GB2267606A

GB2267606A - Electrical contact.

Info

Publication number: GB2267606A
Application number: GB9211295A
Authority: GB
Inventors: David Edward Mead
Original assignee: Electrolux Northern Ltd
Current assignee: Electrolux Northern Ltd
Priority date: 1992-05-28
Filing date: 1992-05-28
Publication date: 1993-12-08
Also published as: GB9211295D0

Abstract

A method of making an electrical connection between a cable and a spring contact, employs a cable terminal made from sheet metal. The terminal has a cable-connection tab 2, the wings of which are folded and crimped to the cable end, joined by a shank 3 to a head portion 4 which is folded and joggled out of its plane to form a shoulder extending beyond the shank on all of the faces of the head. The head prevents the cable terminal from being easily withdrawn when inserted into a spring contact (8). The shank (3) may be tapered. <IMAGE>

Description

ELECTRICAL CONNECTIONS This invention relates to a method of making electrical connections and to a cable terminal for use in the method.

In order to connect a cable to an electrical device, the cable may be provided with a cable terminal which is inserted into a spring contact, the contact spring being so angled as to grip the cable and resist its being readily withdrawn. Such a cable terminal generally consists of a stamping from sheet metal which is crimped or soldered to the end of the cable and which has a slightly widened end which is gripped by the contact spring so as to reduce the possibility of the cable being easily withdrawn.

A disadvantage of such terminals is that when equipment is being assembled in a factory on a large scale the terminals are sometimes incorrectly inserted into the contact springs so that the enlarged head is not gripped by the spring allowing the cable to slip out Terminals with a head shaped so that it can be gripped irrespective of the orientation in which it is inserted, are in general much more expensive to manufacture and attach than simple terminals which can be stamped out of sheet metal.

An object of the present invention, which is defined in the appended claims, is to provide a terminal and connection method which increases resistance of withdrawal of the terminal, irrespective of orientation, and in which the terminals are simple and cheap to manufacture.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which Figures 1, 2 and 3 are respectively side, bottom and end views of a cable terminal attached to a cable end. Figure 4 shows a sheet metal blank from which the cable terminal of Figures 1 to 3 is made. Figure 5 is a section through a spring contact and Figures 6 and 7 show the cable terminal inserted into the spring contact in each of two different orientations.

Referring first to Figure 1, a cable terminal 1 comprises a connection tab 2 joined by a shank 3 to an enlarged head 4. The cable terminal is folded over and crimped firmly to the end 5 of an electrical cable so that the cable can be connected to a device by inserting the head 4 into a suitable contact on the device.

Figure 4 shows the blank from which the cable terminal is formed. These blanks may be stamped out in large numbers from sheet metal and comprise a connection tab 2 having wings 2a and 2b which are folded and crimped over the cable end as shown in Figures 1 to 3. A shank 3 terminates in a head portion 4. In manufacturing the cable terminal, the wings 2a and 2 are folded (see Figure 3) and the head portion 4 is doubled over and joggled out of its plane to form a terminal head slightly wider and thicker than the adjoining portion of the shank 3, so as to form shoulders 4a, 4b, 4c and 4d which serve to resist removal of the cable terminal from engagement with a contact spring which ever way it is inserted.

Figures 5 to 7 show the engagement of the cable terminal with the spring contact. Referring first to Figure 5 which shows in section the spring contact before insertion of the cable terminal, the contact comprises a spring 6 and a conducting strip 7. The spring is opposed to the conducting strip at an acute angle so as to oppose withdrawal of a cable terminal inserted between them.

A number of such contact springs and conducting strips may be located each in a separate cavity 8 within a plastic terminal block 9 and each including an entrance passage 10 for insertion of the cable terminal.

Figure 6 shows the insertion of a cable terminal into such a spring contact arrangement and indicates how the end of the contact spring 6 restricts easy withdrawal of the cable terminal.

Figure 7 is a similar view showing the cable terminal inserted in the incorrect orientation and illustrates how the form of the head 4 still restricts easy withdrawal of the cable terminal.

In another embodiment as shown in Figures 8, 9 and 10 the terminal is shown in side elevation, in section taken on XX of Figure 8 and in perspective respectively.

The terminal may be made by forming a sheet metal blank into an elongate cylinder or tube and then distorting or upsetting a head-end 40A to make it extend outwardly beyond a shank portion 30A around the face of the terminal.

The peripheral face of the head 40A may be continuous i.e. in the form of a flange or discontinuous, eg, castellated.

Although in various figures, the connection tab (2,20) is shown crimped on to end (5) of an electrical cable, if desired, a portion of the cable insulation may also be so crimped.

Claims

1. Method of making an electrical connection, comprising forming a cable terminal by shaping a blank from a metal sheet, the blank comprising a connection tab, a narrower shank and a head extending circumferentially outwardly from the shank, connecting the connection tab of the cable terminal so formed to a cable end and inserting the head into a spring contact so that the head is engaged by the spring contact.

2. Method of making an electrical connection, comprising forming a cable terminal by shaping a blank from a metal sheet, the blank comprising a connection tab, a narrower shank and a head wider than the adjoining portion of the shank, folding and joggling the head so as to provide a shoulder extending beyond the shank on all four of its faces, connecting the connection tab of the cable terminal so formed to a cable end and inserting the head into a spring contact so that a shoulder is engaged by the spring contact.

3. A method according to claim 2 wherein the terminal blank is shaped by stamping.

4. A cable terminal for use in a method according to claim 1 or claim 2 formed from metal sheet and comprising a connection tab, a shank and a head extending circumferentially outwardly from the shank, the head being formed by folding and joggling a head portion of the blank so as to produce a shoulder extending beyond each face of the shank.

5. A cable terminal according to any one of claims 2 to 4 in which the shank tapers from the connection tab to the head.

6. A cable terminal for use in a method according to claim 1 formed from metal sheet and comprising a connection tab, a shank and a head extending circumferentially outwardly from the shank.

7. A cable terminal according to claim 6 wherein the connection tab, shank and head are substantially cylindrical and the head comprises a circumferential flange extending outwardly from the shank.

8. A cable terminal according to any of claims 1 - 6 wherein the shank is substantially flat.