P/00/009 Regulation 3.28 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Invention Title: OVERHEAD WIRING BOOM The invention is described in the following statement, including the best method of performing it known to us: Our Reference: 102032 - 2 OVERHEAD WIRING BOOM The present invention relates to equipment for manipulating overhead wiring and, more particularly, to 5 wiring for pantograph equipped rail vehicles. BACKGROUND Overhead wiring maintenance vehicles are known and widely used in the servicing of the overhead wiring and 10 associated equipment of electrified railway lines, Typically, as shown in Figure 1 (prior art) such vehicles are modified or purpose built all terrain vehicles able to operate on both on and off roads as well as on railway lines. For this latter purpose, these vehicles are provided 15 with ram operated auxiliary wheels which engage with the rails of a railway line and allow the vehicle to travel thereon. For overhead servicing purposes, these vehicles also include an articulated arm and elevated work platform, and 20 may include a wire stagger measuring pantograph. Also typical of these vehicles is the inclusion of a wiring boom, usually comprising a vertically acting ram with a wire capturing structure at its rod end, for lifting a wire to allow maintenance of a wire suspension point for 25 example.
- 3 A major disadvantage of known such booms, is that they provide a simple vertical lift only, so that the wire often continues to provide an obstruction to the work required. It also often requires manual assistance to pull a wire 5 into alignment with the wire capturing structure since the wire may not be exactly central to the railway line at any given point, It is an object of the present invention to address or at least ameliorate some of the above disadvantages. 10 Notes 1. The term "comprising" (and grammatical variations thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the 15 exclusive sense of "consisting only of". 2. The above discussion of the prior art in the Background of the invention, is not an admission that any information discussed therein is citable prior art or part of the common general knowledge of persons skilled 20 in the art in any country. BRIEF DESCRIPTION OF INVENTION Accordingly, in a first broad form of the invention, there is provided an overhead wiring boom; said wiring boom 25 mounted to an overhead wiring maintenance vehicle; said wiring boom adapted for manipulation of an overhead wire; 4 said boom characterised in being articulated in both substantially vertical and in lateral directions. Preferably, said boom includes a substantially vertically acting hydraulic wire lifting ram and at least one 5 laterally acting hydraulic wire displacement ram. Preferably, a base end of said hydraulic wire lifting ram is pivotally mounted to a load bed of said overhead wire maintenance vehicle; said at least one laterally acting hydraulic wire displacement ram pivotally mounted to a 10 supporting frame mounted on said load bed; said at least one laterally acting ram acting on said wire lifting ram to urge said wire lifting ram to a desired inclination. Preferably, a rod end of said substantially vertically acting hydraulic wire lifting ram is provided with a wire 15 supporting bracket; said wire supporting bracket provided with a wire retaining element; said wire retaining element releasably latchable into a closed wire retaining position. In another broad form of the invention, there is provided a method of manipulating an overhead wire; said method 20 including the steps of: (a) positioning an overhead wiring maintenance vehicle at a point proximate a said overhead wire suspension point, (b) raising an overhead wiring boom of said maintenance vehicle and securing said wire in a wire supporting bracket of said boom by means of a releasable latch, (c) releasing said wire from said suspension point, 5 (d) activating a substantially vertically acting hydraulic wire lifting ram and at least one laterally acting hydraulic wire displacement ram of said boom to move said wire clear of said suspension point. 10 BRIEF DESCRIPTION OF DRAWINGS Embodiments of the present invention will now be described with reference to the accompanying drawings wherein: 15 Figure 1 is a typical overhead wiring maintenance vehicle according to the prior art, Figure 2 is an end view of a preferred arrangement of an overhead wiring boom according to the invention, mounted to the load bed of an overhead wiring maintenance vehicle. 20 Figure 3 is a further view of the overhead wiring maintenance boom according to the invention, in use. 25 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS With reference to Fig. 1 an overhead wiring maintenance vehicle 10 according to the prior art is provided with a boom 12 fixed in a vertical orientation. An 5 extension of the operating hydraulic ram is thus restricted to a vertical displacement of the overhead wire only. With reference now to Figure 2, a similar overhead wiring maintenance vehicle 20 has been fitted with an overhead wiring boom 22 according to the invention. In a 10 preferred arrangement, the boom 22 comprises a substantially vertically operating hydraulic lifting ram 24 and, in this instance, two, laterally acting hydraulic displacement rams 26 and 28.. The base end 25 of the hydraulic lifting ram 24 of the 15 boom 22, is preferably supported on a pivoting structure 30 mounted to the load bed 32 of the vehicle 20, and is so arranged that the ram 24 is able to be inclined laterally in either direction, normal to the load bed 32 of the vehicle and the rails 34 on which it is positioned. 20 A wire support bracket 36 is provided at the rod end 38 of the lifting ram 24, either directly mounted to the rod end, or to an extension arm extending from the rod end. The bracket 36 includes a horizontal support bar 40 and vertical plates or fork elements 42 of sufficient height to 25 extend above any wire 44 resting on the support bar 40 (as shown in Figure 3) . A wire retaining element is provided for securing a wire 44 once it has been captured between the fork elements 42. The wire retaining element in one, form comprises a bar 46 hinged at one end from an outermost fork element, and able to rotate between an open position 5 as shown in Figure 2 and a latched closed position shown in Figure 3. When closed, it extends the length of the support bracket and is secured to the opposite outer fork element in the closed position by a quick release catch (not shown), 10 In another preferred embodiment of the wire retaining bracket, the wire securing bar may be activated by a small ram or electric solenoid (not shown) to allow capture of the wire without the need for placement of service personnel within reach of the bracket. 15 Inclination of the lifting ram 24, and hence the lateral displacement of its rod end 38 and bracket 36, is controlled by at least one, preferably two wire displacement rams. The outer ends of the cylinders of wire displacement rams 26 and 28, are pivotally supported from a 20 frame 50 mounted to the load bed 32 of the vehicle, with the rod ends connected to a bracket 52 attached to the cylinder of the lifting ram 24. In the case of two wire displacement rams, the rams act in tandem, one retracting and the other extending to bring the lifting ram 24 to the 25 desired inclination, In Use The overhead wiring boom of the invention, provides greatly improved convenience and flexibility in the maintenance of overhead wiring and supporting equipment. 5 Thus, for example in the case of servicing or replacing a wire suspension point such as a cantilever frame 48 (as shown in Figures 2 and 3) or suspension arm, a user first causes the wire lifting ram 24 to extend with such lateral displacement as required, to bring the horizontal bar 40 of 10 the wire support bracket 36 into contact with the wire 44 to be manipulated. The wire securing bar 46 is then latched or activated to securely retain the wire in the bracket. The wire 44 is then detached from the insulator 54. It is then a simple matter, by a combination of the lifting 15 ram 24 and the lateral wire displacement rams 26 and 28, to move the wire 44 away from the suspension point, allowing unobstructed access for servicing or removal and displacement of the wire suspension equipment. The above describes only some embodiments of the 20 present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention. Thus, although the above description is primarily directed at overhead wiring of railway lines, the overhead wiring boom of the invention 25 may equally be applied in the servicing of electric tram and bus wiring systems.