US3130258A

US3130258A - Electrical connector

Info

Publication number: US3130258A
Application number: US44198A
Authority: US
Inventors: Robert F Cobaugh
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1960-07-20
Filing date: 1960-07-20
Publication date: 1964-04-21
Anticipated expiration: 1981-04-21

Description

P 19644 R. F. COBAUGH ELECTRICAL CONNECTOR Filed July 20. 1960 m F. r

5 n Y M United States Patent 3,130,258 ELECTRICAL CONNECTOR Robert F. Cobaugh, Hershey, Pa., assignor to AMP. Incorporated, Harrisburg, Pa.

Filed July 20, 196i), Ser. No. 44,198 2 Claims. (Cl. 174-71) This invention relates to crimpable electrical connectors particularly of the type intended to connect a branch conductor, such asa power tap, to a through conductor, such as a power service line although other uses of the invention will be apparent from the description set forth below.

Electrical connectors of the class intended to connect branch conductors to through conductors, such as power service lines, must satisfy several requirements which do not apply to other types of connectors and splices. Usually, these connectors are used on relatively large wires, for example A.W.G No. 8 and larger, and must be capable of being applied in the field with manually operable tooling. Furthermore, the connectors must be of relatively simple design sothat they can be assembled to the wires and crimped by means of remotely controlled tooling on one end of a relatively long handle. The necessity for this requirement stems from the fact that in many cases the electrical connections are formed while the service power lines are under high voltages so that the operator or technician cannot work close to the conductor and use tools having relatively short handles. Power line tap connectors must also be capable of giving reliable service over a long period of time and under any of the ordinarily encountered weather conditions. It is particularly noteworthy that such tap connectors are subjected one type of physical force which is not encountered in ordinary electrical connectors which is produced when the tap (which extends transversely of the through conductor) is subjected to a wind load. The

tap, under these conditions tends to be rotated about the through conductor and a torque is thereby applied to the electrical connection which must be capable of withstanding this type of abuse withoutloss of its electrical or mechanical function. This type of force is notchcountered with ordinary electrical connectors which are For example,

tap conductors have been developed which are satisfactory if they can be crimped by an operator working in close proximity to the power service line but they are unsuited for application by remotely controlled devices. Finally, many of the presently available tap type connectors are not adapted to withstand the lateral loading or torque which is discussed above so that the connection tends to become loosened when a heavy wind load is applied to the tap conductor.

It is accordingly an object of the present invention to provide an improved connector for connecting a tap line or branch line to a through conductor such as a power permit telescopic engagement.

FIGURE 1.

service line. A further object is to provide a connector which can be assembled to the wires and crimped by remotely controlled tooling with facility. A still further object is to provide a connector capable of reliable long term service under the adverse conditions encountered with power taps and the like and particularly which is resistant to the torque effects produced by wind loads on the tap conductor.

These and other objects of the invention are achieved in a preferred embodiment comprising a two part connector of which a first part has a substantially V-shaped cross section with reversely extending longitudinal edge portions and in which the root portion provides a generally semi-cylindrical surface. This first part of the connector is telescopically engageable with a second part having, extending along one side thereof, a semi-cylindrical recess which is complementary to the semi-cylindrical surface of the first part so that the surface and the recess form a cylindrical opening in the assembled connector for a; through conductor. The second mating partof the connector has longitudinal surfaces on each side of the recess which conforms to the internal surfaces of the V- shaped first part and also provides grooves to accommodate the inwardly turned edges of the first part to The second part of the conductor is provided with an opening parallel to, and beneath, the semi-cylindrical recess to accommodate the tap conductor so that in use, the V-shaped first part can be placed over the through conductor, the tap conductor can be inserted through, the opening in the second part, and the two parts of the connector can be telescoped together after which they can be crimped by any form of a crimping tool by inward compression. After such crimping, the two parts of the connector are securely locked together in a manner which resists loosening upon the application of torque by the tap conductor and/or relaxation on the. part of the connector.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the draw ings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particularuse. i

In the drawing:

FIGURE 1 is a perspectiveview of a preferred embodiment of the invention.

FIGUREZ is a View of the connector after crimping showing the through conductor and the tap conductor.

FIGURE 3 is a viewtaken along the lines 33 of FIGURE 4 is a view taken along the lines 44 of FIGURE 2.

FIGURE 5 is a longitudinal sectional view of the crimped connector taken along lines 5-5 of FIGURE 4. In the disclosed embodiment the reference numeral 2 denotes a first part of the connector which is of substantially V-shaped cross section and which has a generally rounded apex 4 so that the internal surface 6 of the root is of generally semi-cylindrical form. The longitudinal edges 3 of the first part of the connector are inwardly turned and extend reversely at 10 towards the root portion 6.

The second part 12 of the connector has a semicylindrical recess 14 on the upper side thereof which is complementary to the surface 6 so that when the two parts are assembled a generally cylindrical opening 15 is formed to accommodate the through conductor 26. On each side of the recess 14 the sidewalls 16 of the second part are divergent and conform to the internal surfaces of the first V-shaped part of the connector. Grooves 18 are provided on the opposite sides of the recess for the accommodation of the inwardly turned

edge portions

8, 10 so that the two parts of the connector can be assembled to each other by parallel axial movement. The external surfaces of the second connector part beneath the grooves 18 are generally convergent substantially similar to the

surfaces

2, 4 of the upper V-shaped part so that the general overall configuration of the assembled connector is that of an ellipse. A second opening 22 in the second or lower part of the connector is provided to accommodate the tap conductor 28 through which it extends as shown in FIGURE 2.

Connectors in accordance with the invention can be manufactured from any suitable conductive metal but the principles of the invention are particularly intended for aluminum conductors connections and the connector is advantageously of aluminum alloy for such conductors. The parts can conveniently be formed by extrusion and the extruded sections can be cut to the desired length. Advantageously, the edges of the

openings

15, 22 are beveled or otherwise enlarged as shown at 24 or 25 to facilitate the assembly of the parts to the conductors and the insertion of the tap conductor through the opening 22.

In use, the upper part 2 of the connector is first positioned over the through conductor. The tap conductor is inserted through the opening 22 and temporarily secured in place as by bending one of its strands as shown in FIGURE 2 and the two parts of the connector are thereafter telescoped together so that the tap conductor and the connector are supported by the through conductor 26. The connector is then crimped by the use of any suitable crimping tool, the disclosed embodiment being provided with three crimped areas which are separated by circumferential ridges 32. Advantageously, the crimping operation is carried out by means of a set of crimping dies having, when closed, a generally elliptical cross section with a major axis slightly less than the major axes of the uncrimped connector. With crimping dies of this type, the cross sectional dimensions of the connector are somewhat reduced as shown in FIGURE 4 and the two

openings

15, 22 are flattened until they become generally oval as viewed in cross section. It will be noted from FIGURE 4 that while the major axis of the ellipse is reduced during crimping, the minor axis remains substantially unchanged and the reversely

bent edges

8, 10 of the upper part 2 are securely locked within the longitudinal grooves 18 of the second part. This effect can be achieved in the crimp areas if the terminal is crimped to the extent that its cross sectional area is slightly reduced.

The method described above of assembling the connector to the wires can be carried out by means of suitable remotely controlled tooling. In the co-pending application of Henry Demler, Serial No. 44,199 filed July 20, 1960, for Connector Tool, now Patent No. 3,098,289, issued July 23, 1963, there is shown one form of tool for assembling the connector and the tap wire 28 onto a through conductor. The crimping operation can be carried out with any conventional crimping tool having a suitable force multiplying means.

It will be apparent that connectors in accordance with the invention possess the advantages of ease of application or assembly and crimping and additionally are extremely simple in design and manufacture. A substantial advantage of the invention is that after crimping, the two parts of the connector are securely locked together in a manner such that the stresses imposed thereon are to a large extent counteracted by the connector itself. For example, when the connector is crimped, the cross sec tional area of the

conductors

26, 28 will be very slightly reduced as is apparent from FIGURES 3 and 4. As a result, the portions of the conductors contained within the connectors will be very slightly extruded. Under these circumstances, the normal tendency on the part of the wires will be to return to their original positions or, in other words, to flow inwardly of the connector and to radially expand. Forces of this type ordinarily tend to open up a connector and to cause a relaxation of the contact pressure between the connector and the wire. With the instant connector, however, the upper part 2 is securely locked to the lower part 12 and the imposition of a radial force or stress upon the sidewalls of the part 2 by the compressed connector will merely tend to cause these sidewalls to pivot or swing inwardly towards each other. The normal stress pattern which is established in a crimped connector in accordance with the invention is llustrated in FIGURES 4 and 5. As is apparent from FIGURE 5, the compressed and slightly extruded conductor 26 will tend to contract as shown by the arrows and thereby exert a radial pressure as shown by the arrows of FIGURE 4 against the surface of the recess 14 and against the surface 6. This radial pressure, however, cannot cause the sidewalls of the first part 2 of the connector to open up by virtue of the fact that these sidewalls are securely locked within the grooves 13 of the second part 12 of the connector.

If the tap conductor 28 is subjected to a torque as by a wind load, there can be no opening up of the crimp between the tap conductor and the connector since this conductor is totally surrounded by the body of the second part 12 of the connector. Furthermore, the lower or second part of the connector exerts a radial inward pressure on the conductor which cannot relax by reason of the inter-locked relationship between this lower part and the upper two which, as explained above, is prevented from relaxation by the lower part. Thus, the inevitable stresses to which the connector must be subjected in use are with the instant invention, either substantially neutralized, or, in the case of the through conductor 26, beneficially utilized to maintain a continuing contact pressure between the connector surface and the conductor.

While the invention has been disclosed and explained with particular reference to its use in connecting tap wires to through conductors, it will be apparent that it is of at least equal utility in forming connections between the ends of two wires which extend along a substantially straight line.

I claim:

1. A crimped electrical connection between conductors in which at least one of the conductors is tapped intermediate its ends comprising, a first ferrule member of substantially V-shaped cross section, the inside of the base of said member receiving one of said conductors and the ends of the arms of said member being reversely bent inwardly, a second ferrule member having one side thereof a projection of substantial width and being received between the arms of said V-shaped first ferrule member, flanges on the lateral edges of said projection and extend ing within the recesses defined by the reversely bent ends of said arms, said second ferrule member having an axial opening, a second conductor received within said opening, said first ferrule member and said second ferrule member defining a generally oval shaped cross section for said connection, said connection being crimped by indentation on each of its sides whereby, the arms of said first member and the flanges of said second member are compressed together, and said flanges prevent relaxation of said arms and loosening of said connection.

2. A two part electrical connector for connecting a tap conductor to a through conductor comprising a first part of generally V-shaped cross section, the internal surface portions on each side of the apex of said first part being semi-cylindrical, the longitudinal marginal edge portions of the sidewalls of said first part being bent inwardly towards each other and reversely towards the apex of said first part, a second part of said connector having a semi-cylindrical surface on one side which is complementary to the internal cylindrical surface of said first part, said second part having sloping sidewall portions on each side of its semi-cylindrical surface which conform to the internal sidewalls of said first part, a pair of longitudinally extending grooves on opposite sides of said second part and bordering said sloping sidewall portions, said grooves having a cross section conforming to said inwardly and reversely bent marginal edge portions of said first part, and said second part having an opening extending therethrough for reception of said tap conductor, both of said parts being rigid and said parts being freely telescopically movable together to form a composite connector having a pair of openings extending therethrough, said marginal edge portions of said first part being interlockable with said grooves on said second part upon crimping of said connector by application of a compressing force around said connector.

References Cited in the file of this patent UNITED STATES PATENTS 2,229,758 Metcalf Jan. 28, 1941 FOREIGN PATENTS 667,027 Germany Nov. 3, 1938 312,392 Switzerland Feb. 29, 1956

Claims

1. A CRIMPED ELECTRICAL CONNECTION BETWEEN CONDUCTORS IN WHICH AT LEAST ONE OF THE CONDUCTORS IS TAPPED INTERMEDIATE ITS ENDS COMPRISING, A FIRST FERRULE MEMBER OF SUBSTANTIALLY V-SHAPED CROSS SECTION, THE INSIDE OF THE BASE OF SAID MEMBER RECEIVING ONE OF SAID CONDUCTORS AND THE ENDS OF THE ARMS OF SAID MEMBER BEING REVERSELY BENT INWARDLY, A SECOND FERRULE MEMBER HAVING ONE SIDE THEREOF A PROJECTION OF SUBSTANTIAL WIDTH AND BEING RECEIVED BETWEEN THE ARMS OF SAID V-SHAPED FIRST FERRULE MEMBER, FLANGES ON THE LATERAL EDGES OF SAID PROJECTION AND EXTENDING WITHIN THE RECESSES DEFINED BY THE REVERSELY BENT ENDS OF SAID ARMS, SAID SECOND FERRULE MEMBER HAVING AN AXIAL OPENING, A SECOND CONDUCTOR RECEIVED WITHIN SAID OPENING, SAID FIRST FERRULE MEMBER AND SAID SECOND FERRULE MEMBER DEFINING A GENERALLY OVAL SHAPED CROSS SECTION FOR SAID CONNECTION, SAID CONNECTION BEING CRIMPED BY INDENTATION ON EACH OF ITS SIDES WHEREBY, THE ARMS OF SAID FIRST MEMBER AND THE FLANGES OF SAID SECOND MEMBER ARE COMPRESSED TOGETHER, AND SAID FLANGES PREVENT RELAXATION OF SAID ARMS AND LOOSENING OF SAID CONNECTION.