GB2287841A

GB2287841A - Connector with a contact gripping arrangement

Info

Publication number: GB2287841A
Application number: GB9405602A
Authority: GB
Inventors: William Henderson; Robert Graham Armistead
Original assignee: Oxley Developments Co Ltd
Current assignee: Oxley Developments Co Ltd
Priority date: 1994-03-22
Filing date: 1994-03-22
Publication date: 1995-09-27
Anticipated expiration: 2014-03-22
Also published as: GB2287841B; GB9405602D0

Abstract

A connector comprises a socket member (2) which has a contact receiving bore (10) and at least one outwardly projecting annular protuberance (15, 22) in the vicinity of the bore. A locking sleeve (4) fits over the socket member (2) and has a bore (38) with a diameter smaller than that of the outwardly projecting protuberances (15, 22) so that when a contact (1) is inserted into the contact receiving bore (10) and the locking sleeve is drawn over the protuberances, the internal profile of the contact receiving bore is deformed, gripping the contact (1). The sleeve (4) may have at least one longitudinal slot and may be of a harder material than that of the socket (2). The socket (2) may be of a harder material than that of the contact (1). The annular protuberances (15, 22) may have a back to back frusto-conical shape. The socket (2) and sleeve (4) may include means to allow a tool to grip and draw the sleeve (4) over the socket (2). <IMAGE>

Description

DESCRIPTION CONNECTOR The present invention relates to connectors, and in particular to a connector for forming a connection with a solid core contact.

Solid core contacts are used in a variety of fields of industry for forming electrical connections.

In nuclear reactors, for example, solid core contacts consisting of elongate copper rods are mounted in glass or ceramic seals to provide electrical connections to the insides of vessels. Solid core contacts are also used in circular multiway military connectors.

There is therefore a need for a connector to form a secure, -low resistance connection with a solid core contact. Advantageously, it should be possible to form the connection within a confined space (e.g.

within a circular multiway military connector), and without exerting a significant net force on the solid core contact, which might damage a fragile mounting, such as a glass or ceramic seal.

According to the present invention, there is provided a connector comprising a socket member, which has a contact receiving bore and at least one outwardly projecting annular protuberance in the vicinity of said bore, and a locking sleeve with a through-going bore whose diameter is smaller than the diameter of the outwardly projecting protuberance, so that when a contact is inserted into the contact receiving bore and the locking sleeve is drawn over the protuberance, the internal profile of the contact receiving bore is deformed, gripping the contact.

Preferably, the locking sleeve and socket member are circular in cross section.

Preferably, the locking sleeve is formed of a harder material than the socket member, which is itself harder than the contact to which a connection is to be made.

A specific embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 shows a connector in accordance with the present invention and a solid core contact, before the connection has been made; Fig. 2 is a partly sectional view of the same components after the connection has been made.

The connector in accordance with the present invention shown in Fig. 1 comprises only two components: a socket member 2 formed of brass and a locking member 4 of steel.

One end of the socket member will be referred to as the distal end 6 and the opposite end will be referred to as the proximal end 8.

The external profile of the socket member 2 will now be described. Moving along the socket member 2 from the proximal end towards the distal end, it comprises, in the following order: i. a first constant diameter portion 12; ii. a first annular protuberance 15, comprising an outwardly inclined shoulder 16 (wherein the diameter of the socket increases in the direction of the distal end), an inwardly inclined shoulder 18 and a second constant diameter portion 20; iii. a second annular protuberance 22 of the same shape as the first annular protuberance 15; ivr an enlarged diameter portion 26, bounded at both ends by perpendicular shoulders; v. a recess 28 and; vi. a distal connecting portion 30.

The proximal end 8 of the socket member 2 is penetrated by an axial contact receiving bore 10 which extends into the socket member 2 as far as a point within the enlarged diameter portion 26, and within which the solid core contact 1 is a sliding fit.

The inner surface of the contact receiving bore 10 and the external surface of the socket member 2 are connected by two longitudinally extending slots 32 (only one slot 32 is shown in Fig. 1; the other is radially opposite the slot shown, and identical in other respects).

The distal connecting portion 30 is used to join the socket member 2 to a conductor, for example a wire. In the embodiment shown, it comprises an axial joining bore 34 and a radial bore 36 which communicates with the inside of the axial joining bore 34. A joint with a conductor can be formed by inserting a pre-soldered end of a wire into the axial joining bore 34 and heating the resulting assembly, forming a solder joint. Any gases formed in this process can escape through the radial bore 36.

The joining portion 30 may be made in a different form without departing from the scope of the present invention. For example, where the connection will be required to withstand high temperatures, a solder free connection, eg a screw thread, would be required.

The locking sleeve 4 illustrated in Fig. 1 is in the form of a steel cylinder containing an axial through bore 38 which is a sliding fit on the first constant diameter portion 12 and thus has a diameter which is smaller than the largest diameter of the two protuberances 15,22. The outer surface of the locking sleeve 4 has a tapered recess 9. One end of the axial through bore 38 has a rounded chamfer 40.

To form a connection, the connector, comprising the socket member 2 with the locking sleeve 4 positioned around the first constant diameter portion 12, with the rounded chamfer facing towards the distal end 6, is advanced onto the solid core contact 1, which is received in the contact receiving bore 10.

The socket member 2 is then held fixed while the locking sleeve 4 is drawn towards the distal end, preferably until it approaches or abuts one of the shoulders of the enlarged diameter portion 26.

During this process, the socket member 2 and the solid core contact 1 are deformed into the shapes shown in Fig. 2. The external diameter of the socket member 2 between the proximal end 6 and the enlarged diameter portion 26 becomes substantially constant, but the radial thickness of the material of the socket member 2 in this region also remains substantially constant, so that a mirror image of the original external profile is transferred to the internal profile of the contact receiving bore 10. The solid core contact 1 is correspondingly deformed; that is, its external profile matches the new internal profile of the contact receiving bore 10.

Since the diameter of some regions of the solid core contact 1 is reduced during formation of the connection, some excess material is extruded into the longitudinally extending slots 32.

The choice of materials of this embodiment is particularly advantageous. The locking sleeve 4, being steel, is harder than the socket member 2 made of brass which is itself harder than the solid core contact 1 made of copper. Thus the locking sleeve is not substantially deformed and the socket member 2 retains its radial thickness, while the solid core contact is deformed as described.

Advantageously, a special tool may be used to form the connection, whereby the socket member 2 is held about the recess 28 while the locking sleeve 4, held by means of the tapered recess 9, is drawn over the socket member.

The connection formed in this way has several advantageous characteristics: i. since the socket member 2 is held fixed while the connection is formed, no substantial net force is exerted on the solid core contact, making the connector suitable for use where the solid core contacts are held in a fragile mounting; ii. the connection can be formed in a very confined space; iii. the connection can withstand large tensile forces; iv. the longitudinally extending slots 32 provide a degree of elasticity so that the characteristics of the connection are retained during repeated thermal cycling (that is, repeated heating/cooling); v. since a large contact surface is provided, the electrical resistance of the connection is low; and vi. since no solder is involved in forming the connection, the connector can be used in situations where no heat can be applied to the solid core contact.

Thus, the present invention makes possible a connector of simple construction which allows a connection of low resistance and high tensile strength which withstands thermal cycling to be made to a contact without exerting a significant net force on the contact and without solder.

Claims

1. A connector comprising a socket member, which has a contact receiving bore and at least one outwardly projecting annular protuberance in the vicinity of said bore, and a locking sleeve with a through-going bore whose diameter is smaller than the diameter of the outwardly projecting protuberance, so that when a contact is inserted into the contact receiving bore and the locking sleeve is drawn over the protuberance, the internal profile of the contact receiving bore is deformed, gripping the contact.

2. A connector as claimed in claim 1, in which the locking sleeve and socket member are circular in cross section.

3. A connector as claimed in claim 1 or 2, in which the locking sleeve is formed of a harder material than the socket member, which is itself harder than the contact to which a connection is to be made.

4. A connector as claimed in claim 1, 2 or 3, in which said at least one annular protuberance is of back to back frusto-conical configuration.

5. A connection as claimed in any of claims 1 to 4, in which the socket member and the locking sleeve have respective peripheral recesses whereby the socket member can be held about the recess therein by a tool which also grips the sleeve by way of its peripheral recess and, when operated, draws the sleeve over the socket member.

6. A connector as claimed in any of claims 1 to 5, wherein the socket member contains at least one longitudinally extending slot over at least the majority of the length of said contact receiving bore.

7. A connector substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.