AU2006326884A1

AU2006326884A1 - Hand trolley

Info

Publication number: AU2006326884A1
Application number: AU2006326884A
Authority: AU
Inventors: Neville George Bailey; Troy Anthony Bailey
Original assignee: BAILEY CONCEPTS Pty Ltd
Current assignee: BAILEY CONCEPTS Pty Ltd
Priority date: 2005-12-20
Filing date: 2006-12-20
Publication date: 2007-06-28
Also published as: WO2007070950A1

Description

WO 2007/070950 PCT/AU2006/001942 1 HAND TROLLEY FIELD OF THE INVENTION THIS INVENTION relates to a hand trolley and in particular but not limited to a hand trolley of the type employing a platform, a tilt frame with handles 5 forming an L-shaped configuration and a single pair of wheels supporting the tilt frame. BACKGROUND TO THE INVENTION Hand trolleys or hand trucks as they are sometimes called are used to aid the movement of relatively small loads. They are most often used by couriers 10 or other small goods handlers and rely on the user being able to tilt a load using the trolley with the load positioned on the platform. The trolley and load are in an upright position and together are tilted to a transport position. The load may be placed on the platform as perhaps a number of cartons stacked one on top of the other or for heavier loads the platform is joggled from side to side to work 15 it under the load. Once the load is on the trolley the user applies weight to the ends of the handles and tilts the trolley so that the centre of gravity of the load moves over-centre relative to the fulcrum so that the load is raised and carried by the wheels. In the standard trolley the fulcrum is the wheel axle. In order to obtain a mechanical advantage various arrangements have been devised to 20 move the fulcrum so that less force is required to tilt the trolley. WO 1998/007951 to STORAY describes a hand trolley where a foot control is used to release the wheel axle which moves backward to move the fulcrum forward of the wheel axle so that less force is required to tilt the trolley. The trolley must first loaded and then the foot control is used to unlock the WO 2007/070950 PCT/AU2006/001942 2 wheels. As the trolley is tilted the wheels move rearward relative to the load, thereby shifting the fulcrum temporarily forward to the rear of the platform, the load is then engaged and the load and trolley is titled initially about the rear edge of the platform and then and then as the load goes over-centre the fulcrum 5 moves to the wheel axle. An over-centre linkage is used to ensure that the when the trolley is tilted the wheel axle does not move in the opposite direction when the trolley is say going down stairs or over bumps. When the trolley is righted to the upright position the wheels automatically return and are automatically locked. 10 DE 3629511 to STEINHANSES describes a hand trolley where a similar effect is achieved but by making the platform pivot relative to the rest of the trolley. The platform is normally at right angles to the handles. The platform is loaded and then a foot control is used to unlock the platform so that it may pivot about its rear edge so that the handles can pivot back until a stop is reached and 15 then the platform and load is tilted. As for the STORAY arrangement when the trolley is returned to the upright position the foot control is automatically locked. US patent 4,762,333 to MORTENSON describes a hand trolley where the wheels are mounted between side brackets which are in turn mounted to a frame and may pivot between forward and rearward positions using a foot force applied 20 to a pivot axle extending between side brackets. A pair of gas cylinders having pistons coupled to the side brackets and at their opposite ends to the frame above the wheels, the pistons being pivotally coupled to the respective side brackets and offset from the pivot axle so that the pistons move over-centre as the wheels move between the two positions. The offset of the pistons provides WO 2007/070950 PCT/AU2006/001942 3 a moment arm which in conjunction with the resistence of the cylinders holds the wheels in the selected position until foot pressure is applied. Thus there is no requirement for any mechanical latch. However, due to the parts inventory the trolley is relatively expensive. 5 US patents 1,201,957 and 1,341,171 both to HALL describe hand trolleys where the wheel axle moves in C-shaped guides between forward and rearward positions and may be locked in the forward position. US patent 2,243,915 to MUELLER describes a hand trolley which has a wheel assembly which facilitates movement up or down stairs. 10 US Patent 4,236,249 to SPRAGUE describes a hand trolley has a frame with forks specifically for munitions on a purpose built pallet, where a pair of wheels located above ground and a third wheel part way up the frame takes part of the load in a tri-wheel formation when the trolley is tilted. The forks have small wheels and curved undersides so that the forks may rock to tilt the frame back 15 onto the wheels. This type of trolley does not have general application and is relatively expensive. It is an object of the present invention to provide a trolley where the wheels move between forward and rearward positions similar to the prior art but which provides a simple, inexpensive yet effective alternative to the prior art. 20 OUTLINE OF THE INVENTION In one aspect there is provided a hand trolley having a wheel assembly and a frame supported by the wheel assembly, the wheel assembly and frame being so made and arranged that when the frame is located in an unloading position the wheels may adopt a raised position relative to the surface on which WO 2007/070950 PCT/AU2006/001942 4 the trolley is positioned and there being a latch to hold the wheel assembly in the raised position. Preferably, the wheels are coupled to the frame by a linkage assembly, the linkage assembly typically enables the wheel assembly to move to the raised 5 position where it is automatically latched in the raised position. Typically, the latch is a releasable locking means adapted to lock the wheel assembly in the raised position. Preferably, there is a second locking means adapted to lock the wheel assembly in a lowered position. 10 Preferably, the frame comprises a tilt frame moveable from an upright position to a tilted position and upon release of the locking means the wheel assembly moves to the raised position automatically upon the frame being tilted into a transport position. In this embodiment the wheels are maintained in ground contact such that the frame pivots relative to the wheels and 15 subsequently the wheels are automatically locked in a travel position which also corresponds to the raised position when the frame reverts to its upright position. Preferably, the hand trolley comprises a tilt frame assembly, a wheel assembly and a pivotal locking member. Preferably, the frame assembly comprises handles located at the end of 20 frame members which in conjunction with cross members and a middle member form a back support for a load stacked on a platform, the platform being an apertured tray having a rear upturned pivot support section and depending up from this are respective plates which, in conjunction with struts, brace the whole frame assembly, a locking bar extending across between the plates and there WO 2007/070950 PCT/AU2006/001942 5 is a pivoting locking member, the locking bar being used to lock the wheel assembly in its various positions utilising a pivoting locking member. Preferably, the wheel assembly comprises an axle journalled in a sleeve which has the link assembly comprising pivot links which pivot about respective 5 pivot pins. Preferably, the frame assembly includes respective stops which abut against the upper surfaces of the pivot links when the wheel assembly is in its raised position. Preferably, the locking means includes shoulders on opposite sides and 10 these automatically seat behind a locking bar to hold the wheel assembly in its raised position with the upper surfaces of the pivot links against the stops. Preferably, the locking means includes recesses which register with the locking bar to lock the wheel assembly in its lowered position. Preferably, the locking means has a foot pedal and pivots about a sleeve 15 extending across the frame assembly and co-axial with the wheel axle, the locking means being releasable from its engagement by an operator placing his foot on the foot pedal. Preferably, the trolley includes a pivot coupling connecting the wheel assembly pivotallyto the frame on opposite sides at respective horizontal pivots, 20 the wheel assembly having a wheel axle located in a sleeve, the sleeve being at or adjacent one end of the pivot coupling and rearward of the horizontal pivots to the frame, the pivot coupling being of a fixed radius and allowing the wheel axle to pivot through an arc, the locking means comprising a sliding means moveable between selected locking positions. Preferably, the locking means WO 2007/070950 PCT/AU2006/001942 6 comprises a sliding bar moving over a catch. Preferably, the sliding bar is pivotal about the wheel axle. Typically, the catch is a shoulder and it co-operates with a recess in the sliding means. The sliding means preferably has two recesses in series corresponding to the two positions. The sliding means preferably 5 comprises a pivoting means having an intermediate pivot and foot actuated catch release on one side of the pivot and spaced slots on the other side of the pivot, the slots being engageable with a catch to engage the locking means. BRIEF DESCRIPTION OF THE DRAWINGS In order that the present invention may be more readily understood and 10 be put into practical effect, reference will now be made to the accompanying drawings which illustrate one preferred embodiment of the invention and wherein: Figure 1 is an exploded view of a hand trolley according to the invention; Figure 2 is a front view of the assembled trolley; 15 Figures 3, 4 and 5 show the trolley in its three operative positions. METHOD OF PERFORMANCE Referring to the drawings and initially to Figure 1, there is illustrated, in exploded form, a hand trolley 10 comprising a tilt frame assembly 11, a wheel assembly 12 and a pivotal locking member 13. 20 The frame assembly comprises handles 14 and 15 located at the end of frame members 16 and 17 respectively which in conjunction with cross members 18 and 19 and middle member 20 form a back support for a load stacked on platform 21. The platform 21 is made up of an apertured tray 22 having rear upturned pivot support section 23 and 24 and depending up from this are WO 2007/070950 PCT/AU2006/001942 7 respective plates 25 and 26 which, in conjunction with struts 27 and 28, brace the whole frame assembly. A locking bar 29 extends across between the plates 25 and 26 and this locking bar is used to lock the wheel assembly 12 in its various positions utilising the pivoting locking member 13. This operation will 5 become clearer later in the description. The wheel assembly 12 comprises an axle journalled in a sleeve 30 which has welded thereto pivot links 31 and 32 which pivot about respective pivot pins 33 and 34. The frame assembly includes respective stops 35 and 36 which abut 10 against the upper surfaces 37 and 38 of the pivot links 31 and 32 when the wheel assembly 12 is in its raised position. The locking member 13 includes shoulders 39 and 40 on opposite sides and these automatically seat behind the locking bar 29 to hold the wheel assembly 12 in its raised position with the surfaces 37 and 38 against the stops 15 at 35 and 36. The locking member 13 also includes recesses 41 and 42 on the opposite side which register with the locking bar 29 to lock the wheel assembly in its lowered position. Since the locking member 13 pivots about the sleeve 30 which passes 20 through holes 43 and 44 the bar 29 may be released from its engagement with the shoulders 39 and 40 or the recesses 41 and 42 by an operator placing his foot on either of the foot pedals 45 or 46. In normal operation the wheels would be positioned and locked in the lowered position and an operator may then manually load items onto the WO 2007/070950 PCT/AU2006/001942 8 platform 21 or the tray may be pushed under a load which may be rocked back and supported by frame members 16, 17, 20 and the struts 18 and 19. While the wheels are locked in this position, that is the lowered position, the trolley may be operated in the usual way as a normal hand trolley and for light loads there 5 may be no reason to release the lock. In this case the bar 29 is locked in the recesses 41 and 42. A mechanical advantage arises by enabling the frame assemblyto initially tilt about the rear of the platform rather than about the wheel axles. Thus in the case of heavier loads by operating the foot pedal the wheels may be unlocked 10 and an operator take advantage of the mechanical advantage arising from the use of the pivot links 31 and 32. In this case while the wheels remain in contact with the ground the handles are tilted backward pivoting on surfaces 23 and 24 until such time as the surfaces 37 and 38 engage the stops 35 and 36 when the pivot reverts to the wheel axle. At the same time the shoulders 39 and 40 ride 15 over the locking bar 29 to lock the wheels in the raised position relative to the upright tilt frame. Once locked in the raised position with the frame assembly tilted the operator may operate the trolley in the usual fashion to take the load to its destination. Upon arrival at the destination, the operator has two options; 20 unlock the wheels as the trolley is being moved to the upright position in which case when the trolley reaches the upright position the wheels will automatically lock in the lower position, or, alternatively, not unlock the wheels and as the trolley is raised to the upright position the wheels will remain in the raised position away from the floor. Thus the platform may be rocked from side to side WO 2007/070950 PCT/AU2006/001942 9 and the load removed and the trolley extracted from the load without the wheels being in contact with the floor. This sequence as described is illustrated in Figures 3 to 5 where the trolley is illustrated in its various positions shown in cutaway along line A-A of 5 Figure 2. Figure 3 illustrates the trolley with the wheels in the lowered position and locked in that position. Figure 4 illustrates the wheels in the raised position and locked in that position and Figure 5 illustrates the trolley being returned to the upright position of Figure 3 and the wheels being retained in the raised position. 10 It will be appreciated in relation to Figures 3 and 4 that the wheels remain in contact with the ground and the raised position is in fact the position of Figure 4 but is relative to the trolley frame in the upright position as illustrated in Figures 3 and 5. Once the load has been removed from the trolley in Figure 5, all the operator need do is operate the foot pedals to lift the locking member and then 15 the weight of the wheel assembly will cause the locking memberto slide over the bar 29 and the bar 29 will then slip into and be caught in the recesses 41 and 42 thereby returning the hand trolley to the position of Figure 3. Whilst the above has been given by way of illustrative example of the present invention many variations and modifications thereto will be apparent to 20 those skilled in the art without departing from the broad ambit and scope of the invention as set out in the appended claims.

Claims

1. A hand trolley having a wheel assembly and a frame supported by the wheel assembly, the wheel assembly and frame being so made and arranged that when the frame is located in an unloading position the wheels may adopt a 5 raised position relative to the surface on which the trolley is positioned and there being a latch to hold the wheel assembly in the raised position.

2. A hand trolley according to claim 1 wherein, the wheels are coupled to the frame by a linkage assembly, the linkage assembly enables the wheel assembly to move to the raised position where it is automatically latched in the raised 10 position.

3. A hand trolley according to claim 1 wherein the latch is engaged by a releasable locking means adapted to lock the wheel assembly in the raised position.

4. A hand trolley according to claim 1 wherein there is a second locking 15 means adapted to lock the wheel assembly in a lowered position.

5. A hand trolley according to claim 1 wherein there is a second locking means adapted to lock the wheel assembly in a lowered position, the frame comprises a tilt frame moveable from an upright position to a tilted position and upon release of the second locking means the wheel assembly moves to the 20 raised position automatically upon the frame being tilted into a transport position.

6. A hand trolley according to claim 1 wherein a pivotal locking member is adapted to engage the latch.

7. A hand trolley according to claim 1 wherein the frame assembly comprises handles located at the end of frame members which in conjunction WO 2007/070950 PCT/AU2006/001942 11 with cross members and a middle member form a back support for a load stacked on a platform, the platform being a tray having a rear upturned pivot support section and depending up from this are respective plates which, in conjunction with struts, brace the whole frame assembly, a locking bar extending 5 across between the plates and there is a pivoting locking member, the locking bar being used to lock the wheel assembly in its various positions utilising the pivoting locking member such that the latch comprises the engagement of the locking member and bar.

8. A hand trolley according to claim 1 wherein the wheel' assembly 10 comprises an axle journalled in a sleeve which has a link assembly comprising pivot links which pivot about respective pivot pins forward of the wheels.

9. A hand trolley according to claim 1 wherein the wheel assembly comprises an axle journalled in a sleeve which has a link assembly comprising pivot links which pivot about respective pivot pins, the frame assembly having 15 respective stops which abut against upper surfaces of the pivot links when the wheel assembly is in its raised position and latched.

10. A hand trolley according to claim 1 wherein the latch is engaged by locking means, and the locking means includes shoulders on opposite sides and these automatically seat behind a locking bar to hold the wheel assembly in its 20 raised position.

11. A hand trolley according to claim 1 wherein the latch is engaged by locking means, and the locking means includes recesses which register with a locking bar to lock the wheel assembly in its lowered position. WO 2007/070950 PCT/AU2006/001942 12

12. A hand trolley according to claim 1 wherein the latch is engaged by locking means, and the locking means has a foot pedal and pivots about a sleeve extending across the frame assembly and co-axial with the wheel axle, the locking means being operable to release the latch by an operator placing his 5 foot on the foot pedal.

13. A hand trolley according to claim 1 wherein the trolley includes a pivot coupling connecting the wheel assembly pivotally to the frame on opposite sides at respective horizontal pivots, the wheel assembly having a wheel axle located in a sleeve, the sleeve being at or adjacent one end of the pivot coupling and 10 rearward of the horizontal pivots to the frame, the pivot coupling being of a fixed radius and allowing the wheel axle to pivot through an arc, the latch being engaged by locking means, the locking means comprising a sliding means moveable between selected locking positions.

14. A hand trolley according to claim 1 wherein the latch is engaged by 15 locking means, and the locking means comprises a sliding bar moving over a catch.

15. A hand trolley according to claim 1 wherein the latch is engaged by locking means, and the locking means comprises a sliding bar moving over a catch and the sliding bar is pivotal about the wheel axle. 20

16. A hand trolley according to claim 1 wherein the latch is engaged by locking means, and the locking means comprises a sliding bar moving over a catch and the sliding bar is pivotal about the wheel axle and the catch is a shoulder and it co-operates with a recess in the sliding means. WO 2007/070950 PCT/AU2006/001942 13

17. A hand trolley according to claim 1 wherein the latch is engaged by locking means, and the locking means comprises a sliding bar moving over a catch and the sliding bar is pivotal about the wheel axle and the catch is a shoulder and it co-operates with a recess in the sliding means and the sliding 5 means has two recesses in series corresponding to the two positions of the wheels.

18. A hand trolley according to claim 1 wherein the wherein the latch is engaged by locking means, and the locking means comprises a sliding means moving over a catch, the sliding means comprises a pivoting means having an 10 intermediate pivot and foot actuated catch release on one side of the pivot and spaced recesses on the other side of the pivot, the slots being engageable with a catch to engage the locking means.