GB2085242A - An improved electric connector assembly - Google Patents

Abstract

In an electric plug assembly which is especially suitable for use with socket outlets positioned on a wall adjacent the floor or with socket outlets positioned in the floor itself, the cable 11 carries a sleeve 14 of electrically insulating material having a part 16 of partially spherical shape which engages in, and is movable with respect to, a seating in the cable entry of the plug housing 2, which seating is of such a complementary shape and size as to co-operate with the spherical part 16 to form, in effect, a ball and socket coupling. The cable 11 extending from the plug body 2 can be arranged to lie in any one of several directions differing from one another and at any angle within a wide range to the face of the plug body. <IMAGE>

Description

SPECIFICATION An improved electric connector assembly This invention relates to electric connector assemblies of the kind comprising an electric connector whose electric contact or contacts is or are permanently electrically connected to the conductor or conductors of a length of flexible electric cable.The invention is especially, but not exclusively, concerned with electric connector assemblies of this kind in which the electric connector is a three-pin electric plug whose pin terminals are permanently electrically connected to the ends of associated conductors of a length of flexible electric cable, such an electric plug assembly being suitable for use in domestic and similar wiring systems and being generally referred to as a non-rewirable plug assembly, but it is to be understood that the invention is not restricted to non-rewirable electric plug assemblies and, in some instances, some or all of the contacts of the electric connector of an electric connector assembly may be socket contacts.

In one known form of non-rewirable electric plug assembly, the plug pins protrude through holes in, and associated conductor terminals are mounted on, a preformed body of electrically insulating material, the conductors of a length of insulated multiconductor cable are electrically connected to appropriate terminals of the plug, and a moulded plug body of electrically insulating material wholly or partially encapsulates the preformed body and the plug pins and associated conductor terminals with an appropriate length of each pin protruding from the plug assembly and is permanently bonded to the insulating covering of a part of a length of the cable which extends from the moulded plug body with the axis of said part of the length of cable lying in a plane that is substantially parallel to that face of the preformed body from which the plug pins protrude.

Where a socket contact to which the electric plug of such a non-rewirable electric plug assembly is to be connected is located at the foot of a wall a short distance above the ground, in some circumstances the part of the electric cable to which the moulded plug body is permanently bonded is of such a length that it is difficult to insert the plug in the socket outlet without effecting an undesirable bend in that part of the cable. With a view to overcoming this problem, it has been proposed to arrange for that part of the cable to which the moulded plug body is bonded to extend from the plug body at an acute angle to the face of the plug from which the plug pins protrude.

However, such an electric plug assembly is not suitable for use with a socket outlet positioned in the ground because the length of cable extending from the plug at an acute angle to the ground constitutes a hazard over which a person may trip; such an electric plug assembly is also unsuitable for use with a socket outlet positioned in a wall at a substantial distance above the ground because, in this case, the cable extending from the plug hangs downwardly several centimetres away from the wall and is again a possible hazard.

It is an object of the present invention to provide an improved non-rewirable electric connector assembly which can be readily electrically connected to another electric connector located on the ground or at any position on a wall with substantially less risk that the length of cable to which the connector of the assembly is permanently connected will constitute a hazard than in any other non-rewirable electric connector assembly hitherto proposed and used.

According to the invention, the length of flexible electric cable whose conductor or conductors is or are permanently electrically connected to the contact or contacts of the electric connector of the assembly carries a body of electrically insulating material of partially spherical shape which engages in, and is movable with respect to, a seating in the cable entry of the insulating connector body, which seating is of such a complementary shape and size as to cooperate with the spherical body to form, in effect, a ball and socket coupling, the arrangement being such that the part of the length of the cable extending from the connector body can be arranged to lie in any one of a plurality of directions differing from one another and at any angle within a wide range to the face of the connector body that will abut a face of another connector body when electrically connected thereto.

Preferably, the partially spherical insulating body carried by the length of cable is separately formed with respect to the cable and, in its preferred form, is a sleeve of electrically insulating material which, over at least a part of its length, has a bore of such a diameter that the sleeve fits on the cable and, over at least a part of its length, has an external shape that is partially spherical.Preferably, at one of its ends the sleeve fits on the cable, and, at the other of its ends, the sleeve has an external shape that is partially spherical; the part of the bore of the sleeve bounded by the partially spherical portion of the sleeve is preferably of a diameter that is substantially greater than the diameter of the cable so that, at that part of the sleeve, it is a loose fit on the cable and accommodates for flexing of the cable when the partially spherical body is moved relative to the seating in the cable entry.

The insulating body of the connector of the connector assembly preferably has extending from one of its walls a tubular protrusion which constitutes the cable entry, the partially spherical body on the cable engaging the seating in the cable entry thereby being spaced from the contact or contacts within the connector body to which the conductor or conductors of the cable is or are permanently electrically connected. This arrangement substantially reduces the risk that flexing of the cable by movementofthe partially spherical body within its seating will have any deleterious effect on the electrical connections within the connector body.

Where the connector of the connector assembly is an electric plug, the insulating body of the plug may be a moulded body in which the electrical connections between the cable conductors and the pin terminals are encapsulated. In this case, the moulded body will be formed with a cable entry in one of its side walls in which an appropriately shaped seating is provided for accommodating the partially spherical body of the cable. Alternatively, the insulating body of the plug may be formed of two separately formed premolded body parts which are welded or otherwise permanently secured together to form- a housing enclosing the electrical connections between the cable conductors and the pin terminals. In this case, the housing will have in one of its walls a cable entry with an appropriately shaped seating for the partially spherical body on the cable.In both cases, preferably a separately formed sleeve carrying the partially spherical body is applied to the cable before the electrical connections between the cable conductors and pin terminals are made and is slid along the cable to engage in the seating in the cable entry after the insulating body of the plug has been moulded or assembied around the electrical connections.

To reduce the risk of strain being imparted through the cable to the electrical connections within the connector body when tension is applied in such a direction as to pull the cable away from the connector body, preferably the cable carries between the partially spherical body and the conductor terminals, a separately formed cable gripping member of electrically insulating material which is mounted in the connector body and which grips the cable.

Where the connector body is built up of two separately formed body parts, the cable gripping member may engage in a groove in one or each of said body parts adjacent the cable entry or, where the connector body is a moulded body which encapsulated the connector terminals, it may be wholly encapsulated in the moulded body. The cable griping member is preferably an apertured disc having around the aperture circumferentially spaced outwardly projecting teeth which extend towards the conductor terminals and which will bite into the insulating covering of the cable in the event that tension is applied to the cable in a direction away from the conductor terminals. An electric plug assembly with such a cable gripping member is the subject of our copending Patent Application No.

7921691.

In one alternative arrangement, the sleeve may be divided longitudinally of its length into two separately formed parts which are of such a form that one makes a snap fit with the other. In this case, one part of the sleeve is applied to the cable with part of the partially spherical body positioned in the appropriately shaped seating in the cable entry of the housing and the other part of the sleeve is then brought into engagement with the first part so that the two parts snap together. If desired, the internal surface of this two-part sleeve may have inwardly projecting teeth which extend towards the conductor terminals, or may be serrated or otherwise appropriately roughened, to form a cable grip integral with the two-part sleeve.

The invention is further illustrated by a description, by way of example, of a preferred nonrewirable electric plug assembly with reference to the accompanying drawing which shows a fragmental plan view of one part of a two-part body of the plug.

Referring to the drawing, the non-rewirable electric plug assembly comprises a plug 1 and a length 11 of flexible multi-conductor electric cable, the conductors 12 of the cable being connected to appropriate terminals (of which only one is visible) electrically connected to or integral with the plug pins, in any convenient manner. The plug 1 has a housing 2 of electrically insulating material built up .

of two preformed shells constituting a base 3 and a cover (not shown) each of which has an upstanding peripheral wall 4 and which are welded along the abutting faces of their peripheral walls. The base 3 (and the cover) each has an outwardly extending protrusion 5 of substantially semi-circular transverse cross-section, the protrusion having a semi-circular end wall 6 and, spaced from the end wall, a semi-circular inwardly extending rib 7. When the base 3 and the cover are welded together to form the plug housing, the cable entry 5 define a tubular cable entry through which the cable 11 extends into the housing.Spaced inwardly of the protrusion 5 is a cable gripping member 8 which engages in two grooved shoulders 9 upstanding from the bottom wall of the base 3, and of the cover the cable gripping member being an aperture disc having around the apertured circumferentially spaced outwardly projecting teeth 10 which extend towards the conductor terminals and which bite into the insulating covering of the cable 11.

Over a part of its length extending through the cable entry, the cable 11 carries a separately formed sleeve 14 of electrically insulating material which, over a part 15 of its length, has a bore of such a diameter that the sleeve fits on the cable, and over a part 16 of its length, has an external shape that is partially spherical. The part of the bore of the sleeve 14 bounded by the partially spherical part 16 of the sleeve is of a diameter that is substantially greater than the diameter of the cable 11 so that, at that part of the sleeve, it is a loose fit on the cable.The partially spherical part 16 of the sleeve 14 engages in, and is movable with respect to the inwardly facing surfaces of the end wall 6 and rib 7 of, the cable entry, these surfaces constituting a seating of such a complementary shape and size as to cooperate with the partially spherical part 16 to form, in effect, a ball and socket coupling.

The part of the length of the cable 11 extending from the housing 2 of the plug can be arranged to lie in any one of a plurality of directions differing from one another and at any angle within a wide range to the face of the base 3 that will abut a face of a socket.

outlet when electrically connected thereto. Since the bore of the partially spherical part 16 of the sleeve 14 has a diameter greater than the diameter of the cable 11, that part of the sleeve accommodates for flexing of the cable when the partially spherical part 16 is moved relative to the seating in the cable entry constituted by the surface of the end wall 6 and rib 7.

Claims (15)

1. A non-rewirable electric connector assembly comprising an electric connector whose electric contact or contacts is or are at least partially housed within a body of electrically insulating material and is or are permanently electrically connected to the conductor or conductors of a length of flexible electric cable, wherein the length of flexible electric cable carries a body of electrically insulating material of partially spherical shape which engages in, and is movable with respect to, a seating in the cable entry of the insulating connector body, which seating is of such a complementary shape and size as to co-operate with the spherical body to form, in effect, a ball and socket coupling, the arrangement being such that the part of the length of the cable extending from the connector body can be arranged to lie in any one of a pluraiity of directions differing from one another and at any angle within a wide range to the face of the connector body that will abut a face of another connector body when electrically connected thereto.

2. A non-rewirable electric connector assembly as claimed in Claim 1, wherein the partially spherical insulating body carried by the length of cable is separately formed with respect to the cable.

3. A non-rewirable electric connector assembly as claimed in Claim 2, wherein the partially spherical insulating body is a sleeve of electrically insulating material which, over at least a part of its length, has a bore of such a diameter that the sleeve fits on the cable and, over at least a part of its length, has an external shape that is partially spherical.

4. A non-rewirable electric connector assembly as claimed in Claim 3, wherein, at one of its ends the sleeve fits on the cable, and, at the other of its ends, the sleeve has an external shape that is partially spherical, the part of the bore of the sleeve bounded by the partially spherical portion of the sleeve being of a diameter that is substantially greater than the diameter of the cable so that, at that part of the sleeve, it is a loose fit on the cable.

5. A non-rewirable electric connector assembly as claimed in any one of the preceding Claims, wherein the insulating body of the connector of the connector assembly has extending from one of its walls a tubular protrusion which constitutes the cable entry, the partially spherical body on the cable engaging the seating in the cable entry thereby being spaced from the contact or contacts within the connector body to which the conductor or conductors of the cable is or are permanently electrically connected.

6. A non-rewirable electric connector assembly as claimed in any one of the preceding Claims, wherein the insulating body of the connector of the assembly is a moulded body in which the electrical connection or connections between the cable conductor or conductors and the contact or contacts is or are incapsulated.

7. A non-rewirable electric connector assembly as claimed in any one of Claims 1 to 5, wherein the insulating body of the connector of the connector assembly is formed of two separately formed premoulded body parts which are welded or otherwise permanently secured together to form a housing enclosing the electrical connection or connections between the cable conductor or conductors and the contact or contacts.

8. A non-rewirable electric connector assembly as claimed in any one of the preceding Claims, wherein the cable carries between the partially spherical body and the conductor terminals, a separately formed cable gripping member of electrically insulating material which is mounted in the connector body and which grips the cable in such a way as to reduce the risk of strain being imparted through the cable to the electrical connections within the connector body when tension is applied in such a direction as to pull the cable away from the connector body.

9. A non-rewirable electric connector assembly as claimed in Claim 7, wherein a separately formed cable gripping member engages in a groove in one or each of said separately formed body parts adjacent the cable entry, which cable gripping member is of such a form as to reduce the risk of strain being imparted through the cable to the electrical connections within the connector body when tension is applied in such a direction as to pull the cable away from the connector body.

10. A non-rewirable electric connector assembly as claimed in Claim 8 or 9, wherein the cable gripping member is an apertured disc having around the aperture circumferentially spaced outwardly projecting teeth which extend towards the conductor terminals and which will bite into the insulating covering of the cable in the event that tension is applied to the cable in a direction away from the conductor terminals.

11. A non-rewirable electric connector assembly as claimed in any one of Claims 2 to 5, wherein the sleeve is divided longitudinally of its length into two separately formed parts which are of such a form that one makes a snap fit with the other.

12. A non-rewirable electric connector assembly as claimed in Claim 11, wherein the internal surface of the two-part sleeve has inwardly projecting teeth which extend towards the conductor terminals.

13. A non-rewirable electric connector assembly as claimed in Claim 11, wherein the internal surface of the two-part sleeve is serrated or roughened to form a cable grip integral with the sleeve.

14. A non-rewirable electric connector assembly as claimed in any one of the preceding Claims, wherein the or each contact is a pin protruding from the connector body.

15. A non-rewirable electric plug assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawing.