GB2280067A - Electrical connectors - Google Patents

Abstract

A panel mounted socket for an electrical connector has a hollow housing (2) in which an insulating insert (12) is received. At its front end the insert (12) has a reduced diameter to define an annular region (14) in which a cylindrical wall (16) of a plug (8) may be received. A generally elongate spring arm (34) is provided to releasably retain the plug (8) within the housing (2). A projection (32) of the spring arm (34) forms with a slot (30) in the plug (8) cooperating means for engaging and retaining the plug (8). At its rear end, the spring arm (34) defines an earth tag (36). The cam follower portion of the spring arm (34) is acted upon by a cam (42) which forms part of a generally elongate release bar (44). At one end, the bar (44) is provided with an upstanding protuberance (46) to facilitate movement of the release bar and hence release of the plug (8) by depression of the spring arm (34) against the spring force. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO ELECTRICAL CONNECTORS The present invention relates to a socket for an electrical connector and to a connector incorporating such a socket.

For audio, video or instrumentation systems, for example, it has become common to provide multipole or DIN connectors in which the socket thereof is panel mounted for receipt therein of a mating free plug. It is also known for such sockets and plugs to be provided with releasable latch or other engaging means to ensure that accidental disconnections thereof do not occur.

It is an object of the present invention to provide an improved socket for an electrical connector.

According to a first aspect of the present invention there is provided a socket for an electrical connector comprising a hollow housing having first and second longitudinally spaced open ends, and an insert of insulating material accommodated in said housing and spaced from the interior of the first end thereof so as to define with the housing a peripheral region in which a corresponding plug part may be received, contact sockets and/or contact pins being carried by and/or formed in said insert, and said socket further comprising retention means for retaining a plug part within said peripheral region, said retention means comprising a generally elongate retention member extending longitudinally of said housing and having at or near a first end thereof cooperating means for releasably engaging corresponding cooperating means of a plug part, said retention member being resiliently biassed towards a first, engaged position in which said cooperating means can be engaged, and being movable against the force of the bias to a second, released position, and wherein said elongate retention member is conductive, and at or near a second end thereof said retention member forms or carries an earth tag.

A socket of an embodiment of the present invention has an elongate retention member which is not only able to engage and retain a plug part against disconnection, but also provides an earth path therefor. This simplifies the construction of the connection and also ensures that the retained plug is reliably earthed.

It would be possible to provide a tool, such as a small screwdriver, to move the elongate retention member to its second position when release of a plug from the socket was required. However, it is generally preferred that the socket is provided with releasing means.

In a preferred embodiment, said releasing means comprises a generally elongate release member extending substantially longitudinally of the housing and moveable with respect thereto. At a first end thereof, said elongate release member has a protuberance, which preferably extends at an angle, for example, substantially at a right angle, to the general longitudinal extent of said elongate release member. The protuberance is used to move the elongate release member when required.

In a preferred embodiment, said release member comprises a generally elongate bar supported within said housing for sliding movement longitudinally thereof. The bar is formed to define, or carries, a cam which is arranged to engage a respective cam follower formed by, or carried by, said retention member. Preferably, it is the action of the cam and the cam follower which is able to move said retention member against the force of the bias to its second, released position.

It is possible to arrange for the elongate retention member of said retention means to be resiliently biased towards its first, engaged position by spring means. For example, a spring may be mounted in said insert and arranged to urge said retention member, either directly or via an intermediate member, towards its first position.

Additionally and/or alternatively, said retention member is formed of a resilient material and is shaped and mounted to provide the resilient bias.

In a preferred embodiment, said retention member is formed as a spring arm which is shaped and mounted so as to be resiliently biassed to its first position. For example, said spring arm may have a substantially S-shaped portion defining two spring or pivot points, and said cam follower may be comprised by a cam surface of said spring arm connected to said S-shaped portion.

The cooperating means at or near the first end of said elongate retention member may be any suitable means for removably engaging with corresponding means on a plug part.

For example, the cooperating means may comprise a recess on one of the retention member and the plug part and a corresponding projection on the other of the plug part and the retention member. Additionally and/or alternatively, one of the plug part and the retention member may carry a clip, for example, a spring clip, for engagement with the other of the retention member and the plug part.

In a preferred embodiment, the cooperating means of said elongate retention member is arranged to engage within a slot or recess provided in the plug part. For example, the elongate member may be formed to define, or carry, a projection. In a preferred embodiment, the retention member is a spring arm and said projection has been formed by bending the spring arm at or near its first end.

In a particularly preferred embodiment, the elongate retention member is a spring arm which has been formed from a single strip of resilient material, for example, such as spring metal, so as to define an earth tag at or near the second end thereof. Said earth tag is connected to a substantially S-shaped portion which is connected by a cam follower surface to a projection at or near the first end.

Preferably, the spring arm has been formed by bending a strip of spring metal to form the portions thereof.

A socket of the invention may be provided for any required application. However, the socket is particularly useful as a panel mounted socket. In this case, the housing has a substantially radially extending external flange which projects relative to the housing at or near its first open end. This radially extending flange is used to mount the socket onto a panel.

The socket may be of any required cross-section, it being necessary only that a plug therefor has a mating cross section. However, as is conventional, and for compatibility with existing plugs and sockets it is preferred that the housing be substantially cylindrical.

In a preferred embodiment, the housing is die cast from a suitable metal. The insulating insert is then, similarly, substantially cylindrical.

The insulating insert may carry, or have formed therein, contact sockets or bores and/or contact pins. The corresponding plug would then be provided with mating contact sockets, bores and/or pins. However, it is conventional that a panel mounted socket is provided with contact sockets.

In an embodiment, one or more elongate metal tubes extend through said insert to define contact sockets therein.

The insulating insert may be fixed within the housing in any appropriate manner. Alternatively, it may be constructed to be releasable.

Embodiments of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a longitudinal section through a socket of the present invention in which a mating plug is retained, Figure 2 shows the socket of Figure 1 but illustrating the release of the plug, Figure 3A shows a plan view of a release bar and Figure 3B shows a plan view of a mounting groove therefor in a socket housing, Figures 4A and 4B show respectively a longitudinal section and an end view on line IV - IV of part of a socket housing illustrating the assembly of the release bar therein, Figures 5A and 5B show respectively the longitudinal section of Figure 4A but showing the release bar in its assembled position, and a view on line V - V, Figures 6A and 6B show the longitudinal section and an end view on line VI - VI with the release bar in its fully assembled position.

The socket for an electrical connector which is illustrated in the drawings and which is described hereinbelow is a panel mounted socket for a substantially conventional multipole or DIN connector. Furthermore, the socket has been designed to have the necessary dimensions to interface with conventional mounting bores in panels and to mate with the available conventional plugs.

Nevertheless, it will be appreciated that the present invention is not limited to sockets for such applications, or of such shapes and sizes, and relates to any socket for an electrical connector where it is required to retain the plug and provide an earth connection thereto.

Figure 1 shows a longitudinal section through a socket of the invention showing the retention of a mating plug therein. In this respect, the socket comprises a generally cylindrical, hollow housing 2 made of metal. For example, the housing may be fabricated from the metal by die casting, and in an embodiment is of zinc. The housing 2 defines a substantially cylindrical bore therein which extends between longitudinally spaced open ends 3,4. Near a first one 3 of its open ends, the housing 2 is formed to have a substantially radially extending flange 5. In known manner, this flange 5 is utilised to mount the socket to a panel (not shown). The socket illustrated is designed to be universal in the sense that it can be either front or rear mounted in an appropriate panel mounting hole. To enable this, the external diameter of the housing 2 is identical both to the front and to the rear of the flange 5.

Preferably, a substantially circular, inwardly extending rim 6 extends around and defines the front open end 3 of said housing 2 to facilitate the insertion of a plug 8 into the socket. At its other open end 4, spaced from the first end 3, the cylindrical housing 2 is provided with an internal radially extending shoulder 10 to hold an insert 12 of insulating material within the housing 2.

The insert 12 is generally cylindrical. The insert 12 may be releasably held within the housing 2 or fixed therein. In the illustrated embodiment, the insert 12 is fixed. At its front end, adjacent to the first, front end 3 of the housing 2, the insert 12 has a reduced diameter such that it is spaced inwardly of the interior of the housing 2 and thereby defines a generally annular peripheral region 14 in which a cylindrical part or wall 16 of the plug 8 may be received. A plurality of metal tubes 20 are provided and extend through the insert 12 to form contact sockets therein. In known manner, a metal contact pin 22 is formed with, or connected to, each said tube 20.

Thus, pins (not shown) of the plug 8 received within the contact sockets 20 are electrically connected to the contact pins 22.

Resilient retention means, generally.indicated at 24, are provided to releasably retain the plug 8 within the housing 2. In this respect, near its free end, the cylindrical wall 16 of the plug 8 is provided with a slot 30 for cooperation with a projection 32 of the retention means 24. It will be appreciated that the slot 30 and the projection 32 together form cooperating means for engaging and retaining the plug 8.

In the embodiment illustrated, the retention means 24 comprises a generally elongate spring arm 34 which is formed of a resilient material, such as spring metal, and which is shaped and mounted within the insert 12 to provide the required bias. At its rear end, the spring arm 34 defines an earth tag 36. This earth tag 36 is connected to a generally S-shaped portion of the spring arm 34 which is connected by way of a cam follower portion to the projection 32. Preferably, the spring arm 34 is formed from a generally thin, substantially planar band or strip of spring steel which is bent to form the parts thereof identified above. The spring arm 34 is engaged within a suitably shaped recess formed within the insert 12 such that two bends S of the S-shaped portion form spring pivot points.

The portion of the spring arm 34 which forms the cam follower is in contact with, and acted upon by, a cam 42 which forms part of a generally elongate release bar 44.

At one end, the bar 44 is provided with an upstanding protuberance 46.

It will be seen from Figures 1 and 2 that in the plug engaged position of Figure 1 the protuberance 46 of the bar 44 is spaced outwardly of the one end 3 of the housing 2, whilst at its other end the bar 44 is within the housing 2.

In this position, the bias of the spring arm 34 and its mounting acts to urge the projection 32 thereof upwardly to retain it in the illustrated position within the slot 30 of the cylindrical plug wall 16. When it is wished to release the plug 8, the protuberance 46 is pushed towards the housing 2. This slides the bar 44 longitudinally with respect to the housing 2 and by a camming action the cam 42 depresses the spring arm 34 and thereby moves the projection 32 downwardly against the bias of the spring arm 34. The final release position of the spring arm 34 is shown in Figure 2 and it will be seen that, in this position, the protuberance 46 abuts the housing 2 and the rear end of the release bar 44 projects beyond the housing 2. When the spring arm 34 has been depressed to its release position, as shown in Figure 2, the projection 32 has been disengaged from the slot 30, and the plug 8 may be disengaged. Thereafter, pressure may be released from the protuberance 46 so that the spring arm 34 returns to its engaged position and moves the release bar 44 back to its normal position, as illustrated in Figure 1.

The construction of the retention means 24 of the socket, as illustrated in Figures 1 and 2, has the considerable advantage that the spring arm 34 both forms the cooperating means 32 for engaging with the plug wall 16 and the earth tag 36. Preferably, the spring arm 34 has a unitary or one piece construction and this ensures that it provides reliable earthing for the plug 8 it retains.

In the illustrated embodiment, the resilient biassing of the spring arm 34 arises out of the structure and mounting of the spring arm itself which is constructed of resilient material. It would alternatively be possible to provide separate spring means to bias the arm 34.

Currently this is not preferred as the provision of a unitary spring arm simplifies the manufacture and assembly considerably as only a single element needs to be provided.

The construction of the release bar 44 is also particularly simple and enables the bar to be retained within the housing 2 without any external cavities being required in the housing 2. This has the advantage that the resultant construction is easier to manufacture than heretofore and also prevents the ingress of dirt and other contaminants.

Figures 3 to 5 illustrate the construction of the release bar 44 and its manner of mounting. Figure 3A shows a plan view of the bar 44 illustrating the rear end thereof opposed to the end carrying the protuberance 46. At its rear end the bar 44 is provided with a widened mounting portion 50 which projects laterally with respect to the longitudinal extent of the bar 44. The bar 44 is arranged to slide in a generally U-shaped channel 52 which is provided within the housing 2 and opens into the interior bore of the housing 2. In this respect, and as can be seen in Figure 3B, the channel 52 has a widened portion 54 at its rear end which is formed in the rear end 4 of the housing 2. As is also apparent from Figures 4B and 5B, for example, the open face of the channel 52, which faces into the interior of the housing 2, is partially closed by ribs 56 provided on the interior of the housing 2 to extend longitudinally thereof.

It will be appreciated that because of its widened mounting portion 50 it is not possible simply to slide the release bar 44 along the channel 52 to mount it therein initially. The method by which the bar 44 is mounted within the channel 52 is illustrated in Figures 4 and 5.

Initially, and as shown in Figures 4A and 4B, the bar 44 is positioned within the housing 2 below, but substantially aligned with, the channel 52. The bar 44 may then be lifted upwardly into the channel 52 such that the widened mounting portion 50 thereof is received within the widened portion 54, whereas the rest of the extent of the bar 44 is received within the narrower main channel 52. In this respect, Figure 5B shows a cross-section taken on the line V - V of Figure 5A, whereas Figure 6B is an end view taken on the line VI - VI of Figure 6A and showing the mounting portion 50 within the widened channel portion 54.

Once the release bar 44 has been mounted as described, the rest of the construction of the socket is assembled, and in the assembled position the spring arm 34, because of its upward bias, contacts the bar 44 and retains it in position. Thus, the bar 44 is able to slide within its channel 52 substantially longitudinally of the housing 2 but cannot move radially thereof. Furthermore, the bar 44 cannot be pushed or pulled axially out of the channel 52 because the extent of its axial movement is controlled by the protuberance 46 abutting the one end 3 of the housing 2 and by the abutment between the mounting portion 50 of the release bar 44 and the shoulders defined between the widened portion 54 of the channel and the rest of the channel 52.

The present invention has been described above with particular reference to the embodiment illustrated.

However, it will be appreciated that variations and modifications may be made to the embodiments described within the scope of this application.

Claims (14)

1. A socket for an electrical connector comprising a hollow housing having first and second longitudinally spaced open ends, and an insert of insulating material accommodated in said housing and spaced from the interior of the first end thereof so as to define with the housing a peripheral region in which a corresponding plug part may be received, contact sockets and/or contact pins being carried by and/or formed in said insert, and said socket further comprising retention means for retaining a plug part within said peripheral region, said retention means comprising a generally elongate retention member extending longitudinally of said housing and having cooperating means for releasably engaging corresponding cooperating means of a plug part, said retention member being resiliently biassed towards a first, engaged position in which said cooperating means can be engaged, and being movable against the force of the bias to a second, released position, and wherein said elongate retention member is conductive, and at or near one end thereof said retention member forms or carries an earth tag.

2. A socket as claimed in Claim 1, further comprising releasing means arranged to move the elongate retention member to its second, released position.

3. A socket as claimed in Claim 2, wherein said releasing means comprises a generally elongate release member extending substantially longitudinally of the housing and moveable with respect thereto.

4. A socket as claimed in Claim 3, wherein at a first end thereof, said elongate release member has a protuberance extending at an angle to the general longitudinal extent of said elongate release member, said protuberance enabling movement of the elongate release member when required.

5. A socket as claimed in Claim 3 or Claim 4, wherein said release member comprises a generally elongate bar supported within said housing for sliding movement longitudinally thereof, wherein said bar is formed to define, or to carry, a cam which is arranged to engage a respective cam follower formed by, or carried by, said retention member, and wherein the action of the cam and the cam follower is able to move said retention member against the force of the bias to its second, released position.

6. A socket as claimed in any preceding claim, wherein said retention member is formed of a resilient material and is shaped and mounted to provide the resilient bias.

7. A socket as claimed in Claim 5, wherein said retention member is formed as a spring arm which is shaped and mounted so as to be resiliently biassed to its first position, said spring arm having a substantially S-shaped portion defining two spring or pivot points, and said cam follower being comprised by a cam surface of said spring arm connected to said S-shaped portion.

8. A socket as claimed in any preceding claim, wherein said cooperating means comprises a recess on one of the retention member and the plug part and a corresponding projection on the other of the plug part and the retention member.

9. A socket as claimed in any preceding claim, wherein said cooperating means of said elongate retention member is arranged to engage within a slot or recess provided in the plug part.

10. A socket as claimed in Claim 9, wherein said retention member is a spring arm, and the cooperating means of said retention member is a projection formed by bending the spring arm at or near an end thereof opposed to said one end.

11. A socket as claimed in any preceding claim, wherein said elongate retention member is a spring arm which has been formed from a single strip of resilient material so as to define an earth tag at or near said one end thereof, said earth tag being connected to a substantially S-shaped portion which is connected by a cam follower surface to a projection at or near an end of said retention member opposed to said one end.

12. A socket as claimed in any preceding claim, for use as a panel mounted socket, wherein the housing has a substantially radially extending external flange which projects relative to the housing at or near its first open end.

13. A socket as claimed in any preceding claim, wherein one or more elongate metal tubes extend through said insert to define contact sockets therein.

14. A socket substantially as hereinbefore described with reference to the accompanying drawings.