GB2403204A

GB2403204A - Tail lift with ramp portion

Info

Publication number: GB2403204A
Application number: GB0314919A
Authority: GB
Inventors: Ronald Goodall
Original assignee: RAY SMITH GROUP PLC
Current assignee: RAY SMITH GROUP PLC
Priority date: 2003-06-26
Filing date: 2003-06-26
Publication date: 2004-12-29
Anticipated expiration: 2023-06-26
Also published as: GB2403204B; GB0314919D0

Abstract

A tail lift 10 comprising a tail board 12 and an arrangement 16 for raising and lowering the tail board by moving the tail board from its initial vertical position at the rear of the vehicle body into a horizontal position and then in substantially the same horizontal attitude to ground level and back again. The tail board is adapted to carry loads between the loading area of the vehicle and a lower level, and the tail lift comprises a ramp 14 and an arrangement 22 for operating the ramp during raising and lowering of the tail board. The ramp operating arrangement 22 causes the ramp to fold over or to unfold from the tail board during respective raising or lowering of the tailboard between the horizontal position and the vertical position. The ramp 14 is operated via a link 18 connected to an offset pivot point Y. A releasable stop 22 holds the ramp in a vertical position. A roll stop 30 is also provided.

Description

A TAIL LIFT

The present invention relates to a tail lift for raising and lowering a load platform, particularly but not exclusively to a tail lift for a vehicle such as a heavy goods vehicle.

Conventional tail lifts comprise a tail board and a mechanism for raising and lowering the tail board by moving the tail board from its initial vertical (closed) position at the rear of the vehicle body into a horizontal position and then in substantially the same horizontal attitude to ground level and back again, whereby the tail board is adapted to carry loads between the loading area of the vehicle and a lower level.

An example of such a conventional tail lift is presented in EP0023819 (Peck). In this document, the tail lift also comprises a ramp to facilitate loading and unloading of the load platform. The ramp extends from the rear of the tail board in a vertical direction when the tail board is in the vertical (closed) position thereby increasing the effective height of the tail board. The ramp is in a raised attitude during lifting and lowering of the tail board to prevent the load from rolling or sliding off the tail board. When the tail board is in close vicinity or in contact with the ground the ramp is in a horizontal position to facilitate loading and unloading of the tail board.

The tail board as disclosed in Peck has several disadvantages. As the ramp is in a horizontal position when the tail board is in contact with the ground, the load can slide or roll off the tail board. This is a particular problem if the load has wheels. Furthermore, the arrangement of the ramp extending vertically from the tail board when the tailboard is in the closed position, has the disadvantage that the tailboard and ramp take up a lot of space at the rear of the vehicle. For certain types of vehicles such as small vans, this is undesirable.

The present invention aims to obviate or at least mitigate the above described problems and/or to provide improvements generally.

According to the present invention there is provided a tail lift according to any of the accompanying claims.

In an embodiment of the invention, there is provided a tail....

lift comprising a tail board and an arrangement for raising and lowering the tail board by moving the tail board from À its initial vertical position at the rear of the vehicle A. body into a horizontal position and then in substantially...

the same horizontal attitude to ground level and back again to thereby open and close the loading area of the vehicle, .. A.

whereby the tail board is adapted to carry loads between.. À

the loading area and a lower level, the tail lift comprising a ramp and an arrangement for operating the ramp during raising and lowering of the tail board, whereby the ramp is folded over the tail board when the tail board is in its initial vertical position and the ramp unfolds from or folds onto the tail board during respective lowering or raising.

In this way, loads are prevented from inadvertently slipping or rolling off the tail board when the tail board is in contact or near enough contact with the ground.

In a preferred embodiment of the invention, the raising and lowering arrangement is mounted on the vehicle to which the tail lift has been fitted. The ramp is pivotally connected to the tail board in a ramp pivot point and the tail board itself is pivotally connected in a tail board pivot point provided on the raising and lowering arrangement. The ramp operating arrangement further comprises a ramp link member, the ramp link member being pivotally connected to the ramp in a first link connection point which is offset relative to the ramp pivot point and a second link connection point, the second link connection point being offset relative to the ramp pivot point. The second link connection point is arranged on the raising and lowering arrangement such that the second link connection point remains in substantially the same position relative to the tailboard pivot point during raising and lowering.

As the tail board is raised and lowered, the distance between the first link connection point and the second link connection point is increased and decreased respectively.

As the link member is of a fixed length, this causes the ramp to move between a position in which the ramp is folded over the tail board and a position in which the ramp is in an unfolded, generally upright position which corresponds to the tail board being in an approximate horizontal position.

In a preferred embodiment, the ramp is arranged in a generally upright position when the tail board is in an approximate horizontal position and remains in this position when the tailboard is lowered to ground level and back again.

In another embodiment of the invention, the ramp may comprise a releasable catch for disconnecting the connection between the link member and the ramp to allow the ramp to be lowered onto the ground. The releasable catch may comprise a cam member and the link member may be connected to the cam member. The tail lift may further comprise a cam engaging member connected to the ramp, the cam member engaging with the cam engaging member and the cam member being resiliently biassed on the cam engaging member. The cam engaging member preferably comprises a resilient arrangement such as a spring for biassing the ramp in a generally upright position. Alternatively, the cam engaging member may comprise a serrated wheel. This has the particular advantage that the ramp may be positioned in any desirable position relative to the ground as the cam member may engage with any part of the cam engaging member.

In this way, the ramp can be raised and lowered by releasing the cam member whereby the ramp is moveable in any desired position relative to the ground.

The tail lift may comprise a locking member. The locking member may be provided on or near the surface of the tail board that is in contact with the ground. The locking member prevents lowering of the ramp when the tail board is not in contact with the ground. The locking member preferably comprises ground engaging means which upon engagement with the ground unlock the release mechanism so that it may be operated. In a preferred embodiment, the release mechanism is operated manually or by foot.

In a further embodiment of the invention, the tail board comprises a threshold or stop for preventing the load from moving forward when the tail board is lowered to ground level and back again. This has the important advantage that the load is prevented from getting stuck between the tail board and the vehicle structure or between the tail board and the raising and lowering arrangement. Particularly for loads that have wheels such as trolleys, this is important as it prevents the wheels from getting stuck. Also, the threshold prevents damage to the load and enhances the safety of the tail lift as it prevents the user's feet from getting stuck between the tail board and the vehicle structure or between the tail board and the raising and lowering arrangement.

In a further embodiment of the invention, the tail lift comprises an arrangement for operating the threshold to position the threshold in a generally upright position. The upright position of the threshold prevents load and/or body parts from getting trapped. Preferably, the operating arrangement operates the threshold such that the threshold is arranged flush with the tail board during raising or lowering of the tail board between the vertical position and horizontal position, when the tail board is lowered to the ground from the horizontal position and back again, the threshold extends in an approximate upright position from the tail board. In the horizontal position, as the threshold is flush with the tail board, the load can be exchanged between the tail board and the load area. Also, an important aspect of this arrangement is that the threshold does not take up load space by extending from the tail board when the tail board is in the vertical or closed position.

In another embodiment of the invention, the threshold is pivotally connected to the tail board around a threshold pivot point. The threshold operating arrangement comprises a threshold link member, the threshold link member being pivotally connected to the threshold in a threshold link connection point which is offset relative to the threshold pivot.

In a preferred embodiment the threshold operating arrangement comprises means for resiliently biassing the threshold link member such that the threshold is flush with the tail board during raising and lowering of tail board.

The threshold link member is preferably resiliently biassed against the raising and lowering arrangement during raising or lowering of the tail board between the vertical position and the horizontal position. In this way, the threshold is operated by the threshold link member as the tail board is lowered to ground level and back again whereby the threshold is maintained in the closed position during raising and lowering of the tail board between horizontal position and vertical position. As the tail board is lowered to ground level and back again, the baissing means causes the link member is move outwards which causes the threshold to move into the upright position.

In a preferred embodiment, the biassing means comprises a resilient member such as a spring or a gas cylinder. The threshold may further comprise a further resilient member for resiliently positioning a threshold in the upright position. Preferably, the resilience of the further resilient member is less than the resilience of the first resilient member to allow the threshold to be biassed in the closed position when the biassing means are in contact with the raising and lowering arrangement or the vehicle structure. The further resilient member preferably comprises a spring or a gas cylinder.

The structure of the tail lift is preferably made largely out of aluminium or a similar lightweight material. Most parts of the tail lift such as the tail board, and link members may be fitted to an existing tail lift arrangement for raising and lowering a tail board so that existing systems may be modified as a tail lift according to any of the embodiments of the invention.

The tail lift has various advantageous features which enable the tail lift to be used in ambulances. The ramp and threshold prevent loads and more importantly trolleys for transporting patients from accidental slipping off the tail board as the tail board is lowered to the ground and back again.

It is evident that the tail lift as herein before described may be adapted to a wide variety of applications which are not necessarily limited to tail lifts for vehicles. For example, the tail lift as herein before described may have marine applications as a gangway or gangplank.

As the tail lift as herein described is of a simplesee.

construction, the tail lift can be efficiently and cost effectively manufactured, and fitted to any vehicle structure....

The invention will now been described by way of example only and with reference to the accompanying drawings, in. . which:''.

Figure 1 shows a diagrammatic side view of a tail lift according to an embodiment of the invention, Figure 2 presents a diagrammatic plan view of a tail lift according to the embodiment of Figure 1, Figure 3 presents a diagrammatic side view of part of the tail lift of Figures 1 and 2, Figure 4a presents a diagrammatic side view of part of the tail lift of Figures 1 to 3, Figure 4b presents a diagrammatic side view of part of a tail lift according to another embodiment of the invention, and Figure 5 presents a diagrammatic side view of part of a tail lift according to yet another embodiment of the invention.

The tail lift 10 comprises a tail board 12 and an arrangement for raising and lowering the tail board (not shown) by moving the tail board 12 from its initial vertical position at the rear of the vehicle body into a horizontal position (as shown) and then in substantially the same horizontal attitude to ground level and back again to thereby open and close the loading area of the vehicle, whereby the tail board 12 is adapted to carry loads between the loading area and a lower level. The tail lift 10 comprises a ramp 14 and an arrangement 16 for operating the ramp 14 during raising and lowering of the tail board 12.

The operating arrangement 16 causes the ramp 14 to fold over or to unfold from the tail board 12 during respective raising and lowering of the tail board 12 between the horizontal position and the vertical position, and whereby the ramp 14 is arranged in a generally upright position when the tail board is in an approximate horizontal position and remains in this position when the tail board 12 is lowered to ground level and back again whereby the tailboard remains in the approximate horizontal position relative to the ground.

The ramp 14 is pivotally connected to the tail board 12 around a ramp pivot point P. The tail board 12 is pivotally arranged around a tail board pivot point X. The ramp operating arrangement 16 comprises a ramp link member 18 which is of a fixed length. The ramp link member 18 is pivotally connected to the ramp 14 in first link connection point Q which is offset relative to the ramp pivot axis P and a second link connection point Y. the point Y being offset relative to the pivot point X. The ramp comprises a releasable catch 22 for releasing the connection between the link member 1B and the ramp 14 to allow the ramp 14 to be lowered onto the ground. The releasable catch 22 comprises a cam member 24 which is operated by a lever 26. The link connection point Q is connected to the cam member. The cam member engages with a cam engaging member in the form of a serrated wheel 28. The cam member 24 is resiliently biassed on the serrated wheel 28 by means of a spring (not shown).

The tail board 12 further comprises a threshold 30 for preventing the load from moving forward when the tail board 12 is lowered to ground level and back again. The tail lift comprises an arrangement 32 for operating the threshold to position the threshold in a generally upright position when the tail board is lowered to ground level and back again.

The threshold 30 is arranged flush with the tail board 12 during raising or lowering of the tail board 12 between the vertical position and the horizontal position to allow loads to be exchanged between the tail board 12 and the load area of the vehicle. To that effect, the threshold 30 is located in a recess 34 that is provided in the tail board 12. The recess 34 is adapted to receive the threshold 30. A dampening element such as a rubber can be provided inside the recess to dampen the impact of the threshold 30 on the tail board 12 when the threshold moves into the recessed position.

As shown in Figures 1 to 4a, the threshold or stop 30 is pivotally connected to the tail board around a threshold pivot A, the threshold operating arrangement further comprising a threshold link member 36. The threshold link member 36 is pivotally connected to the threshold in the threshold link connection point B which is offset relative to the threshold pivot A. The threshold link connection point B is preferably provided on a lever 31 which is fixedly connected to the pivot A. The lever 31 is located inside a cover member 38 together with the first link member 18 to provide unobstructed operation of the threshold 30 and the ramp 14 whilst maintaining a clear tail board load area 40 for receiving loads. The link members can be arranged in pairs on both sides of the tail board 12 if required. This is advantageous if the size and/or weight of the various parts of the tail lift necessitate this.

The threshold link member is slidably arranged in a guide member 42. A spring (not shown) is provided in the guide member 24 to bias the threshold link member towards the vehicle structure or the arrangement for raising and lowering of the tail board. As the tail board is lowered to the ground, the link member 36 is released which allows the threshold 30 to be raised.

An alternative releasable catch 122 is shown in Figure 4b.

The catch 122 comprises an operating lever 126 and a cam member 124. The cam member 124 engages with a cam engaging member 128 in the form of a notch or protrusion which is provided on the ramp 214. The catch 122 is resiliently biassed on the protrusion 128. A resilient member in the form of a spring (not shown) is provided to bias the ramp 214 in an upright position 215.

Upon release of the catch 122 by pressing the lever 126 forward, the cam member 124 disengages with the protrusion - 1 1 128 and the ramp 214 is pivoted downwards around the pivot point P in the position 217. The protrusion 128 is then biassed against the lower portion 130 of the cam member 124 to prevent the ramp from moving into the upright position.

To return the ramp 214 to the upright position 215, the lever 126 is again pressed forward to release the protrusion 128 from the lower portion 130 of the cam member 124. This allows the ramp 214 to return to the upright position 215.

A different arrangement for operating the threshold is shown in Figure 5. The parts which correspond to the embodiment as shown in Figures 1 to 4 have been given corresponding reference numerals. In this embodiment, the threshold 30 is resiliently biassed by means of a gas strut or gas cylinder 46 which biasses the threshold 30 against the vehicle structure. This cylinder also has the important advantage that if anything is located between the tail board 12 and the threshold 30 when the threshold 30 is closed by contact of the link member 36 with the raising and lowering arrangement, then the gas cylinder 46 prevents the exertion of an excessive force. This provides an important health and safety advantage. Also, it prevents the load from getting stuck between the threshold 30 and the tail board 12.

In use, the tail lift 10 operates as follows. From a vertical position in which the ramp 14 is folded over the tail board 12, the raising and lowering arrangement lowers the tail board 12 to open the tail gate and to allow entry to the loading area. During lowering of the tail board 12, the ramp 14 unfolds and moves into a generally vertical or upright position as is shown in Figure 1.

The tail board 12 is then lowered to the ground which releases the threshold link member 36 which is biassed against the vehicle structure or the raising and lowering arrangement which causes the threshold 30 to move into an upright position. In this way, the load that may be present on the tail board is secured whilst the tail board 12 moves to the ground.

Upon contact with the ground, an unlocking mechanism is engaged (not shown) which allows the catch 22 to be operated to lower the ramp 14 on the ground in an approximate horizontal position. This allows the load to be removed from the tail board 12 and/or a load to be located on the tail board 12. The ramp 14 is then moved back into an upright or vertical position either manually or by foot.

This can be achieved by operating the catch 12. The tail ' ' board is raised to a level whereby the tail board 12 is.,.

approximately in line with the load area of the vehicle. An, , Upon arriving in this position, the link member 36 again engages with the raising and lowering arrangement which causes the threshold 30 to close. This allows the load to i"' be unloaded off the tail board 12. The raising and lowering arrangement is then further operated to move the tail board in a vertical position such that the ramp 14 folds onto the tail board and is located inside the vehicle.

In this way, an advantageous tail lift is described which has a wide range of applications which are not necessarily limited to applications in vehicles. The tail lift has the important advantage that the load is securely in place on the tail board whilst the tail board is raised and lowered.

Another important advantage is that the tail board requires minimal space on the vehicle structure as the ramp is located on the tail board when the tail board is in a vertical position.

It is evident that modifications may be made to the tail lift which are within the scope of the invention as herein described. For example, the ramp may be located on the outside of the tail board and folded thereover. . À e

I À:e À À. Àc

- À:.

Claims

1. A tail lift comprising a tail board and an arrangement for raising and lowering the tail board by moving the tail board from its initial vertical position at the rear of the vehicle body into a horizontal position and then in substantially the same horizontal attitude to ground level and back again, whereby the tail board is adapted to carry loads between the loading area of the vehicle and a lower level, the tail lift comprising a ramp and an arrangement for operating the ramp during raising and lowering of the tail board, wherein the ramp operating arrangement causes the ramp to fold over or to unfold from the tail board À during respective raising or lowering of the tailboard between the horizontal position and the vertical position.

2. A tail lift according to claim 1, wherein the ramp is pivotally connected to the tail board around a ramp pivot, the tail board is pivotally connected to the raising and lowering arrangement around a tail board pivot, the tail lift further comprising a ramp link member, the ramp link member being pivotally connected to the ramp in a first link connection point which is offset relative to the ramp pivot and a second link connection point, the second link connection point being offset relative to the tail board pivot axis.

3 A tail lift according to claim 2, wherein the second link connection point is located on the raising and lowering arrangement.

4. A tail lift according to any of claims 1 to 3, wherein the ramp is arranged in a generally upright position when the tail board is in an approximate horizontal position and remains in this position when the tail board is lowered to ground level and back again.

5. A tail lift according to claim 4, wherein the ramp comprises a releasable catch for releasing the connection between the link member and the ramp to allow the ramp to be lowered onto the ground.

6. A tail lift according to claim 5, wherein the releasable catch comprises a cam member, the link member being connected to the cam member, the tail lift further comprising a cam engaging member connected to the ramp, the cam member engaging with the cam engaging member and the cam member being resiliently biassed on the cam engaging member. À e À 15. .

7. A tail lift according to claim 6, wherein the cam engaging member comprises a serrated wheel.

8. A tail lift according to any of the preceding claims, ....

wherein the ramp is biassed in an upright position when the. , tail board is in an approximate horizontal attitude À.

relative to the ground.

9. A tail lift according to any of the preceding claims, t wherein the tail board comprises a threshold or stop for preventing the load from moving forward.

10. A tail lift according to claim 9, wherein the tail lift comprises an arrangement for operating the threshold to position the threshold in a generally upright position when the tail board is lowered to ground level and back again.

11. A tail lift according to claim 9 or 10, wherein the threshold is arranged so that the threshold is flush with the tail board during raising or lowering of the tail board between the vertical position and the horizontal position, to thereby allow exchange of a load between the tail board and the load area.

12. A tail lift according to any of claims 9 to 11, wherein the threshold is pivotally connected to the tail board around a threshold pivot axis, the threshold operating arrangement further comprising a threshold link member, the threshold link member being pivotally connected to the threshold in a threshold link connection point which is offset relative the threshold pivot axis. À À > A..

13. A tail lift according to claim 12, wherein the threshold operating arrangement comprises means for resiliently biassing the threshold link member such that the threshold is flush with the tail board.

14. A tail lift according to claim 13, wherein the threshold link member is resiliently biassed against the raising and lowering arrangement during raising or lowering of the tail board between the vertical position and the horizontal position.

15. A tail lift according to any of claims claim 13 or 14, wherein the biassing means comprises a resilient member such as a spring or a gas cylinder.

16. A tail lift according to any of claims 9 to 15, wherein the threshold comprises a further resilient member for resiliently positioning the threshold in the upright position.

17. A tail lift according to claim 16, wherein the resilience of the further resilient member is less than the resilience of the first resilient member to allow the threshold to be biassed in the closed position.

18. A tail lift according to claim 16 or 17, wherein the further resilient member is a spring or a gas cylinder.

19. A tail lift comprising a tail board and an arrangement for raising and lowering the tail board by moving the tail board from its initial vertical position into contact with the ground and back again, whereby the tail board is adapted to carry loads between a loading area of a vehicle and a lower level, the tail lift comprising a ramp and an arrangement for operating the ram during raising and lowering of the tail board, wherein the ramp operating arrangement causes the ramp to fold over or to unfold from the tail board during respective raising or lowering of the tailboard. À.. À À... À.