GB2134331A

GB2134331A - Electrical connectors

Info

Publication number: GB2134331A
Application number: GB08319025A
Authority: GB
Inventors: Keith Noel Astin
Original assignee: CAMBION ELECTRONIC PRODUCTS LI
Current assignee: CAMBION ELECTRONIC PRODUCTS LI
Priority date: 1980-01-17
Filing date: 1983-07-14
Publication date: 1984-08-08
Also published as: GB8319025D0; GB2134331B

Abstract

An electrical connector for a flat flexible cable comprises an inner cable support (40) around which the cable (30) is folded and an outer cable clamp (41) which clamps the cable to the support. The support has a projection (42) and a flap (43) which engage registration apertures 32, 33 in the cable, projection (42) also securing the support in the clamp. The cable is prepared for use by stripping a section of insulation from one side thereof to reveal copper paths beneath, gold plating the revealed copper and punch in the registration apertures. <IMAGE>

Description

SPECIFICATION Electrical connectors The present invention relates to an electrical connector and particularly but not exclusively to electrical connectors for use with printed circuit boards.

With such board there are usually a plurality of conductive paths running very close together. Alignment and electrical connection of one such board with another board or element also having a corresponding plurality of paths with a sufficient degree of accuracy can cause difficulty.

According to one aspect of the present invention, there is provided an electrical connectorforconnect- ing a flat flexible cable to another circuit element comprising a cable support around which a free end of the cable may be wrapped and comprising means for locating the cable on it and a cable clamp shaped to receive the cable support with the wrapped round cable and comprising means complementary to the location means on the support.

According to another aspect of the present invention there is provided a method of providing a flat flexible cable with a terminal connection comprising the steps of stripping a transverse section of the insulation from the cable at a location spaced from the appropriate end, wrapping the cable around a cable support and locating it on that support and inserting the support in a cable clamp such that the stripped section of the cable is clamped between the clamp and support and extends on the cable support out of that side of the cable clamp remote from the remainder of the cable.

In order that the invention may be more clearly understood, several embodiments of the invention will now be described, by way for example, with reference to the accompanying drawing, in which: Figure 1 shows a perspective view of a horizontal connector and interface board assembly, Figures 2a, 2b and2c respectively show plan, side elevational and cross-sectional views of an alternative to the horizontal connector connected to the assembly of Figure 1.

Figures 2d, 2e show side and cross sectional views of a part of the connector of figure 2a-c in greater detail, Figure 3 shows a flat flexible cable prepared for fitting into a connector, Figure 4 shows the cable of Figure 3 fitted into a connector, the connector being suitable for use with the connector of Figures 1 and 2.

Figure 5 shows a cross-sectional view along the line B-B of Figure 4, and Figure 6shows a plan view of an adaptorfor use with the connectors of Figures 1 and 2.

Referring to Figure 1, the arrangement comprises a substantially rigid interface or mother board assembly 1. This comprises seventeen conductor paths or ways 11 produced by copper plating the base board, etching the copper plate to produce the required pattern and then gold plating the copper paths 11 remaining to a minimum thickness of 10-4mm. The paths 11 extend parallelly for a distance and then diverge to meet conductive annuli 12 respectively surrounding apertures in the boards through which terminal rods 13 extend. Disposed above the parallel run of the paths 11 and bolted to the board 1 by means of nuts and bolts 3 and 4 is a horizontal connector 2. This connector 2 comprises a moulded electrically insulating housing 14 of synthetic plastics material which defines a slot 15 in one side and locating and locking aperture 16 in the top.

Locating projections 17 and 18 are provided at the top and bottom lateral edges of respective sides. The housing 14 accommodates a resilient circuit connecting member which is not visible in Figure 1 but which will be described in more detail with reference to Figure 2 which illustrates an alternative but very similar connection member to that of Figure 1.

Figure 2 in fact illustrates the vertical equivalent to the horizontal connector illustrated in Figure 1.

Whereas in Figure 1, the board or other member to be connected to the interface board assembly 1 would be inserted horizontally into the slot 15 in the connector 2 in the connector of Figure 2 the board or other member to be connected would be inserted vertically into a similar slot 25 in the top of the connector.

Referring now more particularly to Figure 2, the connector, here referenced 20 is very similar to the connector 2 but has a moulded housing defining a slot 25 in the top as mentioned above. The slot 25 leads to an inner elongate cavity 21 which accommodates the resilient connecting member 22 not visible in Figure 1. This resilient connecting member comprises a cylindrical elastomeric core 23 around which a seventeen way flexible circuit 24 is wrapped. The member 22 is made by cutting the core 23 to length cutting a piece of flexible circuit somewhat oversize, wrapping it fairly tightly around the core and then heat-sealing to produce a joint between the two free ends of the circuit running parallel to the axis of the core. The waste circuit pieces beyond the joint can then be cropped leaving a small blip 28 projecting from the surface of the cylinder.This member 22 is then inserted into the cavity 21 so that the blip 28 is accommodated in a corner of the cavity as shown. A board or other member to be connected is pushed into the slot 25 from above and resiliently contacts the member 22 on its left side (looking at Figures 2c).

The member 22 resiliently contacts the interface board assembly when the connector 20 is bolted onto it through the aperture 21a defining the entry to the cavity in the base of the housing. Other means such as rivets for connecting the housing to the assembly may be used.

Apart from largely conventional daughter boards, the above described connector can be used to connect many otherforms of circuit member to an interface board or other assembly. Two such other possibilities will now be described. Referring to Figures 3,4 and 5, a form and method of connecting a flat flexible cable to a connector of the type already described is shown. Figure 3 shows a length of such flat flexible polyester cable 30 already prepared at both ends for connection. This preparation comprises, at each end, stripping a section of insulation from one side only of the cable to reveal the seventeen copper paths or ways underneath, gold plating the revealed copper and punching a round and square registration aperture 32 and 33. Referring to Figures 4 and 5, each end of the cable is then folded round the inner part of a two part connection device.The inner part comprises a cable support and is referenced 40 and the outer part a cable clamp which is referenced 41. Both parts are moulded from synthetic plastics material. Considering one end of the cable only, the folded portion is aligned so that a round section projection 42 on the support 40 extends into the aperture 32 and a rectangular stamped out flap 43 extends through the aperture 33. With the cable so formed the cable support and cable are pushed into the cable clamp 41. The bevelled upper edge 44 of the clamp 41 facilitates this and both projections 42 and 43 act to oppose withdrawal of the support from the clamp once insertion has been accomplished.

The connector end so formed can then be inserted into the slot of a connector of the form described with reference to Figures 1 and 2 of the drawings to make a connection between the flat flexible cable and the interface board assembly. The way to way connection is precise becuase of the precise location of the elastomeric cord flexible circuit in the connector, the precise location of the connector on the board assembly and the precise location of the cable in the two part connection device and the device in the slot in the housing of the connector. Location of the flap 43 in the locating and locking aperture 16 holds the connector end fast in the connector.

Contact is excellent since the contacts are resiliently urged together and are all gold plated.

Anotherform of connection is illustrated in Figure 6. This Figure shows an epoxyglass fabric subsidiary connector board to which discrete electrical components can be soldered. The board, generally referenced 60 comprises seventeen ways 61. Each way terminates in an annulus 62 arranged in two spaced apart rows 63 and 64. Each annulus 62 surrounds an aperture through the board through which terminal pins on the components can extend to be soldered.

As previously for good electrical contact the conductive paths or ways 60 are gold plated copper. The board is shaped and dimensioned for insertion in the slot of the connector described and illustrated in Figures 1 and 2. To facilitate insertion of the board into the slot (referenced 15 in Figure 1 and 25 in Figure 2) the edge 65 of the board is chamfered.

Flexible cable to flexible cable connections using the above described connectors may also be produced.

With the above described subsidiary board a series of discrete electrical components or perhaps a single DILIC could be satisfactorily connected in a removable manner to an interface board assembly.

The component or components would first of all be soldered to the board and the board then inserted into the connector. Electrical contacts would again be resiliently urged together and contact would be gold to gold.

Claims

1. An electrical connector for connecting a flat flexible cable to another circuit element comprising a cable support around which a free end of the cable may be wrapped and means for locating the cable on it and a cable clamp shaped to receive the cable support with the wrapped round cable and comprising means complementary to the location means on the support.

2. An electrical connector as claimed in claim 1, in which the means for locating the cable comprises a projection projecting from the cable support and the means complementary to the location means comprises an aperture which receives the projection when the support is pushed into the clamp to lock the cable in its located position.

3. An electrical connector as claimed in Claims 1 or 2, in which one edge of the cable support is bevelled to facilitate entry of the support into the cable clamp.

4. An electrical connector for connecting one electrical circuit member to another electrical circuit member such as a printed circuit board substantially as hereinbefore described with reference to Figures 3,4 and 5 of the accompanying drawings.

5. A method of providing a flat flexible cable with a terminal connection comprising the steps of stripping a transverse section of the insulation from the cable at a location spaced from the appropriate end, wrapping the cable around a cable support and locating and retaining it on that support and inserting the support in a cable clamp such thy the stripped section of the cable is clamped between the clamp and support and extends on the cable support out of that side of the cable clamp remote from the remainder of the cable.

5. A method of providing a flat flexible cable with a terminal connection comprising the steps of stripping a transverse section of the insulation from the cable at a location spaced from the appropriate end, wrapping the cable around a cable support and locating it on that support and inserting the support in a cable clamp such that the stripped section of the cable is clamped between the clamp and support and extends on the cable support out of that side of the cable clamp remote from the remainder of the cable.

6. A method of providing a flat flexible cable with a terminal connection substantially as hereinbefore described with reference to Figures 3,4 and 5 of the accompanying drawings.

Superseded claims 1,5 New or amended Claims:

1. An electrical connectorforconnecting aflat flexible cable to another circuit element comprising a cable support around which a free end of the cable may be wrapped and means for locating and retaining the cable on it and a cable clamp shaped to receive the cable support with the wrapped round cable and comprising means complementary to the location means on the support.