GB2172447A

GB2172447A - Shielded electrical connector

Info

Publication number: GB2172447A
Application number: GB08524418A
Authority: GB
Inventors: Pierre Louis Marie Drogo
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-03-12
Filing date: 1985-10-03
Publication date: 1986-09-17
Also published as: GB8524418D0; FR2579029B1; FR2579029A1

Abstract

A grounding ring in a shielded electrical connector comprises a strip of flexible metal of small thickness folded lengthwise onto itself and bent into an annular ring (4) of which the inner face and outer face (41, 42) are slightly spaced apart from each other. Slots (6) may be provided in one or other face of the ring. <IMAGE>

Description

SPECIFICATION Electrical connector The invention relates to an electrical connector.

Electrical connectors are composed of two parts, one of which is referred to as the "socket", the other as the "plug", and each comprises a metal body containing an insert of insulating material in which are housed the frequently quite numerous (about 100) male or female pins and sleeves which make the electrical connection.

When these two parts of the connector are assembled the two metal bodies are assembled one to the other by any screw or bayonet device, while the male pins penetrate the interior of the female sleeves in order to connect the conductor strands of multi-conductor cables which are connected to the socket and to the plug.

However, these conductor strands generally transmit digital or analogue signals where it is important not to alter the form or composition, in order to avoid any error in the command which such signals are intended to give.

To achieve this result, it is normal practice to protect transmitted signals from external upsets by enclosing the cables in a metal braided shield which is connected to earth, while the socket and plug bodies are connected by an annular metal element situated between the plug body and the socket body to ensure the electrical earthing junction.

It is thus known to make this annular element for shielding the connector in the form of a ring which is fixed to one of the metal bodies of the connector and which comprises cut-out and bent tongues which come elastically in contact with the other body of the connector when the plug and socket are assembled.

However, such a construction is not considered to be satisfactory because the space between the tongues constitutes a zone through which external disturbances can pass.

Likewise, this construction is fragile because during assembly of the plug and socket, certain tongues may become permanently deformed or even cut which would destroy their connector protecting characteristics.

Other constructions provide for such a means of protection to be afforded by a metal wire which is bent in a zig-zag fashion and the two ends of which are connected to each other to form a generally cylindrical sleeve.

However, such a sleeve does not provide satisfactory protection either for the electrical links of the connector to safeguard it against external disturbances because such disturbances can circulate between the folds of the wire.

It is in particular an object of the present invention to remedy these drawbacks and to this end the invention relates to an electrical connector which is composed of two parts which are assembled one with the other, each comprising a hollow metal body which receives on the inside an insert of insulating material in which are housed the male pins and/or female sleeves which make the electrical connection, means furthermore being provided between the body of the two parts to ensure their shielded electrical connection, the said connector being characterised in that the shielded electrical connection means consists of a strip of flexible metal of small thickness, folded transversely onto itself and bent longitudinally in order to form an annular ring of which the inner and outer faces obtained by folding are slightly spaced apart from each other.

According to a further characteristic feature of the invention, one of the faces, the inner or the outer face of the ring is cylindrical.

According to another characteristic feature of the invention, the outer face and/or the inner face are of generally convex form.

According to another characteristic feature of the invention, the folding and bending of the strip are carried out in such a way that the inner and outer faces when at rest form a flattened V-shape, the free edge of the outer face or of the inner face being bent back towards the opposite face.

The invention is illustrated by way of nonlimitative example in the appended drawings, in which: Figure 1 is a view showing the two parts of the connector according to the invention in the dismantled state; Figure 2 is an elevation showing the shielding ring used on the connector in Figure 1.

Figure 3 is a section taken on the line A-A in Figure 2; Figure 4 shows the connector in Figure 1 in the assembled position; Figure 5 is an elevation showing another embodiment of shielding ring, and Figure 6 is a section taken on the line B-B in Figure 5.

Consequently, the object of the present invention is to produce a connector in which the plug and socket bodies are, when the connector is in the assembled position, linked electrically to each other in continuous fashion in order to constitute a shielding ensuring effective protection against external interference of the signals which pass through the connecting pins and sleeves.

This method of shielded electrical connection according to the invention furthermore occupies but little space, that is to say it is of small thickness and short length.

Thus, its small thickness makes it possible to use it on small-dimensioned connectors and generally on connectors where the metal bodies of plug or socket are of small thickness.

Likewise, the short length of this electrical connection means makes it possible that several such connection means can be used one after another in the available space along the plug or socket bodies.

According to the embodiment shown in Figures 1 and 4, the connector is composed of a plug 1 and a socket 2. The plug 1 comprises a hollow metal body 11 inside which is housed an insulating insert 12 which itself accommodates the female sleeve 13 each of which must be connected to a strand of a multi-conductor cable.

The socket 2 likewise comprises a hollow metal body 21 inside which is housed an insulating insert 22 for receiving the male pins 23 each connected to one of the strands of a multi-conductor cable, which must be connected through the intermediary of the female sleeves to the corresponding strands of the cable connected to the plug 1.

The plug body 11 fits into the interior of the socket body 2, by means of grooves and matching ribs such as 3 which are intended to ensure that the plug is not wrongly inserted into the socket.

In order to ensure perfect electrical connection of the socket and plug and therefore satisfactory protection of the electrical junctions of the cables inside the connector vis-a-vis external disturbances, it is according to the invention envisaged to have a metal ring 4, which in the example shown in Figures 1 and 4, is housed partially in an annular groove 14formed in the outer face of the plug body 11. This ring 4 is obtained from a strip of elastic metal of small thickness, which is folded transversely on itself to form a longitudinal fold line and which is bent longitudinally to constitute an annular ring of which the inner face 41 and outer face 42 are slightly spaced apart from each other on their free edge.

As can be seen from the drawings, the transverse folding of the strip determines at 43 at the junction of the inner face 4, and outer face 42 a zone which is circular in shape and the mechanical -resistance to deformation of which is quite considerable, which makes it 'possible to use a flexible metal strip of small thickness, that is to say to obtain a ring of which the inner and outer faces may approach each other elastically a great number of times without reaching the limit of permanent deformation.

The length of the metal strip used is determined in such a way that after folding and bending, the annular ring obtained can be placed in position in the groove 14 of corresponding diameter, the two ends of this strip which face each other defining a slot 5 of small width.

In the embodiment shown in Figure 1, folding of the strip is carried out in such a way that the inner and outer faces form inter se a flattened V-shape of which the inner face 43 is cylindrical and of which the outer face 42 is bent back at 44, at its free end, towards the inner face 41 in order to form at 45 a surface of generally convex shape which is capable of ensuring satisfactory mechanical contact and therefore satisfactory electrical connection to the inner wall of the socket body 21- Thus (see Figure 4), upon assembly of the plug body on the the socket body, the outer face 42 of the ring becomes deformed elastically and progressively from the fold zone 43 in such a way that, having regard to the flexibility of the faces 4, and 42 constituting the ring, an electrical connection is obtained which is of very low resistance (of the order of 10-4 Ohms).

In the embodiment shown in Figures 5 and 6, another embodiment of annular shielding ring is shown.

In this case, indeed, the outer face 42 is provided with longitudinal slots 6 which have adjacent edges and which are regularly distributed and which are intended to allow adaptation of the outer periphery of the ring 4 to all points overthe inner cylindrical face of the socket body 2 . The length of these slots may vary according to the degree of adaptation desired and they could extend to a point very close to the fold zone 42.

Preferably, whatever their form of construction, the rings 4 should have inner and outer faces of substantially identical length and, moreover, instead of providing the groove 14 which receives the ring in the plug body, this could be provided on the inner face of the socket body 2off.

Furthermore, having regard to the short length of the ring, it will be possible to provide on one of the bodies either the socket body or the plug body, a plurality of parallel annular grooves 14 each receiving a ring 4 in order to reduce the electrical junction resistance still further.

Likewise, bearing in mind the small thickness of the ring 4, this latter may be maintained in a shaliow groove 14 so that the plug or socket body in which the said groove is formed may itself have a small wall thickness, as is required for questions of price, weight and bulk.

Claims

1. Electrical connector composed of two parts (1, 2) assembled one to the other and each comprising a hollow metal body (1" 21) receiving on the inside an insulating insert (12,22) in which are housed the male pins and/orfemale sleeves (13,23) for electrical connection, means being furthermore provided between the body of the two parts in order to ensure their shielded electrical connection, the said connector being characterised in that the shielded electrical junction means are constituted by a flexible metal strip of small thickness folded transversely onto itself and bent longitudinally to form an annular ring (4) of which the inner face and outer face (43,42) obtained by folding are spaced slightly apart from each other.

2. A connector according to Claim 1 characterised in that one of the faces, the inner face (43) or outer face (42) of the ring (4) is cylindrical.

3. A connector according to Claim 1 characterised in that the outer face (42) and/or the inner face (41) are of generally convex shape.

4. A connector according to Claim 3 characterised in that the folding and bending of the strip are performed in such a way that the inner face (41) and outer face (42) when at rest form a flattened V-shape, the free edge (44) of the outer face or of the inner face being bent back towards the opposite face.

5. A connector according to any one of the preceding Claims characterised in that the inner face and/or the outer face of the ring (4) are provided with slots (6) which are regularly distributed and parallel with its axis.

6. A connector according to Claim 5, characterised in that the slots (6) have adjacent edges.

7. A connector according to any one of the preceding Claims characterised in that the inner face (43) and outer face (42) are of substantially identical length.