US3662089A

US3662089A - Modifications of wire connectors

Info

Publication number: US3662089A
Application number: US87715A
Authority: US
Inventors: John Patrick Harding
Original assignee: Post Office
Current assignee: Post Office
Priority date: 1969-11-13
Filing date: 1970-11-09
Publication date: 1972-05-09
Anticipated expiration: 1989-05-09
Also published as: BE758872R; ZA707609B; NL7016688A; ES385510A2; CA921585A; FR2074923A6; DE2055583B2; GB1336562A; IT949505B; DE2055583A1; JPS5218916B1; NL157752B; DE2055583C3; CH544415A; SE384294B

Abstract

A clip for use in jointing wires particularly of multi-wire cables the clip being trough like in form of having tangs in its sidewalls in addition to wire engaging means in its base.

Description

I United States Patent 1151 3,662,089 Harding May 9, 1972 s41 MODIFICATIONS OF WIRE [56] Reiereneee Cited CONNECTORS UNITED STATES PATENTS [72] Invent Mm Hardmg Bushey' England 3,514,528 5/1970 Ray ..174/s4 c [73] Assignee: The Post Office, London, England 3,553,347 1/1971 Harding et al ..174/84 C [22] Filed: 1970 Primary Examiner-Darrell L. Clay 2 APPL 7 7 5 AnorneyHall & Houghton [57] ABSTRACT [30] Foreign Application Priority Data I I A I A clip for use in jointing wires particularly of multi-wire cables Nov. 15, 1969 Great Britain ..55,677/69 h li b i trough lik i form f having tangs in its sidewalls in addition to wire engaging means in its base. [52] US. Cl. ..174/84 C, 29/628, 174/90,

339/97 C, 339/276 R 6 Claims, 4 Drawing Figures [51] Int. Cl. ..H02g 15/08 [58] Field of Search 174/84 C, 94 R, 90; 339/95 R,

339/97 C, 276 R, 276 T; 29/628 PATENTEDMAY 9 I972 3, 662.089

SHEET 1 BF 2 INVENTOR ATTORNEY PATENTEDMM 9 I972 3, 662.089

sum 2 UF 2 fa P ///1 za /M,

INVENTOR ATTORNEY MODIFICATIONS OF WIRE CONNECTORS BACKGROUND OF THE INVENTION This invention relates to wire connectors and more particularly to metallic crimping clips for jointing together the individual and corresponding wires offirst andsecond multiconductor cables.

In the past separate wires of, for example, telephone cables to which this invention is particularly directed, have been manually jointed by twisting together and covering the twisted joint with an insulating sleeve. A'number of metallic crimping clips have recently been disclosed for use in conjunctionwith particular jointing machines to provide improved joints, both electrically and mechanically, over suchmanual joints.

SUMMARY OF THE INVENTION By the present invention there is provided a crimping clip for joining together first and second lengths of insulated wire to make electrical connection between the wires, the clip consisting of a substantially trough-shaped electrically conductive member adapted to receive, along the length thereof, the first and second wires, the said member having a base and first'and second upstanding sidewalls, the base containing at least one wire engaging means, characterized in that the sidewalls are formed at a number of places with inwardly projecting tangs.

The wire engaging means in the base may include at least one pair of tongue portions cut from the base and bendable towards, and lying close to, the sidewalls of the clip, the transverse edges of the atleast one opening from which the. tongue portions arebendable curving upwardly and being resiliently yieldable.

Upwardly projecting tangs, may be provided in the base of the clip, either on-their own or in combination with the upwardly curved edges. I

The tangs in the sidewalls of the clip are so positioned that, when crimped,.they cooperate with the tangsin. the base-but do not lie directly above them. The tangs in the base may be arrayed in two longitudinally extending rows,.and some, e.g., half of each row may be of reduced height comparedwith the remainder of the tangs in that row. The-tangs in the sidewalls which arepositionedto cooperate with the tangsin thebase which are of reduced,height, may also be of reduced height.

The clip may be slit to permit resilient movement of one tangindependently of a second tang in a plane perpendicular to the plane of .the base. The base may be slit adjacent both ends of the longitudinal axis thereof to provide first and second substantially triangular projections raiseable adjacent to each end so that their axes are perpendicular to, andtransverse of, the base of the trough-shaped member.

The first and second sidewalls may be provided with embossments adjacent to and engaging upwardly bent tongue portions. The trough-shaped member may be positioned inside an insulatingcover. The cover may be pressed through the holes left .b'ythe piercing of the clip to form the tangs. Further holes may be provided in the clip to receivethe insulation which is pressed through the holes.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of an uncrimped clip; F IG. 2 is a longitudinal section along the line II-ll of FIG.

FIG. 3 is a scrap transverse section along the line III-III of FIG. 2, and,

FIG. 4 is a transverse section along the line IV-IV of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS The crimping clip comprises a substantially trough-shaped member 1 of resilient metal such as hard brass or Phosphor bronze, coated with tin and backed with an insulating cover 2 of polyvinyl chloride or similar plastics material. The insulating cover is not shown in FIGS. 1 and 2 for reasons of clarity.

The cover 2 is wrapped around the longitudinal edges of the clip-as at 3. The member 1 includes a base 4, which is slightly convex towards the open side of the trough, bounded by first and second upstanding sidewalls 5, 6.

Each of the sidewalls 5 and 6 is provided with internal embossments 9 correspondinginposition with the upturned tongue portions 7, 8 and formed by pressing in the outer surface ofthe wall by an appropriate amount.

The base 4 of the member has-a pair of cruciform slits 41, 42 and the base is pierced to provide a series of upwardly projecting tangs 10, ll, 12, and 13 arrayed around the cruciform slits, which permit each of the tangs 10 to 13 a degree of individual freedom to move plane perpendicular to the plane of the base 4, and in two rows symmetrically positioned about the central longitudinal axis of the base as shown in FIG. 1. Half of eachrow of tangs is of reduced height compared with the other half, the tangs l1 and 12-are initially up to the same height as the tangs l0 and 13, and are then reduced in height by being planished. The cruciform slits form four tongues each containing a tang and allowing each tang an individual spring action. Four

triangular portions

14, 15, 16, and 17 are formed symmetrically about the central longitudinal axial plane of the member 1 by cutting the sloping sides of the triangular portions in the base 4 so that they point away from the central transverse axis and bending the triangular portions so formed upwards about the bases of the portions and towards the center of the base 4. The planes of the triangular portions then lie perpendicular to the base plane and to the planes of the sidewalls 5 and 6.

The apertures formed in the base portion on the upward bending of the tongue portions 7 and 8 have slightly upturned edges 18, 19 which form deflectable lips.

The upstanding walls 5 and 6 are pierced to form a series of tangs20, 21, 22, and 23. Thus, as shown, the piercings in the base and in the sidewalls provide inwardly projecting tangs spaced apart on the base and in the sidewalls in alternating relation, the tangs in the sidewalls, when the clip is crimped, lying proximate to the tangs in the base-but not directly above them.

The

tangs

21 and 22 are planished'to reduce their-height to less than that of the

tangs

20 and 23. As can be clearly seen in FIG. 3, the tangs which are not planished have a series of sharp points 24. When seen in plan view, the tangs in the sidewalls can be seen to be staggered with respect to the tangs in the base. The reason for this will be detailed below. Also formed in'the walls 5 and'6 are a pair of

holes

25 and 26.

The insulating cover 2 is pressed into the apertures left by the formation of two of the

triangular portions

14, 15, 16, and 17 to hold the cover in position and stop it sliding axially. In addition, the cover is pressed into the

holes

25 and 26 for the same reason and also to stop the clip sliding upwards out of engagement with the tongues of the cover material pressed into the triangular apertures.

Clips according to the invention can be crimped in a crimping machine as described in US. Pat. No. 3,529,342. To use a clip to join two wires together, the wires are laid out parallel to each other and longitudinally along the length of the clip. One wire is positioned between the

triangular portions

14, 15, 16, and 17 and the

tangs

21 and 23, and the other wire is positioned between the

triangular portions

14, 15, 16, and 17 and the

tangs

20 and 22. The clip is then crimped by bending the sidewalls 5 and 6 inwardly.

As the upstanding sidewalls 5, 6 are bent over during compression of the clip, the tongue portions 7, 8 backed by the embossments 9, engage with the respective wires, the wires then being trapped between the tongue portions and the associated deflectable lips 18, 19. The embossments 9 ensure that the tongue portions penetrate the gap between the deflectable lips 18, 19 and that there is sufficient contact movement between the deflectable lips and the wires to allow a good tearing action by the lips on the insulating cover of the wire. This tearing action strips off the insulating cover at the points of contact with the deflectable lips and scrapes clean the wires in preparation for the final contact. On completion of the compression of the clip, the wire is shorn of its insulation at the two points where the wire is trapped between the tongue portions 7 and 8 which are retained in the fully closed position by the embossments 9, and the deflectable lips 18 and 19; by this arrangement the presence of "insulation at those points, which might induce creep and relaxation, is substantially avoided.

The deflectable lips 18 and 19 are dimensioned to produce a spring restraint which maintains contact pressure against the effects of creep and relaxation. Further, these deflectable lips also yield as cantilevers to close the gaps between the tongue portions and the deflectable lips, the distances between the edges adjusting themselves according to the diameter of the wire which is trapped.

The tangs 20, when the clip has been compressed, lie between the tangs 10, so that the wire is forced to zig-zag between thetangs. The sharp points, for example the points 24, pierce the insulation and make a mechanical and electrical contact with the wire. The

tangs

13 and 23 behave in a similar manner to the

tangs

10 and 20. The tangs 11 and 21, and in the same way, the tangs l2, and 22, also lie in alternate positions in the compressed clip, so that the wire, being forced to adopt a zig-zag path through the clip, is gripped by the tangs. However, the insulation is not pierced, and the gripping action aids in holding the wire in the clip without any appreciable weakening of the wire itself. The wire which lies along the tangs 11 and 13 is severed to the right of the clip (as seen in FIG. 1); and the wire which lies along the tangs l0 and 12 is severed to the left of the clip (as seen in FIG. 1).

In addition to ensuring that the wires to be joined are set in the clip in the correct positions, the

triangular portions

14, 15, 16, and 17 assist in the trapping of the wires in the crimped clip by penetrating the insulation and making contact with the wlres.

When the clip is crimped in a crimping machine as described in the U.S. Pat. No. 3,529,342, the sidewalls 5, 6 are bent towards the base 4, to compress the clip about the wires, between a die and moving punch arrangement. The punch compresses the clip against a substantially flat-ended die, shaped to confine the bends in the sidewalls 5, 6 of the clip to very near the base 4 thus minimizing any relaxation after crimping. It is important, therefore, that the material is not thinned at the junction of the sidewalls and the base during the manufacture of the clip. With such an arrangement the clip is heavily compressed near the base 4 so that the material throughout the section yields and the tensile stress from bending is neutralized. The compression of the clip is augmented by the upward convexity of the base portion which causes the sidewalls 5, 6 to make contact via the wires with the base portion before completion of the compression of the clip.

Completion of compression of the clip results in the base portion being temporarily flattened out with the sidewalls 5, 6 lying approximately parallel to the base portion. On releasing the compression on the clip, the resilient of the metal allows the partial re-assertion of the upward convexity of the base portion and consequent improvement of the grip on the wires.

Additionally, the punch itself may contain a concavity, or the die a protuberance, by which higher crimping force may be delivered to the sidewalls 5, 6 and the base 4 of the clip near their junction, than at the free ends of the sidewalls. Thus the force applied to the free ends of the sidewalls, is partially relieved, reducing the tendency to crush the wires and the free ends of the sidewalls, whilst sustaining a force on the wires by cantilever action after the crimping pressure is released.

The preferred clips of the present invention may be used with aluminum wires as well as with copper wires.

It will be appreciated that the tangs in the sidewalls 5, 6 may be used in conjunction with the tangs in the base only, or with the deflectable lip and tongues only, or with a combination of both of these.

I claim: 1. A crimping clip for joining together first and second lengths of insulated wire to make electrical connection between the wires, the clip comprising a substantially troughshaped electrically conductive member adapted to receive, along the length thereof, the first and second wires, the said member having a base and first and second upstanding sidewalls, the base containing at least one wire engaging means, characterized in that the sidewalls and the base have piercings at a number of places providing inwardly projecting tangs spaced apart on the base and in the sidewalls, the tangs on the sidewalls, when the clip is crimped, lying proximate to the tangs in the base but not directly above them.

2. A clip as claimed in claim 1 and further characterized in that the tangs in the base are arrayed in two longitudinally extending rows, and some tangs of each row are of reduced height compared with the remainder of the tangs in that row.

3. A clip as claimed in claim 2 and further characterized in that the tangs in the sidewalls, which are positioned to cooperate with the tangs in the base which are of reduced height, are also of reduced height.

4. A clip as claimed in claim 1 and further characterized in that the base of the clip is slit to permit one tang in the base to move resiliently in a plane perpendicular to the plane of the base and independently of a second tang in the base.

5. A clip as claimed in claim 1 and further characterized in that an insulating cover is provided to surround the clip and is pressed through the holes left by the piercing of the clip to form the tangs. I

6. A clip as claimed in claim 5 and further characterized in that further holes are provided in the clip to receive the insulation cover when pressed through the holes.

Claims

1. A crimping clip for joining together first and second lengths of insulated wire to make electrical connection between the wires, the clip comprising a substantially trough-shaped electrically conductive member adapted to receive, along the length thereof, the first and second wires, the said member having a base and first and second upstanding sidewalls, the base containing at least one wire engaging means, characterized in that the sidewalls and the base have piercings at a number of places providing inwardly projecting tangs spaced apart on the base and in the sidewalls, the tangs on the sidewalls, when the clip is crimped, lying proximate to the tangs in the base but not directly above them.

5. A clip as claimed in claim 1 and further characterized in that an insulating cover is provided to surround the clip and is pressed through the holes left by the piercing of the clip to form the tangs.