GB2398763A

GB2398763A - Cover deployment system for cargo carriers

Info

Publication number: GB2398763A
Application number: GB0304245A
Authority: GB
Inventors: George Robert Boden
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-02-25
Filing date: 2003-02-25
Publication date: 2004-09-01
Anticipated expiration: 2023-02-25
Also published as: GB0304245D0; GB2398763B

Abstract

Control apparatus (40) for a load cover deployment system, for example, for use on a tipper-bodied road lorry 10. The control apparatus comprises a drive wheel 54 upon which a control element of the deployment system can be wound - this is typically a chain (56) would on a chainwheel (52). The control apparatus also includes a drive mechanism that includes a drive handle 42 operable by a user to turn the drive wheel, and a locking mechanism 80,82 that serves to prevent rotation of the drive wheel other than during operation of the drive handle by a user. The control apparatus allows a cover 22 to be drawn into position against the action of a returning spring 84.

Description

Covers for cargo carriers This invention relates to covers for cargo

carriers. It has particular application to cargo- carrying road vehicles such as tipper-bodied lorries, and it will be described with reference to such applications. However, the invention might also find application to rail vehicles and other applications, both on and off vehicles.

When a tipper lorry is used to carry a cargo, it is common to cover the cargo bay of the lorry with a cover of flexible sheet material. The principal purpose of such a cover is to prevent the load from being blown out of the vehicle when it is underway. In their most basic form, such systems require a cover to be deployed manually. However, it is common (and becoming ever more so) to provide a deployment system whereby the cover can be deployed automatically.

The type of deployment system used most commonly is called a front-torear system. Is such a system, a roller is mounted across the forward end of a cargo container. When the sheet is withdrawn, it is wound onto the roller. A free end of the sheet is secured to a transverse bar, which is carried between a pair of spring arms, disposed to opposite sides of the body. The arms are urged by a spring towards the rear of the body. Thus, as the sheet allowed to unwind from the roller, it is carried to the rear of the body by the arms.

It is known to provide fully-automated deployment systems whereby the cover can be deployed and removed by way of electric motors that control movement of the roller.

However, such systems do not find favour with all vehicle operators because of their complexity. Therefore, an alternative type of manuallyoperated deployment system provides a manual control for the roller, which a user can operate using a manual crank mechanism. Movement of the cover under the action of the spring arms must be controlled. This is not difficult to achieve in automated systems. However, on manually operated systems it is usual to provide a friction brake that must be properly operated by a user. If brake is not operated correctly, the cover may be able move freely under the action of the spring. This will cause it to move rapidly, possibly resulting in damage to equipment or injury to personnel.

An aim of this invention is to provide apparatus to prevent or reduce the likelihood of such unsafe operation of a manually-operated deployment system for a load cover.

From a first aspect, this invention provides control apparatus for a load cover deployment system, the control comprising a drive wheel upon which a control element of the deployment system can be wound, a drive mechanism manually that includes a drive handle operable by a user to turn the drive wheel, and a locking mechanism that serves to prevent rotation of the drive wheel other than during operation of the drive handle by a user.

Thus, when a user simply lets go of the drive handle, the cover does not fly back under the force of the spring arms because the locking mechanism prevents it from so doing by stopping movement of the control element. The cover can be deployed only when the user engages with the handle to control withdrawal of the cover.

Typically, the control element will be a drive chain, in which case, the drive wheel is most usually a chainwheel.

In a preferred embodiment, the handle is operated by way of rotation about a drive axis.

Conveniently, the locking mechanism of such embodiments may be released by application of force to the drive handle in a direction that is generally parallel to the drive axis. For example, the movement required to effect release may cause the handle to pivot about an axis that is substantially normal to, and that may intersect with, the drive axis.

in practical embodiments of the invention, the drive mechanism may include a gear train that connects the drive handle to the drive wheel. The locking mechanism may then operate by locking the gear train. For example, it may operate by bringing an additional locking gear into mesh with the gears of the gear train.

From a second aspect, this invention provides a load cover deployment system comprising a control according to the first aspect of the invention.

A load cover deployment system embodying the invention typically includes a roller upon which the load cover can be carried. Rotation of the roller can wind the cover onto the roller, withdrawing it from the load. In such embodiments, the roller can be driven for rotation by the control. Suitable means for drawing the cover from the roller are typically provided. Such means may include a spring system, for example, including a pair of arms urged by a torsion spring to drive the cover over the load.

Typically, the control is connected to the roller by a continuous drive element, such as a chain.

Embodiments of the invention will now be described in detail, by way of example, and with reference to the accompanying drawings, in which: Figure 1 is a diagram showing a cargo cover embodying the invention installed on a cargo-carrying road vehicle; Figure 2 is an external view of control apparatus embodying the invention for the cargo cover of Figure 1; and Figures 2 and 3 are respectively side and top views of the control apparatus of Figure 1, showing its internal components.

With reference first to Figure 1, an embodiment of the invention will be described that is suitable for installation upon a road lorry 10 that has a tipping body 12, such as may be used for carrying quarried stone, or other heavy material. The tipping body 12 has a cargo container that is shaped as a box which is open upwardly.

The sheeting system comprises a roller 20 that extends across the top of a front wall of the tipping body 12. A sheet 22 of strong, flexible material is carried on the roller 20.

The sheet 22 is rectangular in shape, being dimensioned so that it can cover the upward opening of the container. A fixed end of the sheet 22 is secured to the roller 20, such that rotation of the roller 20 causes the sheet 22 to be wound onto it.

A chainwheel 24 is carried on the roller, fixed for rotation with it. A continuous loop of chain 26 is carried on the chainwheel 24. Movement of the chain causes consequent rotational movement of the roller 20, so it can cause the sheet 22 to be wound onto or off of the roller 20, depending upon the direction of rotation.

The sheeting system includes a pair of spring arms 32, the arms being disposed to respective opposite sides of the body 12. A lower end part of each arm is carried on the body 12 for rotation about an axis that is generally horizontal and transverse to the fore- and-aft axis of the body 12. Each arm 32 is acted upon by a torsional spring, whereby it is urged to rotate about the axis in a direction that urges the arm towards the rear of the body 12. A transverse bar 30 is secured to a free end of the sheet 22. The bar 30 is carried between end portions of the spring arms 32. The effect of the spring force is to urge the bar 30 towards the rear of the body 12, pulling the sheet 22 along with it.

It will, therefore, be understood that the rotation of the roller 20 will control movement of the sheet 22. As the roller is rotated in a direction to unwind the sheer, the action of the arms 32 will be to draw it rearwards, covering the load container in a deployed position, as shown in dotted lines and indicated at 22'. Rotation of the roller 20 in the opposite direction, against the spring force, will cause the sheet 22 to be withdrawn from the load container.

Control apparatus 40, being an embodiment of the first aspect of the invention is provided to control deployment and withdrawal of the sheet 22. The control apparatus allows a user to control operation of the deployment system by controlling rotational movement of the roller 20.

The control apparatus 40 is constructed on fixed inner and outer rectangular plates 44, 46 each of mild steel. The plates 44, 46 are fixed parallel to each other upon posts 48. For use, the inner plate 46 is secured to the tipping part of the vehicle body.

A drive shaft 50 extends through the plates, normal to them, projecting from the outer plate 44. The shaft 50 is carried for free rotation with respect to the plates 44, 46. An output chainwheel 52 is fixed to the shaft 50 for rotation with it, the chainwheel 52 being between the plates, close to the inner plate 44. Also carried on the shaft 50 between the plates 44, 46 is a primary spur gear 54. The chain 56 extends between the output chainwheel 52 and the chainwheel 24 on the roller 20, such that the two chainwheels are constrained to rotate together.

A drive handle 42 is secured to the shaft externally of the control apparatus 40 next to the outer plate 46. The drive handle 42 comprises a metal arm 60. At an inner end of the arm 60 a boss 62 is fixed. The boss 62 is secured to the drive shaft 50 close to its outer end by a pivot pin 64 that passes through an aperture in the boss 62 and the shaft 50. The arm 60 is thereby mounted such that it can pivot with respect to the drive shaft about an axis that is parallel to the outer plates 46.

A roller bearing 70 is carried on the arm 60. An inner race of the bearing 70 is carried on a bar that is fixed to the boss 62. An outer race of the bearing 70 for rotation about an axis that is generally parallel with the length of the arm 60. A hand wheel 72 is carried on the arm 60 close to its outer end, the hand wheel 72 projecting away from the outer plate 46. The hand wheel 72 is mounted such that it can rotate with respect to the arm 60 about an axis that is approximately parallel with the axis of the drive shaft 60.

Thus, a user can use the drive handle 42 to turn the chainwheel 52 and thereby control movement of the roller 20 and cover 22 attached to it through the chain 26.

The primary spur gear 54 is in mesh with an idler spur gear 76. The idler spur gear is carried between the plates 44, 46 for rotation about an axis that is normal to them.

A locking gear 80 is provided for rotation on a carrier arm 82. The carrier arm 82 is free to pivot around one of its end regions around the shaft 50. A tension spring 84 is connected to between the carrier arm 82 and a locating point 86 on the inner plate 44.

The action of the tension spring 84 is to urge the locking gear 80 into mesh with both the primary spur gear 54 and the idler spur gear 76. The result of this meshing is that all of the gears are locked against rotation. Consequently, the drive shaft 50 and the output chainwheel 52 are locked against rotation.

A release lever 90 is carried on a lug 92 that projects from the outer plate 46 such that it can rock about an axis that is substantially parallel with the plates 44, 46. A first end part of the release lever 90 carries a bolt 94 threaded through a lug formed in the release lever 90. The bolt 94 projects towards the carrier arm 82 and by rotation, it can be moved towards or away from the carrier arm 82. A lock nut is provided on the bolt 94 to lock its position on the carrier arm 82. An opposite projecting end part (shown at 96) of the release lever 90 projects through a slot in the outer plate 46.

The release lever 90 is arranged such that displacement of the projecting end part 96 through the outer plate 46 towards the inner plate 44 causes it to rock about its pivot, bringing the bolt into contact with the carrier arm, and then pushing the carrier arm to move the locking gear 80 out of mesh with the primary spur gear 54, so allowing it (and the components connected to it) to rotate.

The outer plate 46 is covered by an actuating plate 98. The actuating plate 98 is pivotable along one of its edge regions such that it can move pivotally towards and away from the outer plate 46.

In its normal condition (as shown in Fig. 3), the release lever 90 pushes the actuating plate 98 away from the outer plate 46. In this condition, the gears are locked. When a user applies pressure to the arm 60, causing it to pivot towards the outer plate 46, the outer race of the bearing 70 is urged against the actuating plate 98.

When sufficient force is applied through the hand wheel 72 to the arm 60 pivots, and this in turn causes pivotal movement of the actuating plate 98. This movement displaces the release lever 90 so releasing the gears. The arm 60 can be rotated by a user to move the chain 26 as described above, thereby allowing the sheet 22 to be deployed or withdrawn, as required. The outer race of the bearing 70 follows a circular path on the actuating plate 98, such that continual force can be applied to the actuating plate without substantially increasing frictional drag on the arm 60. When the user releases force on the arm 60, the spring 84 moves the release lever 90, pushing the actuating plate 98 away from the outer plate 46. This in turn causes the the gears to lock once again, thereby stopping all movement of the sheet 22.

It will, therefore, be understood that the operation of the control apparatus is such that movement of the sheet 22 cannot occur in an uncontrolled manner, because the gears are released only when a user grips and applies force to the arm 60. Even if the user releases the arm suddenly, only a small amount of movement of the sheet 22 will occur before the gears lock and stop any further movement.

Although the invention has been described with reference to use on a tipping lorry, it can be applied to many other applications. For example, it may be applied to a load cover for use on applied to a small, lightweight commercial vehicles, trailers, skips, demountable skip bodies, waste storage containers, railway wagons, articulated tipping trailer bodies of all sizes and of course any size of rigid tipping truck type vehicle and dump truck, to list just several of the entire range of potential applications. Clams

Claims

1. Control apparatus for a load cover deployment system, the control

comprising a drive wheel upon which a control element of the deployment system can be wound, a drive mechanism that includes a drive handle operable by a user to turn the drive wheel, and a locking mechanism that serves to prevent rotation of the drive wheel other than during operation of the drive handle by a user.

2. Control apparatus according to claim 1 in which the control element will be a drive chain.

3. Control apparatus according to claim 2 in which the drive wheel is most usually a chainwheel.

4. Control apparatus according to any preceding claim in which the handle is operated by way of rotation about a drive axis.

5. Control apparatus according to claim 4 in which the locking mechanism may be released by application of force to the drive handle in a direction that is generally parallel to the drive axis.

6. Control apparatus according to claim 5 in which the movement required to effect release causes the handle to pivot about an axis that is substantially normal to, and that may intersect with, the drive axis.

7. Control apparatus according to any preceding claim in which the drive mechanism includes a gear train that connects the drive handle to the drive wheel.

8. Control apparatus according to claim 7 in which the locking mechanism operates by locking the gear train.

9. Control apparatus according to claim 8 in which the locking mechanism operates by bringing an additional locking gear into mesh with the gears of the gear train.

lO.Control apparatus for a load cover deployment system substantially as described herein with reference to the accompanying drawings.

ll.A load cover deployment system comprising control apparatus according to any preceding claim.

12.A load cover deployment system according to claim 11 that includes a roller upon which the load cover can be carried.

13.A load cover deployment system according to claim 12 in which rotation of the roller can wind the cover onto the roller, withdrawing it from the load.

14.A load cover deployment system according to claim 13 in which the roller can be driven for rotation by the control apparatus.

15.A load cover deployment system according to claim 14 in which the control apparatus is connected to the roller by a continuous drive element, such as a chain.

16.A load cover according to any one of claims 11 to 15 including suitable means for drawing the cover from the roller are typically provided.

17.A load cover deployment system according to claim 16 in which the means for drawing the cover includes a spring system

18.A load cover deployment system according to claim 17 in which the spring system includes a pair of arms urged by a torsion spring to drive the cover over the load.

19.A load cover deployment system substantially as described herein with reference to the accompanying drawings.