WO2022189181A1

WO2022189181A1 - A lifting device for lifting a pallet and an excavator incorporating same

Info

Publication number: WO2022189181A1
Application number: PCT/EP2022/054943
Authority: WO
Inventors: James Russell
Original assignee: James Russell
Priority date: 2021-03-11
Filing date: 2022-02-28
Publication date: 2022-09-15
Also published as: EP4304973A1; GB202103387D0; GB2604638A; GB2604638B

Abstract

A lifting device for lifting a pallet comprising a mast upon which is mounted a load carrying means, such as a pair of tines, for supporting a load, wherein at least one ground engaging load bearing member is provided at a lower end of said mast to be moveable with respect to the mast between a raised position, wherein the load carrying means can adopt a loading position at or adjacent the ground, and a lowered position, wherein the ground engaging load bearing member engages the ground and supports the mast with the load carrying means at a load carrying position above the ground. Preferably the lifting device is adapted to be mounted on a dipper arm of an excavator to be parallel to or substantially parallel to the dipper arm.

Description

A lifting device for lifting a pallet and an Excavator incorporating same

Field of Invention

This invention relates to a lifting device for lifting a pallet wherein said lifting device can be fitted to a standard excavator, in particular to a back hoe, in order to use the excavator in the manner of a fork lift, and to an excavator incorporating same.

Background of Invention

The use of a variety of tool attachments for excavators such as buckets, rakes, thumbs, hammers etc. is known in the prior art. In particular it is known to provide a fork attachment in lieu of or attached a bucket of an excavator to enable the excavator to lift palletised objects (for example see GB 1,373,646). However, excavator manufacturers publish tables detailing the lift capacities of their excavators when using attachments mounted at the end of the dipper arm. A disadvantage of using an excavator in lift activities is that the attachment path is severely limited to an arc centred on the dipper hinge, and when the attachment is lifted it moves away from the machine, increasing the radius and decreasing the safe load that may exceed the recommended limits, increasing the risk of instability and overturning of the excavator.

It is therefore an object of the present invention to advance the technology for excavator arm attachments in order to make the swapping between excavator/lift activities more efficient, to increase the safe range of lift capacities for excavators and to introduce a new means of adapting an existing excavator to make it suitable for fork lift activities in a simple and cost effective manner.

Summary of Invention

According to a first aspect of the invention, there is provided a lifting device for lifting a pallet comprising a mast upon which is mounted a load carrying means for supporting a load, wherein at least one ground engaging load bearing member is provided at a lower end of said mast to be moveable with respect to the mast between a raised position, wherein the load carrying means can adopt a loading position at or adjacent the ground, and a lowered position, wherein the ground engaging load bearing member engages the ground and supports the mast with the load carrying means at a load carrying position above the ground.

In one embodiment the load carrying means may comprise a pairs of tines for supporting a pallet thereon.

In a preferred embodiment the ground engaging load bearing member is mounted on the mast via a carriage slideably coupled to the mast to permit movement of the ground engaging load bearing member between its raised and lowered positions. The carriage is preferably slideably mounted on guide tracks provided on the mast. In one embodiment the carriage is slideably mounted between opposed u-shaped guide tracks provided on the mast.

Preferably said at least one ground engaging load bearing member of the lifting device comprises at least one wheel. Said at least one wheel may have an axis of rotation extending transverse to the mast. In a preferred embodiment said at least one ground engaging load bearing member comprises a beam coupled to the carriage and extending transverse the to mast and having a respective ground engaging wheel mounted at or adjacent either end thereof. The beam may be coupled to the carriage via an articulated coupling permitting the beam to tilt with respect to a vertical axis of the mast to accommodate uneven ground. The articulated coupling may comprise a pivot having an axis extending perpendicular to the mast. Said pivot may be adapted to be above the centre of gravity of a load carried by the load carrying means for stability.

A drive means is preferably provided for moving the ground engaging load bearing member between its raised and lowered positions. The drive means may comprise a ram mounted on said mast. The ram may act between the mast and a carriage or slider slideably mounted on the mast and upon which the ground engaging load bearing member may be mounted. Preferably the mast is adapted to be releasably mounted on a dipper arm of an excavator in an upright orientation. The mast may be adapted to be mounted on a dipper arm of an excavator to be parallel to or substantially parallel to the dipper arm.

According to a further aspect of the present invention there is provided an excavator comprising a chassis having a boom mounted thereon and a dipper arm pivotally coupled to a distal end of said boom to which an implement, such as a bucket, may be attached, a lifting device in accordance with the first aspect of the invention being releasably mounted on the dipper arm of the excavator in an upright orientation.

The mast may be mounted on the dipper arm to be parallel to or substantially parallel to the dipper arm. A linkage may extend between a lower end of the mast of the lifting device and the chassis of the excavator. Preferably said linkage is adjustable in length. In one embodiment the linkage may comprise at least one single or double acting ram.

The mast may be releasably coupled to the dipper arm at an upper end thereof and to a quick hitch coupler mounted on the dipper arm at a lower end of the mast. The mast, at an upper end thereof, may be releasably coupled to a pivot pin providing pivotal connection between the boom and dipper arm.

Brief Description of Drawings

An embodiment of the present invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a front view of a lifting device in accordance with a first embodiment of the present invention;

Figures 2 is a side view of the lifting device of Figure 1 with the wheels in a raised position and the tines in a loading position at or adjacent the ground; Figure 3 is a side view of the lifting device of Figure 1 with the wheels in a lowered position and the tines at a load carrying position above the ground;

Figure 4 is an exploded view of the mast of the lifting device of Figure 1 ; and

Figure 5 is an exploded view of the carriage and axle assembly of the lifting device of Figure 1.

Detailed Description of Drawings

A lifting device 2 in accordance with an embodiment of the present invention, as illustrated in the drawings, is adapted to allow a standard excavator to be transformed into a fork lift in order to lift and move a palletised load. The term excavator is understood to cover a vehicle of item of construction equipment which comprises a chassis having a boom 4 mounted thereon and a dipper arm 6 pivotally coupled to a distal end of said boom 4, a quick coupler being provided at a distal end of the dipper arm 6 to which an implement, such as a bucket, may be attached. The boom 4 and dipper arm 6 may be articulated to operate the implement attached to the quick coupler via a series of double acting rams mounted to operate between the chassis and boom 4, between the boom 4 and dipper arm 6 and between the quick coupler and dipper arm 6, as is conventional in the art.

The lifting device 2 comprises a mast 10 which is designed to be releasably coupled to and supported on a front face of the dipper arm 6 of the excavator, such that the mast 10 is supported in an upright orientation on the excavator with the dipper arm 6 arranged as shown in Figures 2 and 3. An adjustable length linkage 12, preferably in the form of a single or double acting ram, extends rearwardly from a rear side of the mast 10 and is coupled to the chassis of the excavator to align and maintain the mast 10 in a vertical orientation. Flowever, said linkage 12 may be omitted.

As illustrated in Figures 2 and 3, the mast 10 may be coupled to the dipper arm 6 of the excavator at an upper end (or at other locations on the dipper arm 6) by means of hooks 14 engaged over laterally extending pins 16 provided on the dipper arm 6. These pins 16 may comprise part of a pivot pin providing pivotal coupling between the boom 4 and dipper arm 6. Latch members (not shown) may be provided for locking the pins 16 within the hooks 14. The mast 10 is coupled to the dipper arm adjacent its lower end via a suitable coupling device, such as a locking pin 18 extending through cooperating apertures in the mast 10 and dipper arm 6 or to a mounting means of a quick hitch coupling provided on a distal end of the dipper arm 6.

A pair of laterally extending tines or forks 20,22 extending from a lower end of the mast 10, perpendicular to the mast, for supporting a pallet thereon. The tines 20,22 may be detachably mounted in position on the mast 10 but, once mounted, are fixed in position with respect to the mast. Instead of tines it is envisaged that a lifting platform or any other load carrying means may be attached to the mast.

Ground engaging wheels 24 are mounted on a carriage 26 slideably mounted on a lower end of mast such that the wheels 24 may be moved between a raised position, shown in Figure 2, wherein the tines 20,22 can adopt a loading position at or adjacent the ground to allow the tines 20,22 to be slid under a palletised load, and a lowered position, shown in Figure 3, wherein the wheels 24 engage the ground and support the mast 10 with the tines 20,22 at a load carrying position above the ground.

Rollers 28 or similar couplings (not shown) may be provided on the carriage 26 engaged with channels 30 or similar cooperating means on the mast 10 to constrain the carriage 26 to movement between its raised and lowered positions on the mast 10.

In the embodiment shown in the drawings, and as best illustrated in Figures 4 and 5, the mast 10 incorporates opposing vertically arranged U shaped channels 30 between which are mounted the carriage 26, with the rollers 28 of the carriage 26 being guided for travel within said channels 30. As best shown in Figures 2 and 3, a ram 32 may be mounted on the mast 10 (or dipper arm 6) and may be coupled to the carriage 26 to move the carriage 26, and the wheels 24, between its raised and lowered positions on the mast 10.

The tines 20,22 are preferably arranged substantially parallel to the ground. Rough terrain forks need to be able to slide into a pallet on uneven ground, and thus the tines 20,22 may be mounted to permit upward displacement or tilting of the tines, as is known in the art.

In the embodiment shown in the drawings, the wheels 24 are mounted at either end of a beam 34 pivotally coupled to the carriage 26 via a pivot pin 36 extending horizontally and perpendicular to the mast 10 such that the beam 34 can tilt with respect to a vertical axis of the mast 10 to accommodate uneven ground while maintaining the mast 10 in a vertical orientation.

In the embodiment shown, the carriage 26 comprises a substantially vertically arranged guide portion extending between the channels 30 of the mast 10 and upon which the rollers 28 are mounted, and a horizontally extending support portion extending from an upper end of the guide portion and from which the beam 34 mounting the wheels 24 is suspended via the pivot pin 36. Preferably the pivot pin 36 is arranged at a position to be above the centre of gravity of a load carrying by the tines 20,22 so that the load is suspended below said pivot pin 36 for added stability.

In use, the lifting device 2 can be readily coupled to the dipper arm 6 of an excavator when it is desired to use the excavator to handle palletised loads. The linkage/ram 12 and boom 4 of the excavator can be initially manipulated to raise the dipper arm 6 and the attached lifting device 2, with the carriage 26 and wheels 24 in their raised position, such that the wheels 24 of the lifting device 2 are raised from the ground, permitting the excavator to be readily manoeuvred into position adjacent a palletised load to be handled.

Once in position, with the wheels 24 and carriage still in the raised position such that the tines 20,22 adopt their loading position at or adjacent the ground, the excavator can be advanced to bring the tines 21,22 into engagement with a pallet. Once in position, the ram 32 of the lifting device 2 can be extended to move the carriage 26 and wheels 24 to their extended position, such that the wheels 24 engage the ground and lift the mast 10, along with the tines 20,22 and pallet, along with the load provided thereon. During such operation, at least a portion of the weight of the load is transferred to the wheels 20,22 of the lifting device 2, and thereby the ground, such that the load is not wholly supported by the boom 4. This greatly increases the lifting capacity of the lifting device 2 compared to the use of the boom 4 and dipper arm 6 alone. The mast 10 is preferably maintained in an upright position and may be tilted forwardly or rearwardy with respect to a vertical axis through an angle of approximately 10° in order to tilt the tines for loading and to retain a load thereon.

The excavator can then be manoeuvred to carry the load to a desired location before the ram 32 operated to move the carriage 26 and wheels 24 to their raised position with respect to the mast 10 to move the tines back to their loading position and place the pallet carried thereon onto the ground or any other desired location.

The articulation of the beam 34 on the carriage 26 allows the excavator and lifting device 2 to traverse uneven ground without placing a twisting load on the carriage 26 or mast 10.

The invention is not limited to the embodiment described herein but can be amended or modified without departing from the scope of the present invention as defined by the appended claims.

Claims

1. A lifting device for lifting a pallet comprising a mast upon which is mounted a load carrying means for supporting a load at or adjacent a lower end of the mast, wherein at least one ground engaging load bearing member is provided at a lower end of said mast to be moveable with respect to the mast between a raised position, wherein the load carrying means can adopt a loading position at or adjacent the ground, and a lowered position, wherein the ground engaging load bearing member engages the ground and supports the mast with the load carrying means at a load carrying position above the ground.

2. A lifting device as claimed in claim 1, wherein said load carrying means comprises a pair of tines for supporting a pallet thereon.

3. A lifting device as claimed in claim 1 or claim 2, wherein said ground engaging load bearing member is mounted on the mast via a carriage slideably coupled to the mast to permit movement of the ground engaging load bearing member between its raised and lowered positions with respect to the mast.

4. A lifting device as claimed in claim 3, wherein said carriage is slideably mounted on guide tracks provided on the mast.

5. A lifting device as claimed in claim 4, wherein the carriage is slideably mounted between opposed u-shaped guide tracks provided on the mast.

6. A lifting device as claimed in any preceding claim, wherein said at least one ground engaging load bearing member of the lifting device comprises at least one wheel.

7. A lifting device as claimed in claim 6, wherein said at least one wheel has an axis of rotation extending transverse to the mast.

8. A lifting device as claimed in claim 7 when dependent upon claim 3, wherein said at least one ground engaging load bearing member comprises a beam coupled to the carriage and extending transverse the to mast and having a respective ground engaging wheel mounted at or adjacent either end thereof.

9. A lifting device as claimed in claim 8, wherein said beam is coupled to the carriage via an articulated coupling permitting the beam to tilt with respect to a vertical axis of the mast to accommodate uneven ground.

10. A lifting device as claimed in claim 9, wherein said articulated coupling comprises a pivot having an axis extending perpendicular to the mast.

11. A lifting device as claimed in any preceding claim, further comprising a drive means for moving the ground engaging load bearing member between its raised and lowered positions.

12. A lifting device as claimed in claim 11, wherein said drive means comprises a ram mounted on said mast.

13. A lifting device as claimed in claim 12 when dependent upon claim 3, wherein said ram acts between the mast and the carriage.

14. A lifting device as claimed in any preceding claim, wherein the mast is adapted to be releasably mounted on a dipper arm of an excavator in an upright orientation.

15. A lifting device as claimed in claim 14, wherein the mast is adapted to be mounted on a dipper arm of an excavator to be parallel to or substantially parallel to the dipper arm.

16. An excavator comprising a chassis having a boom mounted thereon and a dipper arm pivotally coupled to a distal end of said boom to which an implement, such as a bucket, may be attached, a lifting device in accordance with any preceding claim being releasably mounted on the dipper arm of the excavator in an upright orientation, in use.

17. An excavator as claimed in claim 16, wherein the mast is mounted on the dipper arm to be parallel to or substantially parallel to the dipper arm.

18. An excavator as claimed in claim 17, wherein a linkage extends between a lower end of the mast of the lifting device and the chassis of the excavator.

19. An excavator as claimed in claim 18, wherein said linkage is adjustable in length.

20. An excavator as claimed in claim 19 wherein said linkage comprises at least one single or double acting ram.

21. An excavator as claimed in any of claims 16 to 20, wherein said mast is releasably coupled to the dipper arm at an upper end thereof and to a quick hitch coupler mounted on the dipper arm at a lower end of the mast.

22. An excavator as claimed in claim 21, wherein said mast, at an upper end thereof, is releasably coupled to a pivot pin providing pivotal connection between the boom and dipper arm.