EP0015759A1

EP0015759A1 - An improved electric connector assembly

Info

Publication number: EP0015759A1
Application number: EP80300698A
Authority: EP
Inventors: Philip Ramsay Gerrett; Ernest Leonard Charles Barrett
Original assignee: BICC PLC
Current assignee: Balfour Beatty PLC
Priority date: 1979-03-07
Filing date: 1980-03-06
Publication date: 1980-09-17
Also published as: JPS55126972A; GB2046031A

Abstract

An electric connector assembly is of the kind in which electric contacts and associated terminals are mounted in a preformed body (1) of electrically insulating material, the conductors of a length of flexible insulated multi-conductor cable are electrically connected to appropriate terminals of the connector, and a moulded plug body of electrically Insulating material wholly or partially encapsulates the preformed body and is permanently bonded to the insulating covering of a part of the length of the cable, wherein the preformed body (1) comprises, upstanding from its front face (3), a wall (4) which surrounds at least the holes (2) and recesses in the preformed body associated with the line and neutral electric contacts and which has a gap or aperture (5) therethrough for entry of the cable conductors; and wherein the space bounded by said wall (4) is closed by a preformed cap (6) of electrically Insulating material to form an enclosure housing at least the line and neutral terminals.

Description

This invention relates to an electric connector assembly of the kind in which the electric contacts and associated conductor terminals are mounted in a preformed body of electrically insulating material, the conductors of a length of flexible insulated multi-conductor cable are electrically connected to appropriate terminals of the connector, and a moulded plug body of electrically insulating material wholly or partially encapsulates the preformed body and is permanently bonded to the insulating covering of a part of the length of cable. Electric connector assemblies of this kind will hereinafter, for convenience, be referred to as "of the kind described".
The invention is concerned both with electric connector assemblies of the kind described in which at least one of the electric contacts is a pin protruding from the rear face of the preformed body and in which at least one of the electric contacts is a socket within the preformed body.
It has been found that, in manufacturing electric connector assemblies of the kind described, there is a risk that, during moulding of the connector body, a wire or wires of the exposed end of a cable conductor connected to one of the terminals will become detached from the terminal and will protrude through the moulded connector body. A connector assembly which is connected to a domestic electrical appliance and which has a live wire or wires protruding through the connector body is extremely dangerous especially if handled with damp hands - as may be the case when a plug assembly is connected to a domestic washing machine or a socket assembly for an electric kettle is connected to an electric socket outlet.
It is an object of the present invention to provide an improved electric connector assembly of the kind described, in which assembly the aforesaid risk is eliminated or at least substantially reduced.
According to the invention we provide an electric connector assembly of the kind in which the electric contacts and associated conductor terminals are mounted in a preformed body of electrically insulating material, the conductors of a length of flexible insulated multi-conductor cable are electrically connected to appropriate terminals of the connector, and a moulded plug body of electrically insulating material wholly or partially encapsulates the preformed body and is permanently bonded to the insulating covering of a part of the length of the cable, wherein the preformed body comprises, upstanding from its front face, a wall which surrounds at least the holes and recesses in the preformed body associated with the line and neutral electric contacts and which has a gap or aperture therethrough for entry of the cable conductors; and wherein the space bounded by said wall is closed by a preformed cap of electrically insulating material to form an enclosure housing at least the line and neutral terminals.
Preferably, the wall upstanding from the front face of the preformed body surrounds the holes and recesses associated with all of the electric contacts, including, if present, any hole or recess for accommodating a carrier of electric contacts for a cartridge fuse.
The preformed cap is preferably of an electrically insulating material that is substantially harder than the moulded insulating material of the plug body. The cap may be a snap fit over or in the open end of the enclosure bounded by the upstanding wall or it may be in sliding engagement with the wall. In the former case a side-edge of the cap may be hinged to the upper edge of a part of the upstanding wall by a web of insulating material integral with the wall and the cap.
The provision, within the moulded plug body, of an enclosure.housing the conductor terminals eliminates or substantially reduces the risk that a conductor wire or conductor wires may protrude through the moulded plug body.
In some cases, and especially where the electric contacts are electric sockets, the enclosure may serve to prevent the insulating material of the plug body from coming into contact with the electric sockets and their associated conductor terminals, thereby preventing moulded insulating material from forming an obstruction in the sockets relative to the preformed body to facilitate insertion of pins in the sockets.
In other cases, and especially where the electric contacts are pins, the wall and/or cap of the enclosure may have one or more than one aperture through which insulating material of the plug body can flow to encapsulate the conductor terminals and inner ends of the pins. In a preferred embodiment a number of mutually spaced holes are provided in the upstanding wall immediately adjacent the front face of the preformed body.
Where, for example, the moulded plug body is of urea or polyester, preferably the preformed body and the preformed cap are of nylon or polyester.
The conductors of the flexible cable may be electrically connected to the conductor terminals in any convenient manner, a crimped connection being preferred.
The invention also includes an improved method of manufacturing an electric connector assembly as hereinbefore described, which method comprises effecting the electrical and/or mechanical connections between the electric contacts and their associated conductor terminals and the electrical connections between the cable conductors and the conductor terminals; introducing all the electric contacts and their associated conductor terminals, with the cable conductors electrically connected thereto, into holes and recesses in the front face of the preformed body, said preformed body having, upstanding from its front face, a wall which surrounds at least the holes and recesses in the preformed body associated with the line and neutral electric contacts and which has a gap or aperture therethrough for entry of the cable conductors; closing the space bounded by said wall by a preformed cap of electrically insulating material to form an enclosure housing at least the line and neutral conductor terminals; and moulding therearound electrically insulating material to form a moulded plug body which wholly or partially encapsulates the preformed body and said enclosure and which is bonded to the insulating covering of a part of the length of the flexible cable.
The plug body is preferably moulded in one operation. Alternatively the plug body may be moulded in two or more operations, each moulding wholly or partially encapsulating the preformed body and said enclosure and/or the or each previous moulding, and bonding together.
The invention is further illustrated by a description, by way of example, of two forms of preformed body for use in the manufacture of a 13A three pin electric plug with reference to the accompanying drawings, in which:-

Figure 1 is an exploded view of the first preformed body (with the plug pins and conductor terminals qmitted) and its preformed cap;
Figure 2 is a cross-sectional view of the preformed body shown in Figure 1 taken on the line II - II;
Figure 3 is an exploded view of the second preformed body (with the plug pins and conductor terminals omitted) and its preformed cap, and
Figure 4 is an end view of the preformed body shown in Figure 3 looking in the direction of arrow Y, with its preformed, cap in position.

Referring to Figures 1 and 2, the preformed body is made of moulded plastics material and comprises a base 1 having holes 2 and recesses in its front face 3 for the reception of the plug pins and their associated conductor terminals and, surrounding the holes and recesses, a wall 4 which upstands from the front face of the base and which has a gap 5 for introduction of the cable conductors. The space bounded by the wall 4 is closed by a preformed cap 6 which slides in a groove 7 on the inner surface of the wall and which has, at one end, a flange'8 with a gap 9 that _'co-operates with the gap 5 to form the cable entry aperture. After the plug pins and their associated conductor terminals, with the cable conductors electrically connected thereto, have been introduced into the holes 2 and recesses, the enclosure is closed by the cap 6 and electrically insulating material is moulded therearound to form a moulded plug body which encapsulates the preformed body and the enclosure and which is bonded to the insulating covering of a part of the length of the flexible cable.
Referring to Figures 3 and 4, the second form of preformed body is made of moulded plastics material and comprises a base 11 having holes 12 and recesses in its front face 13 for the reception of plug pins and their associated conductor terminals and, surrounding the holes and.recesses, a wall 14 which upstands from the front face of the base and which has a gap 15 for introduction of the cable conductors. The space bounded by the wall 14 is closed by a preformed lid 16 which is hinged to the wall 14 by an integral web 17 and which has a depending peripheral wall 18 with a gap 19 that co-operates with the gap 15 to form the cable entry aperture.
In both cases, where it is desired that the conductor terminals are encapsulated in the material of the moulded plug body, the walls 4 and 14 may have, adjacent the front face of the base, spaced apertures for entry of material into the space enclosed by the enclosure.
The scope of this invention is not restricted to the embodiments shown and described. In the case where the electric connector assembly comprises line, neutral and earth electric contacts, the upstanding wall may surround only the holes and recesses associated with the neutral and line electric contacts, so that the earth contact terminal remains outside the enclosure defined by the walls and the preformed cap.

Claims

1. An electric connector assembly of the kind in which the electric contacts and associated conductor terminals are mounted in a preformed body of electrically insulating material, the conductors of a length of flexible insulated multi-conductor cable are electrically connected to apppro- priate terminals of the connector, and a moulded plug body of electrically insulating material wholly or partially encapsulates the preformed body and is permanently bonded to the insulating covering of a part of the length of the cable, characterised in that the preformed body (1) comprises, upstanding from its front face (3), a wall (4) which surrounds at least the holes (2) and recesses in the preformed body (1) associated with the line and neutral electric contacts and which has a gap or aperture (5) therethrough for entry of the cable conductors; and in that the space bounded by said wall (4) is closed by a preformed cap (6) of electrically insulating material to form an enclosure housing at least the line and neutral terminals.

2., An assembly as claimed in Claim 1, characterised in that the wall upstanding from the front face of the preformed body surrounds the holes and recesses associated with all the electric contacts, including, if present, any hole or recess accommodating a carrier of electric contacts for a cartridge fuse.

3. An assembly as claimed in Claim 1 or 2, characterised in that the preformed cap is of an electrically insulating material that is substantially harder than the moulded insulating material of the plug body.

4. An assembly as claimed in any one of the preceding claims characterised in that the preformed cap is a snap fit over or in the open end of the enclosure bounded by the upstanding wall.

5. An assembly as claimed in Claim 4, characterised in that a side edge of the cap is hinged to the upper edge of a part of the upstanding wall by a web of insulating material integral with the wall and the cap.

6. An assembly as claimed in any one of Claims 1 to 3, characterised in that the preformed cap is in sliding engagement with the upstanding wall.

7. An assembly as claimed in any one of the preceding claims, characterised in that the moulded plug body comprises one layer.

8. An assembly as claimed in any one of Claims 1 to 6, characterised in that the moulded plug body comprises two or more layers, the layers being bonded together.

9. An assembly as claimed in any one of the preceding claims, in which the electric contacts are pins, characterised in that the upstanding wall has a number of mutually spaced holes immediately adjacent the front face of the preformed body through which the insulating material of the moulded plug body has flowed into the enclosure to encapsulate-the conductor terminals and inner ends of the pins.