GB2094569A - A moulded electrical connector - Google Patents

Abstract

An electric connector is made by connecting an electric socket contact (5) to the end of each exposed length of insulated conductor (2), inserting each contact (5) in a preformed tubular insulating housing (7) such that each socket contact is surrounded thereby, moulding electrically insulating material (12) around the housed electric socket contacts and an adjoining part of the cable sheath so as to encapsulate the housing and bond to the housing and to the cable sheath and so that access to the electric socket contacts for effecting electrical connection thereto is not impeded. A dummy pin (11) may be inserted into the socket during moulding. Housings for individual contacts may be formed of two snap-fitting parts (fig. 5, not shown). <IMAGE>

Description

SPECIFICATION An improved electric connector This invention relates to electric connectors and is particularly concerned with electric connectors of the kind comprising one or more than one electric socket contact which is or are electrically connected to an end or ends of the conductor or conductors of an electric cable and which is or are directly embedded in a body of electrically insulating material moulded to the sheath of the cable. During manufacture of an electric connector of the aforesaid kind, there is a substantial risk that the insulating material of the moulded body will flow into the electric socket contact or electric socket contacts to such an extent that the electric connector cannot, or cannot easily, be connected to another electric connector which has an electric pin contact or electric pin contacts and to which it is to be mated.

Such a risk is especially prevalent where a socket contact is slit along at least a part of its length to provide a degree of resilience to the contact because there is a tendency for the insulating material to force its way between the parts of the contact bounding the longitudinally extending slit.

It is an object of the present invention to provide an improved method of manufacturing an electric connector of the aforesaid kind, in which risk of ingress of insulating material into the or each electric socket contact is eliminated or substantially reduced.

According to the invention, the method comprises: cutting back an end of the sheath of an electric cable to expose a length or lengths of insulated conductor; electrically connecting an electric socket contact to the end of the or each exposed length of insulated conductor; inserting the socket contact or socket contacts or each of the socket contacts in a preformed tubular housing of electrically insulating material of such a form that the or each socket contact or the socket contacts is or are completely surrounded by the associated housing; and moulding electrically insulating material around the housed electric socket contact or contacts and an adjoining part of the cable sheath in such a way that the insulating material substantially wholly encapsulates the housing or housings and bonds to the housing or housings and the cable sheath and that access to the electric socket contact or contacts for effecting electrical connection thereto is not impeded.

Preferably, electrically insulating material is so moulded around the housing or housings and adjacent part of the cable sheath that at least a part of the end face of the or each housing remote from the cable remains exposed.

The or each preformed tubular housing may be divided lengthwise into two separately formed shells which are of such a form that, when assembled about a socket contact or two or more socket contacts, the two shells make a snap fit the onewith the other Alternatively, the wall of the or each preformed tubular housing may be slit throughout its length so that the housing can be folded back for insertion of a socket contact ortwo or more socket contacts and afterwards closed by bringing together the two longitudinally extending edges bounding the slit, the two edges of the slit preferably making a snap fit the one with the other.

In all cases, preferably the bore of the tubular housing is of such a form that the or each socket contact housed therein is restrained against lengthwise movement relative to the housing.

Preferably, during the moulding operation, a dummy pin is inserted temporarily in the or each socket contact to prevent insulating material entering the socket through its open end.

The or each electric socket contact may be electrically connected to the associated exposed length of electric conductor in any convenient manner, but preferably, the electric socket contact has an integral ferrule which is crimped or otherwise permanently electrically connected to the associated exposed length of electric conductor.

The outer surface of the or each preformed tubular housing may have flutes, other depressions or protuberances or may be otherwise roughened for assisting in bonding of the moulded electrically insulating material.

The or each preformed tubular housing may be of any suitable plastics insulating material but it is preferred to make it of polyester, nylon or glass-filled polypropylene. The electrically insulating material to be moulded around the housing or housings and the adjoining part of the cable sheath may be of any rubber or plastics insulating material that will readily bond thereto.

The invention also includes an electric connector manufactured by the method hereinbefore described.

The invention is further illustrated by a description, by way of example, of a preferred electric connector made by the method of the present invention with reference to the accompanying drawings, in which Figure 1 is an end view of a preferred electric connector; Figures 2 and 3 are, respectively, cross-sectional views of the preferred electric connector along the lines indicated by numerals ll-ll and Ill-Ill in Figure 1 with the associated cable not in cross-section; Figure 4 is a perspective view of a modified form of the electric connector shown in Figures 1 and 3; and Figure 5 is an exploded perspective view of a partially completed and different connector.

Referring to Figures 1 to 3, an electric cable 1, having three individually insulated conductors 2, is terminated by a connector 3. The termination is formed by first cutting back layers of cable 1 so that a length of each conductor 2 is exposed, then crimping to each of the exposed lengths a corresponding ferrule 4 integral with a socket contact 5 formed by suitably folding a metal-sheet stamping. Each contact 5 is then inserted within a respective aperture 6 in a tubular body section 7 of a preformed polyester insulating housing 8. Oppositely directed projections 9 and 10 of different length extend from body section 7 of housing 8.The apertures 6, each of which is shaped to restrain the contact 5 therein from lengthwise movement, lie parallel to one another within body section 7, their openings describing the corners of an isosceles triangle in each of two opposite faces of body section 7 thereby ensuring that the uppermost wire (in Figure 2), usually the earth line, cannot be inadvertently connected to a connector intended for one of the other two wires, usually the live wires, and vice versa.

With a dummy pin 11 (shown only in broken lines in Figure 2) inserted in each of the socket contacts 5 and with projection 9 abutting the sheath of cable 1, plastics insulating material is moulded around housing 8 and an adjacent section of the cable sheath so as to encapsulate them with only the free end of projection 10 remaining uncovered. Housing 8 has a roughened outer surface (not shown in the Figures) to assist in the bonding of the insulating material thereto. Upon setting of the moulded insulating material to form an outer casing 12 dummy pins 11, having served to prevent the insulating material from entering the socket through its open end, are removed from socket contacts 5. The outer surface of casing 12 has ridges 13 to facilitate gripping of the connector part3 buy a person.

The connector 13 of Figure 4 differs from connector 3 only in that the former includes slots 14 in that section of casing 12 lying against the sheath of cable 1 to facilitate bending of casing 12 in that region.

Figure 5, in which the same numerals as used previously indicate identical features, shows two separately formed shells 15 and 16 which have respectively interengagable ridges 17 and slots 18 so that the shells snap fit together about the socket contact 5 and about the end of conductor 2 to which it is crimped to form a tubular housing about which plastics insulating material can be moulded as described previously. This arrangement substantially prevents the moulding material from entering the socket.

Claims (10)

1. A method of manufacturing an electric connector, the method comprising: cutting back an end of the sheath of an electric cable to expose a length or lengths of insulated conductor; electrically connecting an electric socket contact to the end of the or each exposed length of insulated conductor; inserting the socket contact or socket contacts or each of the socket contacts in a preformed tubular housing of electrically insulating material of such a form that the or each socket contact or the socket contacts is or are completely surrounded by the associated housing; and moulding electrically insulating material around the housed electric socket contact or contacts and an adjoining part of the cable sheath in such a way that the insulating material substantially wholly encapsulates the housing or housings and bonds to the housing or housings and the cable sheath and that access to the electric socket contact or contacts for effecting electrical connection thereto is not impeded.

2. A method of manufacturing an electric con nector, the method comprising: cutting back an end of the sheath of an electric cable to expose a length or lengths of insulated conductor; electrically con necting an electric socket contact to the end of the or each exposed length of insulated conductor; insert ing the socket contact or socket contacts or each of the socket contacts in a preformed tubular housing of electrically insulating material of such a form that the or each socket contact or the socket contacts is or are completely surrounded by the associated housing; and moulding electrically insulating material around the housed electric socket contact or contacts and an adjoining part of the cable sheath in such a way that the insulating material substantially wholly encapsulates the housing or housings and bonds to the housing or housings and the cable sheath and that access to the electric socket contact or contacts for effecting electrical connection thereto is not impeded and that at least a part ofthe end face of the or each housing remote from the cable remains exposed.

3. Amethod according to Claim 1 or Claim 2 wherein, during the moulding operation, a dummy pin is inserted temporarily in the or each socket contact to prevent insulating material entering the socketthrough its open end.

4. A method according to any one of the preceding Claims, wherein the preformed tubular housing has means for assisting in bonding of the moulded electrically insulating material.

5. A method according to any one of the preceding Claims, wherein the bore of the preformed tubular housing in which the or each socket contact is housed is of such a form that the or each socket contact is restrained against lengthwise movement relative to the housing.

6. A method according to any one of the preceding Claims, wherein the preformed tubular housing is divided lengthwise into two separately formed shells of such a form that, when assembled about one or more socket contacts, the two shells make a snap fit the one with the other.

7. A method according to any one of the preceding Claims, wherein the preformed tubular housing is slit throughout its length so that the housing can be folded back during insertion of the socket contact(s) and afterwards closed by bringing together the two longitudinally extending edges bounding the slit.

8. A method according to any one of the preceding Claims, wherein the or each electric socket contact is electrically connected to the end of an exposed length of cable characterised by crimping an integral ferrule of the electric socket contact to the associated exposed length of electric conductor.

9. A method substantially as hereinbefore described with reference to Figures 1 to 3 or Figures 1 to 3 as modified by Figure 4, or Figure 5 of the accompanying drawings.

10. An electric connector manufactured by the method according to any one of Claims 1 to 9.