GB2165708A - Wire connectors - Google Patents

Abstract

A wire connector, particularly for use in connecting telephone wires, whether bare or insulated, which can be crimped onto the wires has an electrically insulating outer cover 2, a deformable resilient outer sleeve 4 inside the outer cover and an electrically conductive inner liner 6 inside the outer sleeve with tangs 8 for penetrating the insulation of the wire (if fitted) and establishing electrical contact with the conductor wire. The inner liner has a pair of inturned lips 10 which divide the interior space of the wire connector into two channels 14 one for each wire. The liner is arranged such that when the wire connector is crimped to deform the outer sleeve the inturned lips curl around the wire so as to constrict each of the wires in the channels and cause the tangs to penetrate the wire insulation (if fitted) and establish electrical contact with the conductor wire. <IMAGE>

Description

SPECIFICATION Wire connectors Field of Invention The invention relates to connectors for wires, particularly telephone wires whether bare or insulated. The wire connectors are of the type which may be joined quickly to the wires to be connected by a simple crimping device.

Background of Invention Wire connectors are known which include an electrically insulating cover, a relatively thick smooth deformable metallic outer sleeve, and relatively thin electrically conductive inner liner in which tangs are formed for penetrating wire insulation and estahlishing electrical contact with the metallic wire conductor. These connectors have one closed end and one open end into which the two wires to be connected are fed. They are known as buttend connectors. The outer cover, outer sleeve and inner liner are all arranged generally cylindrically or approximately so.

Such connectors have been generally satisfactory on copper wires but less so on aluminium wires and it is amongst the objects of the invention to provide an improved wire connector which can be used for aluminium conductors. The electrical performance when used on copper conductor will also be improved.

Otherwise connectors are known (as described for example in the GB Patent Specification 1,179,715) which are trough shaped to provide wire access from the top and which are known as in-line connectors.

Inventive Features The invention provides a wire connector comprising an electrically conductive inner liner formed with tangs and with a pair of inturned lips dividing its interior into a pair of channels each for receiving an optionally insulated conductor wire, the arrangement being such that, on crimping the connector, the lips of the inner liner curl to constrict the wires and to bring the tangs into electrical contact with the conductor wire in each channel.

The novel feature of the inturned lips aids proper reception of the wire and the establishment of a durable electrical connection through its insulation.

The connector may be designed for access from one or both ends without departing from the main inventive principle.

The tangs may be provided in a variety of ways. Preferably they are arranged over the whole liner surface regularly spaced in either staggered or non-staggered rows. Satisfactory results may be obtained if the wires are penetrated by the tangs from opposite sides but most advantageously the arrangement is such that the wire is located predominantly by the tangs and possibly in addition by chamfered edges of the respective lips.

Preferably the connector according to the invention further comprises a resiliently deformable outer sleeve.

Efficient utilisation of the interior space can be achieved by providing that each channel is substantially circular in section prior to crimping, the overall connector having a flat oblong shape. Efficient construction of the wires in the respective channels can be achieved in a variety of ways.

Suitably the outer sleeve has curved edges where the lips turn inwards so that on crimping the lips are moved apart and towards the wires inserted in the respective channels. Alternatively or additionally the outer sleeve and/or inner liner has a longitudinal corrugation which bends on crimping the connector so as to move the inner liner towards the wires in the channels. In any case it is preferred that the lips are bent apart towards their edges so that on crimping the lips slide over a facing liner generally coiling around the wires in the channels. Crimping energy can be stored by the outer sleeve and the inner liner.The storage of energy can be enhanced to ensure proper maintenance of contact by providing that the outer sleeve has transverse slots so that on crimping reversible resilient deformation of the inner liner takes place to ensure that the tangs are urged towards the wires after release of crimping pressure.

The connector according to the invention preferably further comprises an electrically insulating outer cover.

The invention is illustrated by the drawings, of which: DRA WINGS Figure 1 shows a cross-section through a wire connector according to the invention in the uncrimped condition ready for receiving a pair of wires; Figure 2 shows a side view of the wire connector of Figure 1; Figure 3 shows a top view of an outer sleeve of the wire connector of Figure 1; Figure 4 shows a plan view of an inner liner of the wire connector of Figure 1; Figure 5 shows a cross-section through the wire connector of Figure 1 in the crimped condition; Figure 6 shows a cross-section through another form of wire connector according to the invention; and Figure 7 shows a cross-section through yet another wire connector according to the invention.

Description of Particular Embodiments With reference to Figures 1 to 5, a wire connector has a cover 2 of a plastics material so as to make it electrically insulating. Inside the cover 2 there is provided an outer sleeve 4 of phosphor-bronze material which is deformable when crimped but resilient. The sleeve 4 conforms mainly to the shape of the inside of the cover 2. Both the cover 2 and the sleeve 4 have a generally flattened cylindrical shape. The cover 2 has an continuous cylindrical surface however, whereas the outer sleeve 4 is formed with curved edges the purpose of which will explained later.

Inside the outer sleeve 4, there is fitted an inner liner 6 which as can be seen in Figure 1 partly conforms to the inner surface of the outer sleeve 4 but which has two centrally located inturned lips 10 which are positioned back to back. Tangs 8 are formed in the inner liner which is also of phosphor-bronze material. The tangs 8 are formed by punching through a drilled hole with a sharp angular tool of square or triangular section so as to form four or three points at the extremity of the tangs 8. The liner material is considerably thinner than the material of the outer sleeve. It deforms more readily but will also have some inbuilt resilience after deformation. Edges 12 of the inturned lips 10 may be chamfered so as to enable them to penetrate a wire to establish contact with its metallic conductor.

As can be seen the inner liner 6 thus forms two channels 14 which lie side by side and which are approximately of circular shape and suited for receiving the wires to be connected.

Figure 2 shows the wires emerging from the open end 16 of the wire connector. The other end is closed off. In an alternative embodiment it is possible for both ends to be open.

Figure 4 shows the centres of the different tangs 8. For simplicity only some tangs have been indicated. It should however be understood that the tangs may cover the whole of the surface of the inner liner 6. The tangs are shown in a staggered condition. It is however feasible to form them in line or to make each row follow an approximately helical pattern.

In use, a pair of wires is pushed into the respective channels 14 (see Figure 1). The wire connector is then inserted inside a crimping tool the jaws of which are placed on the opposed flat sides of the wire connector. The jaws are then closed which results in a flattening of the wire connector and a deformation of the outer sleeve 4 and the inner liner 6. The curved edges of the outer sleeve 4 wrap round the inner liner as a result of the increasing curvature of the rounded sides of the outer sleeve 4, finally acting as a cantilever decreasing the radius of the inner liner. At the same time the edges 12 of the inturned lips 10 meet the facing part of the inner liner 6. The result is that the inturned lips 10 are further splayed apart, tightening around the individual wires.The final form of this condition is illustrated in Figure 5 where the inner liner 6 is shown coiled around the wires. The wires are held by the tangs 8 which penetrate the insulation 32 and cut into a metallic conductor 34 to establish electrical contact. Whether or not the outer sleeve and/or inner liner is corrugated (as discussed below with reference to Figure 6) in its lower section the act of crimping will, in decreasing the radius of the outer sleeve in its lower section, assist in the constriction of the wires and thus the electrical contact. It should be noted that the wire is virutally held in place by the different tangs mounted at different circumferential positions around the wire. The sequence of events described is of course duplicated for both wires although Figure 5 only illustrates for simplicity the constriction of one wire.

As the crimping tool is removed a small relaxation of the outer sleeve 4 will take place (Figure 5). However because the curved edges of the outer sleeve 4 acting as sprung cantilevers have moved inwards, there will be a residual spring load on the conductors notwithstanding. enabling the constriction of the wires to be maintained even after withdrawl from the jaws of the crimping tool. Further any subsequent movement of the inner liner 6 can only take place by uncoiling which is resisted by the bite of the tangs on the conductors so ensuring good electrical contact.

The different embodiments described in Figures 6 and 7 generally function in a manner similar to that shown in Figures 1 to 5. In the following description these embodiments will only be described in so far as they differ from the embodiment shown in Figures 1 to 5.

In Figure 6 a corrugation 22 is provided in the inner liner and outer sleeve. These corrugations will partially flatten under the crimping load but on release of load will restore elastically and provide a residual spring loading of the tang against the conductors in the channels 14. These corrugations will also facilitate the splaying apart of the inturned lips 10 to constrict the wires in the channels 14.

Figure 7 illustrates the use of transversely extending slots cut in the outer member 26 only to form transverse resilient metal strips with the inner liner. When the connector is crimped the section of inner liner 27 directly above these transverse slots 26 will deform resiliently into the slots. On removal of the crimping force the inner liner will restore elastically thus assisting in the maintenance of appropriate pressure on the tangs and the electrical connection between the tangs and the wire conductor.

Other modifications and refinements may be employed to ensure that the wires are individually constricted between the inturned lips to promote the coiling of the inturned lips around the individual wires.

Where appropriate the wire connectors may be filled with grease or the inner liner may be coated with special metals so as to enhance the electrical connection established by crimping.

Advantages The connector may be used for copper and aluminium wire covered in any insulating material such as paper, polyvinylchloride or polyethylene. Electrical connection can be maintained in a wide range of temperatures and humidity. Simple crimping only is required to make the connection.

The wires in the respective channels are kept separate and cannot ride over each other. Each wire will be penetrated by many tangs. The depth of penetration of the tangs is greater near the closed end of the connector than at the open end thus avoiding weakening of the wires at emergence.

Movement of the electrical insulation of the wire as a result of creep or thermal expansion will be off set by the final sprung condition of the connection since the wires are supported virtually by tangs embedded in the conductor material. Thus expansion or contraction of the electrical wire insulation will not detract from the performance. The tangs penetrate the wire mostly radially so that the points of contact are airtight, reducing oxidation and ingress of extraneous material. Residual spring loading of the tangs ensures that electrical contact is maintained even allowing for the greater expansion and contraction of aluminium wire.

The coiling action provides that if any relaxation takes place, the lips of the inner liner and therefore the tangs tend to move circumferentially and not radially so maintaining contact with the wire.

Claims (14)

1. A wire connector comprising an electrically conductive inner liner, formed with tangs and with a pair of inturned lips dividing its interior into a pair of channels each for receiving an optionally insulated conductor wire, the arrangement being sudh that, on crimping the connector, the lips of the inner liner curl to constrict the wires and to bring the tangs into electrical contact with the conductor wire in each channel.

2. A connector according to claim 1 which is closed at one end and open at the other.

3. A connector according to claim 1 which is open at both ends.

4. A connector according to any preceding claim in which the tangs are arranged so that they contact the conductor wire in each channel on opposite sides.

5. A connector according to claim 4 in which the tangs are arranged so that they contact the conductor wire on at least three sides.

6. A connector according to any preceding claim in which edges of the lips are chamfered.

7. A connector according to any preceding claim in which each channel is substantially circular in section prior to crimping, the overall connector having a flat oblong shape.

8. A connector according to any preceding claim in which the lips are bent apart towards their edges so that on crimping the lips slide over a facing part of the inner liner generally coiling around the wires in the channels.

9. A connector according to any preceding claim further comprising a deformable resilient outer sleeve.

10. A connector according to claim 9 in which the outer sleeve has curved ends so that on crimping the curved ends are moved apart and towards the channels of the inner liner.

11. A connector according to claim 9 or claim 10 in which the outer sleeve or inner liner has one or more longitudinal corrugations to bend further on crimping of the connector so as to move the inner liner towards the wires in the channels.

12. A connector according to any of claims 9 to 11 in which the outer sleeve has transverse slots so that on crimping reversible resilient deformation of the inner liner takes place to ensure that the tangs are urged towards the wires after release of crimping pressure.

13. A connector according to any preceding claim further comprising an electrically insulating outer cover.

14. A wire connector substantially as described herein with reference to the drawings.