WO2007071968A2

WO2007071968A2 - Connector

Info

Publication number: WO2007071968A2
Application number: PCT/GB2006/004765
Authority: WO
Inventors: Michael J. Fawcett
Original assignee: Rota Engineering Limited
Priority date: 2005-12-23
Filing date: 2006-12-19
Publication date: 2007-06-28
Also published as: WO2007071968A3; GB0526237D0

Abstract

A connector, an insert assembly including an earthing plate, and a connector element including a sleeve clamp. The connector is for interconnecting or mutually isolating two or more circuits, and includes first and second interengageable connector elements. The first element includes a socket and the second element includes a spigqt insertable into the socket of the first element, the spigot extending along an axis. The first element supports at least one member projecting radially into the socket, and the second element defines at least one corresponding groove extending from adjacent an end of the spigot and aligned to receive the or a respective member projecting into the socket. At least a first portion of the groove extends in a direction transverse the axis of the spigot, and a second portion of the groove extends axially from the first portion away from the spigot.

Description

CONNECTOR

The present invention relates to a connector, to methods of manufacture of the connector, and to associated components. Particular embodiments of the present invention are particularly relevant to isolating connectors for interconnecting or mutually isolating two or more electrical circuits, and to methods of manufacture thereof.

Electrical connectors are required which can be used safely in applications where the connectors may be exposed to explosive atmospheres. Such applications are found in industrial plants, for example in the oil, gas, petrochemical and mining industries. The explosive atmosphere may be due to the presence of explosive gases or dust (e.g. grain dust).

Industrial plants are zoned according to the likelihood of the atmosphere being explosive e.g. to the likelihood of explosive gases being present. Various protection measures are utilised to prevent explosions. The International Electrotechnical Commission (IEC) has established standards which should be applied in particular circumstances, for example the Exd standard IEC 60079-1. Connectors in accordance with the Exd standard should be capable of being used in an explosive atmosphere such that if two interengageable connector elements of the connector are separated and a spark is generated, any resultant explosion occurs within the connector structure and is prevented from being transmitted to the surrounding environment.

The EEC 60079-0 standard includes particular reduced criteria for plugs and sockets for rated currents not exceeding 1OA and rated voltages not exceeding 250V a.c. or 60V d.c. However, for use in explosive environments, the standard requires that such plugs and sockets break the rated current with a delayed release to permit the arc to be extinguished prior to separation. Further, the plug and socket should remain flameproof to IEC 60079-1 during the arc quenching period. European patent EP 1,149,437 describes an isolating connector for interconnecting or mutually isolating two or more circuits in an explosive environment. However, such a connector is relatively mechanically complex, and can require a relative large number of moving parts. Consequently, such a connector can be relatively costly to manufacture.

Typically, the outer casings of electrical connector elements are formed of an electrically conductive material, such as steel. Such connector elements often include an insert assembly including an electrically insulating body such as plastic. The electrical pins extend through the insulating body of the insert assembly. The insert assembly is in turn enclosed within the conductive outer casing. As a safety measure, it is desirable that the conductive outer casing is earthed or grounded by connection to the appropriate earth pin. Such a connection can be formed by providing an electrically conductive path in the form of a wire extending from the earth pin to the conductive casing. For example, a wire can be connected to both the outer casing and the electrical earth pin via solder connections. However, such a solder connection may detach during use of the connector, and can be relatively time consuming to produce.

In use, the electrical pins within each electrical connector element are typically connected to an associated circuit via soldering of each pin to a respective wire from the circuit. Each pin/wire connection is then enclosed within a separate insulative sheath to prevent accidental electrical connection of different pins/wires.

It is an aim of particular embodiments of the present invention to address one or more problems that the prior art, whether referred to herein or otherwise.

In a first aspect, the present invention provides a connector for interconnecting or mutually isolating two or more circuits, comprising first and second interengageable connector elements; the first element comprising a socket and the second element comprising a spigot insertable into the socket of the first element, the spigot extending along an axis; the first element supporting at least one member projecting radially into the socket, and the second element defining at least one corresponding groove extending from adjacent an end of the spigot and aligned to receive the or a respective member projecting into the socket, wherein at least a first portion of the groove extends in a direction transverse the axis of the spigot, and a second portion of the groove extends axially from the first portion away from the spigot.

By utilising a groove having a portion extending in a direction transverse the spigot axis, there will be a delay in the separation of the first and second connector elements as the elements are pulled (or blown) apart. Such a delay may allow any arc or spark to be extinguished, prior to the complete separation of the two connector elements. Thus, a connector may be provided that is mechanically relatively simple, and that complies the standard IEC 60079-0.

Said first portion of the groove may extend in a direction perpendicular to the spigot axis.

A third portion of the groove may extend axially from the spigot end to the first portion.

The first connector element may further comprise a first contact for connection to a respective electrical circuit, and the second connector element may further comprise a second contact for connection to a respective electrical circuit, wherein the first and second contacts are interconnected when the spigot is inserted into the socket to a position at which said at least one radially extending member is received within the second portion of said corresponding groove, and the first and second contacts are separated when the spigot is inserted into the socket to a position at which said at least one radially extending member is received within the first portion of said corresponding groove.

The first and second contacts may be located within a closed chamber defined within the connector elements when the spigot is inserted into the socket to a position at which said at least one radially extending member is received within the first portion of said corresponding groove.

The first element may comprise a plurality of said radially extending members offset unequally about the first connector element, and the second connect elements comprises a corresponding plurality of grooves in corresponding offset positions about the second connector element.

Said radially extending member may be formed as a radially displaceable locking member protruding into the socket, the first connector element supporting a displaceable collar for controlling the radial position of the or each locking member, the collar being displaceable relative to the first element between a first position in which the or at least one locking member is caused to project at least a first distance into the socket and a second position in which the or at least one locking member is caused to project at least a second, greater distance into the socket, and the or each groove having a first relatively shallow section extending from adjacent the end of the spigot, and a second relatively deep section remote from the end of the spigot, the first relatively shallow groove section being dimensioned to accommodate a locking member projecting the first but not the second distance into the socket, and the second relatively deep groove section being dimensioned to accommodate a locking member projecting the second distance into the socket.

Means may be provided to bias the collar towards the second position.

hi a second aspect, the present invention provides an insert assembly for insertion into an electrically conducting connector casing, comprising: an electrically insulating body extending along an axis; a plurality of electrically conductive pins extending through the body, substantially parallel to the axis, and including an earth pin for connection to an electrical earth; and an earthing plate located substantially within the body in contact with said earth pin, the plate extending transverse the axis, at least a portion of the periphery of the plate extending outside of the electrically insulating body, for providing an earth connection to the electrically conducting connector casing.

Such an earthing plate can easily be implemented within the insert assembly during manufacture. Further, the earthing plate can provide a robust solution, which is relatively unsusceptible to fatigue and vibrational wear.

The earthing plate may be formed as an annulus.

The plate may define an aperture for receiving the earth pin as a push-fit connection.

AU of said pins apart from the earth pin may extend through an aperture defined by the earthing plate.

In a third aspect, the present invention provides a connector element comprising an electrically conducting connector casing, and an insert assembly as described above, the earthing plate being located in electrical contact with the conductive casing.

In a fourth aspect, the present invention provides an earthing plate for insertion into an insert assembly, as described above.

In a fifth aspect, the present invention provides a method of manufacture, comprising the step of forming an insert assembly as described above.

Said forming step may comprise: positioning the electrical pins within a mould; positioning the earthing plate in electrical contact with the earth pin; and forming the electrically insulating body by moulding.

In a sixth aspect, the present invention provides an connector element defining a socket, the element comprising at least one electrical contact extending into the socket, said at least one electrical contact being coupled to a respective wire for connection to an electrical circuit, each coupling being located within an insulating sleeve, wherein the connector element further comprises a sleeve clamp arranged to secure said sleeve in position by pushing the sleeve towards the corresponding electrical contact.

Such a sleeve clamp allows the insulative sleeve to be easily clamped into position, reducing the risk of the sleeve being dislodged during use of the connector element.

Said sleeve clamp may be secured in position by a groove located in an internal surface of the socket.

The sleeve clamp may be formed as a substantially circular plate defining at least one aperture, said sleeve extending through said aperture.

One of the socket and the outer circumference of the sleeve clamp may define a notch, and the other of the socket and the outer circumference of the sleeve clamp may define a corresponding projecting member for insertion into the notch, for location of the sleeve clamp at a predetermined orientation within the socket.

Said sleeve clamp is formed of at least two discrete elements.

A sleeve clamp for insertion in a connector element, as described above.

hi a seventh aspect, the present invention provides a method of connecting a connector element to an electrical circuit, the connector element defining a socket and comprising at least one electrical contact extending into the socket, the method comprising: coupling a wire to said electrical contact for connecting the contact to an electrical circuit; placing an insulating sleeve around the coupling formed between said electrical contact and wire; and securing the sleeve in position with a sleeve clamp. Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

Figure 1 is a perspective view of the socket connector element and the plug connector element of the connector in accordance with an embodiment of the present invention;

Figure 2 is a side view of the plug connector element illustrated in Figure 1;

Figures 3 A - 3D are partial cross-sectional perspective views of the connector in Figure 1, illustrating the connection sequence of the socket connector element to the plug connector element;

Figure 4A is an end view of the connector illustrating the position of cross- sectional axis AA;

Figures 4B and 4C illustrate cross-sectional views along axis AA of the connector, with the elements respectively in the positions illustrated in Figures 3C and 3D;

Figures 5A- 5C illustrate different possible configurations of the groove of the plug connector element;

Figures 6A — 6D illustrate different steps in the manufacture of an insert assembly including an earthing plate in accordance with an embodiment of the present invention;

Figures 7A - 7C illustrate different steps in the location of a sleeve clamp to secure an insulative sleeve in position against the electrical contacts (for clarity, the surrounding outer casing of the connector element has been omitted); and

Figure 8 is a perspective view of the sleeve clamp of Figures 7A-7C securely located in position against an internal surface of the socket defined by the outer casing of the connector element.

Referring to Figure 1, the illustrated connector comprises a female connector element 100 (commonly referred to as a socket), which is interengageable with a male connector element 200 (commonly referred to as a plug). Each connector element 100,200 is connected to a respective electrical circuit via wires. To facilitate appropriate rotational alignment, the female connector 100 includes an alignment mark (groove 120) for alignment with the corresponding alignment mark (dimple 220) on the male connector 200 prior to interengagement of the connector elements 100, 200.

Figure 2 illustrates the male connector element 200 in more detail, with Figures 3 A to 3D showing the connection sequence as the elements 100, 200 are interengaged. Further details of the internal structure of the connectors 100, 200 are illustrated by Figures 4B and 4C, which show axial cross-sectional views of the connector elements 100, 200 at the positions illustrated in Figures 3 C and 3D respectively (i.e. with the connectors partially engaged and fully interengaged). Figure 4A illustrates the cross-sectional axis AA used for Figures 4B and 4C.

The male connector element 200 has a spigot 202 for insertion into a socket 104 of the female connector 100. The spigot 202 is defined by the outer body casing 218 of the connector 200. The spigot extends along an axis 201. The male connector 200 has a groove 210 in the circumference, for receiving a corresponding member (ball 110) of the female connector 100.

The groove 210 is non-linear. The groove 210 of this particular embodiment comprises three portions 212, 214 (defined by 214a, 214b), 216. Groove portion 212 extends transverse the spigot axis 201. Here, the groove portion 212 extends in a plane generally perpendicular to the spigot axis 201. However, it should be understood that the term transverse simply indicates that the groove portion extends at an angle to the axis (i.e. in a plane that crosses the axis, rather than extending parallel to the axis). Groove portions 216, 214 extend axially (i.e. in a direction substantially parallel to the axis 201). Groove portion 216 extends from adjacent the spigot 202, to join with one end of groove portion 212. Groove portion 214 extends axially from the other end of groove portion 212, to terminate at end 214b located distant from the spigot.

The groove 210 is of non-uniform depth. A first section of the groove (corresponding to portions 216, 212, 214a) is relatively shallow, and extends from adjacent the spigot 202. The second, deeper section 214b is located distant from the spigot 202, and forms a ball (or locking member) seat.

The female connector 100 includes an outer collar 112 and an outer body casing 118. Radially internal surfaces 102 of the connector 100 define the socket 104 for receiving the spigot 202. The female connector supports a lock member in the form of a ball 110. The lock ball 110 is located within an aperture opening into socket 104. The aperture is shaped to prevent removal of the ball from the socket in a radially inwards direction. The ball can be in two positions - a first position in which the ball projects a first, relatively small, distance into the socket (Figures 3B, 3C and 4B) for engaging the relatively shallow section (216, 212, 214a) of the groove 210, and a second position in which the ball projects a larger distance into the socket 104 (Figures 3 A, 3D and 4C) for engagement in the ball seat 214b.

The collar 112 is supported on outer body casing 118. The retractable collar 112 has two positions. The first, retracted position is illustrated in Figures 3B, 3C and 4B, and the second, engaged position in Figures 3A, 3D and 4C. In the second, engaged position a radially inwardly projecting rib 114 of the collar 112 displaces the ball 110 in the radially inwards direction, and causes the ball 110 to project by the second, relatively large distance into the socket 104. The collar is resiliently biased to be in the engaged position i.e. the collar is resiliently biased by a biasing means providing force extending in direction indicated by arrow 116 in Figure 3 A. The collar could be resiliently biased by a spring. On retraction of the collar 112, the inwardly projecting rib 114 is axially displaced, such that the rib 114 is not radially aligned with the ball 110, thereby allowing the ball 110 to move in a radially outwards direction. This allows the ball 110 to be pushed back into the aperture, so that the ball 110 extends the first, relatively small distance into the socket.

Both the female connector 100 and male connector 200 include a respective electrical contact component in the form of an insert assembly. Each insert assembly includes an electrically insulating body (132,232) supporting electrical contacts in the form of connector pins (130a, 130b; 230a, 230b). The male ends 230a of the male connector 200 extend towards the spigot 202, and are arranged to engage with the corresponding female connector pin sockets 130a of the female connector 100. The other ends 130b, 230b of the conductive pins are, in use. connected to respective electrical or electronic circuits via wires. The ends 130b, 230b are cup-shaped, to facilitate the coupling of the wires to the pins via soldering, and extend into respective sockets 140, 240.

Figure 3 A illustrates the collar 112 in an engaged position, in which the collar displaces the ball 110 radially inwards (to the second distance) such that the spigot 202 of male connect 200 and socket 104 of female connector 100 cannot engage each other due to the radially inwards projection of the ball 110.

Referring to Figure 3B, on retraction of the collar 112 by exerting pressure against the resilient biasing means, the lock ball 110 is given radial freedom of movement by the collar 112 such that the spigot 202 may push the lock ball 110 radially outwards. However, the clearance provided by the lock ball 110 is only sufficient to allow the spigot to partially engage the socket, unless the lock ball 110 is aligned with groove portion 216. This rotational alignment corresponds to the alignment marks 120, 220 being rotationally aligned.

Figure 3B shows the spigot 202 inserted into the socket 104 defined by surfaces 102, to such an extent that the lock ball 110 has been received in the first portion 216 of the groove 210. In this position, the electrical contacts (pin ends 230a) of the male connector 200 are axially separated from the corresponding electrical contacts (the female connector pin sockets 130a) of the female connector 100. Further, when in the position illustrated in Figure 3B, the male ends are not rotationally aligned (i.e. axially aligned) with the corresponding female connector pin sockets 130a.

It should be noted that, once the connector elements 100, 200 are partially engaged, the collar 112 is prevented from returning to an engaged position as the rib 114 of collar 112 is unable to pass over the lock ball 110 in the radially outwardly displaced position. The lock ball 110 cannot be displaced radially inwards by the collar given that the ball 110 is in the relatively shallow section of the groove.

The connectors are then rotated relative to each other, so as to move the ball 110 along the transverse groove portion 212 to the end of the axial groove portion 214. This position (shown in Figure 3C and 4B) allows further engagement of the connector elements 100, 200 to occur. This alignment ensures that male connector pins 230a are correctly aligned with female connector pin sockets 130a before the male connector 200 is fully mated with female connector 100.

Subsequently pushing the connectors 100, 200 together, results in displacement of the ball 100 along the remaining portion of groove 214a to ball seat 214b. This continued engagement of the spigot 202 into socket 104 causes the male connector pins 230a to meet and engage (mate with) the female connector pin-sockets 130a.

Figures 3D and 4C show the state of full engagement of the female connector 100 and male connector 200. Connector pins 230a are fully mated with connector pin-sockets 130a. Further, lock ball 110 is aligned with ball seat 214b. As the collar 112 is resiliently biased towards the engaged position, the rib 114 pushes the lock ball 110 radially inwards into the corresponding ball seat 214b. Lock ball 110 once again has no radial freedom of movement, as the lock ball is pushed radially inwards by the collar rib 114, thus locking the male connector 200 to the female connector 100. It is thus not possible to pull the connectors apart once locked, without retraction of the collar 112. Collar 112 abuts the outer collar 204 of the male connector.

Disengagement of the connectors 100, 200 occurs in the opposite sequence to connection of the connectors. Firstly, the collar 112 is retracted, so as to give the lock ball 110 radial freedom of movement. If tension is then applied between the two halves of the connector following the retraction of the collar, the male connector 200 and the female connector 100 will partially disengage to the position illustrated in Figures 3C and 4B, at which the connector pins 230a are disengaged from connector pin-sockets 130a i.e. the electrical connection between the connectors is broken.

In order to allow full disengagement of the connector elements, a rotational movement is required, so as to displace the ball 110 from the position shown in Figure 3 C to the figure shown in Figure 3B. Such a rotation provides a delay in the release of the connector elements. It will be noted that the electrical contacts 130a, 230a within the connector element are fully enclosed by the connector elements. Thus, if any arcing or sparking did occur as the electrical connection is broken, the delay in complete separation of the connector elements 100, 200 (as the connector elements 100, 200 have to be rotated) allows any such spark to be extinguished, prior to complete separation of the connector elements. Also it will be noted that groove 212 is positioned such that on disengagement, when ball 110 runs in groove 212, the male and female contacts are at a distance apart such that they comply with Increased Safety standard IEC 60079-7. Preferably, the connector elements 100, 200 are flameproof to standard IEC 60079-1, so as to allow the plug and socket to comply with the IEC 60079-0 standard.

In the above embodiment, the female connector element has a single radially inward projecting member (ball 110) whilst the male connector element has a single corresponding groove 210 for receiving the member. However, it will be appreciated that any number of such members and grooves can be provided. Preferably, the number of grooves and projections are provided. Preferably the grooves and the projections are offset unequally about the respective connector member 100, 200, such that the spigot and socket can only interengage in a predetermined orientation.

Equally, whilst the inwardly projecting members have been described as a ball, it will be appreciated that a shaped pin or other locking element could be utilised instead of a ball. Similarly, the annular collar 112 could be replaced by a sliding rod or the like. Whilst the above embodiment shows the groove 210 having a portion 212 extending in a plane substantially perpendicular to the axis, it will be appreciated that other configurations of groove could be utilised. For example, Figure 5B shows a groove 210' that could be implemented on the connector element, in which the transverse groove portion 212' extends in a plane that is at an angle to, but not perpendicular to, the axis. The direction of the axis is indicated by groove portions 214, 216 which extend axially. The groove 212' extends at an acute angle relative to both axial groove portions 214, 216. Thus, upon release of the connector elements, a twisting and pushing action (so as to push together the connector elements) would be required to make the locking member travel along groove portion 212'. That motion is in opposition to the pulling action required to make the locking member travel along groove portions 214, 216. It will be appreciated that the groove angle thus acts as a further safety feature, decreasing the likelihood of the connector elements accidentally disengaging.

In the preferred embodiment, only a single transverse groove portion 212 is provided, thus requiring only a single relative rotation of the connector elements 100, 200, it will be appreciated that other grooves implemented in accordance as described herein can include two or more transverse groove portions. For example, Figure 5C indicates two transverse groove portions 212a", 212b" connected by an axially extending groove portion 212c".

Although each of the groove portions as described herein are indicated as being linear, it will be appreciated that the transverse groove portion can be curved, thus necessitating a twisting action as the connector elements are pulled apart (or pushed together).

For safety reasons, it is desirable that the conductive outer metal casing of the connector elements is earthed to a respective earth electrical connection. Typically, the outer conductive metal casings of the connector elements 100, 200 are each connected to one of the electrical contacts (e.g. pins 230a, 230b; 130a, 130b) that in use is coupled to the earth of the relevant circuit(s). A typical prior art manner of providing such an earth connection was to simply solder a wire extending between the outer metal casing and the relevant electrical contact (pin).

Advantageously, as described herein, the insert assembly can comprise an integral earthing connection, coupled to the relevant earth electrical connection (i.e. pin), and providing an external surface. The external surface is arranged, such that when the pre-formed insert assembly is located within the outer conductive casing of the electrical connector, the surface is in contact with the conductive casing.

Figure 6A-6D show the steps involved in the formation of such an insert assembly with respect to the assembly for the male connector 200. However, it will be appreciated that a similar assembly is provided in the female connector 100.

Earthing plate 300 provides the earthing connection between the earthing pin (230a, 230b) and the outer metal casing 218 of the male connector. The earthing plate is formed of an electrically conductive material. Preferably, the earthing plate is formed as a single element, and is arranged to provide a direct connection between the earthing pin and the conductive outer casing.

The earthing plate 300 includes an aperture 306 arranged to receive the earthing pin (the only pin 230a, 230b illustrated in Figure 6A) via a push fit connection. Figure 6A shows the earthing pin 230a, 230b secured in position via a push fit connection to the earthing plate 300. The earthing plate 300 further includes a central aperture 308 sized to allow the other pins to protrude through the aperture, without contacting the earthing plate (as shown in Figure 6C). The outer surface 302 of the earthing plate is generally circular, apart from a planar portion 304.

Figure 6B shows the earthing plate 300 in a mould 232' for the electrically insulating body 232. The additional pins are inserted through the aperture 308, and located in the appropriate relative positions as utilised in the final insert assembly. The pins are held in place by the mould 232'. The electrically insulating body 232 is then formed by moulding. The body 232 is formed by pouring a molten material (such as plastic) into the preformed mould 232', and allowing the molten material to cool.

Figure 6C illustrates an end on view, showing the separations 310 between the non-earth pins 230b and the plate 300 when the body is being formed. This separation is filled by molten material during the moulding process.

Figure 6D shows the resulting moulded insert assembly. The periphery 302 of the circular plate extends outside of the electrically insulating body 232. This periphery portion of the earthing plate thus forms a portion of the outer surface of the overall cylindrical insert assembly. It will be appreciated that, when the assembly is located within a conductive outer casing, an electrical connection will be formed between the conductive outer casing and the earthing pin via the earthing plate.

During use, wires from the relevant circuit (not shown) connect to the electrical connections (130b) of a female connector element (e.g. element 170 as shown in Figure 8). The element 170 includes a split retainer 500 defining a socket 540. A split retainer is a retainer that can be split into two or more portions. These wires are typically soldered in position with the electrical contacts 130b. The electrical contacts are located in the corresponding socket or recess 540. Each electrical contact 130b is typically connected to a respective wire 150 (See Figures 7A-7C). The joining point of each wire to the connector (e.g. the coupling of the wire 150 to the electrical contact 130b) is then located within a respective insulative sheath 160. It is desirable to hold the insulative sheath in place.

Figures 7A-7C illustrate the provision of a sleeve clamp 400a, 400b arranged to secure the insulative sheath or sleeve 160 in position, by pushing the sleeve towards the corresponding electrical contact 130b.

In this particular embodiment, the sleeve clamp 400 is formed of two symmetric portions 400a, 400b. The sleeve clamp 400, is annular, and defines a shaped central aperture. In use, the central aperture abuts the sleeves, pushing each sleeve towards the corresponding electrical contact, so as to hold the sleeves in place.

The outer portion of the sleeve clamp is located in a groove 501 in the inner surface of the split retainer 500 to hold the clamp in position against the sleeve 160 To ensure that the sleeve clamp is held at a predetermined orientation relative to the connector element 170, a notch 404a, 404b is provided in the body 402a, 402b of each sleeve clamp portion 400a, 400b. Each notch is designed to receive a corresponding projection 172 from the inner surface of split retainer 500. The notches act as rotation prevention means, preventing rotation of the sleeve clamp within the connector element. Figure 7A-7C shows the steps as the two portions 400a, 400b of the sleeve clamp 400 are located adjacent the sleeves 160.

After each sleeve clamp portion is located in position, the insert assembly and corresponding sleeve clamp can then be located in the outer casing 171, such that the interaction of the sleeve clamp with the outer casing (e.g. the split retainer 500) pushes the clamp towards the corresponding sleeve, thus securing the sleeve against the corresponding electrical contact (see Figure 8).

Whilst the sleeve clamp has been described with respect to the insert assembly of a female connector element 170, it will be appreciate that a similar sleeve clamp would be utilised in locating the sleeves of the insert assembly of a respective male connector element.

Claims

1. A connector for interconnecting or mutually isolating two or more circuits, comprising first and second interengageable connector elements; the first element comprising a socket and the second element comprising a spigot insertable into the socket of the first element, the spigot extending along an axis; the first element supporting at least one member projecting radially into the socket, and the second element defining at least one corresponding groove extending from adjacent an end of the spigot and aligned to receive the or a respective member projecting into the socket, wherein at least a first portion of the groove extends in a direction transverse the axis of the spigot, and a second portion of the groove extends axially from the first portion away from the spigot.

2. A connector as claimed in claim 1, wherein said first portion of the groove extends in a direction perpendicular to the spigot axis.

3. A connector as claimed in claim 1 or claim 2, wherein a third portion of the groove extends axially from the spigot end to the first portion.

4. A connector as claimed in any one of the above claims, the first connector element further comprising a first contact for connection to a respective electrical circuit, and the second connector element further comprising a second contact for connection to a respective electrical circuit, wherein the first and second contacts are interconnected when the spigot is inserted into the socket to a position at which said at least one radially extending member is received within the second portion of said corresponding groove, and the first and second contacts are separated when the spigot is inserted into the socket to a position at which said at least one radially extending member is received within the first portion of said corresponding groove.

5. A connector as claimed in claim 4, wherein the first and second contacts are located within a closed chamber defined within the connector elements when the spigot is inserted into the socket to a position at which said at least one radially extending member is received within the first portion of said corresponding groove.

6. A connector as claimed in any one of the above claims, wherein the first element comprises a plurality of said radially extending members offset unequally about the first connector element, and the second connector element comprises a corresponding plurality of grooves in corresponding offset positions about the second connector element.

7. A connector as claimed in any one of the above claims, wherein said radially extending member is formed as a radially displaceable locking member protruding into the socket, the first connector element supporting a displaceable collar for controlling the radial position of the or each locking member, the collar being displaceable relative to the first element between a first position in which the or at least one locking member is caused to project at least a first distance into the socket and a second position in which the or at least one locking member is caused to project at least a second, greater distance into the socket, and the or each groove of the second connector element having a first relatively shallow section extending from adjacent the end of the spigot, and a second relatively deep section remote from the end of the spigot, the first relatively shallow groove section being dimensioned to accommodate a locking member projecting the first but not the second distance into the socket, and the second relatively deep groove section being dimensioned to accommodate a locking member projecting the second distance into the socket.

8. A connector according to claim 7, wherein means are provided to bias the collar towards the second position.

9. An insert assembly for insertion into an electrically conducting connector casing, comprising: an electrically insulating body extending along an axis; a plurality of electrically conductive pins extending through the body, substantially parallel to the axis, and including an earth pin for connection to an electrical earth; and an earthing plate located substantially within the body in contact with said earth pin, the plate extending transverse the axis, at least a portion of the periphery of the plate extending outside of the electrically insulating body, for providing an earth connection to the electrically conducting connector casing.

10. An assembly as claimed in claim 9, wherein the earthing plate is formed as an annulus.

11. An assembly as claimed in claim 9 or claim 10, wherein the plate defines an aperture for receiving the earth pin as a push-fit connection.

12. An assembly as claimed in any one of claims 9 to 11, wherein all of said pins apart from the earth pin extend through an aperture defined by the earthing plate.

13. A connector element comprising an electrically conducting connector casing, and an insert assembly as claimed in any one of claims 9 to 12, the earthing plate being located in electrical contact with the conductive casing.

14. An earthing plate for insertion into an insert assembly, as claimed in any one ofclaims 9 to 13.

15. A method of manufacture, comprising the step of forming an insert assembly as claimed in any one of claims 9 to 13.

16. A method as claimed in claim 15, wherein said forming step comprises: positioning the electrical pins within a mould; positioning the earthing plate in electrical contact with the earth pin; and forming the electrically insulating body by moulding.

17. A connector element defining a socket, the element comprising at least one electrical contact extending into the socket, said at least one electrical contact being coupled to a respective wire for connection to an electrical circuit, each coupling being located within an insulating sleeve, wherein the connector element further comprises a sleeve clamp arranged to secure said sleeve in position by pushing the sleeve towards the corresponding electrical contact.

18. A connector element as claimed in claim 17, wherein said sleeve clamp is secured in position by a groove located in an internal surface of the socket.

19. A connector element as claimed in claim 17 or claim 18, wherein the sleeve clamp is formed as a substantially circular plate defining at least one aperture, said sleeve extending through said aperture.

20. A connector element as claimed in any one of claims 17 to 19, wherein one of the socket and the outer circumference of the sleeve clamp defines a notch, and the other of the socket and the outer circumference of the sleeve clamp defines a corresponding projecting member for insertion into the notch, for location of the sleeve clamp at a predetermined orientation within the socket.

21. A connector element as claimed in any one of claim 17 to 20, wherein said sleeve clamp is formed of at least two discrete elements.

22. A sleeve clamp for insertion in a connector element, as claimed in any one of claims 17 to 21.

23. A method of connecting a connector element to an electrical circuit, the connector element defining a socket and comprising at least one electrical contact extending into the socket, the method comprising: coupling a wire to said electrical contact for connecting the contact to an electrical circuit; placing an insulating sleeve around the coupling formed between said electrical contact and wire; and securing the sleeve in position with a sleeve clamp.