AU2001100269A4 - Roll-back body vehicles - Google Patents

Description

1' Regulation 3.2

AUSTRALIA

Patents Act 1990 INNOVATION PATENT SPECIFICATION Name of Applicant: Vawdrey Australia Pty Ltd of 220 Boundary Road, Braeside, Victoria 3195, Australia Actual Inventor: VAWDREY, Michael Address for Service: DAVIES COLLISON CAVE, Patent Attorneys, 1 Little Collins Street, Melbourne 3000, Victoria, Australia Petty Patent specification for the invention entitled: "Roll-back body vehicles" The following statement is a full description of this invention, including the best method of performing it known to me/us: -1- Q:\OPER\ARL\2446242 INV 219.DOC 14/8/01 P:OPER\ArI2446242 inv 219do-l4108/01 -1- ROLL-BACK BODY VEHICLES This invention relates to vehicles of the kind having a roll-back body. As used in this specification the term "vehicles" includes complete vehicles and vehicle trailers of the kind attached to prime movers.

Roll-back bodies are provided on vehicles of the kind known as B-double vehicles in which a turntable connection with a trailer is provided behind the load carrying body of the vehicle. The roll-back body is provided to enable the vehicle body to be moved to the rear of the vehicle for loading and unloading through rear doors when the trailer is disconnected. Known roll-back bodies operate by having a set of rollers on which the body is mounted that move along a corresponding set of tracks provided on the chassis or frame of the vehicle. A locking arrangement is provided to lock the body in the forward transport position. A winch structure is also provided to allow the body to be moved between the transport position and the loading/unloading position in which the body is adjacent the rear of the vehicle.

A difficulty with existing roll-back bodies is that the entire weight of the body is supported by the rollers in the transport position. Typically the bodies carry weights up to around 20 tonnes and they are often supported on only four rollers.

This has been found to lead to significant occurrence of roller failure.

It is an object of this invention to provide a roll-back body vehicle that will overcome, or ameliorate this difficulty.

Accordingly, in one aspect this invention provides a roll-back body vehicle including a body, a vehicle frame, spaced apart rollers on one of the frame or body and a corresponding track on the other of said frame and body, the rollers supporting the body on the track as the body is moved from a first transport position to a longitudinally displaced loading/unloading position, and means to support the body on the frame in the transport position and at least substantially reduce the load on said rollers in the transport position.

P:\OPER\Al2446242 inv 219.doc-14/08101 -2- Preferably, the rollers do not carry any load in the transport position. In the preferred form of the invention the track is designed so that the rollers move away from the track as the body moves into the transport position. Preferably, supporting pads on one of the body or frame move into sliding engagement with the tracks to support the body to allow the rollers move away from the track.

This can for example be achieved by providing a dip in the track corresponding to the position of the roller in the transport position and providing a pad adjacent to the rollers that moves into engagement with the track as the rollers move into the dip. It will be appreciated that the body thus moves in a short distance by the sliding of the pads on the track as it moves into and out of the loading position.

The pads preferably include appropriate wear elements that provide for low friction sliding movement. Pads can be made of for example teflon so that they slide relatively easily on a steel track.

In the preferred form of the invention the body slides approximately 70mm on the teflon pads as it moves into and from the transport position.

One embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic elevation of a vehicle trailer according to this invention showing part of the body in a transport position; and Figure 2 is a view similar to Figure 1 showing part of the body in an unloading/loading position.

The drawings show only the parts of a vehicle trailer 1 necessary for an understanding of the invention. The trailer has a frame or chassis 2 supported by road wheels 3. A king pin 4 is provided at the front of the trailer for connection to a turn-table (not shown) on a prime mover (also not shown) in the known manner.

Although not shown in the drawing a turn-table would also be mounted on the P: OPER\ArI2446242 inv 219.dom-14/08/01 -3chassis 2 in the region of the supporting wheels 3 for the connection of a second trailer so as to form a B-double combination. Only the bottom of a vehicle body is shown in dotted outline. It will be apparent to those skilled in the art that the vehicle body can be of any suitable form. For example it can be a curtain sided body, a dry freight body with fibreglass walls or a skeletal structure for container carrying. The body 5 has front rollers 6 and rear rollers 7 mounted to the body by appropriate brackets 8 and 9. The rollers 6, 7 are provided for engagement with a track 10 formed by the upper surface of the chassis 2. Three teflon pads 11 are attached to the bottom of body 5 for engagement with the track 10 as seen in Figure 1. The track 10 has dips 12, 13 formed at positions corresponding to the location of rollers 6, 7 when the body 5 is in the transport position. These dips allow the pads 11 to come into contact with the surface of track 10 and remove the weight from rollers 6, 7. A hydraulic drive system shown at 14 is provided to move the body 5 from the transport position to a longitudinally rearward loading/unloading position as shown in Figure 2. The hydraulic system 14 is of known type including a hydraulic motor and a chain drive. It does not form part of the invention and it is not shown in detail. A locking mechanism 15 is also schematically illustrated. The locking system 15 is of any suitable known type that can be used to lock the body and the frame together when the body 5 is in the transport position. This is provided for obvious safety reasons. Brackets 8, 9 include forward facing arcuate recesses 16 and rearwardly facing arcuate recesses 17. Enlarged views of the brackets are shown above Figure 1 and an enlarged view of the bracket 9 is shown above Figure 2. As best seen in the enlarged views pins 18, 19 are provided adjacent the position of the rollers 6, 7 in the transport position of the body 5. These pins are engaged by the recess 16 in the transport position so as to prevent the body 5 moving vertically with respect to the chassis 2. As seen in the enlarged portion of Figure 2 a further pin 20 is provided adjacent the rollers 7 in the loading/unloading position. These are engaged by the rearwardly facing recesses 17 to prevent vertical movement of the body 5 with respect to the chassis 2 during loading and unloading.

P:\OPER\Ar, 2446242 in 219do- 14/08/01 -4- It will be appreciated that the elevation views show only one side of the chassis and the corresponding parts of the body 5. Each side of the trailer has the same configuration.

In use the body 5 is moved longitudinally from the transport position to the loading/unloading position in much the same manner as prior art roll-back bodies.

That is, the rollers 6, 7 support the body on track 10 and the movement is effected by the hydraulic drive system 14. During the last part of the movement of the body to the transport position the rollers 6, 7 enter dips 12, 13 and the teflon pads 11 come into contact with the track 10 to support the weight of the body 5. The vehicle is designed so that the body slides on the pads 11 over approximately the last 70mm of travel. When the body 5 is moved from the transport position it slides on the teflon pads 11 for approximately the first 70mm until the rollers 6, 7 move out of the dips 12, 13 and engage the tracks 10 to support the weight of the body It will be apparent that because the weight of the body is supported on teflon pads 11 in the transport position the rollers are not required to support the weight of the body and are therefore subject to considerably less wear.

The foregoing describes only one embodiment of the invention and modifications can be made without departing from the scope of the invention.

Claims (4)

1. A roll-back vehicle including a body, a vehicle frame, spaced apart rollers on one of the frame or body and a corresponding track on the other side of said frame and body, the rollers supporting the body on the track as the body is moved from a first transport position to a longitudinally displaced loading/unloading position, and means to support the body on the frame in the transport position and at least substantially reduce the load on said rollers in the transport position.

2. A vehicle as claimed in claim 1, wherein the track is designed so that the rollers move away from the track as the body moves into the transport position so that the rollers do not carry any load in the transport position.

3. A vehicle as claimed in claim 2, wherein said means to support the body include supporting pads on one of the body or frame move into sliding engagement with the tracks to support the body to allow the rollers move away from the track.

4. A vehicle as claimed in claim 3, wherein a dip is provided in the track corresponding to the position of the rollers in the transport position and at least one supporting pad is disposed to move into engagement with the track as the rollers move into the dip. A roll-back vehicle, substantially as described with reference to the drawings and/or the examples. DATED this 14th day of August, 2001. Vawdrey Australia Pty Ltd by DAVIES COLLISON CAVE Patent Attorneys for the Applicant