AU2015100229A4 - Bus bar clamp - Google Patents

Abstract

A bus bar clamp (1) for clamping a first bus bar (3) to a second bus bar (5), the clamp (1) including a bracket having a base section and a pair of opposing arms extending from the base section, the clamp (1) further including a support plate (9) engageable with an abutment surface provided on each arm, a region bound by the base section, opposing arms and support plate defining a first passageway for accommodating a first bus bar (3), each arm further including an aperture, the apertures in the opposing arms being aligned to define a second passageway for accommodating a second bus bar (5) therein, the clamp (1) further including at least one fastener (23) for threading into a hole (21) provided in either the base section or support plate (9), wherein rotation of the fastener (23) in the hole (21) clamps the first bus bar (3) and second bus bar (5) together and urges the support plate (9) into abutment with the abutment surface of each arm. ,~1~ - %~ %"%,~ ~ -4 V >9: K ~-~t I' Al

Description

1 BUS BAR CLAMP FIELD OF THE INVENTION [0001] The present invention relates to a clamp for clamping together electrical conductors. More particularly, the present invention relates to a clamp for clamping together electrical bus bars of an electrical switchboard, distribution board or the like. BACKGROUND TO THE INVENTION [0002] The transmission of electrical energy from incoming supply to outgoing equipment in an electrical switchboard or the like is typically provided by connecting current carrying conductors known as bus bars. Bus bars are usually elongated flat strips of conductive material, for example aluminium or copper. [0003] Bus bars have traditionally been connected together by drilling or punching holes in the bus bars and coupling them together with suitable bolts through the holes. However the process of drilling holes and inserting bolts is time consuming and labour intensive. Bus bars have also traditionally been connected together by some form of clamping device. In both instances, difficulties can be encountered in achieving in a quick and economical manner, a connection which has low connection losses, meets industry standards and is safe. [0004] Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art in Australia and any other country on or before the priority date of the claims herein.

2 SUMMARY OF THE INVENTION [0005] In accordance with the present invention, there is provided a bus bar clamp for clamping a first bus bar to a second bus bar. The clamp includes a bracket having a base section and a pair of opposing arms extending from the base section. The clamp further includes a support plate engageable with an abutment surface provided on each arm. A region bound by the base section, opposing arms and support plate define a first passageway for accommodating a first bus bar. Each arm further includes an aperture, the apertures in the opposing arms being aligned to define a second passageway for accommodating a second bus bar therein. The clamp further includes at least one fastener for threading into a hole provided in either the base section or support plate, wherein rotation of the fastener in the hole clamps the first bus bar and second bus bar together and urges the support plate into abutment with the abutment surface of each arm. [0006] Preferably, the hole provided in either the base section or support plate overlies both the first bus bar and the second bus bar. [0007] Further, the abutment surface of each arm is preferably provided by an edge of each aperture. Further, the support plate preferably includes a groove at each end for engaging with the abutment surface of a respective arm. [0008] Further, an end surface of the fastener preferably engages with either the first bus bar or the second bus bar when clamping the bus bars together. BRIEF DESCRIPTION OF THE DRAWINGS [0009] Further benefits and advantages of the present invention will become apparent from the following description of the preferred embodiments of the invention. The preferred embodiments should not be considered as limiting any 3 of the statements in the previous section. The preferred embodiments will be described with reference to the following figures in which: [0010] Figure 1 is a perspective view of a bus bar clamp in accordance with a first embodiment of the invention, showing a first bus bar connected to a second bus bar; [0011] Figure 2 is a perspective view of the bracket of the bus bar clamp shown in Figure 1; [0012] Figure 3 is a perspective view of the support plate of the bus bar clamp shown in Figure 1; [0013] Figure 4 is a perspective view of the bracket and support plate of the bus bar clamp shown in Figure 1; [0014] Figure 5 is a perspective view of a bus bar clamp in accordance with a second embodiment of the invention, showing a first bus bar connected to a second bus bar; and [0015] Figure 6 is a perspective view of a bus bar clamp in accordance with a third embodiment of the invention, showing a first bus bar connected to a second bus bar. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0016] With reference to the accompanying drawings there is provided a bus bar clamp 1 for clamping a first bus bar, which is preferably in the form of a main bus 3 which is elongate and flat, to a second bus bar which is preferably in the form of a feeder bus bar 5 which is elongate and flat. The clamp 1 includes a bracket 7 (as shown in Figure 2) and a support plate 9. The bracket 7 includes a 4 planar base section 11 and a pair of opposing arms 13 extending from opposite sides of the base section 11 and provide the bracket 7 with the appearance of a C-shaped frame. [0017] With reference to Figure 3, the support plate 9 used in the first and second embodiments shown in Figures 1 and 5, respectively, preferably includes a pair of elongate grooves 15 in a face of the support plate 9. The spacing between the grooves 15 preferably corresponds to the spacing between the abutment surfaces provided on each arm 13 of the bracket 7. In the bracket 7 shown in Figure 2, the opposing arms 13 each include an aperture 17 with the abutment surface of each arm 13 being provided by an edge 19 of the aperture 17 which is furthest from the base section 11. In Figure 1, the support plate 9 is shown mounted through the apertures 17 with the support plate 9 in abutment with the edge 19 of the apertures 17. The resulting configuration provides the bus bar clamp 1 with a D-shape appearance. [0018] A region bound by the base section 11, the opposing arms 13 and the support plate 9 define a first passageway for accommodating the main bus bar 3. Further, the apertures 17 in the opposing arms 13 are aligned to define a second passageway for accommodating the feeder bus bar 15, preferably at 900 to the main bus bar 3. In this regard, the apertures 17 are of sufficient width to accommodate the width of the feeder bus bar 5. Similarly, the opposing arms 13 are spaced apart a sufficient distance to accommodate the width of the main bus bar 3 and enable a face of the main bus bar 3 to lie flat on the base section 11. [0019] With reference to Figures 1, 3 and 4, the support plate 9 utilised in the bus bar clamp 1 of the first embodiment of the invention, includes one or more holes 21 which are preferably threaded and extend through the support plate 9. One or more fasteners, preferably in the form of a threaded screw or bolt 23, are rotatably mounted in each hole 21 and may be locked in place relative to the support plate 9 by a lock nut 25 which can be tightened against the support plate 9. By rotating the one or more threaded fasteners 23 in a clockwise manner 5 relative to the hole 21, an end 27 of the fastener 23 is able to move downwardly into abutment with the main or feeder bus bars 3, 5. In Figure 1, the feeder bus bar 5 is shown on top of the main bus bar 3. Accordingly, when the two threaded fasteners 23 are rotated in a clockwise direction such that the fasteners 23 move downwardly towards the bus bars 3, 5 the ends 27 of the fasteners 23 engage with the feeder bus bar 5. Further rotation of the fastener 23 in a clockwise direction urges the grooves 15 in the support plate 9 into abutment with the edge 19 of the apertures 17 in the opposing arms 13 until the feeder bus bar 5 is securely clamped to the main bus bar 3. The holes in the support plate 21 are positioned such that they overlie the region where the main bus bar 3 intersects with the feeder bus bar 5. This ensures that the clamping force exerted on the bus bars does not result in deformation of the bus bars. [0020] Although only two bus bars are shown in the embodiments depicted in the drawings, the bus bar clamp can accommodate additional bars. Further, the size of the clamp can be varied in height, width and depth depending upon the number of main and feeder bus bars as well as the width and depth of the main and feeder bus bars. [0021] In the second embodiment of the invention shown in Figure 5, the holes 21 for the threaded fasteners 23 are provided in the base section 11 of the bracket 7 rather than the support plate 9. The holes in the base section 11 are positioned such that they overlie the region where the main bus bar 3 intersects with the feeder bus bar 5. As the base section 11 is constructed of a relatively thin sheet material, it may be unable to adequately secure a threaded fastener 23. In which case a threaded insert may first be inserted into each hole 21 and expanded to provide a load bearing thread for the threaded fastener 23. [0022] The third embodiment of the invention shown in Figure 6 is similar to the first embodiment shown in Figure 1. However in Figure 6, the support plate 9 is provided with opposing legs 29 at opposite ends of the support plate 9 instead of grooves 15.

6 [0023] The clamp in accordance with the present invention advantageously enables bus bars to be clamped together without the need for holes to be drilled and bolts inserted into the bus bars. In addition, the surface contact between bus bars is maximised as surface area is not lost to holes being required in the bus bars. Marking is also minimised on the bus bars as clamping is advantageously on the face of the bus bars and not via bolts through the bars. Moreover, by positioning the threaded fasteners in holes 21 which overlie the region where the bus intersect, minimal bending of the bus bars occurs when clamped together, thereby providing longer life for the connection between the bus bars and the clamp. [0024] As the present invention may be embodied in several forms without departing from the central characteristics of the invention, it should be understood that the above described embodiment should not be considered to limit the present invention but rather should be construed broadly. Various modifications and equivalent arrangements are intended to be included in the spirit and scope of the invention.

Claims (5)

1. A bus bar clamp for clamping a first bus bar to a second bus bar, the clamp including a bracket having a base section and a pair of opposing arms extending from the base section, the clamp further including a support plate engageable with an abutment surface provided on each arm, a region bound by the base section, opposing arms and support plate defining a first passageway for accommodating a first bus bar, each arm further including an aperture, the apertures in the opposing arms being aligned to define a second passageway for accommodating a second bus bar therein, the clamp further including at least one fastener for threading into a hole provided in either the base section or support plate, wherein rotation of the fastener in the hole clamps the first bus bar and second bus bar together and urges the support plate into abutment with the abutment surface of each arm.

2. A clamp as claimed in claim 1 wherein the hole provided in either the base section or support plate overlies both the first bus bar and the second bus bar.

3. A clamp as claimed in either claim 1 or 2 wherein the abutment surface of each arm is provided by an end surface of each aperture.

4. A clamp as claimed in any one of the preceding claims wherein the support plate includes a groove at each end for engaging with the abutment surface of a respective arm.

5. A clamp as claimed in any one of the preceding claims wherein an end surface of the fastener engages with either the first bus bar or the second bus bar when clamping the bus bars together. VIJAY WARDHEN, KIRTI WARDHEN AND VAIBHAV WARDHEN WATERMARK PATENT AND TRADE MARKS ATTORNEYS UIP1489AU00