WO2007030884A1

WO2007030884A1 - Mobile goods elevator

Info

Publication number: WO2007030884A1
Application number: PCT/AU2006/001351
Authority: WO
Inventors: Terence George Valentine Morgan
Original assignee: Workright Safety Solutions Pty. Ltd.
Priority date: 2005-09-14
Filing date: 2006-09-14
Publication date: 2007-03-22

Abstract

A goods transfer trolley for loads from 20-120kg has a frame (2, 4, 6) with a rise and fall carriage (34) and tension springs (74) which resist the fall of the carriage under load. The springs act on a slider (58) which is connected to the carriage (34) by a line and pulleys in order to derive large carriage movement from small spring extension. The pulleys increase the velocity ratio. The carriage presents loads at a uniform take off and load height. A variant without wheels is used as a workstation on a production line (78), raising loads (76) to a uniform take off height.

Description

MOBILE GOODS ELEVATOR

FIELD OF THE INVENTION

This invention concerns devices for loading and unloading items of similar weight such as cartons of goods. The invention will be described with reference to the carriage of goods during delivery, for example the replenishment of supermarket shelves and vending machines.

BACKGROUND OF THE INVENTION

When trucks call at business premises the driver takes goods from the truck and deposits them on an upright trolley in a vertical stack. They are wheeled as a stack to the unloading point and the driver lifts them one by one from the trolley to a shelf, a fresh stack or another trolley. This entails repetitive lifting for the driver or operator. The transport industry is already burdened with absences from work and claims arising from back injury.

In a factory setting a similar problem arises. The production line may require a flow of castings delivered at the start of the production line. It is common to have to lift product from a stack or stillage on to a work surface to keep the line flowing. Known spring assisted platforms in industry utilise a scissor linkage beneath the platform which compresses pairs of coil springs. The linkage imposes limited movement on the load.

SUMMARY OF THE INVENTION

One apparatus aspect of the invention provides a goods transfer trolley of the type having an upright frame, a single pair of wheels, handles for inclining the frame to balance a load on the wheels, wherein the frame supports a rise and fall carriage with supporting surface, resilient means to resist the fall of the carriage and bring it to an elevated START position, the carriage and the resilient means being mutually connected by a line and pulley system.

Another aspect of the invention provides an elevator for a workstation comprising an upright frame, a rise and fall carriage supported by the frame, a support surface for accommodating components required at the workstation, resilient means for resisting the fall of the carriage under load and bringing it to an elevated START position, the carriage and resilient means being mutually connected by a line and pulley system.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention is now described with reference to the accompanying drawings, in which: Figure 1 is a front view.

Figure 2 is a side perspective view.

Figure 3 is a diagram of the cord path between the components.

Figure 4 is a section through a fragment of the frame and attached components.

Figures 5a-d show the loading sequence for a factory workstation.

Figures 6a-c show the unloading sequence for the workstation of Figure 5.

DETAILED DESCRIPTION WITH RESPECT TO THE DRAWINGS

Referring now to the drawings, the trolley has a rectangular (400 x 1200mm) metal frame made of parallel square tubular stiles 2 connected by a welded top rail 4 and a welded anchor rail 6. The stiles are strengthened by triangulation tubes 8 to which an axle 10 is welded. Rubber tyred wheels 12 (200mm diameter) secured by R-pins 12 outside the sheet metal base 14. Base 14 allows the trolley to stand upright. Handles 16 enable the operator to tilt the trolley and wheel it about. Pulley mounts 18 depend from the top rail and support top pulley 20 and cord pin 22.

A C-section runner 24, 1200mm long, is screwed to the front of each stile 2 with the runner slot 26 directed forwardly. The runners house an upper pair of bogies 28 and a lower pair of bogies 30. Each bogey has four identical 27mm diameter nylon wheels. The bogies are held by pins 32 projecting through the slots 26 into the rise and fall carriage 34. Carriage 34 consists of a pair of upright metal angles 36 connected by an upper rail 38 and a lower rail 40. Lower rail 40 has mounts for a middle cord pin 42. A detachable cradle 44 of U-shape supports horizontal wooden goods tray 46. Cradle 44 is fixed to upright flat bars 48 which sit on lower rail 40 just inside the angles 36. A cut out 50 allows the bars to sit behind upper rail 38. A pair of metal strip skids 52 extend from top rail 4 to base 14. These pass in front of the angles and the carriage rails so that the carriage is free to rise and fall but the cradle 44, bars 48 and tray 46 remain free to be exchanged for a tray size which suits the load. As the trolley tilts rearwardly at the start of its journey, the load contacts the skids.

Paint tins may require a larger base than, for example, bottles of bleach. The rise of the carriage is adjusted by stops 54 which block the travel of the bogies. The stops have wing nut adjustment.

A metal channel 56, 500mm long, is secured by screws to the inner face of each stile so that the channels face each other and extend to the base plate 14.

A tethered D-shaped slider 58 has an upper rail 60 and a lower rail 62 joining legs 64 which project into the channels. Bottom pulley mounts 66 extend between the upper and lower rails 60, 62 and support lower pulley 68. The lower rail 62 has a row of five shackles 70. Anchor rail 6 has a corresponding row of five shackles 72. The outer pairs of shackles hold two tension springs 74, 300mm long, which keep the slider 58 close to the base. The springs resist the rise of slider 58 but double in length under load.

Cord 76 extends from top cord pin 22 around lower pulley 68, then around pulley 20 to cord pin 42 on the carriage. The pulleys each incorporate a ball bearing. The mechanism relies upon low friction for its efficiency. Consequently the slider 58 must slide smoothly in the channels 56. Arranging springs in pairs symmetrically about pulley 4 ensures the force is applied equally without tending to tilt the slider in the channels. Arrangement of the line path to keep it in the same plane as it changes direction assists in reducing friction. A central groove in each pulley helps to control the line path. Likewise the runners 24 must be parallel and in the same plane so that the carriage motion as allowed by the bogies 28 is precise. Such accuracy is conferred by the support frame and the connections of the runners and channels 56 to the stiles of the frame. Polishing the front faces of the skids 52 also assists.

The cord length is shortened to pretension springs 74. This raises the carriage to abut the stops 54. This START position is adjusted to suit the operator but will be 800-900mm above the base 14.

In a variant, the tension springs are substituted by a single gas strut or preferably a pair of gas struts. The useful range in the trolley embodiment is 20- 120kg.

In another variant, sets of triple wheels are fitted to the trolley version permitting stair climbing.

The load sequence for a factory workstation is shown in Figures 5a-5d. The first, second and third components 76 extend the springs progressively such that the top of the last component finishes level with the top of the skids 52. The unloading sequence is shown in Figures 6a-6c. The components pass along the worksurface 78.

We have found the advantages of the above embodiments to be:

1. When the components are removed one by one, they rise to the preferred height at each transfer.

2. Much more lifting can be done with a straight back than was formerly possible.

3. Multiplication of spring force in a compact machine.

It is to be understood that the word "comprising" as used throughout the specification is to be interpreted in its inclusive form, ie. use of the word "comprising" does not exclude the addition of other elements.

It is to be understood that various modifications of and/or additions to the invention can be made without departing from the basic nature of the invention. These modifications and/or additions are therefore considered to fall within the scope of the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A goods transfer trolley of the type having an upright frame, a pair of wheels, handle means for inclining the frame to balance a load on wheels, wherein the frame supports a rise and fall carriage with a support surface, resilient means to resist the fall of the carriage under load and to bring the carriage to an elevated START position, the carriage and the resilient means being mutually connected by a line and pulley system.

2. A goods transfer trolley as claimed in Claim 1, wherein the resilient means is a slide supported by the frame with one or more tension springs which resist load fall.

3. A goods transfer trolley as claimed in Claim 2, wherein the resilient means exerts force which is adjustable by the addition or subtraction of tension springs.

4. A goods transfer trolley as claimed in Claim 1, wherein the resilient means is a gas strut.

5. A goods transfer trolley as claimed in any one of Claims 1 -4, wherein the frame supports a pair of parallel upright rails and the carriage has bogies which engage the rails.

6. A goods transfer trolley as claimed in any one of Claims 1 -5, wherein the support surface is borne by the carriage and is of exchangeable area.

7. A goods transfer trolley as claimed in Claim 5, wherein the rails have adjustable stops for selecting the START height of the support surface.

8. A goods transfer trolley as claimed in any one of Claims 1 -7, wherein the frame supports one or more upright skids against which the load bears during rise and fall.

9. A goods transfer trolley as claimed in any one of Claims 1 -8, wherein each pulley has a ball bearing.

10. An elevator for a workstation comprising an upright frame, a rise and fall carriage supported by the frame, a support surface associated with the carriage for accommodating components required at the workstation, resilient means for resisting the fall of the carriage under load and bringing the carriage to an elevated START position, the carriage and resilient means being mutually connected by a line and pulley system.

11. A goods transfer trolley substantially as herein described with reference to Figures 1-4.

12. A workstation substantially as herein described with reference to and as illustrated in Figures 5 and 6.