GB2130448A

GB2130448A - Improvements in electrical contact members and electrical connector assemblies

Info

Publication number: GB2130448A
Application number: GB08330346A
Authority: GB
Inventors: Helen Dechelette
Original assignee: Molex LLC
Current assignee: Molex LLC
Priority date: 1982-11-16
Filing date: 1983-11-14
Publication date: 1984-05-31
Also published as: EP0109297B1; EP0109297A1; JPS59101781A; DE3369434D1; JPH0373110B2; GB2130448B; GB8330346D0

Description

1 GB 2 130 448 A 1

SPECIFICATION

Improvements in electrical contact members and electrical connector assemblies This invention relates generally to electrical contact members and electrical connector assemblies for terminating electrical conductors and, more specific ally, to an electrical contact member and a connector assembly having the capability of being highly miniaturized as a result of its contact configuration and contact mounting structure.

Connector assemblies for terminating insulated electrical conductors have become increasingly re lied upon in the manufacture of complex electronic and electro-mechanical equipment. In the manufac ture of video cameras, for example, wherein a plurality of electrical components must be arranged in a preferably compact overall structure, miniature connectors are often a preferred means for intercon- 85 necting printed circuit board assemblies with dis crete wiring leading from other components.

To provide for such interconnection, the printed circuit boards are often adapted with generally elongated pin terminals which have been electrically 90 connected to conductive circuit paths defined on the boards. The pin terminals may either be free stand ing or part of a preassembled unit, customarily called a wafer.

Connectors of a type suitable for terminating discrete insulated conductors to enlongated pin terminals typically comprise a dielectric housing fitted_with a plurality of metallic contact members.

Each contact member has a portion such as a receptacle for selectively receiving or mating with one of the pins.

Connection of the concluctorto the contact may be made by one of several methods. One method is known as insulation displacement. Insulation dis placement comprehends forcing a conductor into a slot formed in a contact such that the conductor insulation is severed and displaced from the region of the electrical interface between the edges Of the slot and the conductor core.

Known connectors for terminating discrete wire to 110 pin terminals have inherent disadvantages when used in miniaturized circuitry applications. These disadvantages result principally from the complexity of known contact structures and from the conse quent inability to manufacture such structures eco nomically on a miniature scale with assurance of their reliable performance throughout the vagaries of use.

The present invention provides a unitary electrical contact member for terminating an insulated con ductor, the contact member comprising a pair of plate portions each with a slot formed therein for severing and displacing the insulation of a conductor disposed within the slot thereby to terminate the conductor to the contact member, the plate portions extending from a body member formed integrally with the plate portions, and a formation or forma tions extending from an edge of the body member and being shaped to provide atleast part of a female terminal portion for biased contact with a generally elongated male terminal member having its longitudinal axis orientated substantially parallel to the longitudinal axis of an insulated conductor terminated to the contact member.

Preferably, said female terminal portion includes a first finger extending from an edge of the body member and a second finger depending from one of the plate portions, the first and second fingers being disposed in opposed, spaced apart relationship and co-operating to provide said biased contact with a generally elongated terminal member having its longitudinal axis orientated substantially parallel to the longitudinal axis of an insulated conductor terminated to the contact member.

Conveniently, said female terminal portion cornprises a pair of said first fingers cantilevered generally outwardly from one another and a pair of said second fingers depending one from each of the plate portions and cantilevered generally toward one another the pairs of first and second contact fingers co-operating to provide a receptacle for establishing said biased contact with a generally elongated pin terminal having its longitudinal axis orientated substantially parallel to the longitudinal axis of an insulated conductor terminated to the contact member.

The present invention includes a connector assembly comprising a dielectric housing fitted with a plurality of electrical contact members in accord- ance with the present invention received in respective recesses of the housing.

One way of carrying out the present invention will now be described by way of example and not by way of limitation with reference to the accompanying drawings in which:- Figure 1 is an exploded perspective view of a circuitry arrangement including a connector assembly of the present invention employing electrical contact members of the present invention; Figure 2 is a plan view of a terminal blank from which a contact member shown in Figure 1 may be formed; Figure 3 is a front elevational view of the contact member in its fully formed state; Figure 4 is a cross-sectional view of the contact member taken generally along the line 4-4 of Figure 3; and Figure 5 is a cross-sectional view of the connector assembly taken generally along the line 5-5 of Figure 1.

Referring now to the accompanying drawings, in Figure 1 there is shown a circuitry arrangement of the type suitable for use in electro-mechanical or electronic applications. The arrangement generally comprises a printed circuit board 12 on which a plurality of semi- conductor or otherelectronic devices (not shown) are mounted. For selective connection to the printed circuit board 12, the circuitry arrangement 10 further includes a wafer assembly, generally designated 14, and a connector assembly in accordance with the present invention generally designated 16, for terminating a plurality of insulated electrical conductors 18.

In order to provide for the mechanically stable coupling of the connector assembly 16to the printed 2 GB 2 130 448 A 2 circuit board 12, the wafer assembly 14 includes a relatively rigid base member 20 through which a plurality of elongated conductive pin terminals 22 have been inserted. The printed circuit board 12 is adapted with apertures 24for receiving the pin terminals 22 such that the pin terminals 22 may be electrically connected by soldering to a plurality of corresponding circuit paths 26 defined on the printed circuit board 12. The wafer assembly 14 is also adapted with latching arms 28 for latching with a cover member 21 (see Figure 5) disposed at the other side of the connector assembly 16 for the purpose of holding the connector assembly 16 in fixed disposition with respect to the printed circuit board 12.

The connector assembly 16 comprises a dielectric housing 30 fitted with a plurality of metallic contact members 32 received in respective recesses 34 of the housing 30 opening at apertures 35 communicat ing with the recesses along an opposite pair of top edges 33 of the housing permitting connection of insulated conductors 18 to the contact members 32.

A plurality of apertures 36 communicate with the recesses 34 along a bottom edge 38 of the housing, permitting connection of the pin terminals 22 to the contact members 32.

Turning to Figure 2, the contact member 32 is illustrated as it would appear in the form of a flat stamped blank, designated generally by the refer ence numeral 40. To facilitate the manufacture and handling of the contact 32, the blank 40 includes a continuous carrier 42 having indexing apertures 44 which may be used to advance the blank 40 in the stamping and forming process. The contact 32, which extends from the carrier 42 by a break-away tang 46, has a central body portion 48 with a pair of substantially identical plate portions 50 extending from each side thereof. Each plate portion 50 has a slot 52 with a chamfered opening 54 for receiving an insulated conductor 18 and establishing electrical contact with the conductor 18 by severing and displacing the conductor's insulative coating. Each plate portion 50 is further adapted with a contact finger 56 cantilevered downwardly from a bottom edge thereof. The body portion 48 of the contact member 32 also has a pair of contact f ingers 58 cantilevered outwardly in opposite directions so as to form a T-shape configuration at its bottom edge.

In Figures 3 and 4, the contact member 32 is illustrated in its fully formed state, wherein the plate 115 portions 50 have been bent at substantially 90 degrees to the body portion 48 and thus are positioned in parallel spaced apart relationship one to another. The contactfingers 56 are also formed inwardly of the plate portions 50 with a slight radius in each of their ends. The contact fingers 58 are bent at substantially 90 degrees to the body portion 48 to lie beneath the contact fingers 56 and each finger 58 is formed with a crown 62. For retention of the contact member 32 in the housing 30, a locking lance 64 is struck outwardly of the body portion 48.

An inwardly directed tang 66 is provided for strain relief of the insulated conductor 18 once the conduc tor 18 has been inserted into the slots 52. A stop 68 not shown in Figure 2 is struck from the body 130 member 48 and is bent inwardly to limit excessive movement of the contact f ingers 60 upon insertion of a pin terminal 22 into the contact member 32.

Turning now to Figure 5, the contact member 22 is seen inserted in a recess 34 of the housing 30. An insulated conductor 18 having its longitudinal. axis disposed substantially normally of the plate portions 50 is terminated to the contact member 3? by means of the insulation displacement slots 52. - - The configuration of the contact fingers 56 and 58 defines, essentially, a receptacle, designated generally bythe reference numeral 70, into which the pin terminal 22 is slidingly receivable in parallel relation to the conductor 18. Multiple points of contact are established with the pin terminal 22 by the radiused portions 60 and crowns 62 of the contact fingers 56 and 58, respectively.

With reference particularly to Figure 2, it can be appreciated that the instant contact 32 is manufac- turable with very little waste of material because of the efficient orientation of the pairs of contact fingers 56 and 58 in the blank 40. Moreover, since relatively few steps are required to form the contact blank 40 into a completed member, the contact 32 may be highly miniaturized without the requirement of intricate and expensive tooling or fixtures. For example, a connector assembly according to the invention can be readily formed to have a contact pitch or center spacing as small as two millimeters. It can be further appreciated from the cross-secti on a I- view of Figure 5 that close spacing of the conductor 18 and pin terminal 22 centerlines is likewise possible, facilitating a highly compact overall assembly.

The receptacle orfernale terminal portion 70 may alternatively be formed entirely from a lower extension of the body portion 48 by means of a progressive bending operation so as to have a generally triangular configuration in transverse section with outwardly flared ends to receive and guide the pin terminal 22. An elastic lance is sheared from the lower extension of the body portion and folded into the interior of the female portion to enhance flexibility and ensure a good biased contact. The female terminal portion as just decribed can be located very close to the insulation displacement part of the contact for optimum miniaturization, and may be supported fully within the respective cavity of its connector housing by means of the insulation displacement part ideally without any part of the female terminal portion in physical contact with any part of the connector housing.

Claims

1. A unitary electrical contact member for terminating an insulated conductor, the contact member comprising a pair of plate portions each with a slot formed therein for severing and displacing the insulation of a conductor disposed within the slot thereby to terminate the conductorto the contact member, the plate portions extending from a body member formed integrally with the plate portions, and a formation or formations extending from an edge of the body member and being shaped to provide at least part of a female terminal portion for A 2 Z 3 GB 2 130 448 A 3 biased contact with a generally elongated male terminal member having its longitudinal axis orientated substantially parallel to the longitudinal axis of an insulated conductor terminated to the contact 5 member.

2. The electrical contact member of claim 1 wherein said female terminal portion includes a first finger extending from an edge of the body member and a second finger depending from one of the plate portions, the first and second fingers being disposed in opposed, spaced apart relationship and cooperating to provide said biased contact with a generally elongated terminal member having its longitudinal axis orientated substantially parallel to the longitudinal axis of an insulated conductor terminated to the contact member.

3. The electrical contact member of claim 2 wherein the second finger is cantilevered in a direction generally inwardly of the space between the plate portions.

4. The electrical contact member of claim 2 or 3 wherein the first finger is adapted with a crown for establishing a point of contact with a generally elongated terminal member.

5. The electrical contact member of claim 2, 3 or 4 wherein said female terminal portion comprises a pair of said firstfingers cantilevered generally outwardly from one another and a pair of said second fingers depending one from each of the plate portions and cantilevered generally toward one another, the pairs of first and second contact fingers cooperating to provide a receptacle for establishing said biased contact with a generally elongated pin terminal having its longitudinal axis orientated sub- stantially parallel to the longitudinal axis of an insulated conductor terminated to the contact member.

6. A unitary electrical contact member substantially as hereinbefore described with reference to, and as shown in, Figures 3 and 4 of the accompanying drawings.

7. A blank for an electrical contact member as claimed in claim 1 substantially as hereinbefore described with reference to, and as shown in, Figure 2 of the accompanying drawings.

8. A connector assembly comprising a dielectric housing fitted with a plurality of electrical contact members as claimed in claim 1 received in respective recesses of the housing.

9. A connector assembly as claimed in claim 8 wherein the housing has a plurality of apertures communicating with the recesses along a bottom edge of the housing, permitting connection of pin terminals to the contact members and a plurality of apertures along a top edge of the housing permitting connection of conductors to the contact members.

10. A connector assembly as claimed in claim 8 or 9 wherein the pitch or center spacing of the contact members is about two millimeters.

11. A connector assembly as claimed in claim 9 or claims 9 and 10 substantially as hereinbefore described with reference to, and as shown in, Figure 1 of the accompanying drawings.

Printed for Her Majesty's Stationery Office, by Croydon Printing Company Limited, Croydon, Surrey, 1984. Published by The Patent Office, 25 Southampton Buildings, London,