GB1586285A

GB1586285A - Electrical terminal

Info

Publication number: GB1586285A
Application number: GB3984177A
Authority: GB
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1976-09-27
Filing date: 1977-09-23
Publication date: 1981-03-18
Also published as: DE2643471B2; DK148046B; FR2365894B1; ES231017Y; AT382737B; GR62668B; DK148046C; DE2643471C3; JPS5341794A; ATA654677A; DE2643471A1; FR2365894A1; DK421077A; IT1086495B; ES231017U; JPS619710B2

Description

(54) ELECTRICAL TERMINAL (71) We, SIEMENS AKTIENGESELLSCHAFT, a German company of Berlin and Munich, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to electrical terminals.

According to the present invention, there is provided an electrical terminal having a body formed from a strip of resilient material which is formed generally as a single loop with two opposite end portions of the strip adjacent one another, projecting away from the loop at one side thereof, the strip being formed, substantially diametrically opposite said end portions, with a central tapped bore for receiving a clamping screw, and the strip being formed at opposite sides of the loop with respective apertures which provide seats for an electrical conductor passing through said apertures and clamped in the seats by said clamping screw, said seats being disposed in the end portions of the strip, externally of the loop.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a side elevation of a terminal in accordance with the invention; and Figure 2 is a front elevation of the terminal.

The illustrated terminal is particularly suitable for use in protection switches, such as line protection switches and earth fault current circuit-breakers.

The terminal comprises a body 1 formed from a strip of conductive resilient material, for example, copper. The strip of material is formed generally as a single loop, with two opposite end portions of the strip adjacent one another. A central tapped bore 5 is formed substantially diametrically opposite the ends of the strip, and is for receiving a clamping screw 4. At opposite sides 6 of the loop, respective apertures 7 form seats 2 for an electrical conductor 3 passing through the apertures 7 and clamped in the seats 2 by means of the clamping screw 4. The seats 2 are formed in the end portions of the strip, externally of the loop. In the illustrated arrangement, the seats 2 are generally Vshaped, and serve to receive an electrically conductive connecting bar 8 of correspondingly V-shaped cross-section. Thus, the clamping screw 4 clamps the conductor 3 and connecting bar 8 against the seats 2, to establish electrical contact between the conductor 3 and bar 8. The connecting bar 8 may typically lead to an appliance to be connected.

Because the connecting bar 8 is seated directly below the centrally guided clamping screw 4, it is not subjected to significant bending forces between the screw 4 and seats 2, and can therefore be made of relatively thin cross-section. The corresponding V-shapes of the seats 2 and bar 8 assist in satisfactorily locating the bar 8 in position in the seats 2, and the V-shape of the bar 8 itself assists in positioning the conductor 3 (and any further conductors) to be connected.

It can be seen from Figure 2 that the width of the apertures 7, across the width of the strip material of the body 1, is greater than the diameter of the shank of the clamping screw 4. Thus, the clamping screw can bear directly onto the conductor 3, such that it is unnecessary to provide any intermediate pressure member between the screw 4 and conductor 3.

Also as may be seen in the Figures, the tapped bore 5 extends through the strip material and also through an outwardly extending neck portion of the body 1. The neck portion extends outwardly so as to leave the connection space between the apertures 7 free.

It may be appreciated that the illustrated terminal is of relatively simple construction, the body 1 being of integral form and not requiring any overlap between the ends of the loop of strip material. As the ends of the opposite sides 6 of the loop are bent back until they are almost in contact, the body 1 can provide a good springing action in the direction of the axis of the clamping screw 4, so as to compensate for clamping pressure variations, caused, for example, by temperature and ageing. This is a particular advantage over previously proposed terminals of which we are aware, in which springs and intermediate pressure members are often used in order to provide a sufficiently resilient electrical contact. Such previously proposed terminals tend to be of relatively large size, and therefore undesirable for use in the construction of small appliances.

By contrast, the illustrated terminal can be made relatively small, requiring little material for its manufacture.

A further important feature of the illustrated terminal is that the conductor 3, together with the connecting bar 8, is supported by the body 1 of the terminal itself, directly under the centrally positioned clamping screw 4, whereby substantially only tensile forces are exerted on the wall of the body 1 at the seats 2.

WHAT WE CLAIM IS: 1. An electrical terminal having a body formed from a strip of resilient material which is formed generally as a single loop with two opposite end portions of the strip adjacent one another, projecting away from the loop at one side thereof, the strip being formed, substantially diametrically opposite said end portions, with a central tapped bore for receiving a clamping screw, and the strip being formed at opposite sides of the loop with respective apertures which provide seats for an electrical conductor passing through said apertures and clamped in the seats by said clamping screw, said seats being disposed in the end portions of the strip, externally of the loop.

2. A terminal according to claim 1, including the clamping screw.

3. A terminal according to claim 2, wherein the widths of the apertures, across the width of the strip, are greater than the diameter of the shank of the clamping screw, such that the clamping screw can bear directly on a conductor to be clamped.

4. A terminal according to claim 1, 2 or 3, wherein said tapped bore extends through said strip and through an outwardly extending neck portion of said body.

5. A terminal according to any preceding claim, wherein said seats are generally Vshaped.

6. A terminal according to claim 5, including an electrically conductive connecting bar of generally V-shaped crosssection for engagement in said seats.

7. A terminal according to any preceding claim, wherein said resilient material is metallic.

8. A terminal according to claim 7, wherein said resilient material is copper.

9. An electrical terminal substantially as hereinbefore described with reference to the accompanying drawings.

10. A line protection switch or an earth fault current circuit-breaker, incorporating a terminal according to any preceding claim.

11. Electrical apparatus incorporating a terminal according to any one of claims 1 to 9 or a switch or circuit-breaker accord

Claims

ing to claim 10.