GB2247437A

GB2247437A - Trailers

Info

Publication number: GB2247437A
Application number: GB9117400A
Authority: GB
Inventors: Brian Trigg
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-08-15
Filing date: 1991-08-12
Publication date: 1992-03-04
Anticipated expiration: 2011-08-12
Also published as: GB9117400D0; GB9017946D0; GB2247437B

Abstract

A vehicle or trailer 10 comprising a load-carrying platform 18 to one end of which is movably mounted an assembly 12. The assembly 12 comprises two similar first 'L' shaped members 14 pivotally connected at one end to support arms 17, which in turn are connected to the platform 18, and at the other end to arm members 22. The arm members 22 are in turn pivotally connected to the axle 24 of the wheels 26. First piston and cylinder arrangements 28 are pivotally attached between respective first members 14 and arms 22. Second piston and cylinder arrangements 34 are pivotally connected between respective first members 14 and further support arms 38 which in turn are connected to the platform 18. In operation, the first and second piston and cylinder arrangements 28, 34 drive the assembly between first and second configurations, in which the wheels 28 are beneath or out from beneath the platform 18, respectively. At the other end of the platform 18 is provided a trapezoidal linkage 50 which permits the necessary height changes of the platform 18 during operation of the assembly 12 without the need to change the height of the towing connection mount. <IMAGE>

Description

Improvements in or relating to Trailers The present invention concerns improvements in or relating to wheeled vehicles, especially but not exclusively, to trailers.

Conventional trailers, especially trailers designed to transport heavy loads such as vehicles and machinery, often comprise a low level platform to aid loading, and a set of wheels located, necessarily due to the low level of the platform, at the rear end of the platform. In such arrangements, the load bearing platform extends between the wheels and the tow bar attachment, and is otherwise unsupported along its length.

Thus, with heavy loads on the platform, a large proportion of the load is carried by the tow bar of the towing vehicle. It would be more advantageous if the wheels carried a larger proportion of the load.

It is an object of the present invention to obviate or mitigate these and other disadvantages.

According to the present invention, there is provided a vehicle comprising a load-carrying platform, wheels and drive means operable tp raise and lower the platform and to move the wheels between a first position in which the wheels are located beneath the-platform and spaced forwardly of its rear end, and a second position in which the wheels are clear of the rear of the platform.

Preferably the vehicle further comprises an assembly movably mounted on the platform and to which the wheels are attached, the drive means being operable to move the assembly with respect to the platform, thereby moving the wheels. Preferably in a first configuration of the assembly the wheels are located in the first position, and in a second configuration of the assembly the wheels are located in the second position. The assembly preferably comprises a first member mounted for pivotal movement relative to the platform and a second member attached to the first member and having the wheels attached thereto. The second member may be pivotally connected to the first member. The second member may be pivotally connected to an axle carrying the wheels.

Alternatively, the second member may be pivotally connected to a frame member adapted to carry a plurality of sets of wheels on parallel axles. There may be a roller mounted on one of the platform and a member which moves under the platform on the wheels, the roller being positioned to roll on the other of said platform and member respectively, to facilitate such movement.

Preferably the assembly further comprises a further member pivotally connected to the first member and rigidly connected to the platform, whereby the pivot axis of the first member is spaced from the platform. The further member may extend away from the platform in a direction which is perpendicular thereto. Preferably the first member is substantially 'L' shaped. Preferably the said further member is pivotally connected to one arm of the first member and the second member is connected to the other arm of the first member.

The drive means may be operable to act between the second member and a point at or near to the pivot between the first and further member to cause the second member to be drawn toward the platform and the assembly to adopt the first configuration. Preferably the drive means is operable to act between the first member and the platform to raise or lower the platform in relation to the first member. The drive means is preferably operable to act simultaneously in both manners as aforesaid.

The vehicle may be a trailer. Preferably a towing arm is provided at the front end of the platform. Preferably the towing arm comprises a linkage, so formed as to allow the platform to move vertically in relation to the point of attachment to a vehicle, whereby the point of attachment may remain stationary as the platform is raised or lowered. The linkage is preferably a parallelogram linkage. Preferably, the linkage may incorporate further drive means to facilitate the aforesaid relative vertical movement. A releasable lock means may be provided to prevent movement of the linkage.

An embodiment of the present invention will now be described by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a diagrammatic representation of a trailer according to the present invention with an assembly in a first configuration; Fig. 2 is a perspective view of the assembly of Fig. 1 in the first configuration; Fig. 3 is a diagrammatic representation of a trailer according to the present invention with the assembly in a second configuration; and Fig. 4 is a perspective view of the assembly of Fig. 3 in the second configuration.

A trailer 10 comprises an assembly 12. Two similar first 'L' shaped members 14, each having first and second arms 14A, 14B, are pivotally connected at the free end of the arms 14A thereof, about a pivotal axis 16, to support arms 17 which are upright on a load bearing platform 18.

The free ends of the-other arms 14B are connected at further pivot axes 20 to similar, parallel second members 22. The second members 22 are in the form of elongate arms, extending towards and pivotally connected to the axle 24 of the wheels 26 of the trailer 10.

First hydraulic or pneumatic piston and cylinder arrangements 28 are attached at one end to the free end of respective arms 14A, to pivot about the axis 16. The other end is attached to the free end 30 of a respective arm 22 to pivot about the pivot axis 32.

Second piston and cylinder arrangements 34 extend from a respective arm 14A to which they are pivotally connected about an axis 36, to a corresponding further support arm 38. The arrangements 34 are pivotally connected to the arms 38 about a further pivot axis 40.

Each support arm 38 extends upwards from the platform 18 and is securely attached thereto. The support arms 38 are shorter than the support arms 17. Two strengthening bars 42 extend between the two arms 14B of the first members 14. Further strengthening bars 44, 46 extend between the arms 148 and between the arms 22 respectively. Rollers 47 are mounted on the bar 46 above the members 22.

At the other, forward end of the platform 18, an extension 48 extends centrally from the platform 18 to provide a mount for a towing connection of conventional design. A trapezoidal linkage 50 is provided within the extension 48, to accommodate height changes of the platform 18 which occur during operation of the assembly 12 (as will be described), without changing the height of the towing connection mount. A further piston and cylinder arrangement (not shown) is provided within the trapezoidal linkage 50 and is operable to draw the ends of the linkage 50 together.

A trailer 10 as described above is of particular benefit when large, heavy objects such as machinery and vehicles are to be transported.

When an object is to be loaded, the piston and cylinder arrangements 28, 34 are extended and the assembly 12 assumes the configuration as shown in Figs. 3 and 4. The wheels 26 are out from beneath the platform 18, and the platform 18 is at its lowest postion. The linkage 50 is fully extended so that the extension 48 lies on the ground.

The trailer 10 is now in a convenient state for easy loading of heavy objects onto the platfrom 18. Once the load is in position on the platfrom 18, the assembly 12 is actuated, together with the piston and cylinder in the linkage 50. Each piston and cylinder 28 contract to cause the arms 22 to be drawn toward the platfrom 18, the pivotal axes 16, 20 and 32 allowing such movement.

Simultaneously, the contraction of each piston and cylinder 34 raises the platform 18. The combined action drives the wheels 26 beneath the platform 18, the rollers 47 rolling along the underside of the platform 18, bearing most of the weight thereof and thereby facilitating the assembly assuming the first configuration (Figs. 1 and 2). In that configuration, the arms 14A and 17 and the cylinders 28 stand upright alongside each other.

Alternatively, the piston and cylinders 34 may contract to raise the platform 18 and drive the wheels 26 underneath, while the cylinders 28 are free to contract as a result.

The arms 148 reach under the platform 18 adjacent and parallel to corresponding arms 22.

While the assembly 12 is moving the wheels 26 under the platform 18, the piston and cylinder in the linkage 50 contracts to draw the ends of the linkage together and raise the end of the platform 18, thereby maintaining the platform 18 horizontal. The trailer can now be towed away in a conventional manner.

Various modifications may be made without departing from the spirit and scope of the invention. Drive means other than piston and cylinder arrangements can be used, as can other configurations of the assembly.

Claims

Claims:

1. A vehicle comprising a load-carrying platform, wheels and drive means operable to raise and lower the platform and to move the wheels between a first position in which the wheels are located beneath the platform and spaced forwardly of its rear end and a second position in which the wheels are clear of the rear of the platform.

2. A vehicle according to Claim 1, including an assembly movably mounted on the platform and to which the wheels are attached, the drive means being operable to move the assembly with respect to the platform, thereby moving the wheels.

3. A vehicle according to Claim 2, in which in a first configuration of the assembly the wheels are located in the first position, and in a second configuration of the assembly the wheels are located in the second position.

4. A vehicle according to Claim 2 or 3, in which the assembly comprises a first member mounted for pivotal movement relative to the platform and a second member attached to the first member and having the wheels attached thereto.

5. A vehicle according to Claim 4, in which the second member is pivotally connected to the first member.

6. A vehicle according to Claim 4 or 5, in which the second member is pivotally connected to an axle carrying the wheels.

7. A vehicle according to claims 4 or 5, in which the second member is pivotally connected to a frame member adapted to carry a plurality of sets of wheels on mutually parallel axles.

8. A vehicle according to any of the preceding Claims, in which a roller is mounted on one of the platform and a member which moves under the platform with the wheels, the roller being positioned to roll on the other of said platform and the member respectively, to facilitate such movement.

9. A vehicle according to any of Claims 4 to 8, in which the assembly further comprises a further member pivotally connected to the first member and rigidly connected to the platform, whereby the pivot axis of the first member is spaced from the platform.

10. A vehicle according to Claim 9, in which the further member extends away from the platform in a direction which is perpendicular thereto.

11. A vehicle according to any of Claims 4 to 10, in which the first member is substantially 'L' shaped.

12. A vehicle according to any of Claims 9 to 11, in which the said further member is pivotally connected to one arm of the first member and the second member is connected to the other arm of the first member.

13. A vehicle according to any of Claims 9 to 12, in which the drive means is operable to act between the second member and a point at or near to the pivot between the first and further member to cause the second member to be drawn tpward the platform and the assembly to adopt the first configuration.

14. A vehicle according to any of Claims 4 to 13, in which the drive means is operable to act between the first member and the platform to raise or lower the platform in relation to the first member.

15. A vehicle according to any preceding Claim, in which the drive means is operable to act simultaneously in both manners as aforesaid.

16. A vehicle according to any preceding Claim, in which the vehicle is a trailer.

17. A vehicle according to any preceding Claim, in which a towing arm is provided at the front end of the platform.

18. A vehicle according to Claim 17, in which the towing arm comprises a linkage, so formed as to allow the platform to move vertically in relation to the point of attachment to a vehicle, whereby the point of attachment may remain stationary as the platform is raised or lowered.

19. A vehicle according to Claim 18, in which the linkage is a parallelogram linkage.

20. A vehicle according to Claim 18 or 19, in which the linkage incorporates further drive means to facilitate the aforesaid relative vertical movement.

21. A vehicle according to any of Claims 18 to 20, in which a releasable lock means is provided to prevent movement of the linkage.

22. A vehicle substantially as hereinbefore described with reference to the accompanying drawings.

23. Any novel subject matter or combination including novel subject matter disclosed in the foregoing specification or claims and/or shown in the drawings, whether or not within the scope of or relating to the same invention as any of the preceding claims.