AU625719B2 - A busbar connector for circuit breakers - Google Patents

Description

625719 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 Form COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: PI 9936 17 August 1989 0* 000 0*00 00*0o Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: 0* *04 0 0 4 L o 0 t TO BE COMPLETED BY APPLICANT i cLI Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: H.P.M. INDUSTRIES PTY. LIMITED 4 Hill Street, Darlinghurst, New South Wales, 2010, Australia PETER SIMON and DAVID BROWN GRIFFITH HACK CO.

71 YORK STREET SYDNEY NSW 2000

AUSTRALIA

Complete Specification for the invention entitled: "A BUSBAR CONNECTOR FOR CIRCUIT BREAKERS" The following statement is a full description of this invention, including the best method of performing it known to me/us:- I S00956 1 17/:OS/89 3844A 2 This invention concerns a busbar connector for circuit breakers. More particularly, the invention concerns a busbar to which a number of electrically parallel circuit breakers and a common line may be connected.

Electrical switchboards and distribution panels typically have a number of circuit breakers (which term is intended to include switches etc) removably connected to a common power line. The circuit breakers are arranged in parallel with each other by connecting them to respective fingers of a common busbar and this avoids the time consuming process of wiring them together. The power line is attached to the busbar by means of a terminal clamp which is either riveted to the busbar, or connected to a spare finger. A "master" circuit breaker, if used, may conveniently be connected in series with the other circuit breakers by connecting it between the busbar and the power line.

These arrangements have inconvenient aspects, either 20 in terms of component manufacture or installation rol° o difficulties, In contrast with the prior art arrangements the present invention provides a busbar to which, in use, a number of parallel circuit breakers and a common power 25 line are connected. The busbar comprises a conductive material bar, a plurality of integrally formed parallel fingers extending outwardly in a transverse direction from one edge of the bar, the fingers being spaced apart from one another by a distance corresponding to the 4 30 centre spacing of the circuit breakers and the fingers being arranged to project into and be clamped within terminals of the circuit breakers. Each finger comprises a first straight portion which is joined to the bar, a second, distal, straight portion which lies parallel with the first portion and a stepped portion connecting the two straight portions. The stepped portion of each finger serves in use to limit the extent of penetration of the finger into the associated circuit breaker when 1S Q S:04210LQ/SMcL

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I I II -2Athe finger is clamped within the terminal of the circuit breaker, whereby the circuit breaker is maintained in spaced relationship from the bar and whereby the circuit breaker may be moved toward the bar when the finger is not clamped in the terminal of the circuit breaker. The busbar further comprises a lug formed integrally with and projecting laterally from an edge of the bar which is opposite that from which the fingers extend, the lug and the fingers being orientated in opposite generally parallel directions which lie perpendicular to the bar.

The lug is shaped and sized to receive a tunnel-type terminal clamp by which the a a a o a oo o i~~ a o i a r a a r o a rr

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a a i or r rr a r**u* a 'S:0421 OLQ/SMcL 3 common power line is in use of the busbar connected.

The invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a busbar embodying the present invention; Figure 2 is a front elevational view of a series of circuit breakers connected to the busbar Figure 1; Figure 3 is a side elevational view of a circuit breaker connected to the busbar of Fig. 1; and Figure 4 is a side elevational view of an alternative circuit breaker showing how it is detached from the busbar.

Referring now to Figure 1, the busbar 1 comprises a flat bar 2 from the front of which depend a series of fingers 3, and from the back of which extends an upstanding lug 4.

Each finger 3 depends generally downward but includes a step which is formed by a bend 5, a reverse bend 6 and, a forwardly extending portion 7, so that the distal end 8 is spaced forwardly of, and below, bar 2.

o 'Lug 4 includes a shoulder portion 9 attached to bar 2, and a seat portion 10 shaped and sized to receive a tunnel-type terminal clamp. Seat portion 10 is spaced from bar 2 leaving a gap 11, and terminates in a forwardly projecting end portion 12.

Figures 2 and 3 show a series of circuit breakers 13 attached to respective fingers 3 of busbar 1, and a terminal clamp 14 in position on seat 30 Clamp 14 comprises a body 15 and tightening screw 16. The end of a power line 17 is connected to the busbar by inserting it between seat portion 10 and screw 16, and the tightening the screw to clamp the line 17 against the seat; end 12 prevents terminal clamp 14 slipping from the seat .0421 OLQ/SMcL Since lug 4 projects above busbar 1 in the opposite direction to fingers 3, access to screw 16 is facilitated.

Each circuit breaker 13 is clamped to the distal end of a finger 3 by means of a screw actuated clamp 18. Clamp 18 comprises a screw 19 and jaws 20, and as the screw is turned the jaws are moved. The reverse bend 6 of each finger 3 limits the penetration of the finger into the clamp 18. This ensures a gap 21 remains between the circuit breaker 13 and the busbar 1.

In addition to the electrical connections between circuit breakers 13 and busbar 1 brought about by the cooperation of fingers 3 and clamps 18, each circuit breaker 13 is also supported by a mounting rail 22. The mounting rail 22 engages a recess 23 in the rear of each circuit breaker 13 when it is attached to the busbar 1.

Each circuit braker 13 contains a conventional releasing mechanism 24 which includes a lever 25. When lever 25 is pulled away from mounting bar 22, the circuit breaker 13 is released and can be lifted off. Access to the lever 25 is often only from the front, or switch 26, side of the circuit breaker; and gap 21 allows a screwdriver or similar tool to be conveniently passed between busbar 1 and w op current breaker 13 to move the lever 25. If there was no gap 21, access to the lever 25 would be much more difficult.

An alternative release mechanism, known as a "tilt out", is illustrated in Figure 4. Here circuit breaker 13' can be pulled away from the bottom of rail 22 because the bottom of recess 23 has a chamfered corner 26. Thereafter, j *circuit breaker 13' can be pvtdabout point 27. This 30 mechanism also relies on a gap 21, because without it the top of circuit breaker 13' would be unable to tilt up towards bar 2.

Although the invention has been described with reference to particular embodiments, it should be appreciated that the invention could be embodied in many other forms. For instance, a number of lugs 4 could be provided at intervals along bar 2 to allow several power lines to be connected.

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Claims (4)

1. A busbar to which, in use, a number of parallel circuit breakers and a common power line are connected, thae busbar comprising: a conductive material bar, a plurality of integrally formed parallel fingers extending outwardly in a transverse direction from one edge of the bar, the fingers being spaced apart from one another by a distance corresponding to the centre spacing of the circuit breakers and the fingers being arranged to project into and be clamped within terninals of the circuit breakers, each finger comprising a first straight portion which is joined to the bar, a second, distal, straight portion which lies parallel with the first portion and a stepped portion connecting the two stzaight portions, the stepped portion of each finger serving in use to limit the extent of penetration of the finger into the associated circuit breaker when the finger is clamped within the terminal of the circuit breaker, whereby the circuit breaker is maintained in spaced relationship from 20 the bar and whereby the circuit breaker may be moved toward the bar when the finger is not clamped in the terminal of the circuit breaker, and a lug formed integrally with and projecting laterally from an edge of the bar which is opposite that from which the fingers extend, the lug and the fingers being orientated in opposite generally parallel directions which lie perpendicular to the bar, and the lug being shaped and sized to receive a tunnel-type terminal clamp by which the common power line is in use of the busbar connected.

2. The busbar as claimed in claim 1, wherein a portion of the lug which receives the terminal clamp lies parallel to and is spaced from the bar portion of the busbar, whereby the terminal clamp when connected to the busbar lies adjacent and parallel to the bar portion of the busbar.

3. The busbar as claimed in claim 2, wherein the lug has a distal end which is formed with a bend arranged to inhibit sliding of the terminal clamp fromL the lug. V ~f'S:O421OLQISMcL I" u 6

4. A busbar substantially as shown in the accompanying drawings and substantially as hereinbefore described with reference thereto. DATED this 14th day of April 1992 H.P.M. INDUSTRIES PTY. LIMITED By their Patent Attorneys GRIFFITH HACK CO. oa Q 1* S e o *o *0 0 0 o*00 0o*0 a e o 0 10 00 I o •0 I :}0 I