US 3210720 A
Description (OCR text may contain errors)
Oct. 5, 1965 T. c. HARRIS, JR
CABLE CONNECTORS Filed April 28, 1961 w @wb2 W Q United States Patent Oil 3,219,720 Patented 9ct. 5, 1965 ice 3,210,720 CABLE CONNECTORS Thurman C. Harris, r., Elberfeld, End., assigner of thirty-three and one-third percent to .lames C. Julian, Lynnville, and thirty-three and one-third percent to Bradford E. ingle, Evansville, lud.
Filed Apr. 28, 1961, Ser. No. 106,322 1 Claim. (Cl. 339-149) This invention relates to electrical cable, and more particularly, to connectors for use with high duty electrical cable.
Electrical cable, to which this invention is addressed, comprises high duty electrical cable formed of one, and preferably two or more, conductors, each of which embodies a plurality of strands, sheathed with filler strips and ground wires. Terminals are provided in longitudinally spaced apart portions throughout the length of the cable in the form of potheads from which the separate conductors issue as insulated leads adapted to be connected to extensions for electrically joining the electrical source with a device adapted to be operated thereby in the field.
The respective ends of the leads and cable extensions are adapted to be releasably connected onto the other to stretch the cable to the sections for use of electrical energy which may be some distance from the main cable and the pothead from which the leads originally issue. For this purpose, use has been made of a male member at one end and a female member at the other adapted to receive the male member in intertting relation to effect an electrical connection therebetween. The male and female members are formed of copper, brass, or other electrically conductive material with the opposite ends of said male and female members being joined, as by welding, to the respective conductors, such as the conductor in the lead from the pothead and the conductor through the extension, or with a male member at one end of the extension and the female member at the other end to more or less interconnect the extensions one with another in stretching the cable to the station of use. Such use of multiple extensions is occasioned by the limitation as to the length of any one extension because of the excessive weight ofthe cable.
The male and female connectors are encased within a relatively thick sheath of insulating material, such as molded neoprene, with the exception of the length of the male member or pin adapted to be received in telescoping relation within the female member. The molded insulation extends throughout the length of the female member and to the base of the pin of the male member with the facing ends of the insulation being congured to establish a sealing relationship therebetween when the male member is properly inserted into the female member for establishing an electrical connection therebetween.
It has been found that the pin and/or the insulation in the male and female members adjacent the pin is subject to rapid deterioration in normal use whereby it becomes necessary frequently to disconnect the cable for replacement or repair. Such deterioration often results from slight separations between the male and female members whereby insulation is not available to prevent arcing of the electrical current to ground or cross the members whereby the hot spark causes erosion of the pin or the generated heat causes breakdown of the insulation. This is evidenced by the noticeable deterioration or thermal breakdown of the insulation in the end portions of the male and female members adjacent the pin and it is also evidenced by the pitting of the pin at its base whereby the metal is eaten away to cause deterioration of the pin. Separation between the male and female members can result from normal operation wherein the male and female members tend to work apart or it may result from the laying of the cable wherein the motive force used to stretch the cable may impose sufficient tension to cause slight tension at the connection or it may result from the forces of nature whereby movement of the earth across the path of the cable may cause slight separation between the male and female members to enable the current to short from the pin to the female member or to ground and cause excessive heating for thermal breakdown of the insulation or erosion. of the metallic pin or it may result further from the partial breakdown of the insulation whereby arcing can occur to accelerate deterioration of the connection.
Whatever the reason, when deterioration becomes eX- cessive, often every sixty to ninety days, it becomes necessary either to replace or repair the broken down portion of the connection. This necessitates disconnection of the cable until a new connector and the cable portion connected thereto can be spliced into the end portion of the conductor for replacement. This procedure is objectionable for a number of reasons:
(l) For replacement, it is necessary to sever the cable leading to the connector member which has been subject to deterioration in order to splice a new connector onto the cable. This requires a highly skilled technician for splicing the multiple stranded cables together, thereby to make it necessary either to have readily available such highly skilled technician in the field or otherwise to hold up the repair until such highly skilled person can be made available.
(2) The process of splicingr such multiple stranded cables and the making available a highly skilled technician for splicing takes considerable time during which the material being fed with electrical current is forced out of service. In many instances, the loss of service of such equipment may further exceed the cost of replacement or repair and may add up to thousands of dollars per shutdown.
(3) The necessity of replacement of the deteriorated connector portion with a new one markedly increases the maintenance cost of the cable.
(4) Another problem sometimes encountered in the field of use stems from the laying of the extension such that the adjacent ends of the lengths of cable to be connected are both found to have male members or female members. Under such circumstances, it is necessary to turn the cable about. This is no easy task when it is appreciated that the cable is usually laid in lengths of one thousand feet and may weigh many tons. Again, the reversal of the cable leads to frustration, loss of service of the power equipment and the expenditure of considerable effort, all of which adds up to considerable cost in use.
It is an object of this invention to provide an entirely new system for cable connection, and it is a related object to provide a new and improved cable means.
More specically, it is an object of this invention to produce a connector for cables of the type described which is simple in construction and easy in operation; which does not require splicing of the cables for repair of the portion of a connector which has been subject to deterioration; which does not require the use of highly skilled labor for the repair or replacement of parts of the connector; which enables repair easily and quickly carried out in the field, thereby to minimize the length of time that the power equipment is taken out of service; which permits replacement of a male member for a female member with the opposite member to avoid the necessity for turning the length of cable about in the event that the cable length is 4laid with two male or two female members in end-to-end relation; and which provides for improved water proofing of the joined connector elements, thereby to minimize the breakdown of the insulation or pin as a result of leaking or arcing across the connector elements.
These and other objects and advantages of this invention will hereinafter appear, and for purposes of illustration, but not of limitation, an embodiment of the invention is shown in the accompanying drawings, in which:
FIGURE l is a schematic view diagrammatically il- 4lustrating a cable arrangement embodying the features of this invention;
FIGURE 2 is a perspective view of the connector in its assembled relation;
FIGURE 3 is a sectional View taken lengthwise across the center of the connector shown in FIGURE 2;
FIGURE 4 is a sectional View of the separate connector elements in their relative positions for connection but without the insulation; and
FIGURE 5 is a sectional view similar to that of FIG- URE 4 but with the insulation molded about the elements.
Referring now to the drawings, the numeral represents a high duty cable of conventional construction which, as dened in the co-pending application Serial No. 821,863, filed June 22, 1959, entitled, Cable Repair, and now abandoned is formed with three multiple strand conductors and ground wires separated one from the other and enclosed by a molded insulation, such as neoprene. A pothead 12 is provided at the terminus of the cable from which the conductors 14, I6 and 18 issue as separate insulated leads having a connector embodying the features of this invention interconnecting the free ends of each lead with a length of cable for stretching the leads to distant stations for use.
As illustrated in the drawings, the connector is fabricated of a male member Z2 and a female member 24. The male segment of the connector is formed of two separate parts, one of which is referred to as the male base member 26 and the other which is referred to hereinafter as the male adaptor 28. Similarly, the female segment is fabricated of two separable parts, one of which is referred to hereinafter as the female base rnember 30 and the other as the female adaptor 32. The female base member 30 and the male base member 26 are substantially identical in construction. A cylindrical section 34 is formed in which an end portion 36 of a large dimension is formed with a cylindrical cavity 38 in which the end 40 of the multiple strand conductor is adapted to be received in telescoping relation for joinder, as by means of brazing, welding or the like to secure the base member onto the end of the conductor to establish a permanent electrical connection therebetween. The outer end portion of small dimension in cross-section is also formed with a cylindrical cavity 42 which is provided with screw threads 44 threadably to receive the corresponding threaded shank 46 of either the female adaptor or the male adaptor, as the case may be.
Other than the threaded shank portion which permits the female adaptor or the male adaptor interchangeably to be threaded onto a base member, the adaptors are substantially unlike one another. The male adaptor is formed with a body portion 48 dimensioned in crosssection substantially to correspond to the cross-section of the base portion. The peripheral surface of the body portion is formed with a plurality of axially spaced ribs 50 for the purpose of anchorage of the insulator material molded thereon and the mid-section of the body portion is preferably knurled, as at 52, or otherwise provided with surface roughness for better anchorage of the insulation molded about the body portion as will hereinafter be described. The pin 54 of substantial length and of smaller cross-section than the body portion extends axially from the body portion. rlhe pin is CFI formed integrally of the body portion of the same electrically conductive metal and it is formed with a rounded face 56 to facilitate entrance of the pin for sliding displacement of the cavity into the female member for effecting an operating connection therebetween.
The female adaptor is also formed with a -threaded shank 58, as in the male adaptor, and with a body portion of uniform dimension extending throughout the remainder `of the female adaptor. rThe cavity 60 in the female adaptor is dimensioned to have a length corresponding to and preferably slightly less than the pin 54 of the male member and a cross-section corresponding to the cross-sectional dimension of the male member to receive the male member in fitting relationship therein. It is preferred to dimension the cavity to have a length slightly less than the length of the pin so that a smaller 4spaced relation will exist between the body portions of the male and female members when the pin is inserted in the cavity of the female member in position of use. To enhance the electrical contact between the male and female members, the body portion 32 of the female member is provided with slits 62 from the forward end substantially to the base of the cavity and the metal is treated in forming to cause warpage of the separate sections inwardly resiliently to engage the pin when inserted therebetween into the cavity. An additional spring coil 64 encircles the body portion adjacent the slitted ends resiliently to urge the slitted sections towards their inwardly displaced position.
When the base members are secured onto the ends of the conductors, a thick sheath 65 of neoprene or other resilient electrical insulating material is molded or otherwise formed about the base member and the conductor permanently to join the base member and the conductor in a permanently insulated unitary structure. With a base member, the electrical insulation extends about the base member to the end thereof, as illustrated in FIGURE 5.
The insulation is molded about the adaptors completely to cover the body portion leaving the pin 54 free in the male adaptor for insertion into the cavity of the female adaptor and leaving the threaded Shanks 46 and 58 of both the male and female adaptors free for threading into the threaded cavities of the corresponding base members. It is desirable to construct the end faces of the insulation sections of the intertting members to effect a sealing relationship therebetween when properly interconnected one to the other to prevent the entrance of moisture and the like foreign materials which might otherwise permit leakage or arcing over to accelerate the deterioration of the parts.
For this purpose, the insulation sections molded about the base members terminate in an end portion of cylindrical sections and '72 of decreasing dimension with a frusto-conical section 74 interconnecting the cylindrical sections to provide a larger amount of surface area between which the desired sealing relationship can be effected. The adjacent end portions of the male or female adaptors are formed with a cavity or recessed portion 76 which is the exact counterpart of the end construction in the base member so that the one end section will be received in fitting relationship within the other to effect sealing relationship therebetween when the threaded Shanks 46 or 58 are turned into the threaded recesses 44 of the base members. While the illustrated modication makes use of a pair of cylindrical sections 70 and 72 of reducing dimension in the end construction, it will be understood that only one or more than two such intertting cylindrical sections in correspondingly shaped recesses in the adjacent adaptor may be provided or the end construction may be formed of a combination of stepped sections and. or curvilinear members adapted to define a tortuous path with increased area of surface contact to block the passage of moisture therebetween.
It will be understood that instead of forming the recesses in the adaptor end and the corresponding cylindrical or contoured sections in the corresponding end of the base member, the recessed portions may be provided in the base member for receiving their counterpart in the interfitting end of the adaptor with the end faces '7S and S0 being dimensioned to abut one another to effect a sealing relation therebetween when the threaded shank is turned tightly into the threaded recess.
Once the adaptor has been fitted onto the base member, the assembled male and female members are maintained in their assembled relationship until it is desirable either to interchange the adaptors of the male or female members for replacement or for repair. Since the assembled relation of the base and adaptor is effected by turning the threaded shank of the adaptor into the threaded cavity oi the base member, it becomes possible to make use of the screw concept of forcing the `adaptor onto the base member thereby to permit the intertting portions of the insulation to be dimensioned to close tolerances for a better and more permanent seal.
The assembled male and female members are adapted removably to be interconnected by displacement of the male member into and out of the female member. Yet, at the same time, it is still desirable to effect a moisture seal between the elements in their interconnected relation. For this purpose, the male member is formed with a vertical .abutment 82 which functions as a stop against which the corresponding face S4 of the female member is received in abutting relationship when the pin 54 is rammed home into the cavity 60. The abutment 82 terminates in a frusto-conically shaped portion 86 which in turn terminates in a cylindrical section S8 of small dimension about the base of the pin for use as an additional abutment and insulation. The end construction of the insulation in the female member is recessed to form the counterpart of the male member so that the end portion of the insulation layer in the male member will be received in abutting and intertting relationship within the end construction of the insulation of the female member when the elements are properly joined. As previously described, the end construction in the male and female members can be interchanged and other contoured surfaces may be used, such as a plurality of stepped or conical or curvilinear end sections, free of re-entrant portions with the counterpart being recessed in the end construction of the other.
By way of modification, instead of forming the base members with the threaded cavity threadably to receive the threaded pins of the adaptors, the elements may be reversed to provide the threaded shank on the base member and the threaded cavity on the adjacent end portion of the adaptor but it is desirable to be consistent in the location of the threaded recesses either in the base members or the adaptors so that the male adaptor can be readily interchanged for the female adaptor or vice versa to obviate the dilhculties heretofore encountered when the line extension is laid with two male or two female members in end-toend relation.
When the end portion of the male member or when the end portion of the female member or both become deteriorated in use such as to require replacement, it is only necessary, in a system embodying the features of this invention, to unscrew the corresponding adaptor from the base member for replacement with a new adaptor, extra ones of which can be made easily available in the field. Such interchange to replace the adaptor can be effected in a matter of but a few minutes with tools readily avail able in the field and by labor other than highly skilled technical labor. As a result, the electrical line need be taken out of service for only the few minutes required to replace adaptors thereby markedly to reduce the time that the line and connected equipment is out of service.
The need only to replace a tip of the female or male connector operates markedly to reduce the cost of maintaining the connectors in suitable condition for use and it materially reduces the inventory of parts required to be maintained in the field for proper maintenance of the electrical line equipment. When, by chance, the length of line is laid with two male members or two female members in endwise alignment, instead of reversing the heavy length of cable, a considerable savings in time will be experienced and a considerable savings: in effort will be achieved by correcting the error in a manner which calls merely for unscrewing one of the matching adaptors for replacement with the counterpart to provide an interiitting male and female member in the adjacent ends for interconnection.
It will be apparent that various modifications can be embodied in an assembly of the type described. For eX- ample, instead of making use of a threaded shank and threaded cavity for interconnecting the adaptors and base members, other suitable connecting means may be employed to iiX the adaptor onto the base member. Instead of forming the base members and the body portions of the adaptors to curvilinear or cylindrical shape, the elements can be formed to rectangular or other polygonal shape in the outer contours for receiving the insulation layer thereon. Similarly, the pin and recess may be formed to shapes other than cylindrical shape but the latter is preferred to permit interchangeability of parts as well as use of the concept of this invention With connector elements which are now in use. Instead `of making use of a molded insulation of neoprene and the like elastomeric materials, other insulation systems suitable for electrical cable of the type described may be employed.
It Will be understood that changes may be made in the details of construction, arrangement and operation without departing from the spirit of the invention, especially as defined in the following claim.
An electrical cable connector comprising the combination of a male member and a female member of electrical conductive material, said male member being formed of a male base and a male adaptor, means on one end of the male base for permanent connection with an electrical conductor at one end of a length of cable, a pin on one end of the male adaptor, means for releasably connecting the male adaptor and the male base comprising a cavity in the other end of one of the members including the male base and male adaptor provided with screw threads in the periphery thereof and a threaded shank on the other end of the other of the male base and male adaptors dimensioned to be received in threaded relationship in the threaded cavity to bring the other end of the male base member and adaptor in abutting relationship one with the other when the threaded shank is properly received Within the threaded cavity, said female member being formed of a female base and a female adaptor, said female base being of the same construction as the male base for interchangeability therewith, and said female base having means on one end for permanent connection with an electrical conductor at one end of another length of cable, a cavity in one end of the female adaptor dimensioned to have a cross-section corresponding to the crosssection of the pin of the male adaptor slidably to receive the pin therein, means on the other ends of the female adaptor and Athe female base for releasably interconnecting the other end of the female adaptor and the female base comprising a cavity in the other end of one of the members including the female base and female adaptor provided with screw threads in the periphery thereof and a threaded shank on the other end of the other of the female base and female adaptors dimensioned to be received in threaded engagement within the threaded cavity to bring the other end of the base member and the other end of the adaptor in abutting relationship one with the other, and electrical insulating material covering the male and female bases and separate insulating material covering the male and female adaptors with the electrical insulating material enclosing said bases having a configura- 7 tion adapted to mate with said separate insulating material whereby a substantially continuous outer surface is presented by said cable connectors when the respective bases and adaptors are interconnected.
References Cited by the Examiner UNITED STATES PATENTS 593,442 11/97 Tailleur 339-89 X 762,684 6/04 Case 339-28 1,701,646 2/29 Taylor 339-29 JOSEPH D. SEERS, Primary Examiner.
PATRICK A. CLIFFORD, Examiner.