GB2203411A

GB2203411A - Load transporting device

Info

Publication number: GB2203411A
Application number: GB08708890A
Authority: GB
Inventors: Alan Cartwright
Original assignee: CARTWRIGHT FREIGHT SYSTEMS LIM
Current assignee: CARTWRIGHT FREIGHT SYSTEMS LIM
Priority date: 1987-04-14
Filing date: 1987-04-14
Publication date: 1988-10-19
Also published as: GB8708890D0

Abstract

A transport vehicle (11), adapted to removably support a load carrying structure (12), has primary locating means (17, 23) provided to enable lateral positioning of the structure (12) as it and the vehicle (11) are brought into contact with each other. These locating means comprise freely rotatable rollers (19) mounted on the vehicle (11) which engage in concave recesses (24) on the underside of the load carrying structure. At the centre of each recess (24) is a smaller central recess (25) which is positionally located on the rollers (19). Secondary locating means (18, 22) comprise a conical spigot (18) on the vehicle (11) which engages in a locating ring (22) on the load carrying structure when the rollers (19) enter the central recesses (25). To engage the locating means the vehicle is located beneath the structure (12), the vehicle suspension raised beyond its normal operating position to raise the load carrying structure (12) on supporting legs, and the suspension then lowered to its normal position after the legs have been retracted or removed. Alternatively the beam 16 on which the locating means are mounted may be raised and lowered. Rollers (19) may be replaced by balls so that positioning in any direction is possible. <IMAGE>

Description

LOAD TRANSPORTING DEVICE.

This invention relates to load transporting devices, and in particular to such devices which are incorporated in transport vehicles whereby a load carrying structure may be removably mounted on a wheeled chassis.

Devices of this type are known, for example from British Patent No. 1168902. The arrangement described in that patent comprises a load carrying structure having four hydraulically extensible legs which are able, when extended, to support the structure sufficiently clear of the ground for a. vehicle to be backed underneath it.

The legs may then be retracted so that the load carrying structure is lowered onto the chassis of the vehicle.

Locating means associated with the legs move, when the legs are moved from their retracted position to a transporting position, to cooperate with abutments on the vehicle to correctly locate and secure the load carrying structure on the chassis of the vehicle. Such movement is also actuated hydraulically. However such an arrangement requires an hydraulic actuating system incoporated in the load carrying structure.

To overcome this problem an alternative arrangement is known. In this alternative arrangement the legs on the load carrying structure are inextensible but support the structure sufficiently clear of the ground to enable a vehicle to be backed underneath it. Hydraulically operated jacks provided on the vehicle chassis are then extended to raise the load carrying structure off the ground so that the legs may be removed or moved to a transporting position.

The hydraulic jacks are then retracted so as to lower the load carrying structure onto the vehicle chassis. In this way the hydraulic actuating system of the vehicle may be used and no such system is required on the load carrying structure. To locate the load carrying structure correctly on the vehicle chassis the hydraulic jacks are provided with mushroomshaped heads which may be received in relatively large dome-shaped recesses provided in the base of the load carrying structure. These serve as a primary approximate location means. As the load carrying structure is lowered onto the vehicle chassis acone-shaped spigot on the chassis is received in a locating ring on the load carrying structure, these serving as a secondary accurate locating means.

However, many vehicles, and in particular draw bar trailer vehicles, do not have an hydraulic actuating system. In consequence in such cases for either of the above described arrangements, a separate hydraulic actuating system must be available. Many. vehicles have mechanical spring suspensions and increasingly more vehicles are provided with pneumatic suspensions, particularly draw bar trailer vehicles for which hydraulic systems are a nuisance due to spillage at each coupling to or uncoupling from the tractor vehicle.

The invention seeks to provide a load transporting device which avoids the aforementioned disadvantages and is suitable for use with vehicles having a pneumatic actuating system, particularly draw bar. trailer vehicles.

The invention provides a load transporting device comprising a support structure adapted to receive and support a load carrying structure thereon, said support structure having lifting means operable to raise and lower said support structure relative to a surface on which it stands, said support structure also having primary locating means adapted to locate said load carrying structure on said support structure and said locating means comprising freely. rotatable rolling means operable to engage said load carrying structure and to-allow lateral movement thereof relative to -said support structure.

Said support structure may comprise a wheeled vehicle, and may be a draw bar trailer. vehicle. Said lifting means may comprise a suspension device of said vehicle and may comprise a pneumatic actuating system.

Said support structure may also-comprise secondary locating means which may comprise at least one conical spigot.

The load transporting device may comprise a support structure as aforesaid and a load carrying structure.

Said load carrying structure may comprise primary locating means adapted to receive said rolling means in rolling-contact therewith. Said load carrying structure primary locating means may comprise a concave recess of larger lateral dimensions than said rolling means. Said concave recess may have a central second recess therein adapted to receive therein and be positionally located by said rolling means. Said load carrying structure may also comprise secondary locating means which may comprise a locating ring adapted to receive therein and be positionally located by said conical spigot.

One embodiment of load transporting device in accordance with the invention will now be described with reference to the accompanying drawings in which: Fig. 1 is a sectional rear view of part of a load carrying structure and a support structure adapted to receive and support such load carrying structure, and Fig. 2 is a section on line 7I-Th ofFig, 1 to a slightly enlarged scale.

Referring now to the drawings there is shown a load transporting device 10 comprising a support structure 11 adapted to-receive and support a load carrying structure 12 thereon. The support structure 11 may be a wheeled vehicle as shown in Fig. 2 comprising wheels 13 and a pneumatic suspension arrangement 14 supporting a chassis 15 which has a cross beam 16. Mounted on the cross beam 16 at locations equally spaced on opposed sides of the longitudinal centre line of the vehicle 11 are primary locating means 17, and on the centre line of the vehicle 11 is mounted a secondary locating means 18. The primary locating means 17 comprises freely rotatable rolling means in the form of three coaxial rollers 19 supported by a fork bracket 20. The secondary locating means 18 comprises a conical spigot.

The load.carrying structure 12 may have any form of construction and is shown diagrammatically in Figs. 1 and 2 as having on its underside a box beam central spine 21 in which is mounted, on the centre line of the load carrying structure 12, a secondary locating ring 22 which is adapted to.receive and be a relatively close fit on the conical spigot 18. This arrangement ensures the accurate final location of the load carrying structure 12 on the. vehicle 11. Also provided on the underside of the load carrying structure 12 are two primary locating means 23 in the form of a concave recess 24 Of. larger lateral dimensions than the primary locating means 17 of the. vehicle 11.The recesses 24 are located on opposed sides of and equi-spaced from the centre line of the- load carrying structure by the same distance as the primary locating means 17 of the vehicle 11. At the centre of each recess 24 is a second recess 25 adapted to receive therein and positionally locate the rollers 19.

In operation the load carrying means 12 is supported on legs (not shown) and the vehicle 11 is backed underneath. The pneumatic suspension 14 is then extended to raise the chassis 15 and cross-beam 16 until the rollers 19 engage the walls of the larger recess 24. Further extension of the suspension 14 takes the legs of the load carrying structure 12 out of contact with the ground and the load carrying structure 12 is then able to move laterally whilst the rollers 19 roll along the wall of the larger recess 24. This lateral movement will continue until the load carrying structure 12 is positioned for the rollers 19 to enter the smaller, central recess 25. At the same time the locating ring 22 will then be positioned above the locating conical spigot 18 so that the latter can enter the ring 22 and correctly locate the load carrying structure 12 on the. vehicle 11. The legs of the load carrying structure are then -retracted, removed or moved to a non-functional transporting position and the suspension 14 is lowered to its normal operating configuration. Twist- lock devices 26 on each end of the cross beam 16 are operated to engage in channels 27 of the load carrying structure 12 to secure the latter in position on the vehicle 11.

Although the embodiment described above comprises a pneumatic suspension system 14, the invention is suitable for use with other elevating suspension systems, e.g. mechanical or hydraulic. However the invention is particularly suited for vehicles, in particular draw-bar trailers, having pneumatic suspension systems, which are particularly advantageous for sensitive loads. Alternative embodiments will be readily apparent to persons skilled in the art. For example lifting means, pneumatic, mechanical or hydraulic, may be provided on the chassis 15 to elevate the cross-beam 16 instead of using the suspension 14.

The lifting arrangement at the front of the vehicle may be different from that at the rear, for example a pneumatic suspension may be provided at the rear and an hydraulic system, operated by a small portable hydraulic pack, may be provided at the front. In this case the need for hydraulic piping connecting front and rear of the vehicle is avoided and the necessity for equalising hydraulic pressure at the front and rear.

Since the amount of lift available from a pneumatic suspension system is usually limited, it is in such cases important that the height of the locating spigot 18 is similarly restricted and that the dimensions of the recess 24 and the bracket 20 and rollers 19 are such that the spigot 18 is not in contact with the locating ring 22 whilst the rollers 19 are still in contact with the walls of the larger recess 24.

The embodiment herein described is only concerned with lateral positioning of the load carrying structure 12 relative to the vehicle 11, since correct fore-andaft positioning of the vehicle 11 relative to the load carrying structure 12 is far easier. However, if it is desired two facilitate fore-and-aft positioning as well as lateral positioning the rollers 19 may be replaced by a ball rotatably held in a cup so that rolling in any direction is possible.

Claims

1. A load transporting device comprising a support structure adapted to receive and support a load carrying structure thereon, said support structure having lifting means operable to raise and lower said support structure relative to a surface on which it stands, said support structure also having primary locating means adapted to locate a load carrying structure on said support structure, and said locating means comprising freely rotatable rolling means operable to engage said load carrying structure and to allow lateral movement thereof relative to said support structure.

2. A load transporting device according to claim 1 comprising a wheeled vehicle.

3. A load transporting device according to claim 2 comprising a draw bar trailer vehicle.

4. A load transporting device according to claim 2 or claim 3, wherein said lifting means comprises a suspension device of said vehicle.

5. A load transporting device according to any one of claims 1 to 4, wherein said lifting means comprises a pneumatic actuating device.

6. A load transporting device according to any one of claims 1 to 5, wherein said support structure comprises secondary locating means adapted to locate a load carrying structure on said support structure.

7. A load transporting device according to claim 6, wherein said secondary locating means comprises at least one conical spigot.

8. A load transporting device according to any one of claims 1 to 7 comprising a load carrying structure.

9. A load transporting device according to claim 8, wherein said load carrying structure comprises respective primary locating means adapted to receive said rolling means in rolling contact therewith.

10. A load transporting device according to claim 9 wherein said load carrying structure primary locating means comprises at least one concave recess of larger lateral dimensions than said rolling means.

11. A load transporting device according to claim 10, wherein the or each concave recess has a central second recess therein adapted to receive therein and be positionally located by said rolling means.

12. A load transporting device according to any one of claims 9 to 11 when dependent on claim 7, wherein said load carrying structure comprises respective secondary locating means adapted to engage said support structure secondary locating means.

13. A load transporting device according to claim 12 wherein said load carrying structure secondary locating means comprises a locating ring adapted to receive therein and be positionally located by said conical spigot.

14. A load transporting device according to any one of claims 1 to 13, wherein said primary locating means comprises a rolling means disposed on opposed sides of a longitudinal centre line of said support structure.

15. A load transporting device according to any one of claims 1 to 14, wherein the or each rolling means comprises at least one roller supported by a bracket.

16. A load transporting device according to claim 15, wherein said rolling means comprises three coaxial rollers supported by said bracket.

17. A load transporting device according to claim 12 or any claim dependent thereon, wherein said secondary locating means are located on the centre lines of said support structure and said load carrying structure.

18. A load transporting device according to claim 8 or any claim dependent thereon, wherein said load carrying structure comprises a plurality of legs.

19. A load transporting device according to claim 18, wherein said legs are movable to non-supporting positions.

20. A load transporting device according to claim 18, wherein said legs are detachable from said load carrying structure.

21. A load transporting device according to any one of claims 1 to 20, wherein said support structure comprises at least one twist lock device adapted to engage a load carrying structure to secure the latter in position on said support structure.

22. A load transporting device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.