US3861772A

US3861772A - Insulation piercing contact and connector

Info

Publication number: US3861772A
Application number: US396929A
Authority: US
Inventors: Howard Richard Shaffer
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1973-09-13
Filing date: 1973-09-13
Publication date: 1975-01-21
Anticipated expiration: 1992-01-21

Abstract

An improved insulation piercing contact and connector is disclosed which contact strips the insulation from at least two sides of a conductor when making the insulation piercing contact. The subject contact includes a cylindrical member having a sharp annular edge and a pin member of wedge shaped configuration with at least one transverse step formed in the inclined surface of the pin. A conductor inserted into the cylindrical member is pinched between the cylindrical wall and the pin member with the insulation being stripped from the conductor by the annular edge of the cylindrical member and the step in the pin member.

Description

United States Patent [1 1 Shaffer 1 Jan. 21, 1975 INSULATION PIERCING CONTACT AND CONNECTOR I Howard Richard Shaffer, Harrisburg, Pa.

Assignee: AMP Incorporated, Harrisburg, Pa.

Filed: Sept. 13, 1973 Appl. No.: 396,929

Inventor:

US. Cl. 339/99 R, 339/223, 339/97 R Int. Cl H01r 9/06 Field Of Search 339/95, 96, 97, 98, 99,

References Cited UNITED STATES PATENTS 6/1965 Cobaugh 339/97 R 9/1966 Cobaugh 339/97 R 3,492,629 1/1970 Hirsch 339/97 R Primary Examiner-Roy D. Frazier Assistant Examiner-Robert A. Hafer [57] ABSTRACT An improved insulation piercing contact and connector is disclosed which contact strips the insulation from at least two sides of a conductor when making the insulation piercing contact. The subject contact includes a cylindrical member having a sharp annular edge and a pin member of wedge shaped configuration with at least one transverse step formed in the inclined surface of the pin. A conductor inserted into the cylindrical member is pinched between the cylindrical wall and the pin member with the insulation being stripped from the conductor by the annular edge of the cylindrical member and the step in the pin member.

14 Claims, 8 Drawing Figures PATENTEI] JANZI I975 SHEET 2 UF 4 INSULATION PIERCING CONTACT AND CONNECTOR BACKGROUND OF THE INVENTION 1. The Field Of The Invention The present invention relates to an insulation piercing contact and connector and in particular a contact which insures stripping of the insulation from at least two sides of a conductor to assure good electrical and mechanical connection therewith.

2. The Prior Art There have been many attempts to produce an electrical contact which may be rapidly and directly applied to a conductor with the insulation of the conductor being pierced during the application of the connector. Not all of these devices have proved to be completely satisfactory because of the manner of attachment and the possibility for inadequate piercing of the insulation which results in poor electrical and mechanical contact. An example of the prior art is shown in US. Pat. No. 3,492,629. The device disclosed in this patent has somewhat limited application since it requires a ring to be threaded on a bolt with the insulated wire being pinched therebetween. The threading operation of this device limits its use to the connection of single wires and it is not readily adaptable for use in gang terminations or high speed operations.

SUMMARY OF THE INVENTION The subject insulation piercing contact and connector includes a cylindrical metal ring member having a sharp annular edge, and a pin member having an inclined surface including at least one transverse step. An electrical termination connector means is fixed to one of said members. Said members are coaxially positioned and adapted to move relatively towards each other to pinch an insulated wire therebetween, the insulation being pierced and stripped from the wire by the annular edge and transverse step.

It is therefore an object of the present invention to produce an insulation stripping contact which can be applied to stranded or single conductor wire without the use of special tools.

It is a further object of the present invention to provide an improved insulation piercing contact which strips insulation from at least two sides of a conductor in order to assure adequate electrical and mechanical connection therewith.

It is a further object of the invention to produce an improved insulation stripping contact which may be arranged in gang fashion for attachment of a plurality of wires to a connector in rapid fashion.

It is yet another object of the present invention to produce an improved insulation stripping contact which may be readily and economically produced.

The means for accomplishing the foregoing and other objects and advantages, which will become apparent to those skilled in the art, are discussed below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing a first embodiment of the subject insulation stripping contact and connector;

FIG. 2 is a vertical longitudinal section through a single contact of the connector prior to the introduction of a wire therein;

FIG. 3 is a vertical longitudinal section, similar to FIG. 2, showing the wire fully inserted into the subject contact; I

FIG. 4 is a vertical longitudinal section, similar to FIGS. 2 and 3, showingthe stripping of the insulation from the wire during application of the contact;

FIG. 5 is a vertical longitudinal section, similar to FIGS. 2, 3 and 4, showing the subject contact fully engaging a wire;

FIG. 6 is an exploded perspective view of an alternate embodiment of the subject insulating stripping contact;

FIG. 7 is a vertical longitudinal section through the alternate embodiment in an open condition; and

FIG. 8 is a. vertical longitudinal section through the alternate embodiment in a closed condition engaging a wire.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The first embodiment of the present connector. is shown as a six position connector in FIG. 1, however, it is to be understood that the present invention may be adapted for use with any number of wires. The subject connector has a two part housing 10 with a front portion 12 and a rear portion 14. The front portion includes mounting apertures 16 and a plurality of contact bores 18. Each bore 18 includes an inwardly directed annular positioning flange 20. The rear portion 14 has a like plurality of bores 22, each aligned with a respective contact bore 18 of the front housing portion. A key stop projection 24 is formed at the outer rear edge of each bore 22. The front and rear portions of the housing are fixed together by any known means (not shown), such as adhesives.

Each contact 26 includes an electrical contact terminal 28, which may be either a socket configuration (as shown) or a pin, a pin member 30, and a cylindrical member 32. The terminal 28 includes a rearwardly directed, coaxial, annular bore 34 and an adjacent outwardly directed annular positioning flange 36. The terminal 28 is mounted in a bore 18 with

flanges

20 and 36 engaging to properly position the contact. The pin member 30 is coaxially fixedly mounted in bore 34 by outwardly directed mounting flange 38. While terminal 28 and pin member 30 have been shown as separate members, they clearly can be formed as a unitary member. The pin member 30 includes an inclined surface 40 having at least one transverse step 42 therein forming a sharp edge 44. Each of the cylindrical members 32 includes a barrel portion 46 having a sharp inner annular edge 48 and a drive extension 50. The wire 52 includes a conductor 54, which may be either stranded or solid wire, sheathed in insulation 56.

FIGS. 2 to 5 show the steps of attachment of the subject connector to an insulated wire. Referring to FIG.

insulation piercing or electrical connection has yet taken place.

FIG. 4 shows the beginning of making the insulation piercing and stripping movement. The cylindrical member 32 is moved toward the pin member 30, to the left as shown, causing the insulation 56 of the wire 52 to be pinched between the annular edge 48 of the barrel 46 and the edge 44 of step 40 and stripped from the conductor 54. It should be noted that during this movement, as the insulation is stripped from the wire, a good electrical and mechanical contact is made between conductor 54 and the barrel 46 and the ramp surface 40.

FIG. shows the wire fully seated in thesubject contact. The cylindrical member 32 is fully inserted into housing 14 so that only the wire 52 extends from the rear of the housing. The insulation 54 has been stripped from part of the conductor 54 which is held under compression by the stored energy between the cylindrical member 32 and the pin member 30. It should also be noted that the stripped insulation is compressed between the bore 18, pin member 30 and cylindrical member 32 and serves as an effective strain relief for the wire 52.

If it is desired to remove or replace the wire, the contact can be disassembled by pulling the cylindrical member 32 out of housing 14, to the right as shown in the drawings. This will allow the wire to be released so that it can be pulled out of the connector. The same wire or another wire may be reinserted into the connector and engaged as noted above.

The alternate embodiment of the subject contact, see FIGS. 6 to 8, reverses the relative positioning of the pin and cylindrical members. In this embodiment the cylindrical member 58 and electrical connection terminal 60 are shown as an integral stamped and formed unit. The electrical connection terminal 60 can be either a pin or socket and includes locking lances 62. The cylindrical member has a profiled free end 64 including a sharp wedge shaped edge 66 and at least one keying projection 68. The pin member 70 likewise is a stamped and formed unit having a double ridged inclined surface 72 with at least one transverse step 74 formed therein. An extraction notch 76 is formed near one end and a slot 78 runs substantially the entire length of the pin member.

Mating flanges

80 and 82 join together at each end of the slot 76.

The pin member 70 is normally received in the free end 64 of the cylindrical member with keying projections 68 extending into slot 78 to both align and retain the pin member in the cylindrical member. The mating flanges 80 and 82 prevent unintended separation of the members. The wire 84 is inserted into the contact with the pin member 70 in the open position, as shown in FIG. 7. The pin member is then driven into the cylindrical member by conventional means, not shown, causing the insulation 86 to be stripped from conductor 88. Mating flanges 80 limit the inward movement of the pin member. Good electrical and mechanical engagement is made between the conductor and the contact in much the same manner as previously described with reference to the first embodiment. The conductor 88 is held in compression between the pin and cylindrical members while the stripped insulation serves for strain relief. The extraction notch 76 aids in withdrawal of the pin member from the cylindrical member should it be desirable to replace the wire 84.

It was mentioned above that the inclined surface 72 is preferably a double ridge surface. The purpose of the longitudinally inclined surfaces forming this double ridge configuration is' to achieve better insulation separation in baring the conductor. This is not the only possible configuration which will achieve this effect. Likewise other configurations are possible for the notched profiled free end 64 of the cylindrical member. The important feature-is that both the free end and the inclined surfaces should have opposing transversely extending sharp surfaces which will penetrate and strip the insulation from the conductor.

It will be appreciated that the subject contact is readily adaptable for making rapid connections on a large scale, high production basis. It is likewise adaptable for use in making individual connections since no specialized equipment or tooling is necessary to fasten the contact to a wire and no preparation of the wire is necessary.

The present insulation stripping contact has been found to work well on both stranded wire and solid wire conductors. In the case of stranded wire the application of the contact causes some unwinding of the individual strands which are then held in compression between the pin and cylinder members.

The provision of a number of transverse steps in the inclined surface of the pin member allows the contact to beused with wires of various sizes. The insulation will still be stripped from both sides of the conductor by the sharp inner annular edge of the barrel and at least one transverse step regardless of the wire size. The pin member must be driven into the barrel only far enough toget the desired stripping and need not be fully seated in the barrel.

The present invention may be subject to many modifications and changes without departing from the spirit or essential characteristics of the subject invention. For example, the electrical contact terminal can be either a male or female terminal and can be made integral with either the pin or cylindrical member. The housing also may be a two piece housing, as shown, or a single piece housing. Therefore, the present embodiments are to be considered in all respects as illustrative and not restrictive.

What is claimed is:

1. An insulation stripping contact comprising:

a pin member having an inclined surface extending longitudinally along said pin and at least one transverse step formed in said surface;

a cylindrical member including a barrel portion having a sharp inner annular edge at one end;

electrical terminal means connected to one of said members and adapted to mate with compatable electrical terminal means;

said cylindrical member and said pin member being axially slidably movable with respect to each other 5. An insulation stripping contact according to claim 4 wherein said unit is stamped and formed.

6. An insulating stripping contact according to claim 1 further comprising:

a recess on the end of said pin means opposite said inclined surface whereby said pin means can be engaged and extracted from said cylindrical member releasing wire engaged therebetween.

7. An insulation stripping contact according to claim 1 further comprising:

interengaging keying means on said cylindrical member and said pin member whereby said members are loosely held together.

8. An insulation stripping contact according to claim 7 wherein said interengaging keying means includes a longitudinal slot in said pin member and at least one projection on said cylindrical member extending into said slot.

9. An improved electrical connector for electrically and mechanically engaging a conductor of an insulated wire by piercing and stripping the insulation from the conductor, said connector comprising:

a housing having at least one contact receiving bore therein; and

an insulation piercing contact received in each said at least one bore, each said contact including a pin member having an inclined surface with at least one transverse step in said surface, a cylindrical member having a sharp inner annular edge at one end, and an electrical connection terminal attached to one of said members,

said members being axially slidably movable relative to each other in said housing whereby wire passing through said cylindrical member is pinched between said inclined surface and said annular edge with the insulation being stripped from the conductor by the relative axial movement of said annular edge and said step.

10. An improved electrical connector according to claim 9 wherein said pin member and said electrical connection terminal are an integral unit fixedly mounted in said housing.

11. An improved electrical connector according to claim 9 wherein said cylindrical member and said electrical connection terminal are an integral unit fixedly mounted in said housing.

12. An improved electrical connector according to claim 9 wherein said pin member further includes means at the end opposite said inclined surface whereby said pin member can be withdrawn axially away from said cylindrical member to release wire held therebetween.

13. An improved electrical connector according to I claim 9 wherein said cylindrical member further includes means at the opposite end from said sharp annular edge whereby said cylindrical member can be withdrawn axially away from said pin member.

14. An improved electrical connector according to claim 9 wherein said housing'further includes means for fixedly holding one of said pin member and said cylindrical member in each contact bore; and

means preventing the complete withdrawal of the other of said members from said contact bore.

Claims

1. An insulation stripping contact comprising: a pin member having an inclined surface extending longitudinally along said pin and at least one transverse step formed in said surface; a cylindrical member including a barrel portion having a sharp inner annular edge at one end; electrical terminal means connected to one of said members and adapted to mate with compatable electrical terminal means; said cylindrical member and said pin member being axially slidably movable with respect to each other whereby insulated wire passing through said barrel and laying against inclined surface will be engaged and the insulation stripped from the conductor by said step and said annular edge to effect good electrical and mechanical contact.

2. An insulation stripping contact according to claim 1 wherein said pin member and said electrical terminal means are an integral unit.

3. An insulation stripping contact according to claim 2 wherein said unit is stamped and formed.

4. An insulation stripping contact according to claim 1 wherein said cylindrical member and said electrical terminal means are an integral unit.

5. An insulation stripping contact according to claim 4 wherein said unit is stamped and formed.

6. An insulating stripping contact according to claim 1 further comprising: a recess on the end of said pin means opposite said inclined surface whereby said pin means can be engaged and extracted from said cylindrical member releasing wire engaged therebetween.

7. An insulation stripping contact according to claim 1 further comprising: interengaging keying means on said cylindrical member and said pin member whereby said members are loosely held together.

9. An improved electrical connector for electrically and mechanically engaging a conductor of an insulated wire by piercing and stripping the insulation from the conductor, said connector comprising: a housing having at least one contact receiving bore therein; and an insulation piercing contact received in each said at least one bore, each said contact including a pin member having an inclined surface with at least one transverse step in said surface, a cylindrical member having a sharp inner annular edge at one end, and an electrical connection terminal attached to one of said members, said members being axially slidably movable relative to each other in said housing whereby wire passing through said cylindrical member is pinched between said inclined surface and said annular edge with the insulation being stripped from the conductor by the relative axial movement of said annular edge and said step.

13. An improved electrical connector according to claim 9 wherein said cylindrical member further includes means at the opposite end from said sharp annular edge whereby said cylindrical member can be withdrawn axially away from said pin member.

14. An improved electrical connector according to claim 9 wherein said housing further includes means for fixedly holding one of said pin member and said cylindrical member in each contact bore; and means preventing the complete withdrawal of the other of said members from said contact bore.