GB2236915A

GB2236915A - Plug and/or socket for an electrical connector

Info

Publication number: GB2236915A
Application number: GB9019750A
Authority: GB
Inventors: Hans Joachim Buescher; Peter Kroeplin
Original assignee: Souriau Electric GmbH
Current assignee: Souriau Electric GmbH
Priority date: 1989-09-09
Filing date: 1990-09-10
Publication date: 1991-04-17
Also published as: IT9021398A1; IT1243009B; DE3930210A1; FR2651928A1; GB9019750D0; DE3930210C2; IT9021398A0

Abstract

A plug 12 and/or socket 10 for a two part electrical connector comprising an electrically conductive housing 14, and a plurality of elongate contacts 34 extending parallel to a longitudinal axis of the plug and/or socket and at a distance from one another, said contacts 34 being displaceable in the axial direction between a contacting position with associated connecting contacts 22 and the contacts of the other pan of the connector 22 and a releasing position not contacting either set of other contacts, said contacts 34 projecting through openings 44 in a plate 18 of electrically conductive material, said plate 18 extending substantially perpendicular in relation to the contacts 34 and being secured to the electrically conductive housing 14, wherein the contacts 34 have electrically conductive thickened portions 36 and are guided so that, in the releasing position, they rest in a tensioned state by means of the electrically conductive thickened portion 36 in electrical contact with the plate 18 but are designed and arranged so that for other positions they are electrically insulated with respect to the plate. This provide em shielding when the two part connector is disconnected. <IMAGE>

Description

1 - 97.55879A.523 Plug andZor Socket for an Electrical Connector

Connectors, consisting of a plug and a socket, wherein the electrical connection is produced by inserting the plug or its contact pins into the socket or its corresponding openings, are known, e.g. from DEA-35 12 026 and DE-A-37 28 739. The connector according to DE-A-37 28 739 is designed in such a way that RF impenetrability to electromagnetic interference, i.e. EMP protection or NEMP protection, is possible. The known connector has proven to be successful.

In order to protect the components of the connector against electromagnetic radiation interference, it is known to design the plug and the socket in such a way that when the components of the plug or of the socket are connected together they form a type of Faraday cage.

In the case of the known plug the contact pins contact via their circumferences a device which is displaceable within the housing body and is electrically connected to the housing body, the contact between the pins and the device being interrupted when the plug is inserted in the socket. In the case of the associated socket, the contact pins are arranged so that they are longitudinally displaceable and, in the unplugged position, contact a fixedly arranged device of electrically conductive material, this device in turn being electrically connected to the housing body. As a result of the relative movement of the contact pins in relation to the respective device, the corresponding concentrically arranged conducting surfaces rub against one another, which, after a relatively large number of insertion-withdrawal cycles, can result in a loss of all-over contact and electromagnetic interference protection such that currents may still partially be drained.

Accordingly, the object of the invention is to design a connector of the aforementioned type in such a way that the friction between the parts that move in relation to one another is reduced as far as possible, whilst simultaneously fully guaranteeing protection from electromagnetic interference. The plug and socket of the connector should, if possible, be designed in such a way that they can receive as many contacts as possible within a small space.

The plug and socket should be designed in such a way that their elongate contacts are axially displaceable between extreme positions as the plug or socket is inserted or withdrawn and also such that in the withdrawn or release position the contacts come to bear against an element of electrically conductive material, so that there is an electrical connection between the contacts via the element and between the housing and a ground connection on the side of the housing.

According to the present invention, there is provided a plug or socket for an electrical connector comprising a electrically conductive housing, a plurality of elongate contacts extending parallel to longitudinal axis of the plug or socket and at a distance from one another, said contacts being displaceable in the axial direction between a contact position in which they make electrical connection between associated connecting contacts and respective further contacts of the other part of the connector, and a release position in which the contacts do not make contact with either set of other contacts, said elongate contacts projecting through openings in a plate of electrically conductive material, said plate extending substantially perpendicular in relation to the elongate contacts and being connected to the electrically conductive housing, wherein the elongate contacts have electrically conductive thickened portions and are guided so that, in the release position, the electrically conductive thickened portions are resilently urged against the plate but in the contact position the elongate contacts are electrically insulated with respect to the plate.

Thus, there is no longer any friction between the electrically conductive portions of the contacts and the electrically conductive element during the insertion or withdrawal operation. The electrical connection between the contacts and the element is in fact released without any friction whatsoever immediately the insertion or withdrawal operation is begun. The contacts may be electrically insulated for a portion of their length protruding through the plate to prevent undesired connection when not in the release position.

The contacts, then, have the thickened portion in front of the plate in the direction of insertion, said thickened portion being electrically conductive at least in its region of contact with the plate. As the plate is supposed to serve simultaneously as a stop for the contact pins, it is implicit that the cross section of the thickened portions of the contact pins is greater than the cross section of the corresponding through openings in the plate.. By means of the tensioning of the contact pins, which will be described in more detail hereinafter, said contact pins are guided by their thickened portions towards the electrically conductive plate. A ground connection secured to the housing results in a type of Faraday cage when the components are connected together, in order to form an EMP/NEMP shield.

In order to optimise the positioning of the contact pins with respect to the plate and thus simultaneously with respect to the contacts of the associated part of the connector, it is proposed that the openings on the side facing the thickened portion of the contacts are conical and that the thickened portions of the contacts have corresponding inclined surfaces. This results in a type of centering for the contact pins when they move towards the openings in the plate.

Centering and contacting can be further improved if the corresponding faces of the openings and/or the thickened portions are overlaid with electrically conductive spring segments. The contact pins are then pressed is against the spring segments in the releasing position, thereby ensuring the adjustment of any tolerances. The segments can be designed in the form of a segmented ring, the outer ends of the segments being secured to the associated part (the plate, the thickened portion), while the front ends project slightly from the associated surface in the direction of insertion and are thus resilient.

There are various possible embodiments of the arrangement of the contacts within the housing of the plug and the socket. In each case, it must be ensured that the contacts are arranged so that they are electrically insulated in relation to one another (except in the releasing position), the contacts preferably being arranged in one common body within the housing. The body consists of an insulating material, e.g. plastic.

The body as a whole can be arranged so that it is displaceable against the force of a spring between stops fixed with respect to the housing and accordingly takes the contacts with it, or else the individual contacts are displaceable against the force of appropriate J springs between stops fixed with respect to the body. In this arrangement, the springs are designed in such a way that the contact pins rest against the plate in the unplugged position but are released from the connecting contacts, while in the inserted.position the electrical connection between the contacts via the plate is released and the contacts rest against the connecting contacts.

The region of contact between the individual contacts and the associated connecting contacts is preferably again designed in such a way that tolerances can be adjusted. In this connection, it is possible to arrange additional segmented rings, as described hereinbefore, in the region of the end faces of the contacts and/or the connecting contacts.

The fixed positioning of the contacts within the body can be effected if the contacts are moulded within an appropriate plastic material. In this arrangement, it is particularly advantageous if at least the portion of the body on the insertion side consists of a deformable material, so that it can withstand deformation upon contact with the plate or the connecting contacts.

The embodiment of the plug and/or socket described hereinbefore makes it possible, by simple means, to protect the components against electromagnetic radiation interference in the unplugged position. In this arrangement, the plug and socket are assembled in such a way that they can receive a plurality of contacts in the smallest possible space without affecting the safety of the device.

In various fields of application, the operational reliability of connectors of the aforementioned type must be tested between the individual insertion- withdrawal operations, in order to detect faults and defects in good time. Different functional groups are often tested separately from one another. In the present state of the art, this is only possible with the aid of expensive external measuring instruments, the use of which is not always acceptable owing to problems of both space and time.

is According to one advantageous embodiment of the invention, it is provided that the connecting contacts (i.e. those within the plug and/or socket contactable with the movable contacts) are formed, again circumferentially, of an electrically conductive material only in their region of contact with the corresponding movable contacts, whilst the other portions have an insulating easing. In this embodiment, individual connecting contacts can be short-circuited mutually or in preselectable groups via the circumferential surfaces of the connecting contacts. To this end, the insulating body holding the movable contacts may have axial channels at its end facing the connecting contacts, said channels engaging over the connecting contacts and being designed with inner electrically conductive elements which, in the unplugged position, produce an electrical connection between specific connecting contacts for testing purposes, but which eliminate an electrical connection with the movable contacts. In the inserted position, these elements rest against the circumferentially insulated portions of the connecting contacts. It is obvious that an embodiment of this kind can be realised if the body as a whole is arranged displaceably in the housing. The elements are preferably sprung elements of an electrically conductive material, guaranteeing firm contacting.

Two embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings in which:

Figure 1 shows a section through a connector consisting of a plug and a socket, the upper half showing the inserted position and the lower half showing the unplugged position, and Figure 2 shows another embodiment, again in the inserted 10 position (upper half) and in the unplugged position (lower half).

In the drawings, identical components or components with identical functions are indicated by identical reference is numerals.

In Figure 1, 10 designates a socket and 12 a plug of an electrical connector.

The socket 10 and the plug 12 each have a metal housing 14, in which an insulating body 16 is fixedly arranged. The insulating body 16 is fixed in the socket 10 towards the plug 12 by a plate 18 of conductive material and at the opposite end by a base 20 of an insulating material, in this case, plastic.

Connecting contacts 22 are disposed in the base 20, these contacts projecting out beyond the socket 10 at the connection side and projecting towards the insulating body 16 into axially extending channels 24.

The base 20 comprises openings 26 in its portion directed towards the insulating body 16, said openings having a greater cross section than the openings 28 on the connection side for receiving the connecting contacts 22. The openings 26 serve to receive a thickened portion 30 of the connecting contacts 22, the thickened portions 30 being acted upon by means of springs 32 from the connection end in the direction of the insulating body 16. The insulating body 16 forms a stop for the thickened portions 30 in the direction of the plug 12.

Contacts 34 of a generally circular cross-section are enclosed in the channels 24, the cross section of said contacts corresponding to the cross section of the base portion of the connecting contacts 22. The contacts 34 also have a thickened portion 36 approximately halfway across their axial extent. To this end, in the portion of the insulating body 16 disposed on the right in the drawings, the channels 24 are designed with an extended cross section. This forms an annular channel 38, in which a compression spring 40 is enclosed, resting on the connection side against a step 42 of the insulating body 16 and towards the plug 12 against the thickened portion 36 of the contacts 34.

The compression springs 40 press the contacts in the unplugged position (lower part of Figure 1) towards the right, wherein the front portions of the contacts 34 project through openings 44 in the plate 18, while the thickened portions 36 rest against the plate 18.

As shown by Figure 1, the corresponding surface portions of the openings 44 and the thickened portions 36 have inclined surfaces, so that the resulting taper of each thickened portion 36 rests against the corresponding conical surface of the associated opening 44. Centering of the contacts is simultaneously achieved in this manner.

In the unplugged position, the contacts 34 are separated from the connecting contacts 22, the connecting contacts 22, by means of the springs 32, resting against the insulating body 16 by means of their thickened portions 30.

With the exception of the contact ends 34a, 34b and the thickened portions 36, the contacts 34 are provided with a circumferential electrically insulating casing 46.

In the position illustrated (unplugged position), a permanent electrical connection into the metal housing 14 and a ground connection 48 is achieved via the plate 18 and the thickened portions 36, thereby forming a type of Faraday cage for EMP or NEMP protection.

If the corresponding plug 12 is guided to the socket 10, is the contacts 34 of the plug 12 first contact the portions 34a of the contacts 34 of the socket 10 and press the latter against the resistance of the springs in the direction of the connecting contacts 22, until an electrical connection is produced between the contacts 34 of the socket 10 and the associated connecting contacts 22 (upper part of Figure 1) and the connecting contacts 22 are pushed away against the resistance of the springs 32.

In order to ensure good connection between the end face 34b of the contact 34 and the end face of the contact 22, these end faces may be formed with cup-shaped faces comprising radially extending segments, secured at their edges and flexible at their free ends so as to produce a 30 sprung or elastic connection.

Previously, the thickened portions 36 were released from the plate 18, thus releasing the electrical connection between the contacts 34.

The plug 12 can be designed with fixed contacts 34, although it is equally possible to guide the individual - contacts via compression springs, as in the case of the socket 10, which then preferably have a higher spring constant than the springs 40 and/or the springs 32, so that they can precompress the socket contacts 34 accordingly during the insertion-withdrawal operation.

Figure 2 shows an alternative embodiment of the plug and socket. In this case, the socket contacts 34 are arranged fixedly in the insulating body 16 and the insulating body 16 itself is slidably guided in the housing 14 by means of a compression spring 40. To this end, the insulating body 16 has a circumferential recess 50, thereby forming, once again, a type of annular channel 51, in which the compression spring 40 is enclosed. The insulating body 16 is narrower than in the embodiment according to Figure 1, in order to ensure movability between the plate 18 and the base 20.

The base 20 in this case is formed of two pieces for reasons of assembly.

A further difference from the embodiment according to Figure 1 consists in that metal segments 52 are arranged on the plate 18 in the region of the openings 44, the individual segments in the inserted position (upper part of Figure 2) being at a slight distance from the inclined surface of the opening 44. This has the advantage that in the unplugged position (lower part of Figure 2) the contacts contact the segments 52 via their thickened portions 36 slightly before the actual surface contact and subsequently press against their spring force against the inclined surface of the associated opening 44, resulting in a particularly strong electrical connection and simultaneous positioning of the contacts 34 with respect to the plate 18.

Figure 2 further shows that the contacts 34 of the plug 1 12 are also acted upon by the force of associated springs 54 in the socket 12 and are enclosed in an axially displaceable manner within appropriate openings 56 in the insulating body 16.

While the unplugged position corresponds substantially to Figure 1, when the socket 10 and the plug 12 are connected, the contacts 34 of the plug 12 are pushed axially against the force of the springs 54 slightly towards the connection end, allowing for improved adjustment of tolerances, in order to achieve a secure insertion position in the interlocking position between the socket 10 and the plug 12.

However, in the embodiment according to Figure 2 it is again ensured that directly following contacting of associated contacts 34 of the plug 12 and the socket 10, the thickened electrically conductive portions 36 of the contacts 34 of the segments 52 or of the plate 18 are 20 released before the contacts 34 contact the connecting contacts 22 by means of their ends 34b.

As shown by the preceding functional description, the corresponding faces of each thickened portion 36 only meet the associated inclined surface of the opening 44 in a planar manner, thus preventing any friction.

centering is simultaneously achieved as a result of the conical design. If the insulating body 16 is at least in part made of an elastic material, any tolerances can in addition be adjusted. The arrangement of the contacts 34 described hereinbefore makes it possible to arrange a plurality of contacts within the smallest possible space in the housing 14.

The connecting contacts 22 may further have an electrically insulating casing (not shown) outside of the region of contact with the contacts 34, and the body 16 may have engaging channels or sleeves (not shown), joined with electrically conductive elements which extend over the connecting contacts 22 so as to short circuit pre-selected groups of the connecting contacts when in the unplugged position. When in the inserted position the conductive elements will move down over th insulated parts of the connecting contacts.

5,

Claims

1. A plug or socket for an electrical connector comprising an electrically conductive housing, a plurality of elongate contacts extending parallel to a longitudinal axis of the plug or socket and at a distance from one another, said contacts being displaceable in the axial direction between a contact position in which they make elctrical connection between associated connecting contacts of the plug or socket and respective further contacts of the other part of the connector, and a release position in which the elongate contacts do not make contact with either set of other contacts, said elongate contacts projecting through is openings in a plate of electrically conductive material, said plate extending substantially perpendicular in relation to the elongate contacts and being connected to the electrically conductive housing, wherein the elongate contacts have electrically conductive thickened portions and are guided so that, in the release position, the electrically conductive thickened portions are resilently urged against the plate but in the contact position the elongate contacts are electrically insulated with respect to the plate.

2. A plug or socket according to claim 1, wherein the openings on the side facing the thickened portion of the contacts are conically bevelled and the thickened portions of the contacts have corresponding inclined surfaces.

3. A plug or socket according to claim 1 or claim 2, wherein the corresponding faces of the openings and/or the thickened portions are overlaid with electrically conductive spring segments.

A plug or socket according to claim 3, wherein the segments are substantially concentric in relation to the central longitudinal axis of the associated contact.

5. A plug or socket according to any of claims 1 to 4, wherein the contacts are arranged in a common insulating body within the housing so that they are electrically insulated in relation to one another.

6. A plug or socket according to claim 5, wherein the body is arranged so that it is displaceable by the force of a spring or springs between stops fixed with respect to the housing.

7. A plug or socket according to claim 5 or claim 6, wherein the individual contacts are arranged so that they are displaceable by the force of a spring or springs between stops fixed with respect to the body.

8. A plug or socket according to any of claims 1 to 7, wherein the contacts are designed and arranged in such a way that only in the completely inserted position of the connector do they rest in an electrically conductive manner against the corresponding connecting contacts.

9. A plug or socket according to any of claims 1 to 8, wherein the contacts and/or the associated connecting contacts are of elastic design at their corresponding end faces.

10. A plug or socket according to claim 9, wherein the end faces are cupshaped and have radially extending segments, which are secured at the edges and are flexible at their inner free ends.

11. A plug or socket according to any of claims 5 to 10, wherein the body for receiving the contacts consists at least at its insertion end of a deformable or elastic f - is - material.

12. A plug or socket according to any of claims 1 to 11, wherein the connecting contacts have an electric insulating casing outside their region of contact with the elongate contacts and the insulating body receiving the contacts is formed with electrically conductive elements, which, in the unplugged position of the connector, short circuit individual connecting contacts in a pre-determined arrangement, whilst in the inserted position of the connector, the elements rest against the insulating casing of the connecting contacts.

13. A part for an electrical connector comprising an is electrically conductive housing surrounding a first contact and a second movable contact, said second contact being arranged to protrude through said housing and to make electrical connection between the first contact and a complementary other part of the electrical connector, said second contact being resiliently biased such that, when not in use to connect said first contact as described, it moves away and disconnects from said first contact and instead makes electrical contact with said housing so as to complete with said housing a protective shield against electromagnetic interference around said first contact.

14. A plug or socket for an electrical connector substantially as herein before described with reference for Fig. 1 of the drawings.

15. A plug or socket for an electrical connector substantially as hereinbefore described with reference to Fig.2 of the drawings.

Published 1991 at The Patent Office. State House. 66/71 High Holborn, London WC I R47P. Further copies may be obtained from Sales Branch. Unit 6, Nine Mile Point. Cwmfelinfach, Cross Keys. Newport NPI 7HZ. Printed by Multiplex techniques ltd, St Mary Cray. Kent