WO2006120411A1

WO2006120411A1 - An improved sheeting system

Info

Publication number: WO2006120411A1
Application number: PCT/GB2006/001664
Authority: WO
Inventors: Ian Paul Couch; Benjamin Harrington
Original assignee: C & C Hydraulics Ltd; Dawbarn & Sons Ltd
Current assignee: C & C Hydraulics Ltd; Dawbarn & Sons Ltd
Priority date: 2005-05-06
Filing date: 2006-05-08
Publication date: 2006-11-16
Anticipated expiration: 2007-11-06
Also published as: GB0509220D0; WO2006120411A8

Abstract

A sheeting system is disclosed to respectively open and cover an open-topped container body to allow goods to be loaded into or from the container and to be covered during transit. The system has a tarpaulin sheet fixed along one of its edges to one edge of the container body. The sheet is fixed along its second edge to a pivotally mounted arm (14) whose pivoting action draws the second edge of the sheet from one side of the container to the other. A roller means (15) is provided intermediate to the first and second edges of the sheet to accordingly engage the sheet and so roll the sheet up when it is not covering the container. Actuators (12) to drive the pivotally mounted arm (14) are operated hydraulically and, where two actuators (12) are used, using a balanced system. Arcuate supports (10A, 10B) can be used to lift the sheet above the load.

Description

AN IMPROVED SHEETING SYSTEM

Field of the Invention

The present invention relates to apparatus for use in covering over the load- bearing container of a commercial vehicle. In particular, the apparatus is for use in a side-to-side or rollover sheeting system.

Background to the Invention

Many commercial vehicles used in the transport of loose goods such as sand, gravel, grain or other food commodities, typically retain the goods in a container which has no permanent roof, the absence of which facilitates loading of the container. Such vehicles do however often incorporate a retractable sheeting system to cover the load and so protect it from the elements or from being blown away in transport. Many fleet operators, in compliance with increasingly strict regulations governing such sheeting systems, now specify that the operation of the sheeting system should be carried out at ground level and preferably with the operator within the cab of the vehicle. The latter systems are increasingly favoured, as even when the operator is standing on the ground - thereby reducing the risk of falling or slip injuries - they are still exposed to the dangers from other vehicles and other activities in the vicinity of their own vehicle.

Many sheeting systems devised are of a manually operated type in which the operator physically moves the sheeting into the required position. However, such manual systems are time consuming to operate and require the operator, usually the driver of the vehicle to be beside the vehicle. Moreover, manual systems are not always easy to operate, requiring a degree of physical strength. They can also be slow to operate. The latter problem can result, when it is raining or snowing for example, in the load increasing in weight, which weight must be borne by the vehicle until the water drains away.

Motorised systems have been devised such as that disclosed in EP 1 232 889.

It is an object of the present invention to seek to improve on the above systems.

Summary of the Invention

According to a first aspect of the invention there is provided a sheeting system for extending and retracting a sheet over the mouth of an open-topped vehicle container body, the system comprising a sheet having a first edge fixed to a first side of the container body and a second edge, opposed to the said first edge;

a pivotally mounted arm mounted such that the end of the arm describes an arc from said first side of the container body to a second, opposite side of the container body;

an actuator to pivot the arm;

the sheet being attached along its second edge to the pivotally mounted arm, whereby motion of the end of the arm between the first and the second sides of the container body causes the sheet to respectively furl and unfurl across the container body;

the system further comprising a roller means mounted across the container body, windingly engaging the sheet intermediate the first and second edge.

The sheet can be readily brought between a position covering a load in the container body and a position in which the load is uncovered, whereby the leading edge of the sheet remains clear of any load.

Preferably, the container body includes arcuate supports, to engage the remaining edges of the sheet and lift them above the general level of the top of the container. The entire sheet can thereby be lifted above material in the container.

The pivotally-mounted arm is preferably elongate and orientated to be substantially parallel to the first and second side of the container body.

The system advantageously includes two actuators, conveniently hydraulic actuators, each operably connected to an end of the elongate pivotally-mounted arm to drive the pivoting action. The need for manual operation of the system is thereby obviated. Particularly advantageously, fluid from the actuators is coupled to maintain a balanced flow and ensure that both ends of the pivotable arm move at the same rate. Conveniently, the fluid passes from a first one of the actuators to the second.

Optionally, the or each actuator is located centrally with respect to the first and second edges of the container body. Alternatively, the or each actuator is offset by the same distance towards the first edge.

Preferably, a motor is operable to drive the rotation of the roller means to assist in furling and unfurling the sheet. The roller means is advantageously mounted to track elements to guide motion of the roller means across the container body. Particularly, advantageously, the track elements are located on the arcuate supports.

According to a second aspect of the invention there is provided a vehicle having a container body including a sheeting system as described above.

Brief Description of the Drawings

The invention will now be described with reference to the accompanying drawings, which show by way of example only one embodiment of a sheeting system. In the drawings:

Figure 1 is an illustration of a mechanism showing a pivotable arm bar in a number of positions; Figure 2 is an actuator mechanism;

Figure 3 illustrates a control mechanism.

Figure 4 is a perspective view of a hydraulic system, including manifold; and

Figure 5 is a partially cut away perspective view of a lock.

Detailed Description of the Invention

Referring initially to Figure 1, this shows in representation, the upper body of a container (not illustrated) typically found as part of a goods vehicle and designed to hold solid materials such as gravel, sand, tar, loose waste material etc. The container for use in conjunction with the present invention has two arcuate canopies 1OA, 1OB across the width of the container at the front and rear of the container. The canopies 1OA, 1OB perform a dual function; the first function is to support the tarpaulin (also not illustrated) and to allow it to arch over the load so enabling more material to be transported. This is particularly useful where particulate material is normally added to the container in such a way that more material is present in the middle of the container. The second function of the canopies is to protect the actuator mechanism described below. As a consequence of the actuators being mounted in relatively enclosed canopies; pivot points 11 pertaining to an actuator 12 should be provided with maintenance free bushes.

The tarpaulin material, which functions as a protective cover is square or rectangular in shape and fixedly mounted along a first edge to the side of the container. The opposed edge of the tarpaulin is attached along the straight section 13 of the tubular tarpaulin arm 14. Intermediate the two above opposed ends of the tarpaulin, the tarpaulin engages and is windably mounted around a roller 15.

In order to extend the tarpaulin across the container, the arm 14 is pivotally attached at a pivot point 11 from a first position (shown at 16A) to the second position (shown at 16B). To enable pivoting to occur, the tarpaulin arm 14 is coupled to an actuator arm as shown in Figure 2 via a rotatable shaft 20. Pressure firom the hydraulic system contained in the cylinder 21 causes extension or retraction of the actuator cylinder arm 22 therefore is converted into rotational motion of the tarpaulin arm 14 by the coupling elements 23-25. Furthermore, the roller 15 is mounted to a hydraulic motor which acts to wind the tarpaulin about the roller 15 and so take up any slack and avoid damage to the tarpaulin as it is rolled up.

Operation of the apparatus is achieved through the use of a balanced hydraulic system which acts to keep both actuators in synchronised operation. It is known however that such balanced systems have problems in their being set up. Moreover once set up, due to the closed nature of the system, effective sealing must be provided. To set up such a system is time consuming and can lead to wastage of large amounts of hydraulic oil as air is bled out of the system. In order to alleviate this problem a relief valve is mounted into the line on the full bore side of the master cylinder, with a line teed off onto the annular side of the master cylinder. When the master cylinder is operated for the first time the master cylinder fills with oil until the end of the first stroke is reached. The relief valve lifts and the oil is allowed to enter the balanced line. The slave actuator then commences operation. If necessary the hoses are slackened to enable air to be purged from the balanced line. In a further modification the relief valve is directly incorporated into the master cylinder which reduces space usage along with the number of hoses and fittings.

In use, to retract the tarpaulin from closed to an open position the hydraulic system causes the actuator cylinder to retract the arm. Pressurised oil from a DC power pack 30 is fed into the annulus side of the rear cylinder actuator. Oil from the full bore side of the rear cylinder actuator is supplied directly to the annulus side of the front canopy cylinder activator. By this means a balanced system is ^' achieved in that the volume of oil displaced from the rear actuator is the same as the volume supplied to the front actuator.

At the same time as actuation of the canopy cylinder, oil is supplied to the roller hydraulic motor which acts to wind the tarpaulin and provides initial lift to start the furling of the tarpaulin. The roller hydraulic motor is mounted to a track located on the upper surface of the front canopy. The roller motor is capable of moving with the roller as the tarpaulin is furled and unfurled.

In order to unfurl the tarpaulin and draw it across the container then, to a large extent, the reverse process is followed to that described above. However, oil is not supplied to the roller motor and the motor itself, as it turns, serves as a breaking means to prevent too rapid motion of the arms. The roller also thereby serves to keep the tarpaulin tightly wound about the roller until the tarpaulin is in the fully closed position. When in the fully closed position the end of the tarpaulin arm 14 can extend over and lie below the edge of the container. Alternatively the shaft 13 can rest on the edge of the container.

The above system provides a safer means of covering and uncovering the load as the DC motor can be operated by remote control from the cab, or via a pendant control operated inside the cab as illustrated in Figure 3.

A number of alternative embodiments of the elements can be contemplated which do not depart from the overall scope of the invention. The main pivot arm 14 can be assembled as follows. Firstly, a first cranked linkage is pressed onto the main shaft with the drive key of the cranked linkage in place. A spacer is slid onto the smaller shaft diameter. This both correctly sets the mounting distance and additionally provides support. The pivot arm is pressed onto the main shaft the drive key again in place and a bolt and washer fastened into place and secured by means of a proprietary adhesive. This assembly is then passed through the main body of the actuator 12 and the second cranked linkage and key pressed into position.

An alternative to the above assembly of the arm 14 is to cast the main shaft and the first cranked linkage as a single component. This alternative significantly reduces the number of components and the assembly time required. Moreover, the cast component is stronger (probably more than 3 times so) than the first assembly with respect to shear across the shaft and to its rotational characteristics.

The hydraulic system to operate the actuators can incorporate standard control valves. For example a Cetop 3 directional valve is mounted onto a manifold, a double over centre valve and check valve are mounted into the line together with a flow control valve. In order to decrease the assembly time and overall weight of the system, the valves can be incorporated into the manifold block 40 shown in Figure 4. This feature also enables the manifold, including thereby the valves to be fitted directly onto the power pack.

In addition to the features shown in Figure 1, the system also includes a locking mechanism, illustrated in Figure 5 to hold the tarpaulin arm 14 in position when the vehicle is in transit. The lock 50 includes a retractable bolt 51 and is operable by the same hydraulic system used to move the tarpaulin across the container body. The connectivity is such however that the bolt 51 is extends only when the tarpaulin is in the closed position. The extended bolt 51 then acts to prevent the tarpaulin arm 14 from lifting up due to the torque imported to the tarpaulin arm 14 when the vehicle is moving. The locks are also teed into the hydraulic system such that they withdraw when the user operates the system, thereby allowing the tarpaulin to be furled and unfurled. The locks are further made safe through the use of spring loading is included to lock in position, with pressure being required to lift. Brackets 52 are provided to secure the lock to the container.

In addition as an alternative to the use of the lock, the strength of the materials used can be increased. This option obviously increases the cost of materials and is also alone not sufficient for all purposes in particular those situations in which high torque forces are generated.

Although the actuators can be mounted centrally along the edge of the container body, it has been found advantageous to offset the mounting towards the closed side. For a typical container body the size of the offset can be around 0.1m. The advantage of the offset is that the tarpaulin and the roller 15 can be kept within the vehicle body width when the system is open. The tarpaulin arm 14 can moreover be produced without the curve shown in Figure 1. This allows cost savings to be made in manufacture. Moreover, the tarpaulin no longer overhangs the container body when in the open position which minimises potential damage from accidental knocks. A further advantage of re-positioning the actuator is that due to the geometry of the system, closure occurs without the need for full movement of the tarpaulin/arm system. The clamping force when the system is closed 13 is therefore increased.

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible with the scope of the appended claims.

Claims

CIaims

1. A sheeting system for extending and retracting a sheet over the mouth of an open-topped vehicle container body, the system comprising a sheet having a first edge fixed to a first side of the container body and second edge, opposed to the said first edge;

a pivotally mounted arm (14) mounted such that the end of the arm (14) describes an arc from said first side of the container body to a second, opposite side of the container body;

an actuator (12) to pivot the arm (14)

the sheet being attached along its second edge to the pivotally mounted arm (14), whereby motion of the end (13) of the arm (14) between the first and the second sides of the container body causes the sheet to respectively furl and unfurl across the container body;

the system further comprising a roller means (15) mounted across the container body, windingly engaging the sheet intermediate the first and second edge.

2. A system according to Claim 1 wherein the container body includes arcuate supports (10A₅IOB) to engage the remaining edges of the sheet and lift them above the general level of the top of the container.

3. A system according to Claims 1 or Claim 2, wherein the pivotally- mounted arms (14) is elongate and orientated so as to be substantially parallel to the first and second side of the container body.

4. A system according to any preceding claim, having two actuators.

5. A system according to Claim 4 wherein each actuator is a hydraulic actuator

6. A system according to Claim 4 or Claim 5 wherein each actuator is operably connected to an end of the elongate pivotally-mounted arm to drive the pivoting action.

7. A system according to Claims 5 and 6 wherein fluid from the actuators is coupled to maintain a balanced flow and ensure that both ends of the pivotally mounted arm move at the same rate.

8. A system according to Claim 7, wherein the fluid passes from a first one of the actuators to the second.

9. A system according to any preceding claim, wherein the or each actuator is located centrally with respect to the first and second edges of the container body.

10. A system according to Claims 1 to 8, wherein the or each actuator is offset by the same distance towards the first edge of the container.

11. A system according to any preceding claim, wherein a motor is operable to drive the rotation of the roller means (15) to assist in furling and unfurling the sheet.

12. A system according to any preceding claim, wherein the roller means (15) is mounted to one or more track element to guide motion of the roller means (15) across the container body.

13. A system according to Claims 12, wherein the or each track element is located on the arcuate supports (10A₃IOB).

14. A vehicle including a container body and a sheeting system according to Claims 1-13.

15. A sheeting system substantially as herein described with reference to the accompanying drawings.