AU2015218477A1 - Device and method for handling cross arms - Google Patents

Description

2 2015218477 26 Aug 2015

DEVICE AND METHOD FOR HANDLING CROSS ARMS FIELD OF INVENTION

[0001] The present invention relates to the field of distribution line maintenance, particularly line maintenance of the type carried out in the electricity and telecommunications industries.

[0002] In one form, the invention relates to a means for facilitating maintenance of lines and structures for electricity distribution.

[0003] It will be convenient to hereinafter describe the invention in relation to cross arms for supporting electricity lines, however it should be appreciated that the present invention is not limited to that use only and can be used for cross arms that support other types of lines, such as those used for communications (eg telegraph, telephone).

[0004] Furthermore, while the present invention will be described with particular reference to travel towers, the present invention is not so limited and can be used in conjunction with a wide range of mobile elevation devices used by linesmen including cherry pickers, cranes, boom trucks and scissor lifts.

BACKGROUND ART

[0005] It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor. Moreover, any discussion of material such as documents, devices, acts or knowledge in this specification is included to explain the context of the invention in terms of the inventor’s knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein. 2015218477 26 Aug 2015 3 [0006] Travel towers are used in a wide range of industries, including the mining, electrical, renewable energy and telecommunications industries. Other applications include use in the construction and communications industries, and in film, television and photography.

[0007] Travel towers are often used as fully mobile, elevated work platforms for linesmen and others to access electricity and communications lines and the upper parts of the poles and pylons that support them. They typically comprise basket located at one end of a truck mounted extendable boom. The truck helps to counterbalance the boom and basket. Travel towers are self-bracing end-to-end, but outriggers may be used to brace one or both sides of the truck, depending on how the boom is going to be deployed.

[0008] Power linesmen work on electrically energized (live) and de-energized (dead) power lines. They perform numerous tasks including installation or replacement of distribution equipment such as capacitor banks, transformers, insulators and fuses which may be at elevated locations atop poles.

[0009] High voltage transmission lines can be worked live with proper setups, and providing that the linesman is isolated from the ground. Linesman wear special conductive clothing that is connected to the live power line, at which point the line and the linesman are at the same potential, allowing the linesman to handle the wire. The linesman may still be electrocuted if he completes an electrical circuit, for example by handling both ends of a broken conductor. Isolated line work is only used for transmission-level voltages and sometimes for the higher distribution voltages. Live wire work is commonly carried out within the UK and Australia by linesmen who are appropriately trained.

[0010] All linesmen use personal protective equipment (PPE) as protection against inadvertent contact. This includes rubber gloves, rubber sleeves, bucket liners and protective blankets. Linesmen must also wear special rubber insulating gear when working with live wires to protect against any accidental contact with the wire. 2015218477 26 Aug 2015 4 [0011] For applications where electrical wires pose a risk of injury to workers, electrically insulated travel towers are used and must conform to all relevant local regulations and guidelines governing electrical work. The travel tower buckets in which the linesman stand and work are routinely insulated with a non-conducting material such as fibreglass.

[0012] Linesmen need to be elevated to access some structures, particularly those that support overhead lines. The structures may be as simple as wooden, concrete, or occasionally steel poles directly set in the earth carrying one or more cross-arm beams to support conductors. Some poles have "armless" construction with conductors supported on insulators attached to the side of the pole. High-voltage lines are often carried on lattice-type steel towers or pylons.

[0013] Single pole structures are very widely used and typically have up to three cross arms, which may be staggered or all to one side. The insulators are attached to the cross arms. Alternatively, an "H"-type wood pole structure may be used, comprising two poles placed in the ground with a crossbar on top, extending to both sides. The insulators are attached at the ends and in the middle.

[0014] Most of the weight of the cross arm is supported on the pole by a single large bolt. In order for the linesman to access all parts of the cross arm and the insulators, the cross arm is often released from the electricity wires and any supporting braces and unbolted from the pole. The linesman can then work on the cross arm in the travel tower bucket, often with the cross arm supported on the bucket walls. However, one of the problems associated with this type of work is that the cross arm can fall off the bucket wall, or fall as it is being bolted or unbolted to the pole. There is a clear risk of injury for anyone at ground level who is underneath or near the basket. There is also a risk of damaging insulators or any other devices attached to the cross arm.

[0015] There is a clear need for improvements in the handling of cross arms to reduce the risk of injury and damage. 2015218477 26 Aug 2015 5

SUMMARY OF INVENTION

[0016] An object of the present invention is to provide improved safety for linesmen when working at elevated positions.

[0017] Another object of the present invention is to provide improvements in the efficiency of servicing electricity supply systems or other systems relying on elevated lines.

[0018] A further object of the present invention is to alleviate at least one disadvantage associated with the related art.

[0019] It is an object of the embodiments described herein to overcome or alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems.

[0020] In a first aspect of embodiments described herein there is provided a device for supporting a cross arm, the device comprising: a first portion adapted to receive a cross arm, a retainer for releasably retaining the cross arm adjacent the first portion, and a second portion, integral with the first portion, for maintaining the device in association with an insulated bucket/liner of a mobile elevation vehicle.

[0021] The first portion is typically of a shape that provides a secure rest for the cross arm. The first portion may include means for limiting lateral movement. For example the first portion may comprise a flat elongate surface on which the cross arm can rest, with longitudinal walls to limit lateral movement such as rolling of the cross arm, so that the first portion has a generally L-shaped or U-shaped cross section. 6 2015218477 26 Aug 2015 [0022] The retainer is preferably elongate, such as in the form of a strap or belt and a closure that can be secured and tightened against the cross arm. For example the strap may include a buckle or by a strip having Velcro® closures at either end. The retainer is typically integral with the first portion. For example it may pass around, or through slots, belt loops or keeper rings associated with the first portion.

[0023] The second portion may keep the device associated with the insulated bucket/liner by any convenient means that ensures that both the liner and the device remain electrically insulated. For example, association may be maintained by mechanical fit or interference fit between the second portion and the bucket/liner. In another example, the association may be maintained by adherence between the second portion and the bucket/liner. In another embodiment, the device is connected to the bucket/liner by plastic or polymer insulating bolts, clips or other mechanical fixing means.

[0024] In yet another example, the second portion and the bucket/liner may be formed as a single unit.

[0025] The device may be made of any convenient electrical insulating material, such as a polymer, or a composite such as fibreglass. When the support and bucket/liner liner are unitary in structure they may for example, be cast as one piece of fibreglass or polymer.

[0026] In another aspect of embodiments described herein there is provided a method for handling a cross arm using the device of the present invention, the method comprising the steps of: detaching a cross arm from a pole, locating the cross arm on the first portion, and encircling the cross arm with the retainer.

[0027] Once the linesman has completed maintenance on the cross arm, the method may include the further steps of: 7 2015218477 26 Aug 2015 releasing the cross arm from the retainer, removing the cross arm from the first portion, and reattaching the cross arm to the pole.

[0028] In another embodiment, instead of carrying out maintenance the linesman may simply use the device to transport an old or damaged cross arm from the top of the pole to ground level on the boom of the travel tower then, transport a new cross arm from ground level to the top of the pole.

[0029] In yet a further aspect of embodiments described herein, the device is adapted to removably receive an organiser comprising a body portion and multiple retainers. The retainers may include, for example loops or compartments.

[0030] For example, the organiser may comprise compartments that are appropriately configured to hold accessories including tools, cables, wires, tapes, test instruments, sensors, scanners, cleaners, flashlights and the like. The organiser could have a dual purpose, such as functioning as an electrician’s belt when it is not attached to the device.

[0031] The organiser may be made of any convenient insulating material including canvas, leather, or synthetic materials such as nylon. Typically the organiser is adapted such that the body portion may be connected to the second portion of the device for supporting the cross arm. The connection may be made by any convenient releasable mechanical means such as clips, hooks or bolts of electrically insulating material.

[0032] Other aspects and preferred forms are disclosed in the specification and/or defined in the appended claims forming a part of the description of the invention.

[0033] In essence, embodiments of the present invention stem from the realization that the insulated bucket/liner can be more effectively used to support a cross beam as it is being worked on or transported.

[0034] Advantages provided by the present invention comprise the following: 8 2015218477 26 Aug 2015 • improved occupational health and safety for the linesman in a travel tower bucket/liner by reduction of manual handling of cross arms; • reduced risk of injuring other workers by falling cross arms; • easier access for the linesman to all parts of the cross arm during maintenance and repair at elevated positions; and • increased safety when transporting cross arms between ground level and elevated positions.

[0035] Further scope of applicability of embodiments of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure herein will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Further disclosure, objects, advantages and aspects of preferred and other embodiments of the present application may be better understood by those skilled in the relevant art by reference to the following description of embodiments taken in conjunction with the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the disclosure herein, and in which: FIG. 1 illustrates a perspective view of one embodiment of the device of the present invention; FIG. 2 illustrates a plan view of one embodiment of an organiser suitable for use with the device of claim 1; FIG. 3 illustrates a further embodiment of the device of the present invention depicted in front (FIG. 3a), top (FIG. 3b) and end (FIG. 3c) views. 9 2015218477 26 Aug 2015 DETAILED DESCRIPTION List of parts depicted in the figures: 1 Device 5 First portion 7 Retainer (first end) 8 First slit 9 Retainer (second end) 10 Second slit 11 Second portion 12 End flange 13 (Device) holes 15 Inner flange 17 Outer flange 20 Organiser 22 First pocket 24 Second pocket 26 Organiser holes [0037] FIG. 1 illustrates one embodiment of a device (1) according to the present invention for supporting a cross arm. The device is substantially in the form of a bracket device comprising a first portion (5) that is substantially planar and can thus support a cross arm. Threaded through two slots in the first portion (5) is a retainer in the form of a strap having a first end (7) and a second end (9) that comprise a Velcro® closure. The strap can be wrapped around the cross arm to releasably retaining the cross arm adjacent the first portion (5).

[0038] A second portion (11) integral with the first portion (5) keeps the device in association with an insulated bucket/liner of a travel tower. In this embodiment the second portion (11) includes an inner flange (15) and an outer flange (17) to fit either side of the wall of a bucket/liner. Preferably the second portion can be located at any convenient position on any wall of the bucket/liner. The second portion (11) includes a number of holes (13) that can receive a clip, bolt, hook or other electrically insulated means for attaching the device to the bucket/liner.

[0039] FIG. 3 illustrates a further embodiment of the device of the present invention depicted in front (Fig.3a), top (Fig.3b) and end (Fig.3c) views. This embodiment of the device differs from the embodiment of Fig. 1 in so far as it exhibits a slightly different 10 2015218477 26 Aug 2015 arrangement of flanges. It will be appreciated that the configuration of the second portion, and first portion, can be adapted to fit different shaped bucket/liner.

[0040] In use, the travel tower can be located in an appropriate position relative to an electricity pole and the boom used to manoeuvre the basket into position with the device on one edge of a wall of the bucket/liner located close to the cross arm. The linesman can then uncouple the electricity wires from the insulators on the cross arm, release any braces between the cross arm and the pole, then unscrew the bolt holding the cross arm to the pole. With the device located in close proximity to the cross arm, the linesman expends minimal effort to lift the cross arm onto the first portion (5) of the device. The ends (7,9) of the retainer can then be engaged, so that the retainer to encircles the cross arm.

[0041] Once it is securely held in the device, the linesman can immediately carry out maintenance on the cross arm, or operate the boom to transport it to ground level for maintenance or replacement.

[0042] To return the cross arm to the pole, the basket and device are manoeuvred into position as close as possible to the desired position. The ends (7,9) of the retainer are disengaged so that the cross arm can be manually lifted (if necessary) from the first portion (5) into position for inserting a bolt and reattaching it to the pole. If the device is able to be appropriately positioned, it may not be necessary to manually lift the cross arm into position.

[0043] FIG. 2 illustrates one embodiment of an organiser (20) suitable for use with the device (1) of the present invention. The organiser (20) includes a first pocket (22) and a second pocket (24) divided up into compartments that are appropriately configured to hold accessories such as tools, cables, wires, tapes, test instruments, sensors, scanners, cleaners and flashlights. The organiser (20) includes holes (26) which can be used to attach the organiser to corresponding holes (13) in the device (1) using electrically insulating clips, hooks or bolts.

[0044] The organiser may be made of any convenient insulating material including canvas, leather, or synthetic materials such as nylon. Typically the organiser is adapted 11 2015218477 26 Aug 2015 to be connected to the second portion of the device for supporting the cross arm. The connection may be made by any convenient means such as clips, hooks or bolts of electrically insulating material.

[0045] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth.

[0046] As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. The described embodiments are to be considered in all respects as illustrative only and not restrictive.

[0047] Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures.

[0048] “Comprises/comprising” and “includes/including” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words ‘comprise’, ‘comprising’, ‘includes’, ‘including’ and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

Claims (12)

1. A device for supporting a cross arm, the device comprising: - a first portion adapted to receive a cross arm, - a retainer for releasably retaining the cross arm adjacent the first portion, and - a second portion, integral with the first portion, for maintaining the device in association with an insulated bucket/liner of a mobile elevation vehicle.

2. A device according to claim 1 wherein the first portion is generally L-shaped or U-shaped in cross section.

3. A device according to claim 1 wherein the retainer comprises a strap and closure.

4. A device according to claim 1 wherein the retainer comprises a strap and a buckle closure, the strap passing through slots associated with the first portion.

5. A device according to claim 1 wherein the device and liner are maintained in association by mechanical fit, adherence or mechanical fixing means.

6. A device according to claim 1 wherein the device and liner are unitary in structure.

7. A device according to claim 1 wherein the mobile elevation vehicle is chosen from, travel towers, cherry pickers, cranes, boom trucks and scissor lifts.

8. A method for handling a cross arm using the device of claim 1, the method comprising the steps of: - detaching a cross arm from a pole, - locating the cross arm on the first portion, and - encircling the cross arm with the retainer.

9. A method for handling a cross arm using the device of claim 1, the method including the steps of: - releasing a cross arm from the retainer, - removing the cross arm from the first portion, and - attaching the cross arm to a pole.

10. A method for maintaining a cross arm using the device of claim 1, the method comprising the steps of: - detaching a cross arm from a pole, - locating the cross arm on the first portion, - encircling the cross arm with the retainer, - performing maintenance work on the cross arm, - releasing the cross arm from the retainer, - removing the cross arm from the first portion, and - reattaching the cross arm to the pole.

11. An organiser suitable for removable attachment to the device of claim 1, the organiser comprising a body portion and multiple retainers.

12. An organiser according to claim 11 wherein the organiser includes a body portion attached to the second portion of the device by a releasable mechanical means.