GB2203115A

GB2203115A - Load moving trolley

Info

Publication number: GB2203115A
Application number: GB08708057A
Authority: GB
Inventors: Raymond Percy Haddock
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-04-03
Filing date: 1987-04-03
Publication date: 1988-10-12
Also published as: GB8708057D0

Abstract

A trolley for use in lifting an object, e.g. a pool table, comprises a frame 12, having supporting wheels 14 and a set of lifting members or plates 16 arrayed around the frame and pivotally attached thereto. A lip on each of the lifting members 16 is arranged to engage an object to be lifted, e.g. the table leg, and a lever mechanism 22 causes the lifting members to pivot, thereby lifting the object. The supporting wheels 14 are mounted under each of the plates 16. <IMAGE>

Description

Lifting Trolley The present invention relates to trolleys for use in lifting articles. The invention relates in particular, but not exclusively, to trolleys for use in lifting pool tables and the like.

Pool tables are very heavy items which must be stably located during use. Castors or wheels are therefore not normally provided on the table legs. The lack of wheels and the great weight combine to make pool tables very difficult to move. As many as three or four strong men may be required to move a table, without mechanical assistance.

A wheeled trolley for use in moving pool tables has previously been proposed. This would be rolled into position beneath the table. Operating mechanisms on either side of the table are then used to raise the table from the floor. The table may then be rolled away. This arrangement is convenient when access to both sides of the table is available. However, if the table is rolled away for storage, for instance against a wall, it may become impossible or very inconvenient to operate one or both of the lifting mechanisms to lower the table. The table may therefore need to be stored on the trolley, in the raised position. The trolley cannot then be used on another table.

Furthermore, the table can still be rolled, and may therefore be unsafely stored. This type of trolley has been found to be unduly heavy and difficult to transport.

The present invention seeks to obviate or mitigate these or other disadvantages of the prior art.

The present invention provides a trolley for use in lifting articles and comprising a frame, supporting wheels, and a plurality of lifting members arrayed around the periphery of the frame and pivotally attached thereto, the lifting members being arranged to engage an object to be lifted and to lift the object by pivoting on the frame.

Preferably at least some of the lifting members carry supporting wheels. The lifting members may comprise plates pivotable about a generally horizontal axis, whereby the upper plate surfaces may engage downwardly facing surfaces of an article to be lifted.

Preferably a control mechanism is provided which co-operates between the frame and one or more lifting members and is operable to cause the lifting members to pivot with respect to the frame. The control mechanism is preferably operable remotely of the frame. The mechanism preferably comprises a lever pivotally mounted on one of the frame or a lifting member and bearing on the other, and pivotable to cause pivotal movement of the lifting member with respect to the frame. Preferably the lever is pivotable on the frame.

Preferably a rigid member extends between at least two lifting members and the lever of the control mechanism bears on the rigid member. Preferably the lever carries a roller which bears on a bearing surface on the rigid member. The lever may have a foot pad for use during operation.

Preferably the control mechanism further comprises a releasable latch means operable to lock the lifting members in their lifting position. The latch means may act between the lever and the rigid member. The latch means may comprise a latching hook and a co-operating latching bar. Preferably the hook is resiliently biased to its latching position and is manually movable out of its latching position against the resilient bias, to release the latch. The foot pad may be pivotally mounted on the lever and a connecting bar may connect the latch hook and foot pad, the foot pad having first and second positions corresponding to the latching and released positions of the hook.Preferably the outer surface of the hook forms a lead surface shaped to bear on the latching bar to move the hook out of its latching position as the hook approaches the bar while an object is being lifted, the hook moving back to its latching position under the influence of the resilient bias when the lead surface is clear of the latching bar, whereby the bar becomes located within the curve of the hook, and the latch is engaged.

Preferably the frame comprises an extensible frame member, whereby the size of the frame and the relative positions of lifting members may be changed.

Preferably the extensible frame member comprises first and second longitudinally aligned sleeves, a bar located partially within both sleeves, and releasable means operable to press the bar against the sleeves to retain the relative positions of the sleeves and bar.

The releasable means may comprise a second bar located partially within both sleeves, and wedge members mounted on the sleeves and movable between the bars to wedge the bars apart and against the sleeves. The wedge members may extend through the sleeve walls and be attached thereto by means of a screw thread, the wedge members being rotatable from outside the sleeves, to wedge or release the bars.

In another aspect of the invention, there is provided a trolley for use in lifting articles and comprising a frame, supporting wheels mounted on axles which are pivotally attached to the frame, and a control mechanism operable to cause the axles to pivot on the frame to lift or lower an article supported by the trolley.

The trolley may further comprise lifting members arranged to engage an object to be lifted and to pivot on the frame with corresponding axles, to lift the object. The lifting members may be pivotally attached to the frame, the axles being mounted on the lifting members. Alternatively, the frame may engage an article to be lifted.

The lifting members may comprise plates as defined above, and the trolley may comprise a control mechanism as defined above and operable to cause the axle to pivot. The mechanism may act between the frame and the axles or between the frame and the lifting members.

The frame may comprise an extensible member as defined above.

One embodiment of a trolley according to the present invention and some possible variations to it will now be described in more detail, by way of example only, and with reference to the accompanying drawings, in which: Fig. 1 is a plan view of the trolley, showing a first design for the operating levers; Fig. 2 is a partial elevation along the line 2-2 in Fig. 1; Fig. 3 is a partial elevation along the line 3-3 of Fig. 1, and showing an alternative design of operating lever; Fig. 4 is a plan view of the portion of the trolley shown in Fig. 3.

Turning to the figures, there is shown a trolley 10 for use in lifting articles, and comprising a frame 12, supporting wheels 14, and a plurality of lifting members 16 arrayed around the periphery of the frame 12 and pivotally attached thereto. The lifting members 16 are arranged to engage an object to be lifted and to lift the object by pivoting on the frame 12.

In more detail, the frame 12 is generally H-shaped and comprises two end bars 18 connected by a cross bar 20. A lifting member 16 and supporting wheel 14 is located at each end of each end bar 18. A foot-operated lever 22 is mounted on the cross bar 20 adjacent each end bar 18 and forms part of a control mechanism to be described, which operates the lifting members 16 on the corresponding end bar 18, when an article is to be lifted or lowered.

The arrangement of the lifting members 16 and wheels 14 is shown more clearly in Fig. 2. Each wheel 14, which may be a castor wheel, mounted on an axle which is, in turn, mounted on the corresponding lifting member 16. The lifting member 16 is in the form of a square or rectangular plate. Near one edge, the plate 14 is pivotally mounted on the end bar 18 by means of a hinge 24. The main body of the plate 14, to the right of the hinge 24 as seen in Fig. 2, forms part of the operating mechanism by which the plate 16 is caused to pivot with respect to the end bar 18. The remainder of plate 16, which projects to the left of the hinge 24 as seen in Fig 2, forms a lip 16A which can engage under a suitable surface of an article to be lifted. For instance, the lip 16A may engage under the downwardly facing rim which is commonly found on pool table legs, a few inches above the ground.

In Fig. 2, the lip 16A is shown beneath an article 26. Fig. 2 also shows the position of the wheel 14, lip 16A and article 26 after the plate 16 has pivoted about the hinge 24. In each case, the alternative position is indicated by the corresponding reference numeral, supplemented by an apostrophe, and the integer is shown in broken lines.

The control mechanism for pivoting the plate 16 will now be described with particular reference to Figs. 3 and 4.

The axle of each wheel 14 is attached to the plate 16 by nut and bolt assemblies 28, which are shielded by downturned flanges 30 at the edges of the plate 16. A rigid bar 32 is attached, e.g. by welding, to the lower edges of the flanges 30. The bar extends across the trolley and is connected at its other end, in like manner, to down-turned flanges on the plate which forms the lifting member 16 at the other end of the same end bar 18. The connecting bar 32 therefore causes the two plates 16 to pivot together about their respective hinges (whose hinge axes are aligned). Strengthening ribs 34A and 348 are provided in the middle region of the bar 32. The upper surface 36 of the rib 34A forms a bearing surface. At the lower end of the bearing surface 36, a latching bar 38 is mounted above the bar 32 on mounting pillars 40.The pillars 40 and latch bar 38 form a closed eye above the bar 32.

The foot lever 22 is pivotally attached at one end 42 to the cross bar 20, by means of a bracket 43. Near this end 42, two lugs 44 form a mounting for a roller 46. Only one lug 44 can be seen in Fig. 3. The roller 46 is located so that it may bear on the surface 36 and roll along the surface 36 as the lever 22 pivots on the cross bar 20.

A hook 48 is pivotally mounted on the lever 22, further along the lever, at a position where it may engage and hook onto the latching bar 38 mounted on the bar 32. The position of the hook 48 about its pivot axis 49 is biased by an extension spring 50 which urges the lower end of the hook 48 to rotate towards the pivotally-mounted end of the lever 22.

At the free end of the lever 22, a foot pad 52 is pivotally mounted on the lever 22. The lever 22 is of sufficient length to allow the foot pad 52 to be engaged by the foot of a user, when the trolley 10 is located beneath a pool table which is to be lifted. A connecting rod 54 connects the foot pad 52 and hook 48, so that rotation of the foot pad 52 can cause the hook 48 to rotate, thereby engaging or disengaging the latching bar 38. The biasing of the spring 50 is augmented by a compression spring 56 which acts between a surface within the lever 22 and a collar carried on the connecting rod 54. Consequently, the hook is held in the position shown in Fig. 3 unless the bias of the springs 50,56 is overcome to force the hook 48 to rotate and disengage from the latching bar 38.

The cross bar 20 has been described as extensible.

The cross bar comprises two hollow, rectangular section sleeves which are longitudinally aligned and attached to respective ones of the end bars 18. Upper and lower inserted bars 58 are located partially within each sleeve, so as to bridge any gap between the sleeves, thereby forming a continuous structural member extending between the end bars 18. The length of the cross bar 20 is a set length according to the desired relative positions of the lifting members 16. The cross bar 20 can be locked to a chosen length by operation of wedging devices 60 (Fig. 1). These comprise lengths of threaded circular bar mounted by means of their threads to extend through the walls of the sleeves 20. The outer ends of these devices are turned over to form handles by which the devices may be rotated. The ends of the devices within the cross bar 20 penetrate the space 62 between the inserted bars.The penetrating ends have a tapering cross section and the depth of their penetration into the space 62 can be changed by rotation of the devices 60. As the devices 60 are rotated to drive the penetrating ends into the space 62, the inserted bars 58 are wedged apart and into increasingly strong frictional engagement with the inner walls of the sleeves of the cross bar 20. This friction is used to lock the sleeves in a relative position, and therefore to set the length of the cross bar 20. Conversely, the inserted bars 58 can be released by counter-rotation of the wedging devices 60, thereby withdrawing the penetrating ends from the space 62. This allows the cross bar to be reset to a different length.

The lifting mechanism associated with only one of the end bars 18 has been described above. The mechanism associated with the other end bar is constructed according to identical principles, but so that both foot pads 52 are located on the same side of the trolley 10. The levers 22 shown in Figs. 3 and 4 are straight, whereas those shown in Fig. 1 are not, so that the foot pads 52 are brought out to a convenient operating position away from the lifting members 16, and away from the legs of a pool table being lifted.

The particular shape of the lever can be chosen according to the circumstances in which a trolley is to be used, so as to be most convenient for that use.

The trolley 10 is used to lift a pool table in the following manner. The hooks 48 on each lever are disengaged from their corresponding latching bars 38 by operation of the foot pads 52. This allows the foot pad to rise and as it does so, the roller 46 rolls along the bearing surface 36 which is, in turn, allowed to rise. As the bearing surface 36 and bar 32 rise, the plate 16 pivots on the end bar 18 so that the lip 16A drops. The end bar 18 will also drop as the plate 16 pivots, as can be seen from the two wheel positions indicated in Fig. 2. It is expected that the mechanism can be constructed to allow these actions to take place under the influence of gravity, but appropriately acting spring bias may be provided to assist, if necessary.

After releasing the hooks 48, the trolley 10 is rolled under the pool table so that the lip 16A of each plate 16 is below a suitable surface on a corresponding leg of the pool table, by which the table may safely be lifted. In order to position the lip 16A in this manner, the length of the cross bar 20 may need to be adjusted. This can be done while the trolley is under the table, or before it is rolled under the table, if more convenient.

Once the trolley is correctly positioned under the table, the levers are lowered in turn, by pressing on the corresponding foot pads 52. As the levers 22 lower, the roller 46 bears on the bearing surface 36. This forces the bar 32 to move down and so pivots the plate 16 on the end bar 18. This in turn raises the lip 16A until it bears on the corresponding surface of the pool table, and eventually, lifts that leg of the table. The end bar 18 will also rise during this pivotting. As the hook 48 approaches the latching bar 38, the outer surface of the hook acts as a guide surface which deflects the hook against the action of the spring 50, to allow the hook to move around the latching bar 38.

Eventually, the lead surface moves free of the latching bar 38 and the hook moves back under the influence of the spring 50 to hook onto the latching bar 38 which is then positioned within the curve of the hook. Once the hook has engaged the latching bar 38, the lever 22, bar 32 and lip 16A are locked in position, with the lip 16A supporting the corresponding table leg clear of the floor. The user's foot may be removed from the foot pad 52. Once both levers 22 have been operated in this manner, the four legs of the table will be clear of the floor and the table can be rolled away on the wheels 14.

Once the table has been moved to its new position, it can be lowered onto the floor by reversing the lifting process described above. In particular, the user operates the foot pad 52 in order to disengage the hook 48 from the latching bar 38. He can then gently release the lever 22, allowing it to rise slowly and so allow the bar 32 to rise and the lip 16A and the corresponding table leg to descend to the floor. The mechanical advantage provided by the length of the lever 22 allows a relatively small force to be used to control the considerable weight of the pool table. Once both levers have been released, all four legs of the pool table will be resting safely on the floor and the trolley may be rolled out from beneath the table and used again on another table.

Alternatively, lifting may make use of the movement of the frame, especially the end bars 18, as the plates 16 pivot. That is, the article to be lifted may be engaged by the top surface of the end bars 18 and lifted by the upward movement of the end bars 18 as the foot pads 52 are depressed. If it is envisaged that the trolley will only be used to lift in this manner, the plates 16 can be formed without a lip 16A for engaging an article. In this arrangement, the plates 16 would merely serve the function of allowing the wheel axles to pivot on the frame.

It will be understood from the above that the arrangement of the levers 22 is such as to require access to only one side of the pool table. The table may therefore be moved up against a wall or into an alcove and then lowered onto the floor, while still allowing the trolley to be removed and reused, and the table to be safely stored resting on the floor.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A trolley for use in lifting articles and comprising a frame, supporting wheels, and a plurality of lifting members arrayed around the periphery of the frame and pivotally attached thereto, the lifting members being arranged t6 engage an object to be lifted and to lift the object by pivoting on the frame.

2. A trolley according to claim 1, wherein at least some of the lifting members carry supporting wheels.

3. A trolley according to claim 1 or 2, wherein the lifting members may comprise plates pivotable about a generally horizontal axis, whereby the upper plate surfaces may engage downwardly facing surfaces of an article to be lifted.

4. A trolley for use in lifting articles and comprising a frame, supporting wheels mounted on axles which are pivotally attached to the frame, and a control mechanism operable to cause the axles to pivot on the frame to lift or lower an article supported by the trolley.

5. A trolley according to claim 4, further comprising lifting members arranged to engage an object to be lifted and to pivot on the frame with corresponding axles, to lift the object.

6. A trolley according to claim 5, wherein the lifting members are pivotally attached to the frame, the axles being mounted on the lifting members.

7. A trolley according to claim 4, wherein the frame engages an article to be lifted.

8. A trolley according to any of the preceding claims, wherein a control mechanism is provided which co-operates between the frame and one or more lifting members or axles and is operable to cause the pivotally attached members to pivot with respect to the frame.

9. A trolley according to claim 8, wherein the mechanism comprises a lever pivotally mounted on one of the frame or a lifting member and bearing on the other, and pivotable to cause pivotal movement of the lifting member with respect to the frame.

10. A trolley according to claim 9, wherein a rigid member extends between at least two lifting members and the lever of the control mechanism bears on the rigid member.

11. A trolley according to claim 8, 9 or 10, wherein the control mechanism further comprises a releasable latch means operable to lock the lifting members in their lifting position.

12. A trolley according to claim 11, comprising a foot pad pivotally mounted on the lever and a connecting bar connecting the footpad and the latch means, the foot pad having first and second positions corresponding to the latching and released positions of the latch means.

13. A trolley according to any of the preceding claims, wherein the frame comprises an extensible frame member, whereby the size of the frame and the relative positions of lifting members may be changed, the extensible frame member comprising first and second longitudinally aligned sleeves, a bar located partially within both sleeves, and releasable means operable to press the bar against the sleeves to retain the relative positions of the sleeves and bar.

14. A trolley according to claim 13, wherein the releasable means comprise a second bar located partially within both sleeves, and wedge members mounted on the sleeves and movable between the bars to wedge the bars apart and against the sleeves.

15. A- trolley according to claim 14, wherein the wedge members extend through the sleeve walls and are attached thereto by means of a screw thread, the wedge members being rotatable from outside the sleeves, to wedge or release the bars.

16. A trolley substantially as described above with reference to the accompanying drawings.

17. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.