GB2234401A - Electrical connectors - Google Patents

Abstract

An electrical connector, such as a break-in adapter 10 for telephone use, includes a shutter 22 for preventing access to a socket 20. When a special key (not shown) is inserted into an aperture 30, it engages a projecting part 28 of an extension portion 26 of the shutter 22. When the projecting part 28 has been urged clear of the aperture 30, the shutter 22 can be lifted by a lip 24 against a spring 32, and a jack plug can be inserted into the socket 20. When the jack plug is removed, the spring 32 closes the shutter 22, and the projecting part 28 re-engages in the aperture 30. <IMAGE>

Description

ELECTRICAL CONNECTORS This invention relates to electrical connectors, and in particular to such connectors which may be used as telephone connectors, for example, as so-called break-in adaptors.

It is known to provide electrical connectors such as sockets with a shutter, so as to prevent access to the interior of the connector unless the shutter is removed. In telephone jack sockets currently used in the United Kingdom by British Telecom, a shutter is provided which has to be displaced by a sliding action before a corresponding jack plug can be inserted into the socket. Whereas this prevents access to the socket to a certain extent, the manner in which the shutter can be made to open can readily be deduced and therefore the effectiveness of the shutter is reduced.

The suppliers of ancillary telephone equipment, such as facsimile machines, telephone answering machines and the like, would ideally like to make connection of such equipment to the telephone network as easy as possible. Such easy connection can readily be achieved by providing a telephone jack plug at the end of the connection lead for the equipment. This is effective in situations where a separate telephone line is dedicated to the use of the equipment, but if the user requires the telephone line to be shared between the equipment and, for example, an ordinary telephone, connection problems will result. For this reason, it has previously been proposed to provide a so-called breakin adaptor which is an electrical connector having a plug part, a socket part and provision for attachment to a connection lead of ancillary equipment.When the plug part of the adaptor is inserted into a telephone jack socket, connection between the telephone network and the equipment is provided. However, if desired, another item of equipment such as an ordinary telephone can be plugged into the socket part of the adaptor. Thus use of the ancillary equipment is not dependent on the provision of a dedicated telephone line. However, the shuttering problem outlined above is equally applicable to a break-in adaptor.

According to the present invention there is provided an electrical connector comprising a housing, an opening in the housing for providing access to a socket within the housing, a shutter biased to mask the opening and prevent access to the socket, and means for inhibiting opening of the shutter, the inhibiting means being overridable by insertion of a key into an aperture in the housing such that, upon overriding of the inhibiting means, the shutter can be opened to provide access to the socket.

In a preferred embodiment of the invention, to be described in greater detail hereinafter, the connector forms part of a break-in adaptor with a rectangular telephone-type jack plug moulded to the adaptor. The shutter prevents access to the socket, and an outlet is provided for a cable connection to ancillary equipment. Since a special key is required to open the shutter, prevention of access to the socket is substantially improved compared to that of the previously-known shutter mechanism.

The invention will now be further described, by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which: Figure 1 is a partially broken-away perspective view of a breakin adaptor according to an embodiment of the invention; and Figure 2 is a sectional view of the break-in adaptor of Figure 1, taken along a plane through the cable connector and a line joining plug and socket parts.

Referring to the drawings, a break-in adaptor 10 includes a main housing 12 and a jack plug part 14 projecting from the housing 12. The preferred break-in adaptor is intended for use with current UK telephone installations, and accordingly the plug part 14 is a rectangular telephone-type jack plug according to British Standard No.

6312, including a latch member 16. The plug part 14 is preferably integrally moulded with the main housing 12, the preferred material being a thermoplastic polyester.

The main housing 12 has an opening 18 behind which a socket part 20 is located. In the case of an adaptor as shown for use in telephone installations, the socket part 20 is a rectangular telephone-type jack socket designed to receive a complementary jack plug as described above. In that case, the opening 18 will be rectangular, as shown in Figure 1. Just behind the opening 18, a shutter 22 is provided for sliding movement between lower and upper positions, the lower position of the shutter 22 masking the opening 18 and preventing access to the socket part 20, and the upper position allowing access to the socket part 20 through the opening 18. The shutter 22 includes an outwardly projecting lip 24 for ready engagement by a finger, screwdriver or the like during shutter opening.The shutter 22 also includes an extension portion 26 with a projecting part 28 normally fitting into an aperture 30 in the front face of the main housing 12. The extension portion 26 is arranged to be resilient in the direction of disengagement of the projecting part 28 from the aperture 30, and this is preferably achieved by making the extension portion 26 have a thinner crosssection than the main part of the shutter 22. As shown the thickness gradually decreases towards the projecting part 28. Accordingly, when a key (not shown) of complementary shape to the aperture 30 is inserted therethrough, it can be used to push the projecting part 28 away from the aperture 30 against the resilience of the extension portion 26.A spring 32 is positioned to act between a top mounting 34 of the main housing 12 and a spring member 36 which is arranged to contact the top of the extension portion 26 and slide in a similar manner to the shutter 22.

Within the main housing 12, there is also included a printed circuit board 38 which makes it possible for the break-in adaptor 10 to be made suitable for any one of a number of different applications by the simple expedient of inserting the corresponding type of circuit board.

As shown in Figure 2, the main housing 12 also includes an outlet 40 for a cable connection, the outlet 40 being arranged to accept and retain a cable grommet 42 for preventing strain on the cable from breaking the cable connections within the adaptor. Alternatively or in addition to the grommet 42, a cable strain relief clamp may be provided.

In operation, the break-in adaptor is connected to a cable from ancillary equipment such as a facsimile machine or an answering machine, the cable passing through the outlet 110. The plug part 14 of the adaptor can then be inserted into a telephone jack socket connected to a telephone network. If it is required also to connect further equipment such as a telephone, it is necessary to open the shutter 22.

This is achieved by inserting the special key into the aperture 30 and pushing back the projecting part 28 of the extension portion 26 until it is clear of the aperture 30. It is then possible to raise the shutter 22 against the force of the spring 32 (applied by means of the slidable spring member 36) using the lip 24. A jack plug can then be inserted through the opening 18 into the socket part 20. Upon removal of the plug, the shutter 22 will be moved downwards by spring pressure applied from the spring 32 via the slidable spring member 36. When the shutter 22 has fully closed, the projecting part 28 will be aligned with the aperture 30 and, in view of the resilience of the extension portion 26, will move back into the aperture. Thus further movement of the shutter 22 will not be possible without further use of the special key.

In Figures 1 and 2, the projecting part 28 and the aperture 30 are shown to be circular, but they could be any other suitable shape; of course, the special key must be able to pass through the aperture and engage the projecting part. The projecting part 28 is preferably dimensioned to remain recessed within the aperture 30 in the closed position of the shutter, so as to make access thereto difficult if using an implement other than the special key.

Claims (13)

1. An electrical connector comprising a housing, an opening in the housing for providing access to a socket within the housing, a shutter biased to mask the opening and prevent access to the socket, and means for inhibiting opening of the shutter, the inhibiting means being overridable by insertion of a key into an aperture in the housing such that, upon overriding of the inhibiting means, the shutter can be opened to provide access to the socket.

2. An electrical connector according to claim 1, wherein the shutter is slidable, and the inhibiting means comprises an inhibiting member which is moveable away from an obstruction by insertion of the key so as to allow sliding movement of the shutter.

3. An electrical connector according to claim 2, wherein the inhibiting member comprises an extension portion of the shutter.

4. An electrical connector according to claim 3, wherein the extension portion is resilient in the direction of insertion of the key, and includes a projection arranged to fit in the aperture thereby constituting the obstruction, insertion of the key urging the projection clear of the aperture and enabling opening of the shutter.

5. An electrical connector according to claim 11, wherein the projection is dimensioned to remain recessed within the aperture when viewed from the outside, in the movement inhibiting position.

6. An electrical connector according to claim 4 or claim 5, wherein the resilience of the extension portion is provided by the extension portion being thinner in cross-section than the remainder of the shutter.

7. An electrical connector according to claim 6, wherein the extension portion is progressively thinner in cross-section between the shutter and the projection.

8. An electrical connector according to any one of the preceding claims, for use as a telephone connector, wherein the socket is a rectangular telephone-type jack socket.

9. A break-in adaptor comprising an electrical connector according to claim 8, a rectangular telephone-type jack plug attached to the housing, and an outlet for a cable connection.

10. A break-in adaptor according to claim 9, wherein the jack plug is integrally moulded with the housing.

11. A break-in adaptor according to claim 9 or claim 10, including a printed circuit board within the housing.

12. A break-in adaptor according to claim 9, claim 10 or claim 11, including a cable grommet fitting within the outlet.

13. An electrical connector or a break-in adaptor substantially as hereinbefore described with reference to the accompanying drawings.