GB2410926A

GB2410926A - Cover for a transport container

Info

Publication number: GB2410926A
Application number: GB0416258A
Authority: GB
Inventors: Alan Stephen Rogerson
Original assignee: TAILOR MADE METAL FABRICATIONS
Current assignee: TAILOR MADE METAL FABRICATIONS
Priority date: 2004-02-11
Filing date: 2004-07-21
Publication date: 2005-08-17
Anticipated expiration: 2024-07-21
Also published as: GB0403003D0; GB2410926B; GB0416258D0

Abstract

A transport container has a cover 14 which is fixed to the container along one longitudinal edge and can be rolled up at that longitudinal edge to open the container. A central pole 28 extends the length of the container and a motor 30 rotates this pole to roll up the cover. To unroll the cover, ie to close the container, a fixed length rope 60 runs through an edge pole on the longitudinal edge of the cover which is not fixed. Pulling on this rope drags the edge pole across the top of the container. The rope is pulled by a hydraulic ram 70, and the rope is pulled by the ram into a rope accumulator arrangement 66, from which it is withdrawn when the cover is next rolled up.

Description

- 1 - 2410926 Cover for a Transport Container This invention relates to a

cover for a transport container, particularly a container for road transport, and to apparatus for deploying and retracting the cover.

It is desirable, and indeed in many cases a legal requirement, to cover bulk goods which are being transported by road in a container which is loaded from above, so that none of the goods are scattered while the container is on the move. Most such containers are trailers, towed behind a tractor unit, but in some cases the containers are load containers mounted on a lorry chassis.

It is know from EP 1 232 889 to provide apparatus for removing and extending a cover (often referred to as a sheeting) where motors are used to extend and to retract the cover. A central pole is attached to the cover and runs the length of the container. Rotation of this pole winds up the cover on both sides of the central pole, as the pole travels towards the fixed edge of the cover where the cover is retained when it is open.

According to the present invention, there is provided apparatus for extending and retracting a cover over an open-topped container, the apparatus comprising guide tracks forming part of the container and extending - 2 transversely across the container at the top of each end thereof, a cover adapted to extend across the open top of the container, one of the edges of the cover being fixed to a longitudinal edge of the container, the opposite edge of the cover being fixed to an edge pole which extends the length of the cover, and a centre pole fixed along the centreline of the cover, such that the ends of the edge and centre poles run on the guide tracks, wherein opening of the cover is achieved by rotating the centre pole about its own axis to wind up the cover on the pole, and closing of the cover is achieved by pulling on a rope which extends through the edge pole while allowing the centre pole to rotate freely, and both opening and closing actions are powered by a single hydraulic pump.

A single closure rope preferably runs from a fixed point at one end of the vehicle, through the pole from one end thereof to the other, and to an accumulator provided with a hydraulic ram so that when the ram is retracted, the rope is pulled to draw the edge pole to the edge of the vehicle.

It will be understood that the term 'rope' includes any flexible traction member and thus the term 'rope' encompasses a wire, strap, cable, chain or the like.

The edge pole preferably has a bush at each end which allows the rope to be drawn freely through the pole. - 3 -

The bushes can be ceramic bushes, secured in the ends of the edge pole.

The accumulator can comprise a rope path having two fixed sheaves and two movable sheaves, with the movable sheaves being mounted together on the end of the ram so that they can move towards or away from the fixed sheaves.

The single hydraulic pump can be conveniently mounted on a side of the vehicle, with the direction of ram extension being along the side of the vehicle.

Radius arms can be fitted at each end of the container, one end of each arm being mounted on a pivot axis lying substantially on the longitudinal centre line of the container, and the other end of each arm being attached to the edge pole such that the edge pole is constrained to move in an arc centred on the pivot axis, above the guide tracks.

The guide tracks will normally be arcuate.

A remote control unit can be used to control the hydraulic pump.

A quick-release fastening can be provided between the centre pole and the cover retraction motor to allow the two to be separated for servicing, and the cover - 4 retraction motor and the torque arm can form a single unit on the torque arm.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective end view of a container fitted with apparatus according to the invention; Figure 2 is a perspective view similar to that of Figure 1 but on a larger scale and showing the cover fully retracted; Figure 3 is a perspective view opposite to that of Figure 2; Figure 4 is a side view of the container, in the form of a trailer with a drawbar, showing the hydraulic system; Figure 5 is a side view of the power pack; Figure 6 is a perspective view of the power pack; Figure 7 shows a schematic hydraulic circuit; Figure 8 is a hydraulic diagram showing the hydraulic circuit driving the hydraulic motor; and - 5 Figure 9 shows a further constructional feature.

Figure 1 shows the top half of a container 10 which has an open top 12 which can be closed by a cover 14. In Figure 1, the cover 14 is shown just partly opened.

The cover 14 is a flexible web-type material. In most cases it will be a waterproof sheet, but it could also be a net or mesh of some sort.

The open top of the container 10 has guide tracks 16, 18 at its opposite ends and (in this embodiment) a central guide track 20. The guide tracks are curved so that when the cover is in place it sheds water. On containers of shorter length a central guide track 20 may be omitted.

The cover 14 has one edge 22 permanently secured to a longitudinal edge of the container 10. The opposite edge 24 is mounted on a pole 26, for example, by forming a sleeve in the edge 24 and fitting the pole inside the sleeve.

A central pole 28 runs the length of the cover 14, with its ends supported on the guide tracks 16, 18. The central pole 28 is fixed alog a line 29 to the cover 14, so that when the pole is rotated about its axis, the cover 14 winds up around the pole. - 6

To retract the cover a motor 30 mounted at one end of the pole 28 is energized to rotate the pole in the direction indicated by an arrow 32. The motor 30 is fixed on a torque arm 34, and this presses against the guide track 16 to provide a reaction surface against which the motor can work in rotating the pole 28. As the pole rotates, the material of the cover 14 is wound onto it from both sides, and the pole 28 travels towards the edge 22. The contact surface 36 of the torque arm 34 slides along the guide track 16 as this happens.

When the cover is fully wound up (as can be seen in Figure 2) the poles 24, 28 and all the material of the cover 14 come to lie above the right hand edge 22 of the container, where retaining arms 38 serve to retain the cover in a position from which it can be returned to its extended position covering the open top 12 of the container.

To close the cover, the pole 26 has to be pulled across the container, while the pole 28 is allowed to rotate freely, thus unrolling the rolledup cover.

Figure 4 shows an arrangement with a fixed length rope anchored at both ends, 62 and 64. The rope passes through the pole 26, being guided through low-friction ceramic bushes at each end, and is then passed over a system of pulleys 66. Two pulleys 66a and 66b are fixed. The other two pulleys 66c and 66d are carried - 7 - on the end of a piston rod 68 which is connected to a piston 69 guided in a hydraulic cylinder 70.

In Figure 4, the cover is shown closed. To open the cover, the motor 30 is energised, as described earlier, and the cylinder 70 is set to allow flow from one side of the piston 69 to the other. As the cover opens, the rope 60 will be pulled off from the pulley system 66 which acts as an accumulator so that, when the cover is fully open, the pulleys 66d and 66c will end up close to the fixed pulleys 66a and 66b.

To close the cover, the cylinder will be set so that the right hand side of the piston will be pressurized to retract the piston rod 68 into the cylinder and to draw the rope 60 into the accumulator 66. This will draw the pole 26 and the cover over the top of the container. At the same time, the motor 30 will be unpressurized and will be allowed to rotate freely.

Both the opening and the closing operations are driven from a hydraulic power pack 40 (Figure 5). The power pack comprises an electrically operated motor 42 which drives a pump 43 to pump hydraulic fluid from a reservoir 44, via a manifold 46 through hoses 48, 50 to the motor 30. The motor 42 is energised by a solenoid 52 which itself is controlled by a control unit 54 (Figure 7), the control unit also controlling a valve 56 mounted on the manifold 46. - 8

The power pack 40 can be mounted together with the cylinder 70 in a frame mounted on the side of the container. Longitudinal adjustment of the frame relative to the fixed pulleys 66a, 66b may be desirable and possible to fine tune the cover closing arrangement.

The pump 43 is housed within the reservoir 44, and is driven by a drive shaft of the electric motor 42 which passes through the centre of the manifold block 46.

Figure 8 shows the hydraulic circuit, with a pressure connection P and a return to tank connection T. corresponding to the hoses 48 and 50. A oneway check valve 47 and a pressure relief valve 49 are both included in the circuit.

Figure 7 shows the electrical circuit which controls the apparatus in combination, with a simplified illustration of the hydraulic circuit. The control unit 54 can be remote from the trailer. For example, it can be located in the tractor cab, so the driver can extend or retract the cover from the safety of his cab.

Preferably the control unit 54 will be hard-wired to the power pack 40, but those skilled in the art will realise that a remote, wireless link could also be used.

To open the cover, the solenoid 52 will be energised to drive the motor 42 which in turn drives the pump 46 to pump hydraulic fluid around the circuit 48, 50 and thus - 9 - to rotate the pump 30. During this stage of operation, a valve 56 associated with the motor 30 will be closed so that the hydraulic pressure generated by the pump drives the motor in rotation. At the same time, a second valve 57 in a bypass passage 59 will be open because the piston 72 has to move to the right (in Figure 7) to allow the rope 60 to be withdrawn from the accumulator and this will require flow from one side of the piston to the other. When the cover is to be closed the valve 56 will be opened, so that the motor is no longer driven, the valve 57 and a third valve 61 will be closed, so that the hydraulic pressure will act on the piston 72 which will than move to the left to draw the rope 60 into the accumulator 66 and thus to close the cover as previously described.

It will be seen from Figure 3 that the centre pole 28 rotates in a flange plate 64 which is mounted on a backing plate 66 fixed to the arm 34. Two quick release pins 68 can be removed, to allow the pole 28 and the cover 14 to be separated from the arm 34.

Either the cover 14 and/or the arm 34 together with the drive unit 40 can then be replaced or serviced independently. In the case of the arm 34, it may be necessary to disconnect the electrical connections to the control unit 54, but this can simply be done by unplugging plug-in electrical connections.

There are occasions when a container will be fully loaded up to or even slightly above the limits of the - 10 guides 16, 18. In order to avoid dragging the loaded material off the top of the container, the container may include radius arms 80 (Figure 9) which can be connected to the pole 26 at each end. When the pole is moved across the container, it then has to follow an arcuate path 82, centred on the pivot point 84 where the radius arm is attached to the container, and thus the pole is lifted above the guide tracks until it reaches the other side of the container.

In comparison with known systems for extending and retracting covers, the arrangement described here saves weight, provides a compact installation and allows simple servicing of the components. 11

Claims

Claims 1. Apparatus for extending and retracting a cover over an

open-topped container, the apparatus comprising guide tracks forming part of the container and extending transversely across the container at the top of each end thereof, a cover adapted to extend across the open top of the container, one of the edges of the cover being fixed to a longitudinal edge of the container, the opposite edge of the cover being fixed to an edge pole which extends the length of the cover, and a centre pole fixed along the centreline of the cover, such that the ends of the edge and centre poles run on the guide tracks, wherein opening of the cover is achieved by rotating the centre pole about its own axis to wind up the cover on the pole, and closing of the cover is achieved by pulling on a rope which extends through the edge pole while allowing the centre pole to rotate freely, and both opening and closing actions are powered by a single hydraulic pump.
2. Apparatus as claimed in Claim 1, wherein a single closure rope runs from a fixed point at one end of the vehicle, through the pole from one end thereof to the other, and to an accumulator provided with a hydraulic ram so that when the ram is retracted, the rope is pulled to draw the edge pole to the edge of the vehicle. - 12
3. Apparatus as claimed in Claim 2, wherein the edge pole has a bush at each end which allows the rope to be drawn freely through the pole.
4. Apparatus as claimed in Claim 3, wherein the bushes are ceramic bushes, secured in the ends of the edge pole.
5. Apparatus as claimed in any one of Claims 2 to 4, wherein the accumulator comprises a rope path having two fixed sheaves and two movable sheaves, with the movable sheaves being mounted together on the end of the ram.
6. Apparatus as claimed in any one of Claims 2 to 5, wherein the single hydraulic pump is mounted on a side of the vehicle, and the ram extension is along the side of the vehicle.
7. Apparatus as claimed in any preceding claim, wherein radius arms are fitted at each end of the container, one end of each arm being mounted on a pivot axis lying substantially on the longitudinal centre line of the container, and the other end of each arm being attached to the edge pole such that the edge pole is constrained to move in an arc centred on the pivot axis, above the guide tracks.
8. Apparatus as claimed in any preceding claim, wherein the guide tracks are arcuate. - 13
9. Apparatus as claimed in any preceding claim, wherein the hydraulic pump is controlled by a remote control unit.
10. Apparatus as claimed in any preceding claim, wherein a quick-release fastening is provided between the centre pole and the cover retraction motor to allow the two to be separated for servicing.
11. Apparatus as claimed in Claim 10, wherein the cover retraction motor and the torque arm form a single unit on the torque arm.
12. Apparatus for extending and retracting a cover over an open-topped container substantially as herein described with reference to the accompanying drawings.