coupled with said female end;

a seal member interposed between said male and female ends;

each said housing including an insulated support member and being adapted to sealably receive at said other end a length of cable with the individual conductors thereof extending inwardly into said housing;

plug terminals supported by said insulated support member in one of said housings and socket terminals supported by said insulated support member in said other housing, said plug terminals interconnecting co-axially with said socket terminals when said female and male ends are coupled together with said insulated support members having means for encapsulating said interconnecting terminals comprising mating insulating male and female caps concentric about said terminals with said male caps having an exterior surface and said female caps having an interior surface, each interior surface being adapted to mate with one of said exterior surfaces to provide an additional seal means at the coupling ends of said housings;

means in each said housing connecting each end of said individual connectors in one said housing to a plug terminal in said housing and each end of said individual conductors in said other housing to a socket terminal in said housing, comprising a sleeve for covering an electrical conductor splice which provides electrical insulation and means for relief of electrical stress, said sleeve comprising a heat recoverable member sleeve having an inner layer of elastomeric material bonded thereto;

connecting means operably attached to said first and second housings to axially move said female and male ends together for the coupling thereof and to compress said seal member there between.

2. The coupler of claim 1, wherein one end of said sleeve is cylindrical with projections extending about the outer circumference of the cylindrical end.

3. The coupler of claim 1, wherein the inner surface of the elastomeric layer is semiconductive.

4. The coupler of claim 3, wherein the semi-conductive layer comprises elastomeric material with conductive particles dispersed therein.