BACKGROUND ART In this connection it is increasingly the custom of some manufacturers of telephone equipment to supply their equipment with a captive telephone plug in a single standard, irrespective of where in the world the equipment is made or supplied.

It is an object of the invention to provide an electrical connector, e. g. a telephone plug or adapter, of simple construction and assembly to reduce costs of manufacture, and of improved robustness.

DISCLOSURE OF INVENTION According to the invention there is provided a telephone plug comprising a body and a resilient latch adapted to secure the plug in a corresponding socket, the latch comprising a limb having opposed inner and outer ends wherein a inner end of the limb is integral with the body and a retention member which is integral with the body and limits movement of a outer end of the limb.

The limb is preferably elongate and may be resiliently deflected to effect latching and unlatching. The limb may extend away from the body at an acute angle, for example at an angle of less than 30° to the insertion direction of the plug in the socket.

The retention member may be generally at right angles to the body, i. e. the retention member may extend outwards from the body substantially perpendicular to the insertion direction. The retention member may be rigid.

The retention member may be integral with the outer end of the limb. In this way, the latch member is integral with the body. One end of the latch members of conventional U. K. telephone plugs is free and can become snagged as the latch member is manipulated; this in turn can cause the

latch member to break off in use. The telephone plug according to this embodiment of the invention has a latch member that is much less likely to be broken off in use since the outer end of the limb is held by the retention member.

Alternatively, the retention member may comprise a catch mechanism for restricting the freedom of movement of the outer end of the limb. The catch mechanism may comprise a hook on the outer end of the limb and a hole in the retention member, the hole having an axis substantially parallel to the insertion direction of the plug in the socket. The hole may be rectangular in form.

When the outer end of the limb is captured in the hole, the latch member is much less likely to be broken off, since its movement is limited and it can no longer become snagged as the telephone plug is manipulated in use.

This arrangement has the advantage that the flexibility of the latch member is greater than in the alternative arrangement. This may allow less flexible plastics to be used to form the latch member.

Alternatively, the retention member may be attached to the limb is attached to the retention member via a joint. In this embodiment the retention member is preferably made of a flexible material.

A projection may be positioned between the latch and the body to limit inward deflection of the latch member.

The projection may be positioned adjacent to the retention member.

Cut outs may be integrally moulded in the latch member, for example to improve its flexibility or to engage with corresponding projections in the socket. The body may be formed of moulded plastics.

According to another aspect of the invention, there is provided an electrical telephone adapter comprising a hollow body of electrically insulating material having a first part defining a plug portion and a second part defining a socket portion, the plug and socket portions conforming to different electrical standards and a carrier member of electrically insulating material mountable in the body to extend into the plug and socket portions, the carrier member having an upper and lower face and comprising an area which partly defines the plug portion, an area of the upper face which defines a wall of the socket, opposed sets of grooves on at least one face of the carrier member in the respective areas, a plurality of unitary wire members extending from the plug to the socket portion, each of which comprises a free end portion defining a resiliently displaceable electrical contact in the socket portion, and an intermediate portion disposed'in a corresponding groove on the carrier member, so that the unitary wire members are maintained in spaced relationship.

The sets of grooves may be on the lower face of the

carrier member and the free end portions of the wires may be bent around the carrier member to extend into the socket at an acute angle to the upper face of the carrier member.

The carrier member may be mountable through the socket portion into the hollow body.

The wire will be of a kind which can be bent into a desired shape and which will retain that shape, or at least which will tend to regain that shape when resiliently deflected. The wire may be of any desired cross-sectional shape, e. g. round or square, and the contact portions may be plated to resist corrosion, e. g. gold plated, if desired.

BRIEF DESCRIPTION OF DRAWINGS The invention is diagrammatically illustrated, by way of example, in the accompanying drawings, in which:- Figure 1 is a perspective view of a telephone adapter according to the present invention; Figure 2 is an exploded perspective view of the adapter of Figure 1 taken from the socket end; Figure 3 is an exploded perspective view of the adapter of Figure 1 taken from the plug end; Figures 4 to 6 are respective exploded opposite side and plan views of the adapter of Figure 1; Figures 7 and 8 are respective end views of the assembled adapter of Figure 1; Figure 9 is a perspective view of a telephone plug according to a second embodiment of the present invention; Figures 10 to 12 are respective side, plan and end

views of the plug of Figure 9; Figure 13 is a side view of a telephone adapter according to another embodiment of the invention; Figure 14 is an end view of the adapter of Figure 13, and Figure 15 is a side view of the adapter of Figure 13 and Figure 16 is a side view of a telephone adapter according to another embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION Figures 1 to 8 show a telephone adapter comprising a hollow housing (1) of electrically insulating material having a first part defining a plug portion (3) and a second part defining a socket portion (5). The plug (3) comprises a body (23) and a resilient latch (31) adapted to secure the plug (3) in a corresponding socket (not shown),-for example a standard U. K. telephone socket.-The latch (31) comprises a limb (32) having opposed inner and outer ends (34,36) and a retention member (33) which is integral with the socket portion of the housing (1). An inner end (34) of the limb (32) is integral with the body (23) of the plug and an outer end (36) of the limb (32) is integral with the retention member (33). Effectively, the latch is moulded integrally with the body.

The limb (32) of the latch is approximately parallel to the line of insertion of the plug (3) in the socket, i. e. the limb is at an acute angle of less than about 30°

to this insertion direction. The retention member 33 extends sideways from one side of the socket portion (5) of the housing (1).

The latch (31) is shaped to engage the corresponding socket, for example cut outs (47) and projections (49) are integrally moulded in the limb (32) to engage with corresponding projections and indentations in the socket (not shown).

A projection (35) extends from the housing (1) towards the latch (31) to limit inward deflection of the latch (31). The projection (35) is positioned adjacent to the retention member (33).

In this embodiment, the plug and socket portions conform to different electrical standards, for example, the electrical standards of telecommunications authorities in different countries.

The adapter further comprises a separate carrier member (7) of electrically insulated material mountable in the housing (1). As shown in Figures 2 and 3, the carrier (7) is inserted into an opening (21) defined by the hollow housing.

The lower face (53) of the carrier member is formed with a plurality of wire supports, here grooves (11) defined between adjacent flanges (12), which locate a plurality of wires (13), so that the unitary wire members are maintained in spaced relationship. An area of the upper face (55) of the carrier member (7) defines a wall (57) of the socket portion (5).

The wires (13) extend from the plug (3) to the socket

portion (5) and each wire comprises opposed inner and outer free end portions (15,17) and an intermediate portion (19) disposed in a corresponding groove (11) on the carrier member (7). The inner free end portions (15) form a resiliently displaceable latch mechanism to secure the carrier member (7) in position in the finished article.

The outer free end portions (17) define a resiliently displaceable electrical contact in the socket portion.

Both the inner and outer the free end portions of the wires are bent around the carrier member to extend at an acute angle to the upper face of the carrier member.

The shape of the body is not critical and Figures 9 to 12 show an embodiment having a different form of body. In particular, the retention member (33) is generally semi- circular and extends from the face (43) of the socket end (5) of the adapter. The limb (32) of the latch (31) is formed integrally with the retention member (33).

Figures 13 to 15 show an alternative embodiment which differs in the design of the latch and the retention member. In this embodiment, the inner end (34) of the limb (32) of the latch is integrally formed with the body (as with the previous embodiments) but the outer end (36) is free. The retention member (33) comprises a catch mechanism (45) to limit movement of the outer end (36).

The catch mechanism (45) comprises a hook (41) on the outer end (36), said hook being displaced towards the body from the line of the rest of the limb. The hook (41) is adapted to engage with a hole (39) in the retention member (33).

The hole (39) passes through the retention member (33) in a direction that is substantially parallel to the insertion direction of the plug in the corresponding socket (not shown).

Alternative catch mechanisms could also be used. For example, instead of a hole the retention member could be formed with a projection adapted to co-operate with the outer end of the latch.

When the outer end (36) of the limb (32) is captured in the hole (39) the latch is much less likely to be broken off in use, since its movement is limited and it can no longer become snagged as the telephone plug is manipulated.

Figure 16 show an alternative embodiment which differs in the design of the latch and the retention member. In this embodiment, the inner end (34) of the limb (32) of the latch is integrally formed with the body (as with the previous embodiments) but the outer end (36) is attached to the retention member (33) via joint (51). The joint is flexible to allow deflection of the limb (32). The retention member (33) is slightly curved and is at an acute angle of approximately 30° to a side of the socket portion (5). The retention member is made of more flexible plastics than the previous arrangements of latch (31).

INDUSTRIAL APPLICABILITY The invention thus provides a novel telephone plug and adapter which solves significant problems in known arrangements.