US3646503A

US3646503A - Handling means for a cable termination housing having stress isolating means between the housing and the handling means

Info

Publication number: US3646503A
Application number: US27613A
Authority: US
Inventors: Henry N Tachick
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1970-04-13
Filing date: 1970-04-13
Publication date: 1972-02-29
Anticipated expiration: 1989-02-28

Abstract

An electric cable termination housing is provided with an integral handling means mounted thereon in the form of a hook stick receiving handle that is mounted on one end of a resilient, flexible cylinder, which in turn is fastened to the termination housing. The resilient cylinder between the termination housing and the handling means serves to isolate from the housing stresses applied to the handle when a hook stick is used to manipulate the termination housing by applying force to the handle at a variety of different angles.

Description

[4 Feb.29,1972

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m m m B A .H. U M ve n m a. m m a w m mm m m n E Q n e 08 mm. e .1 s m A n M U H An electric cable termination housing is provided with an integral handling means mounted thereon in the form of a hook stick receiving handle that is mounted on one end of a resilient [21] Appl. No.:

, flexible cylinder, which in turn is fastened to the termination housing. The resilient cylinder between the termination housing and the handling means serves to isolate from the 339/110, 108, 60 101 102, housing stresses applied to the handle when a hook stick is 45 used to manipulate the termination housing by applying force to the handle at a variety of different angle 521 U.S.Cl..... 51 1m.c|.. 5s FieldofSearch a l a ma g l m m N m M A .a w s E m M e .m H m m U N U U HANEDLlNG MEANS FOR A CABLE TERMINATKON HOUSING HAVIING STRESS llSOLATlING MEANS BET-W THE HOUSENG AND THE HANDMNG MEANS In the field of high-voltage power distribution, it has become common practice for linemen to manipulate energized high-voltage cables by grasping the cables with suitable hotsticks or other insulating means that are adapted to protect the lineman from possible electrical shock, while also affording adequate manual control of the cable during its manipulation. To accomplish such objectives, it is also well known to provide high-voltage cable termination housings with hotstick rings or other suitable handling means, which provide surfaces having configurations that can be easily and securely grasped by the pivotal hooks of a linemans hotstick, thus assuring a positive locking engagement between the hotsticks and such housings when they are being manipulated.

A major disadvantage encountered in such prior art hotstick ring arrangements was that they were frequently destroyed or badly damaged when a hotstick was twisted at a sharp angle with respect to the termination housing on which the ring was mounted, while the hooks of die stick were locked to the ring. Therefore, to prevent such damage it was necessary for a lineman to always exercise care to make sure that his hotstick was maintained in proper alignment with the hotstick ring or other handling means on the termination housing. Since cable terminations, particularly those used on underground distribution systems, often must be manipulated in relatively confining areas, such as those available in underground distribution transformer vaults, it is often very difiicult or nearly impossible for a lineman to maintain such proper alignment of his hotstick with the hotstick ring on the termination housing, so damage to the rings frequently occurs.

Another disadvantage of prior art handling means for cable termination housings was that hotstick rings frequently were formed of flexible material that was adapted to stretch significantly when a hotstick was locked into the handling means and pulled sharply to manipulate the termination housing in a given direction. Such resilient rings were, in fact, deemed to be an advantage in some applications, because the resilience of the ring imparted a snap-action movement to the termination housing when a hotstick engaged with it was jerked rapidly away from the housing. For example, in US. Pat. No. 3,4 74,386 Link, issued Oct. 2 l 1969, it is explained that such a snap-action is desirable in manipulating a cable termination housing in a load-break operation, because the rate of circuit interruption is accelerated, thus reducing the duration of an are formed between the contacts being separated.

A further disadvantage of prior art flexible handling means for cable termination housing wm that they did not transmit a uniform manipulating force from a hotstick to the housing for all angular degrees of movement of the handling means.

An object of the present invention is to provide a cable termination handling means that overcomes the foregoing disadvantages of handling means known in the prior art.

Another object of the invention is to provide a cable termination housing with an integral handling means resiliently mounted thereon in a manner such that stresses applied to the handling means are absorbed in a resilient coupling means, which operates to prevent such stresses from damaging either the termination housing or the handling means.

A further objective of the invention is to provide a cable termination handling means that can be flexibly manipulated to transmit force from a linemans hotstick to a termination housing through a limited range of angles, without damaging the handling means.

Still another object of the invention is to provide a cable termination handling means that has a limited amount of resilience so that only a controlled snap-action is generated by the handling means when a hotstick engaged therewith is jerked rapidly away from the termination housing.

Yet another object of the invention is to provide a stressisolating means between a cable termination housing and a termination-handling means, such that the handling means can be freely moved in a limited angular range, but it is not easily mechanically distorted by a linemans hotstick applying pressure in other angular directions to the handling means.

Still another object of the invention is to provide a handling means for a cable termination housing that enables transmission of a uniform manipulating force therethrough independent of the angular displacement of the handling means with respect to the housing.

In one preferred form of the invention, a cable termination housing is provided with a handling means in the form of an elastomeric hotstick-receiving ring having a metal plate embedded therein to limit the stretchability of the ring. In addition, a resilient coupling means in the form of a cylindrically shaped body of elastomeric material is mounted between the termination housing and the hotstick-receiving ring to isolate stresses applied to the ring from the housing. In some embodiments of the invention, the cylindrically shaped resilient coupling means has one or more relatively rigid discs embedded in it in order to stiffen portions of the coupling means so that they are not distorted by the locking apparatus of a linemans hotstick when such a stick is engaged with the termination handling means.

Further objects and advantages of the invention will become apparent from the following description taken in conjunction with the appended claims and the attached drawing, in which:

FIG. 1 is a perspective view of an electric power cable termination housing having a handling means and a resilient coupling means mounted on it pursuant to my invention.

FIG. 2 is a side elevation view of the invention shown in FIG. I, illustrated with respect to a portion of a conventional linemans hotstick of a type normally used to manipulate such cable termination housings.

FIG. 3 is a perspective view, partly in cross section, of a portion of a cable termination housing similar to that shown in FIGS. 1 and 2 illustrating a second embodiment of a termination handling means and resilient coupling of my invention.

FIG. 4 is a perspective view of several component parts of a cable termination handling means and resilient coupling means constructed pursuant to yet another embodiment of my invention.

Referring now to FIGS. 1 and 2 of the drawing wherein the same numbers are used to identify like parts of the apparatus described, there is shown a cable termination housing ll formed of a suitable insulating elastomeric material that may be of any type that is now well known in the underground cable termination field. For example, the type of elastomeric insulating material discussed in the above-identified U.S. Pat. No. 3,474,386 is suitable for forming such a termination housing. in order to uniformly distribute and contain the electric field present around the high-voltage contacts 2 and 3 embedded in housing 1, the entire exterior surface of the housing 1 is covered with a flexible semiconductive coating 4 (see FIG. 3). This coating 4 may be formed by a high temperature molding process that bonds it to the insulating body 5 (see FIG. 3) in a manner well known in the present art, or by any other suitable means. Additional information regarding such high temperature bonding techniques may be obtained from a reading of U.S. Pat. No. 3,243,756 Ruete, which issued Mar. 29, I966, and which discloses a cable termination housing having a conductive coating bonded to its outer surface.

Pursuant to the present invention, a handling means 6 in the form of a hotstick-engageable ring 7 is mounted adjacent the housing 1 by being bonded to the upper surface of a resilient coupling means 8 comprising a generally cylindrically shaped body of elastomeric material that is mounted on the body of insulating material 5 of housing 1. In the embodiment of my invention shown in FIGS. 1 and 2, the resilient coupling means 8 is formed in a molding process integrally with the insulating body 5 of housing I and with the ring 7 of handling means 6. The length of the cylinder 8 comprising the resilient coupling means is ideally between one-eighth of an inch and one-half inch so that it will not be unduly distorted from its generally cylindrical form when force is transmitted to it from handling means 7. in addition, as can be seen in FlG. 2 of the drawing, the resilient coupling means g comprises a reduced diameter portion tie that allows the remaining portion of the means 8 to be operable to yield within a predetermined range of angular movement with respect to the body 5 of housing ll when forces are transmitted to the handling means 7 by movement of the handling means when it is grasped by the books 9 of a lineman s hotstick 19 and manipulated to bend portion 8a through an angle with respect to the housing 1. It is important to note that this unique construction enables the handling means 7 to yield with a uniform resisting force through the entire range of angular movement of coupling means 8 so that a uniform force is transmitted to housing 1 for any angular position of coupling means 8.

It should be understood that the invention as disclosed herein may be used with any conventional linemans hotstick, but for a further understanding of the operating principles of such a hotstick, reference may be had to copending US. Pat. application, Ser. No. 881,564, filed Dec. 2, 1969 by Richard F. Propst et al., and assigned to the assignee of the present invention. As described in that copending application, such a hotstick may include, in addition to pivotal hooks, such as the hooks 9, a hollow cylindrical body 11 the end 110 of which would normally engage the outer surface of resilient coupling means 8 when the hooks 9 of hotstick 10 are engaged with the tool-engageable surfaces of ring 7 of the handling means 6 of the present invention.

When such a coupling is effected between a hotstick l0 and the handling means 6, it will be apparent that the engagement between the resilient coupling means 8 and the end 110 of cylinder 11 on hotstick 10 will serve to bias the hotstick 10 into alignment with the vertical axis of the ring 7. Moreover, if the hotstick 10 is manipulated within a predetermined angular range with respect to the termination 1, the handling means 7 and resilient coupling means 8 are forced to move substantially simultaneously in the same direction so that the force transmitted from handle Ill causes the flexible portion 8a of the resilient coupling means 8 to bend so it prevents undue mechanical stresses from being applied at the junction of handling means 6 and the resilient coupling means 8. Accordingly, the risk of damaging the handling means 6 is substantially reduced and, at the same time, a positive, forcetransmitting coupling is maintained between the hotstick 10 and the body of termination I while the hotstick 10 is being manipulated through a variety of different angular positions with respect to termination 1.

It will be apparent that the diameter of resilient coupling means 8, in combination with the spacing of the enlarged diameter portion thereof from the termination 1, serves to define the range of angular movement through which a hotstick 10 may be easily manipulated before an undesirably high stress is applied to the ring 7. In a preferred form of my invention, the thickness of reduced diameter portion 8a of resilient coupling means 8 measured along an axis perpendicular to its diameter, falls in a range between one-eighth inch and onehalf inch, but it will be apparent that in given applications of the invention where more than a 20 angle of relatively free movement for a hotstick 10 is desired, other dimensions for this portion of the invention may be utilized From the discussion of the operation of my invention just given it will be apparent that one of its major advantages is that it affords better control of a termination manipulating function by a lineman manipulating hotstick 10 than was possible heretofore with the conventional prior art type of hotstick engageable ring that was rigidly mounted directly on the body of a cable termination, such as termination 1. In addition to this primary advantage, further desirable features of my invention will now be pointed out with reference to FIGS. 3 and 4 of the drawing. Referring first to FIG. 3, there is shown a second embodiment of the invention in which component parts similar to those discussed above with reference to FIGS. 1 and 2 are identified with like reference numerals. Thus, a

portion of a termination housing 1 is shown. having mounted thereon a generally cylindrically shaped resilient coupling means 3 that is formed as an integral part of the molded imitlating body 5 of a termination l, and includes a reduced diameter portion 811. Also bonded to the upper surface of resilient coupling cylinder 8 is an integrally molded hotstickengageable ring 7 of a handling means 6. All of these com ponent parts of this embodiment of the invention are formed in the same manner and perform like functions to those described above with reference to FIGS. 1 and 2 of the drawmg.

In addition to these fundamental components of the invention, this embodiment of it includes a nonresilient member l2 that is fastened to one surface of the resilient coupling means 8 by being molded in place thereon. Of course, in this molding operation the nonresilient member 12 is also coupled to the handling means 6 and is generally interposed between handling means 6 and the flexible, reduced diameter portion 8a of resilient coupling means 8. This unique arrangement serves to rigidify the resilient coupling means 8 and distribute the stresses applied to it evenly over the entire cylindrical body thereof, since in this embodiment of the invention the nonresilient member 12 is disc-shaped and only slightly less than coextensive with the diameter of the resilient coupling means cylinder 8, as seen in FIG. 3. In addition to the stress distributing function of the embedded nonresilient member 12, it serves the function of preventing the resilient coupling means 8 from being drawn up into a cylinder 11 such as that on a hotstick 10 (as seen in FIG. 2) when the hooks 9 of hotstick 10 are locked in engagement with ring 7 of handling means 6. This embodiment of the invention also further improves the ability of resilient coupling means 8 to force the longitudinal axis of a hotstick 10 to be maintained in alignment with the vertical axis of ring 7 when the hooks 9 are engaged in the tool engageable surfaces of ring 7, in the desirable manner discussed above. Moreover, to vary the ability of limiting the resilience of resilient coupling means 8, the nonresilient member 12 can be varied in shape or size to help determine the degree of angular movement through which resilient coupling means 8 and 8a can be manipulated. Although wide variations in angular movement can thus be achieved, it has been found in previous experiments with the invention that it is desirable not to limit the angle of movement of resilient coupling means to less than 10 with respect to the body 5 of housing 1, because at least such a range of movement is generally desired in manipulating the termination l in confined underground vaults. It should be understood that the nonresilient member 6, in addition to being variable in configuration, can also be formed of either electrical insulating material such as a suitable plastic resin or of electrically conducting material such as copper, since its primary function in the present invention is to afford mechanical strength rather than to attain electrical characteristics in housing 1.

A further improvement of the invention illustrated in the embodiment shown in FIG. 3 comprises a rigid core member l3 that is embedded in the elastomeric material of hook-eye handle ring 7 to reduce the ability of the handle 7 to elongate in response to forces transmitted to it by a terminationmanipulating tool such as hotstick 10. In the preferred embodiment of the invention illustrated in FIG. 3 the rigid core member 13 is a metal plate having an aperture or groove 13a formed therein and also having a flattened edge 14 that is ar ranged generally parallel to a flattened surface of nonresilient member 12, when these component parts of the invention are in their respective positions on termination housing ll. This arrangement allows member 13 to force member 12 to pivot when force is applied to ring 7 by a hotstick. It will be appreciated that

members

12 and 13 can be formed as one integral part if preferred in other embodiments of the invention.

In both embodiments of the invention discussed thus far, the resilient coupling means 8 and handling means 6 are mounted on a cable termination housing 1 that is molded in the form of an elbow and they are mounted thereon closely adjacent to the bend of the elbow, on its outer radial surface. Of course, it will be understood that similar coupling means and handling means can be mounted on other forms or configurations of cable termination housings and such modifications are contemplated within the scope of the invention.

Reference is now made specifically to FIG. 4 of the drawing, wherein a further embodiment of the invention is shown and component parts thereof that are identical to the component parts shown in FIG. 3 of the drawing are identified with like reference numerals. lt will be understood that in FIG. 4, although the depicted component parts are shown in the relative asernbled positions that they would maintain on a cable termination housing, such as termination housing 1, no such housing 3 is shown in H6. 6 in order to simplify the descrip tion of this embodiment. Thus, a rigid core member 13 having a generally flattened edge l4 mounted adjacent the upper surface of a disc-shaped nonresilient member 12 is shown mounted in spaced-apart relation with respect to another nonresilient member 15. in this embodiment of the invention, the cylindrically shaped resilient coupling means 8 is further rigidified by positioning at least a portion of its resilient body between the spaced-apart pair of

nonresilient members

12 and 15 thereby to reduce the flexibility of the resilient coupling means 8 even further than it was reduced in the embodiment of the invention depicted in FIG. 3, wherein only a single nonresilient member 12 was employed. it will thus be apparent that a resilient coupling means 3 can be strengthened in this manner to further guard against distortion of the coupling means 3 when the hooks 9 of the hotstick 10 are locked within the handling means 6 in the manner discussed in detail above with reference to FIG. 2 of the drawing. Such stiffening means are often desirable when the length of coupling means 8 is increased to enlarge the angle of relatively free movement of handling means 6; because the coupling means 5 must be maintained rigid enough to allow fairly positive manipulation of the housing 1. Of course, if more than two nonresilient members, such as disc-shaped members 312 and are desired to further stiffen the resilient-coupling means 8, additional members may be molded into the resilient means 8 as described above with reference to member 12 in FIG. 3 of the drawing. if desired, the lower nonresilient member 15 may be located in the reduced-diarneter portion 8a rather than in the large diameter portion of coupling means 8, as shown by phantom disc 15a in FIG. 3.

Additional modifications and embodiments of the invention will be apparent to those skilled in the art and all such embodiments and modifications are intended to be encompassed within the scope of the following claims.

What i claim and desire to secure by Letters Patent of the United States is:

l. A voltage grading termination housing for a high-voltage electrical conductor comprising a body of insulating material of predetermined configuration, handling means mounted adjacent said body to provide tool-engageable surfaces that are adapted to be grasped by a manually operable terminationmanipulating tool, said handling means comprising a hook-eye handle resilient coupling means comprising a generally cylindrically shaped body of elastomeric material that is mounted on said body by thermosetting adhesive means and fastened to said handling means to afford a resilient, force-transmitting and distributing connection between said handling means and the housing, said resilient coupling means being constructed as to be operable to yield within a predetermined range of angular movement with respect to said body when subjected to forces transmitted to it from said handling means due to movement thereof when the handling means is operably grasped and moved by a termination-manipulating tool, thereby to distribute said forces over an area of said body of insulating material to reduce the risk of said body of insulating material being torn.

2, An invention as defined in claim 1 wherein said coupling means exerts a substantially uniform force to the housing through the entire range of angular movement of said coupling means.

3. An invention as defined in claim 3 wherein said nonresilient member is disc-shaped and said body of elastomeric material is generally cylindrical in configuration, one end of said generally cylindrical body of elastomeric material being fastened to a flattened surface of said disc-shaped nonresilient member.

4. A voltage grading termination housing for a high voltage electrical conductor comprising a body of insulating material of predetemiined configuration molded around a pair of electrically interconnected electrical contacts, handling means mounted adjacent said body to provide tool-engageable surfaces that are adapted to be grasped by a manually operable tennination-manipulating tool, resilient coupling means mounted on said body and fastened to said handling means to afford a resilient, force-transmitting connection between said handling means and the housing, said resilient coupling mews being constructed as to be operable to yield within a predetermined range of angular movement with respect to said body when subjected to forces transmitted to it from said handling means due to movement thereof when the handling means is operably grasped and moved by a termination-manipulating too], said resilient coupling means comprising a body of elastomeric material that is mounted on said body of insulated material, and includes a nonresilient member that is fastened to a surface of said body of elastomeric material, said nonresilient member also being coupled to said handling means thereby to interpose a relatively rigid stress-distributing member between said handle means and said body of elastomeric material.

5. An invention as defined in claim 4 wherein said handling means comprises a hook-eye handle formed of elastomeric material, said cylindrical body of elastomeric material being sufficiently long and flexible to allow the disc-shaped, nonresilient member to be moved through an angular range of at least 10 responsive to a bending force being transrriitted to it from said hook-eye handle before the elastomeric material of said handle is stretched beyond a predetermined limit of its elasticity by a torsion force applied to it from a terminationmanipulating tool.

6. An invention as defined in claim 5 wherein said termination housing, said coupling means and said handling means comprise component parts of an integral termination housing that is formed of thermosetting, moldable elastomeric material.

7. An invention as defined in claim 6 wherein said nonresilient member comprises a disc of electrical insulating material embedded in a coating of elastomeric material that forms an integral part of said termination housing.

8. An invention as defined in claim 7 including a rigid core member embedded in the elastomeric material of said hookeye handle thereby to reduce the ability of said handle to elongate in response to forces transmitted to it by a temiinationmanipulating tool.

9. An invention as defined in claim 8 wherein said rigid core member is a metal plate having an aperture therein and having a flattened edge that generally parallels a flattened surface of said disc-shaped nonresilient member when said components are in their respective assembled positions on said termination housing, and said disc-shaped nonresilient member comprises a metal plate.

10. An invention as defined in claim 6 wherein said predetermined configuration for said termination housing forms an elbow, said handling means being mounted on one leg of said elbow closely adjacent the bend therein and on the outer radial surface thereof.

11. An invention as defined in claim 3 wherein said resilient coupling means includes a second nonresilient member mounted in spaced-apart relation with respect to the other nonresilient member therein, whereby at least a portion of the body of elastic material is positioned between said nonresilient members to thereby reduce the flexibility of said resilient coupling means.

Claims

1. A voltage grading termination housing for a high-voltage electrical conductor comprising a body of insulating material of predetermined configuration, handling means mounted adjacent said body to provide tool-engageable surfaces that are adapted to be grasped by a manually operable termination-manipulating tool, said handling means comprising a hook-eye handle resilient coupling means comprising a generally cylindrically shaped body of elastomeric material that is mounted on said body by thermosetting adhesive means and fastened to said handling means to afford a resilient, force-transmitting and distributing connection between said handling means and the housing, said resilient coupling means being constructed as to be operable to yield within a predetermined range of angular movement with respect to said body when subjected to forces transmitted to it from said handling means due to movement thereof when the handling means is operably grasped and moved by a terminationmanipulating tool, thereby to distribute said forces over an area of said body of insulating material to reduce the risk of said body of insulating material being torn.

2. An invention as defined in claim 1 wherein said coupling means exerts a substantially uniform force to the housing through the entire range of angular movement of said coupling means.

4. A voltage grading termination housing for a high voltage electrical conductor comprising a body of insulating material of predetermined configuration molded around a pair of electrically interconnected electrical contacts, handling means mounted adjacent said body to provide tool-engageable surfaces that are adapted to be grasped by a manually operable termination-manipulating tool, resilient coupling means mounted on said body and fastened to said handling means to afford a resilient, force-transmitting connection between said handling means and the housing, said resilient coupling means being constructed as to be operable to yield within a predetermined range of angular movement with respect to said body when subjected to forces transmitted to it from said handling means due to movement thereof when the handling means is operably grasped and moved by a termination-manipulating tool, said resilient coupling means comprising a body of elastomeric material that is mounted on said body of insulated material, and includes a nonresilient member that is fastened to a surface of said body of elastomeric material, saiD nonresilient member also being coupled to said handling means thereby to interpose a relatively rigid stress-distributing member between said handle means and said body of elastomeric material.

5. An invention as defined in claim 4 wherein said handling means comprises a hook-eye handle formed of elastomeric material, said cylindrical body of elastomeric material being sufficiently long and flexible to allow the disc-shaped, nonresilient member to be moved through an angular range of at least 10* responsive to a bending force being transmitted to it from said hook-eye handle before the elastomeric material of said handle is stretched beyond a predetermined limit of its elasticity by a torsion force applied to it from a termination-manipulating tool.

8. An invention as defined in claim 7 including a rigid core member embedded in the elastomeric material of said hook-eye handle thereby to reduce the ability of said handle to elongate in response to forces transmitted to it by a termination-manipulating tool.