AU746630B2

AU746630B2 - Overhead trolley systems

Info

Publication number: AU746630B2
Application number: AU76190/98A
Authority: AU
Inventors: Barry McFarlane
Original assignee: BOMAC ENGINEERING Pty Ltd
Current assignee: BOMAC ENGINEERING PTY Ltd
Priority date: 1997-08-01
Filing date: 1998-07-15
Publication date: 2002-05-02
Anticipated expiration: 2018-07-15
Also published as: AU7619098A

Description

-1- Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

(ORIGINAL)

0600 O.

0. 0

S.

S. Name of Applicant: Actual Inventors: Address for Service: BOMAC ENGINEERING PTY.LTD.

DAVIES COLLISON CAVE, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

"Overhead trolley systems" Invention Title: Details of Associated Provisional Application(s) No(s): P08367/97 filed 1 August, 1997.

The following statement is a full description of this invention, including the best method of performing it known to us: Q:\OPER\RSH\P08367.196 15/7/98 P:\OPER\RSH\P08367.SPE 817/98 -2- OVERHEAD TROLLEY SYSTEMS The present invention relates to overhead trolley systems of the type comprising a trolley movable along an overhead track for carrying a load suspended beneath the trolley. More particularly the invention relates to trolleys for such systems.

Overhead trolley systems of the type mentioned above are usually installed in factories, workshops, or production areas where it is required to move a suspended load from one area of the worksite to another. Typically, the overhead track may comprise a circular section pipe (a so-called pipe trolley system) or a flanged girder (a so-called girder trolley system).

Trolleys for use in such systems comprise a body carrying wheels in a configuration to run along the track, with the body having means enabling a load to be suspended from the body.

Such overhead trolley systems are designed whereby the trolley is relatively freely moveable along the track so that displacement of the trolley along the track can be effected by pushing 15 or pulling the suspended load in the direction of the track. Although most overhead trolley systems of this type are designed primarily for manual traction of the trolley via the load, for some applications a powered drive may be required. Prior proposals for a powered drive system have included a separate, powered, drive trolley attached to the load-carrying trolley or a purpose-built powered load-carrying trolley with drive motor and drive wheels. In either 20 the case, previously proposed constructions of powered drive trolley or powered load-carrying trolley have been relatively complex and expensive to produce.

According to the present invention there is provided a trolley for use in an overhead trolley system of the type comprising an overhead track with the trolley being moveable along the track and being adapted to carry a suspended load, said trolley comprising a body, wheels carried by the body to support the body from the track for movement along the track, and a drive assembly attached to the body, said drive assembly comprising a chassis attached to the body for pivotal movement about a substantially horizontal axis, a power-driven drive wheel carried by the chassis, and means for attaching a suspended load to the chassis such that the weight of the load pivots the chassis in a sense to urge the drive wheel carried thereby into P:\OPER\RSH\P08367.SPE 8n198 -3driving engagement with the track.

In a preferred embodiment of the invention, the drive wheel is adapted to engage an undersurface of the track, with the drive wheel and load being at opposite sides of a pivot mounting of the chassis to the trolley body whereby the load carried by the chassis pivots the chassis in a sense to urge the drive wheel in an upwards direction. Preferably, the drive wheel is driven from an electric motor carried by the chassis at the same side of the pivot axis as the load carrier whereby the weight of the motor and associated drive components such as a gearbox will add to the load acting to urge the drive wheel into driving engagement with the track.

oe Advantageously, means may be provided for optionally retaining the drive assembly in a nondriving configuration relative to the track to permit manual displacement of the trolley. In one preferred form, this can readily be achieved by releasably retaining the chassis in a 15 configuration in which the drive wheel is displaced from the track; as an example, this may be effected by insertion of a pin or other locking member into the body and/or the chassis so eooas to prevent pivotal movement of the chassis into a driving configuration.

*.*":Advantageously a drive assembly as defined above may also be of such construction that it 20 can be fitted to an existing overhead trolley, preferably by application to the trolley at the existing load mounting zone of the trolley.

Accordingly, in accordance with a further aspect of the invention there is provided a drive assembly for a load carrying trolley of an overhead trolley system, said drive assembly comprising a chassis for mounting to the trolley, a powered drive wheel carried by the chassis, and means for carrying a suspended load such that application of a trolley load to said load carrying means displaces the chassis relative to the trolley in a sense to force the drive wheel into driving engagement with the track.

P:\OPER\RSH\P08367.SPE -81/98 -4- An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a side view showing an embodiment of a drive assembly in accordance with the invention applied to a pipe trolley; and Figures 2 and 3 are vertical sections through the trolley and drive assembly.

In the embodiment of the invention shown in the accompanying drawings, a pipe trolley system comprises an overhead track in the form of a pipe 2 having along its length a vertical upstanding flange 4 by which the pipe 2 is supported from support structure. A pipe trolley .0 0.

6 which is moveable along the pipe 2 comprises a body 8 generally configured to the shape of the pipe 2, the body 8 carrying pairs of inclined wheels 10 moveable along the upper surface of the pipe 2 at opposite sides of the supporting flange 4. As shown, the body 8 also 15 has pairs of guide wheels 12 which cooperate with the supporting flange 4, although these wheels are not essential and may be omitted in some applications. The body 8 has in its lower part beneath the track a load-carrying zone from which the load is suspended. This o*o* zone is located substantially midway between the respective sets of wheels 10 and comprises a horizontal passage 14 by which a shackle bolt can be attached to the body 8, with the load 20 being suspended from the shackle. The construction thus far described is conventional.

A powered driving capability is provided for the trolley 6 by means of drive assembly which is attached to the body 8 and will now be described. The drive assembly 20 comprises a chassis 22 carrying at one end a drive motor 24 and gearbox 26, and at the other end a drive wheel 28 which is linked to the output of the gearbox 24 via a suitable transmission such as a drive belt or drive chain 30. The chassis 22 of the drive assembly 20 comprises opposed, plate-like, members 22a symmetrically arranged at opposite sides of a central vertical plane through the trolley 6. The drive wheel 28 lies between the plates 22a at the end of the chassis 22 and is mounted by suitable bearings carried by the plates 22a. Each plate 22a has an upstanding lug 32, the two lugs 32 being adapted to lie at opposite sides of the lower part of P:\OPER\RSH\P08367.SPE 8n198 the trolley body 8, the lugs 32 being apertured to receive a connecting bolt by which the chassis 22 can be attached to the body 8 by insertion of the bolt through the load-carrying passage 14 of the trolley body 8 in such a manner that the drive assembly 20 is suspended from the body 8 and is able to pivot about a horizontal axis defined by the axis of the connecting bolt.

A load-carrying shackle plate 36 is pivotally attached to the chassis 22 at a position rearwardly of a vertical plane passing through the pivot axis of the chassis 22, that is at the opposite side of that plane to that at which the drive wheel 28 is located. The shackle plate 10 36 extends beneath the chassis 22 and is appropriately configured to permit suspension of a load therefrom; as shown the shackle plate 36 is apertured for easy coupling of the suspended load. Preferably the shackle plate 36 is also mounted in a position between the two plates 22a otoon a pin 40 passing between the plates 22a whereby the shackle plate 36 is approximately aligned with a vertical central plane through the trolley 6 to provide approximate symmetry of loading to the trolley 6.

•As will be apparent the weight of the motor 24 and gearbox 26 and also the weight of the applied load at the opposite side of the pivot axis of the chassis 22 to the drive wheel 28 will 2act to pivot the chassis 22 so that the drive wheel 28 is urged upwardly into driving engagement with the undersurface of the track. The force of driving engagement between the drive wheel 28 and the track will, of course, be dependent on the load and will increase with increasing load. It is to be noted that although as shown, the drive surface of the drive wheel 28 is concave in cross section to match the profile of the pipe 2. This is not essential and satisfactory drive can be achieved with a drive surface of straight cross section.

If, for some reason, a powered drive is not required, the chassis 22 can be pivoted and retained in a position in which the drive wheel 28 is out of driving engagement with the track. This may be achieved simply by insertion of a locking pin through the body 8 of the trolley to cooperate with the chassis 22 so that the chassis 22 is retained in a position in which the drive wheel 28 is displaced slightly below, and out of engagement with, the undersurface of the track. This capability may be of advantage in circumstances where, for example, there P:\OPER\RSH\P08367.SPE 87/98 -6is a malfunction in the drive assembly and ready conversion of the trolley to manual operation enables continued operation of the trolley system prior to repair of the drive assembly.

In the embodiment described, the drive assembly is able to be fitted to the load-carrying zone of existing trolley designs without any adaptation in the basic construction of the trolley. As a result of this, the drive assembly can be supplied as a separate unit to be retro-fitted to existing trolleys of this type already in use. Of course, in some cases a new trolley may be supplied to a user with the drive assembly already installed although it is advantageous that the overall design is such that the same trolley body can be used either for powered or manually propelled designs.

*o°0* Although the preferred embodiment of the invention has been described specifically in relation to a drive assembly for pipe trolleys, the principles described are applicable to drive assemblies for other forms of overhead trolley such as girder trolleys. The basic construction and operation will be substantially as described, but with the configuration of the chassis and pivot mounting of the chassis being adapted to suit the configuration of the trolley in question.

0In our earlier patent application 14833/95 there is described an overhead trolley system comprising parallel overhead tracks, with a trolley running on each of the two tracks and the load being suspended from the two trolleys. Reference should be made to this application for a full description. A twin track system as described in this earlier application can easily be adapted to powered drive by application of the drive assembly described herein to one of the two trolleys, it being unnecessary for both trolleys to be powered trolleys.

Throughout this specification and claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers.

The embodiments have been described by way of example only and modifications are possible within the scope of the invention.

Claims

1. A trolley for use in an overhead trolley system of the type comprising an overhead track with the trolley being moveable along the track and being adapted to carry a suspended load, said trolley comprising a body, wheels carried by the body to support the body from the track for movement along the track, and a drive assembly attached to the body, said drive assembly comprising a chassis attached to the body for pivotal movement about a substantially horizontal axis, a power-driven drive wheel carried by the chassis, and means for attaching a suspended load to the chassis such that the weight of the load pivots the chassis in a sense to 10 urge the drive wheel carried thereby into driving engagement with the track.

2. A trolley according to claim 1, wherein the drive wheel is adapted to engage an S. undersurface of the track, with the drive wheel and load being at opposite sides of the axis of i a pivot mounting of the chassis to the trolley body whereby the load carried by the chassis pivots the chassis in a sense to urge the drive wheel in an upwards direction.

3. A trolley according to claim 2, wherein the drive wheel is driven by an electric motor carried by the chassis at the same side of the pivot axis as the load carrier whereby the weight see of the motor and associated drive components will add to the load acting to urge the drive 20 wheel into driving engagement with the track.

4. A trolley according to any one of claims 1 to 3, further comprising means for optionally retaining the drive assembly in a non-driving configuration relative to the track to permit manual displacement of the trolley.

A trolley according to claim 4, wherein the retaining means is operable to releasably retain the chassis in a configuration in which the drive wheel is displaced from the track.

6. A trolley according to claim 5, wherein the retaining means comprises a locking S member releasably actuable to prevent pivotal movement of the chassis into a driving P:\OPER\RSH\PO8367.SPE 15/7/98 -8- configuration.

7. A drive assembly for a load carrying trolley of an overhead trolley system, said drive assembly comprising a chassis for mounting to the trolley, a powered drive wheel carried by the chassis, and means for carrying a suspended load such that application of a trolley load to said load carrying means displaces the chassis relative to the trolley in a sense to force the drive wheel into driving engagement with the track.

8. A trolley substantially as hereinbefore described with reference to the accompanying drawings. 0 0

9. A drive assembly substantially as hereinbefore described with reference to the *0 accompanying drawings. DATED this 15th day of July, 1998. BOMAC ENGINEERING PTY.LTD. By its Patent Attorneys: DAVIES COLLISON CAVE