US3594713A

US3594713A - Electrical connector

Info

Publication number: US3594713A
Application number: US17238A
Authority: US
Inventors: Woodrow William Thoman
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1970-03-06
Filing date: 1970-03-06
Publication date: 1971-07-20
Anticipated expiration: 1988-07-20

Abstract

An electrical connector is provided with a sleeve having one section secured on a wire-crimping section of a contact member and another section extending outwardly from the wire-crimping section which has an inwardly directed annular projection having a V-shape in cross section. The annular projection is located adjacent an entrance to the wire-crimping section to define funnel means to guide a stripped end of an electrical conductor within the wire-crimping section. The annular projection has a diameter less than the diameter of the wire-crimping section to provide stop means against which the insulation engages to prevent the conductor from being improperly positioned in the connector prior to the connector being crimped to the conductor. In a modification of the invention the wire crimping section is deformed to form a projection extending axially along the wirecrimping section. This projection provides a stop against which the insulation engages.

Description

United States Patent [.72] Inventor Woodrow William'lhoman Glen Rock. Pa. [2|] Appl. No. 17,238 {22] Filed Mar. 6. 1970 [45] Patented July 20, 1971 (73] Assignee AMP Incorporated Harrisburg, Pa.

Continuation-impart of application Ser. No. 878,115, Nov. 19, 1969, now abandoned.

[54] ELECTRICAL CONNECTOR l Claim, 7 Drawing Figs.

52 user 339/223, 339/276 511 mu ..H0lrlS/l2 50 FieldoISeal-ch 339/223, 276,65

[5 6] References Cited uwmao STATES PATENTS 2,468,!69 4/1949 Carlsonetal ..339/276(T)X 3,098,688 7/1963 Crimmonsetal 339/223 3,356,987 12/1967 Gillespie 339/223 Primary Examiner-James A. Leppink Assistant ExaminerRobert A. Hafer Au0rneys'-Curtis, Morris and Safford, William J. Keating,

Ronald D. Grefe, William Hintzc, Adrian J. LaRuc, Frederick W. Raring, Jay L. Seitchik and John Pv Vandenburg ABSTRACT: An electrical connector is provided with a sleeve having one section secured on a wire-crimping section of a contact member and another section extending outwardly from the wire-crimping section which has an inwardly directed annular projection having a V-shape in cross section. The annular projection is located adjacent an entrance to the wirecrimping section to define funnel means to guide a stripped end of an electrical conductor within the wire-crimping section. The annular projection has a diameter less than the diameter of the wire-crimping'section to provide stop means against which the insulation engages to prevent the conductor from being improperly positioned in the connector prior to the connector being crimped to the conductor.

In a modification of the invention the wire crimping section is'deformed to form a projection extending axially along the wire-crimping section. This projection provides a stop against which the insulation engages.

PATENTEU JUL20I971 359471 3 INVENTOR WOODROW WILLIAM THOMAN ELECTRICAL CONNECTOR This application is a continuation-in-part of copending application Ser. No. 878,115, now abandoned filed Nov. l9, 1969.

This invention relates to electrical connectors and more particularly to electrical connectors for connection onto stripped ends of electrical conductors having thin insulation.

Prior electrical connectors as disclosed in US Pat. Nos. 2,40S,l ll and 3,356,987 are provided with a sleeve having one section secured onto a wire-crimping section of a contact or ferrule member and this sleeve includes an inwardly directed projection adjacent an entrance to the wire-crimping section. This projection has a diameter greater than the diameter of the wire-crimping section, and it is used as a funnel to guide the stripped end of an electrical conductor into the wire-crimping section with the insulation engaging the projection or the end of the wire-crimping section to limit the movement of the stripped end within the connector and to properly position the stripped end in the wire-crimping section.

At the present time, insulation on electrical conductors is a great deal thinner than conventional insulation, because the plastic material from which the insulation is made provides the necessary protection of the wire so that thick insulation is unnecessary. This insulation is just slightly greater in diameter than that of the wire.

If the connectors disclosed in the above-identified patents are used to terminate strippedends of electrical conductors having thin insulation and no wire locator is used on the terminating means, the stripped ends of the electrical conductors are improperly positioned in the wire-crimping sections of the connectors due to the thin-walled insulation not engaging the inwardly directed projections or the outer ends of the wirecrimping sections thereby resulting in improper terminations when the wire-crimping sections are crimped onto the stripped ends.

If a wire locator is used on the terminating means and the ends of the electrical conductors are not stripped to bare the proper length of wire, part of the insulation will be crimped in the wire-crimping section which overcrimps the conductor at this location thereby work hardening the wire which provides a termination that is readily susceptible to failure when the termination is subjected to stresses such as, for example, tensile and vibration.

An object of the invention is to provide an electrical connector having means to properly position a stripped end of an electrical conductor within a wire-crimping section thereof.

Another object is the provision of a sleeve having one part secured on a wire-crimping section or ferrule and another part extending rearwardly from the ferrule, an annular inwardly directed projection provided in the sleeve adjacent an entrance to the ferrule and having a diameter less than the diameter of the ferrule.

A further object is to provide an inwardly directed projection means in a sleeve secured on a ferrule and located adjacent an entrance to the ferrule with the projection means having a diameter less than an inside diameter of the ferrule to provide funnel means to guide a stripped end of a thin insulation conductor means into the ferrule and stop means against which thin insulation engages to limit movement of the conductor means within the sleeve and ferrule.

An additional object is the provision of an inwardly directed projection having a V-shape in cross section located in an insulation support sleeve secured onto a ferrule with the projection disposed adjacent an entrance to the ferrule and having a diameter less than the inside diameter of the ferrule.

An additional object is the provision ofa projection directly on the ferrule of an electrical connector. The projection extends axially along the ferrule and one end serves as a stop for the thin insulation of an electrical conductor which is inserted directly into the ferrule.

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 drawings 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 ofa particular use.

In the drawings:

FIG. I is a perspective view partly broken away illustrating an electrical connector prior to being crimped onto thin insulation electrical conductor means;

FIG. 2 is a longitudinal crosssectional view of the electrical connector of FIG. I with the thin insulated electrical conductor means exploded therefrom;

FIG. 3 is a view similar to FIG. 2 with the electrical conductor means in position within the crimping area of the electrical connector; and

FIG. 4 is a view similar to FIG. 3 with the crimping area of the electrical connector crimped into position on the electrical conductor means. A modification of the invention is shown in FIGS. 57.

Turning now to the drawings, an electrical connector EC is illustrated in FIGS. ll through 4 and it comprises a contact section 1 and a sleeve assembly 2. Contact section 1 is for connection with another conductive means and is illustrated in the form of a ring tongue and it includes a wire barrel or ferrule 3 having grooves 4 axially spaced therealong.

Sleeve assembly 2 includes a metallic sleeve 5 and a dielectric sleeve 6 secured thereover. Sleeve 5 is provided with a first section 7 secured along wire barrel 3 and a second section 8 extending outwardly from wire barrel 3 but coaxial therewith.

An inwardly directed projection 9 is formed in metallic sleeve 5 adjacent the entrance to wire barrel 3. As can be discerned, inwardly directed annular projection 9 has a V- shape in cross section and the inner and outer legs are disposed at a 45 angle with respect to the longitudinal axis of the connector and therefore they are at right angles with respect to each other. The inner leg of projection 9 defines an inner stop means to limit the movement of wire barrel 3 within first section 7 of sleeve 5, and once wire barrel 3 is positioned in section 7, the end of section 7 is clinched to secure wire barrel 3 therein. The outer leg and bight of projection 9 defines a funnel to funnel a stripped end R0 of stranded insulated electrical conductor lll into wire barrel 3. The inside diameter of projection 9, which is the bight of the legs, is less than the inside diameter of wire barrel 3 so that the end of thin insulation 12 engages the outer leg of projection 9 thereby limiting the movement of the electrical conductor within electrical connector EC so that stripped end Ill) is properly positioned within wire barrel 3 which is the wire-crimping section of the electrical connector. The inside diameter of projection 9 is however only slightly greater than the diameter of the bared wire. Projection 9 therefore defines funnel means to effectively funnel the stripped end 10 of the electrical conductor II within the wire barrel even if a loose strand or strands extend outwardly beyond the circumference of the wire and stop means against which the end of the thin insulation of the electrical conductor engages to limit the movement of the electrical conductor within the electrical connector so that the stripped end 10 can be properly positioned within wire barrel 3 as illustrated in FIG. 3.

After the electrical conductor 11 has been properly inserted within electrical connector EC, the electrical connector is subjected to a crimping operation via manual or automatic crimping means to crimp the wire-crimping section consisting of wire barrel 3 and first section 7 into engagement with stripped end 10 and second section 8 of sleeve 5 is crimped into engagement with thin insulation 12 as illustrated by FIG. 4. Grooves 4 enable extrusion of wire thereinto to break down oxide coatings thereby enhancing the electrical characteristics of the termination. The outer end of sleeve 5 is folded inside of section 8 and it is provided with a serrated edge 13 which bites into the thin insulation when the crimping operation is performed so that second section 8 and serrated edge 13 increase the tensile of the termination. Electrical connector EC can be provided with only sleeve 5 but it is desirable to have dielectric sleeve 6 secured thereon and the crimping die is crimped through dielectric sleeve 6, which is generally made of nylon or vinyl plastic, without any damage thereto.

Projection 9 can, of course, be formed with circumferentially spaced, inwardly directed projections.

A modification of the invention is shown in FIGSv 57. FIG. 5 shows an electrical connector 15 for an insulated electrical conductor 16. The connector includes a contact section 17 and a ferrule section 18. The ferrule section 18 is deformed slightly inwardly by a blade and mandrel to form a

projection including legs

19 and 20 and a bight 21 connecting the legs together. The distance from the bight to the opposite wall of the ferrule is slightly greater than the bared conductor 22. The projection extends axially along the ferrule section 18. When the bared conductor is inserted into the ferrule section one end of the projection forms a stop for the insulation. This limits the movement of the stripped end of the electrical conductor into the ferrule so that the bared wire of the electrical conductor is properly positioned in the ferrule section. Thereafter the ferrule is crimped on the conductor with a standard crimping tool.

It will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiment of the invention, which is shown and described herein, is intended as merely illustrative and not as restrictive of the invention.

The invention I claim is in accordance with the following:

1. An electrical connector comprising a metal wire barrel, a metallic sleeve having a first section disposed over said wire barrel and a second section extending from said first section, an annular inwardly directed projection between said first section and said second section and having inner and outer legs connected together by a bight and defining a V-shape in cross section, said bight defining an annular inner diameter smaller than the smallest inner diameter of said wire barrel, said legs being disposed at 45 relative to a longitudinal axis ofsaid connector and with respect to one another, said inner leg defining stop means for engaging said wire barrel to limit movement of said barrel into said sleeve, said outer leg and said bight defining funnel means for guiding a wire connector into said wire barrel, a wire conductor, relatively thin insulation covering said conductor, one end of said conductor being stripped and inserted through said bight and into said wire barrel, said outer leg and said bight further defining stop means for engaging against said insulation and preventing said insulation to pass through said bight, said bight having an inner diameter slightly greater that the diameter of said stripped conductor end, said conductor end being received in said wire barrel and maintained in spaced relationship from the smallest inner diameter thereof, said first and said second sections of said sleeve being connected respectively to said first and said second legs, said first section being no larger in diameter than said second section, and a dielectric sleeve receiving said metallic sleeve therein, said dielectric sleeve having a first portion overlying said first section and a second portion overlying said second section, said first portion being no larger in diameter than said second portion.

Claims

1. An electrical connector comprising a metal wire barrel, a metallic sleeve having a first section disposed over said wire barrel and a second section extending from said first section, an annular inwardly directed projection between said first section and said second section and having inner and outer legs connected together by a bight and defining a V-shape in cross section, said bight defining an annular inner diameter smaller than the smallest inner diameter of said wire barrel, said legs being disposed at 45* relative to a longitudinal axis of said connector and 90* with respect to one another, said inner leg defining stop means for engaging said wire barrel to limit movement of said barrel into said sleeve, said outer leg and said bight defining funnel means for guiding a wire connector into said wire barrel, a wire conductor, relatively thin insulation covering said conductor, one end of said conductor being stripped and inserted through said bight and into said wire barrel, said outer leg and said bight further defining stop means for engaging against said insulation and preventing said insulation to pass through said bight, said bight having an inner diameter slightly greater that the diameter of said stripped conductor end, said conductor end being received in said wire barrel and maintained in spaced relationship from the smallest inner diameter thereof, said first and said second sections of said sleeve being connected respectively to said first and said second legs, said first section being no larger in diameter than said second section, and a dielectric sleeve receiving said metallic sleeve therein, said dielectric sleeve having a first portion overlying said first section and a second portion overlying said second section, said first portion being no larger in diameter than said second portion.