GB2569834A

GB2569834A - Vehicle for spreading aggregate chippings

Info

Publication number: GB2569834A
Application number: GB1809617.2A
Authority: GB
Inventors: Dearing Keith
Original assignee: Pavemac Ltd
Current assignee: Pavemac Ltd
Priority date: 2017-11-21
Filing date: 2018-06-12
Publication date: 2019-07-03
Anticipated expiration: 2038-06-12
Also published as: GB201809617D0; GB2569834B; IE87331B1; IE20180458A1

Abstract

A vehicle for spreading aggregate chippings comprises an elongate hopper 32 and an extension hopper 34 for receiving and dispensing chippings, the elongate hopper having a fixed length along an axis of the hopper. The extension hopper also has a fixed length and is moveable relative to the elongate hopper in a direction parallel to the axis of the elongate hopper. This allows the vehicle to dispense chippings over a variety of road widths. A feed mechanism 92 conveys aggregate chippings from the elongate hopper to the extension hopper. A pair of wheels 100, 102 convey the vehicle in a direction substantially perpendicular to the axis of the elongate hopper, the wheels being moveable relative to each other to change a distance between them. A pair of tracks may be carried by the wheels. The feed mechanism may be a screw conveyor and the vehicle may include a second extension hopper 36. The movement of the extension hoppers may be independent, and the vehicle may comprise a power unit to drive the wheels.

Description

Vehicle for Spreading Aggregate Chippings

BACKGROUND

This invention relates to a vehicle for spreading aggregate chippings over a road surface. In particular the invention relates to a self-powered vehicle for spreading aggregate chippings.

In the UK, one method of maintaining a road surface is to apply a surface dressing. In this method a layer of bituminous binder is spread over the surface of the road. Aggregate chippings are then spread evenly over the binder and compacted into the binder. The road can then be re-opened with a speed restriction in place and the slow moving traffic further embeds the aggregate chippings into the bitumen. After a period of time any remaining loose chippings are swept away.

In a similar process, one method of resurfacing a road surface is, with a first machine, to lay a base coat of asphalt and, with second machine, to lay on top of this a coating of stone chippings that have been pre-coated in bitumen. The chippings are then rolled into the asphalt layer by a roller. Small protrusions of the stones above the asphalt provides improved skid resistance to the road surface. As with surface dressing, the road can be re-opened with a speed restriction in place and the slow moving traffic will further embed the aggregate chippings into the bitumen. After a period of time any remaining loose chippings are swept away.

To complete the surface dressing or resurfacing a number of pieces of equipment or vehicles are needed including a bitumen binder spreader or an asphalt paver, a chip spreading machine or chippings spreader and a roller to compact the chippings. Chippings spreaders typically comprise an elongate hopper or trough for receiving and holding chippings to be spread. A base of the elongate hopper includes a mechanism for dispensing the chippings from the hopper at a predetermined rate. The chippings spreader may also include a feed hopper for

-2dispensing chippings into the elongate hopper. Chippings spreaders are preferably self-propelled or self-driven and have wheels located at the ends of the elongate hopper.

The length of the trough, between the wheels, should be at least as long as the width of the area of freshly laid bitumen or asphalt so that the wheels of the chippings spreader run on solid ground on either side of the area and do not run over the freshly laid bitumen or asphalt. Preferably the trough is not significantly longer than the width of the area of bitumen or asphalt so that excess stone chippings are not wasted at the edges. As such, known chippings spreaders come in three fixed widths of 12 foot, 14 foot and 16 foot between the wheels. Companies must, therefore, maintain a number of each size of vehicle to be able to provide the correct vehicle for a given job. Furthermore, frequently an incorrect width of chip spreader is deployed on a job and must be returned and a further vehicle dispatched. This is, therefore, costly both in terms of money and time.

It is an aim of the present invention to provide a vehicle for spreading aggregate chippings that overcomes some of the disadvantages of prior art chippings spreaders, whether mentioned herein or otherwise.

SUMMARY OF THE INVENTION

The present invention provides a vehicle for spreading aggregate chippings comprising:

an elongate hopper for receiving and dispensing aggregate chippings, the elongate hopper having a fixed length along an axis of the hopper;

an extension hopper for receiving and dispensing aggregate chippings, the extension hopper having a fixed length and being moveable relative to the elongate hopper in a direction substantially parallel to the axis of the elongate hopper;

a feed mechanism for conveying aggregate chippings from the elongate hopper to the extension hopper; and

-3a pair of wheels arranged to convey the vehicle in a direction substantially perpendicular to the axis of the elongate hopper, the two wheels of the pair of wheels being moveable relative to each other to change a distance between the two wheels.

The extension hopper is moveable or slidable with respect to the elongate hopper so as to increase an overall length of hopper in a direction parallel to the axis of the elongate hopper. The elongate hopper has a first end and a second end, the axis extending between the first and second ends. The extension hopper has a first end and a second end, and an axis of the extension hopper extends between the first and second ends. The axis of the extension hopper is preferably parallel to but offset from the axis of the elongate hopper.

The extension hopper is preferably moveable into a position in which it overlaps the first end of the elongate hopper. Preferably at least a part of the length of the extension hopper overlaps or is disposed adjacent to at least a part of the length of the elongate hopper.

The extension hopper may be moveable between a first, retracted position in which a first end region of the extension hopper does not extend beyond the first end of the elongate hopper and a second, extended position in which a first end region of the extension hopper extends beyond the first end of the elongate hopper. In the first position the first end of the extension hopper may be flush with or aligned with the first end of the elongate hopper. Alternatively, in some embodiments, a first end region of the elongate hopper may extend beyond the first end of the extension hopper when the extension hopper is in the first position.

Preferably the feed mechanism is only engaged with or engageable with the extension hopper when the extension hopper is in the second position. In other embodiments the feed mechanism may be engaged with the extension hopper at all times, but the feed mechanism may only be operable to transfer aggregate chippings into the extension hopper when the extension hopper is in the second

-4position. The feed mechanism may comprise a screw conveyor or an auger conveyor.

In preferred embodiments one of the wheels is connected to the extension hopper such that movement of the extension hopper relative to the elongate hopper changes the spacing between the two wheels. Preferably the other of the two wheels is connected to the elongate hopper.

In some embodiments the vehicle comprises a second extension hopper moveable with respect to the elongate hopper. Preferably a second feed mechanism is arranged to convey aggregate chippings from the elongate hopper to the second extension hopper.

The second extension hopper is preferably moveable or slidable with respect to the elongate hopper so as to increase an overall length of hopper in a direction parallel to the axis of the elongate hopper. The second extension hopper has a first end and a second end, and an axis of the second extension hopper extends between the first and second ends. The axis of the second extension hopper is preferably parallel to but offset from the axis of the elongate hopper. Preferably the axis of the second extension hopper is aligned with the axis of the first extension hopper.

The second extension hopper is preferably moveable into a position in which it overlaps the second end of the elongate hopper. Preferably at least a part of the length of the second extension hopper overlaps or is disposed adjacent to at least a part of the length of the elongate hopper.

The second extension hopper may be moveable between a first, retracted position in which a first end region of the second extension hopper does not extend beyond the second end of the elongate hopper and a second, extended position in which the first end region of the second extension hopper extends beyond the second end of the elongate hopper. In the first position the first end of the second

-5extension hopper is preferably flush with or aligned with the second end of the elongate hopper. Alternatively, in some embodiments, a second end region of the elongate hopper may extend beyond the first end of the second extension hopper when the second extension hopper is in the first position.

Preferably the second feed mechanism is only engaged with or engageable with the second extension hopper when the second extension hopper is in the second position. In other embodiments the second feed mechanism may be engaged with the second extension hopper at all times, but the second feed mechanism may only be operable to transfer aggregate chippings into the second extension hopper when the second extension hopper is in the second position. The second feed mechanism may comprise a screw conveyor or an auger conveyor.

In embodiments including first and second extension hoppers the movement of the first and second extension hoppers may be linked so that movement of the first extension hopper is matched by a corresponding movement of the second extension hopper. Each of the extension hoppers may be moveable into a third or intermediate position between the first and second positions. In particular, in preferred embodiments the first and second extension hoppers are moveable into the intermediate position in which the first end region of the first extension hopper extends beyond the first end of the elongate hopper by a first distance and the first end region of the second extension hopper extends beyond the second end of the elongate hopper by the first distance. The first and second extension hoppers are also moveable into the second position in which the first end region of the first extension hopper extends beyond the first end of the elongate hopper by a second distance and the first end region of the second extension hopper extends beyond the second end of the elongate hopper by the second distance, the second distance being greater than the first distance.

Alternatively, the first and second extension hoppers may be moveable independently. In these embodiments, for example, the first extension hopper may be moveable into the second position while the second extension hopper is in the

-6first position.

In embodiments including first and second extension hoppers the first wheel of the pair of wheels may be connected to the first extension hopper and the second wheel of the pair of wheels may be connected to the second extension hopper.

In preferred embodiments the elongate hopper has a length of between 9 feet and 14 feet, and most preferably has a length of 12 feet. The or each extension hopper preferably has a length of between 2 feet and 4 feet, and most preferably has a length of about 3 feet.

In a particularly preferred embodiment in which the vehicle comprises two extension hoppers, the elongate hopper has a length of 12 feet and the first and second extension hoppers are moveable into a position in which there is a distance of 14 feet between the outermost first ends of the extension hoppers and into a further position in which there is a distance of 16 feet between the outermost first ends of the extension hoppers.

The vehicle of the present invention is preferably self-powered or self-driving. Accordingly, the vehicle does not need to be towed or moved using another vehicle. The vehicle preferably comprises an engine configured to drive the wheels of the vehicle to confer motion to the vehicle. Power from the motor may also be used to drive the first and/or second feed mechanisms. Alternatively, a different power unit may be provided for this purpose such as a battery.

The vehicle may comprise two pairs of wheels. In this way there are two wheels disposed at a first side of the vehicle and two wheels disposed at a second side of the vehicle. The two wheels disposed at the first side of the vehicle may both be connected to the first extension hopper. The two wheels disposed at the second side of the vehicle may both be connected to the second extension hopper when present. Alternatively, two wheels may be connected to the first extension hopper and two wheels may be connected to an opposite end of the elongate hopper.

-7 In another arrangement, the vehicle may comprise a pair of tracks, with each track being carried by a respective one of the pair of wheels. In this case, each of the pair of wheels may comprise a drive or a guide wheel for the tracks. At least one further pair of wheels for guiding the tracks may be provided. The provision of tracks can be helpful in improving the stability of the vehicle and for reducing the pressure on the ground, for example when the vehicle is to be used on rough or uneven ground or on soft verges.

In some embodiments the vehicle may comprise a feed hopper configured to hold aggregate chippings and to dispense the aggregate chippings into the elongate hopper. The feed hopper is preferably disposed above the elongate hopper. The feed hopper may be movable with respect to the elongate hopper, preferably in a direction along the axis of the elongate hopper. Alternatively, in some embodiments, the feed hopper may remain in a fixed position with respect to the elongate hopper. In other arrangements, the feed hopper may extend along the length of the elongate hopper, or the elongate hopper may have an open top to allow chippings to be loaded directly into the elongate hopper. In both of these arrangements, chippings can be loaded into the vehicle from either side.

The elongate hopper may comprise a distribution mechanism for distributing aggregate chippings along the length of the elongate hopper. The distribution mechanism may comprise a screw conveyor or auger conveyor.

In some embodiments the or each extension hopper comprises a screw conveyor or auger conveyor for distributing aggregate chippings along the length of the extension hopper.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described by way of example only and with reference to the accompanying drawings, in which:

-8Figure 1 illustrates a prior art vehicle for spreading aggregate chippings;

Figure 2 is a schematic view from above of a prior art vehicle for spreading aggregate chippings moving along a road;

Figure 3 is a view from above of a vehicle for spreading aggregate chippings according to a first embodiment of the present invention;

Figure 4 is a view from the side of the vehicle of Figure 3;

Figure 5 is a cross sectional view of the vehicle of Figure 3 along the line V - V;

Figure 6 is a view from above of the vehicle of Figure 3 in a retracted configuration, showing hoppers with feed and distribution mechanisms;

Figure 7 is a view from above of the vehicle of Figure 6 in an extended configuration;

Figure 8 is a view from above of a vehicle for spreading aggregate chips according to a second embodiment of the invention;

Figure 9 is a view from the side of the vehicle of Figure 8; and

Figure 10 is a perspective view of the vehicle of Figure 8.

DETAILED DESCRIPTION

Figures 1 and 2 illustrate a prior art vehicle 10 for spreading aggregate chippings, commonly referred to as a chippings spreader 10. The chippings spreader 10 comprises a chassis 12 on which is mounted a feed hopper 14 and a dispensing hopper 16. The dispensing hopper 16 is elongate and extends across the width of

-9the vehicle 10. The feed hopper 14 is disposed above the dispensing hopper 16. Wheels 18 are mounted to the chassis 12 at either end of the dispensing hopper

16. The chippings spreader 10 will typically be self-powered or self-driving, and is not towed by another vehicle. As such, the chippings spreader 10 includes its own engine and controls.

In use, the chippings spreader 10 deposits a layer of aggregate chippings along a road or path 20 that is being re-surfaced. Aggregate chippings are stored in the feed hopper 14 and are released from the feed hopper 14 into the dispensing hopper 16. The chippings are then dispensed or released from the dispensing hopper 16 onto the road surface, which will have typically been coated with a layer of bitumen or asphalt with which the aggregate chippings bind.

The length of the dispensing hopper 16 is such that this hopper 16 spans the full width of the road or path 20, as illustrated in Figure 2. As such, the wheels 18 of the chippings spreader 10 travel along ground either side of the road or path 20, and do not contact the freshly laid bitumen or asphalt.

To ensure that an even layer of aggregate chippings is deposited on the road surface, the aggregate chippings are preferably distributed evenly along the length of the dispensing hopper 16. This may be achieved by moving the feed hopper 14 along the length of the dispensing hopper 16 as aggregate is released from the feed hopper 14 into the dispensing hopper 16. Alternatively or additionally, the dispensing hopper 16 may comprise a distribution mechanism such as a screw conveyor that conveys aggregate chippings along the length of the hopper 16. If the dispensing hopper 16 includes a screw conveyor, the feed hopper 14 may remain in a fixed or stationary position with respect to the dispensing hopper 16, for example at one end of the dispensing hopper 16.

The aggregate chippings are dispensed from the bottom of the dispensing hopper 16 by a suitable dispensing mechanism as is known in the art.

-10Figures 3 to 7 illustrate a vehicle 30 for dispensing aggregate chippings according to an embodiment of the present invention.

The vehicle 30 comprises an elongate hopper 32 and two extension hoppers 34,

36. Each of the elongate hopper 32 and extension hoppers 34, 36 are suitable for holding aggregate chippings and dispensing aggregate chippings onto a road surface. The elongate hopper 32 preferably comprises a base 38, two side walls 40 and two end walls 42, 44. A length of the elongate hopper 32 is defined along a longitudinal axis 46 extending between the two end walls 42, 44. A top edge 48 of the side walls 40 and end walls 42, 44 defines an opening 50 of the elongate hopper 32. In preferred embodiments the side walls 40 and end walls 42, 44 are sloped so that a perimeter of the opening 50 is larger than a perimeter of the base 38. In this embodiment the base 38 of the elongate hopper 32 includes a dispensing aperture 52 through which the aggregate chippings are dispensed from the hopper 32 onto a road surface or similar. The elongate hopper 32 may include a mechanism for restricting or limiting the amount of aggregate chippings dispensed through the dispensing aperture 52.

Each of the extension hoppers 34, 36 preferably comprises a base 54, two side walls 56 and two end walls 58, 60. A length of each of the extension hoppers 34, 36 is defined along a longitudinal axis 62 extending between the two end walls 58,

60. A top edge 64 of the side walls 56 and end walls 58, 60 defines an opening 66 of the extension hopper 34, 36. In preferred embodiments the side walls 56 and end walls 58, 60 are sloped so that a perimeter of the opening 66 is larger than a perimeter of the base 54. In this embodiment the base 54 of each of the extension hoppers 34, 36 includes a dispensing aperture 68 through which the aggregate chippings are dispensed from the hopper 34, 36 onto a road surface or similar. Each of the extension hoppers 34, 36 may include a mechanism for restricting or limiting the amount of aggregate chippings dispensed through the respective dispensing aperture 68.

The elongate hopper 32 and the extension hoppers 34, 36 are preferably

-11 configured such that the longitudinal axes 62 of the extension hoppers 34, 36 are parallel to the longitudinal axis 46 of the elongate hopper 32. Furthermore, the longitudinal axes 62 of the extension hoppers 34, 36 are preferably aligned with each other. In this embodiment the extension hoppers 34, 36 are disposed in a side by side configuration with the elongate hopper 32, such that a side wall 56 of each of the extension hoppers 34, 36 is disposed adjacent a side wall 40 of the elongate hopper 32. Preferably the top edge 48 of the side walls 40 and end walls 42, 44 of the elongate hopper 32 and the top edge 64 of the side walls 56 and end walls 58, 60 of each of the extension hoppers 34, 36 all lie in the same plane. The extension hoppers 34, 36 are preferably disposed adjacent one of the side walls 40 of the elongate hopper 32 such that second end walls 60 of the extension hoppers 34, 36 face each other and are disposed between first end walls 58 of the extension hoppers 34, 36.

Each of the extension hoppers 34, 36 are moveable with respect to the elongate hopper 32. In particular, each of the extension hoppers 34, 36 is moveable between a first, retracted position and a second, extended position. Figure 6 illustrates an embodiment of a vehicle 30 with the extension hoppers 34, 36 in the retracted position and Figure 7 illustrates an embodiment of the vehicle 30 with the extension hoppers 34, 36 in the extended position.

In preferred embodiments, when the extension hoppers 34, 36 are in the retracted position, a first end wall 58 of a first one of the extension hoppers 34 is substantially aligned with a first end wall 42 of the elongate hopper 32 and a first end wall 58 of the second one of the extension hoppers 36 is substantially aligned with the second end wall 44 of the elongate hopper 32. When the extension hoppers 34, 36 are in the extended position, a first end region 70 (adjacent the first end wall 58) of the first extension hopper 34 extends beyond the first end wall 42 of the elongate hopper 32 and a first end region 70 (adjacent the first end wall 58) of the second extension hopper 36 extends beyond the second end wall 44 of the elongate hopper 32.

-12 In this way a distance between the first end walls 58 of the extension hoppers 34, 36 when the extension hoppers 34, 36 are in the retracted position is less than the distance between the first end walls 58 of the extension hoppers 34, 36 when the extension hoppers 34, 36 are in the extended position.

In some embodiments, when the extension hoppers 34, 36 are in the retracted position the first end region 70 of the first extension hopper 34 extends beyond the first end wall 42 of the elongate hopper 32 by a first distance and the first end region 70 of the second extension hopper 36 extends beyond the second end wall 44 of the elongate hopper 32 by the first distance, and when the extension hoppers 34, 36 are in the extended position the first end region 70 of the first extension hopper 34 extends beyond the first end wall 42 of the elongate hopper 32 by a second distance and the first end region 70 of the second extension hopper 36 extends beyond the second end wall 44 of the elongate hopper 32 by the second distance, the second distance being greater than the first distance.

In further embodiments, when the extension hoppers 34, 36 are in the retracted position, the first end region 70 of the first extension hopper 34 does not extend beyond the first end wall 42 of the elongate hopper 32 and the first end region 70 of the second extension hopper 36 does not extend beyond the second end wall 44 of the elongate hopper 32.

The extension hoppers 34, 26 are preferably slidable between the retracted position and the extended position. The extension hoppers 34, 36 preferably slide in a direction parallel to the longitudinal axis 46 of the elongate hopper 32.

In preferred embodiments the movement of the first and second extension hoppers 34, 36 is connected or linked such that movement of the first extension hopper 34 is matched by a corresponding movement of the second extension hopper 36. Alternatively, the first and second extension hoppers 34, 36 may be moveable independently. In these embodiments, the first extension hopper 34 may be moveable into the extended position while the second extension hopper 36 is in

-13the retracted position.

In some embodiments the extension hoppers 34, 36 may be moveable into any position between the retracted and extended positions. However, in preferred embodiments the extension hoppers 34, 36 are moveable into one or more predefined positions between the retracted position and the extended position. Each of the extension hoppers 34, 36 may be moveable into a third or intermediate position between the retracted and extended positions. In this intermediate position the distance between the first end walls 58 of the extension hoppers 34, 36 is greater than the distance between the first end walls 58 when the extension hoppers 34, 36 are in the retracted position and is less than the distance between the first end walls 58 when the extension hoppers 34, 36 are in the extended position.

The vehicle 30 further comprises a feed hopper 72 that is arranged to dispense aggregate chippings into the elongate hopper 32. In this embodiment the feed hopper 72 is disposed above the elongate hopper 32. The feed hopper 72 preferably comprises a base 74, two side walls 76 and two end walls 78. A length of the feed hopper 72 is defined along a longitudinal axis 80 extending between the two end walls 78. A top edge 82 of the side walls 76 and end walls 78 defines an opening 84 of the feed hopper 72. In preferred embodiments the side walls 76 and end walls 78 are sloped so that a perimeter of the opening 84 is longer than a perimeter of the base 74. In this embodiment the base 74 of the feed hopper 72 includes a dispensing aperture 86 through which the aggregate chippings are dispensed from the feed hopper 72 into the elongate hopper 32. The feed hopper 72 may include a mechanism for restricting or limiting the amount of aggregate chippings dispensed through the dispensing aperture 86.

The feed hopper 72 is preferably arranged such that the longitudinal axis 80 of the feed hopper 72 is parallel to the longitudinal axis 46 of the elongate hopper 32. The length of the feed hopper 72 may be less than the length of the elongate hopper 32. Accordingly, in order to dispense aggregate chippings from the feed

-14hopper 72 evenly along the length of the elongate hopper 32, in some embodiments the feed hopper 72 is moveable relative to the elongate hopper 32 along the length of the elongate hopper 32. Preferably the feed hopper 72 slides relative to the elongate hopper 32 in a direction parallel to the longitudinal axis 46 of the elongate hopper 32. In other embodiments the feed hopper 72 is in a fixed position relative to the elongate hopper 32. In these embodiments the elongate hopper 32 preferably comprises a distribution mechanism 88 that distributes aggregate chippings held within the elongate hopper 32 along the length of the hopper 32. A further possibility is that the feed hopper 72 is substantially the same length as the elongate hopper 32. It will be appreciated that in embodiments in which the feed hopper 72 moves relative to the elongate hopper 32, or in which the feed hopper 72 extends along the length of the elongate hopper 32, the elongate hopper 32 may still include a distribution mechanism 88 to ensure that the aggregate chippings are distributed evenly along the length of the elongate hopper 32. The distribution mechanism 88 preferably comprises a screw conveyor 90 or auger conveyor. The distribution mechanism 88 may extend along the length of the elongate hopper 32 at least substantially parallel to the longitudinal axis 46 of the elongate hopper 32.

In this embodiment the feed hopper 72 is arranged to dispense aggregate chippings only into the elongate hopper 32. To transfer aggregate chippings from the elongate hopper 32 to each of the extension hoppers 34, 36 the vehicle 30 preferably further comprises a first feed mechanism 92 configured to convey aggregate chippings from the elongate hopper 32 into the first extension hopper 34 and a second feed mechanism 94 configured to convey aggregate chippings from the elongate hopper 32 into the second extension hopper 36. Each of the feed mechanisms 92, 94 may extend in a direction substantially perpendicular to the longitudinal axes 46, 62 of the elongate hopper 32 and the extension hoppers 34, 36. The first and second feed mechanisms 92, 94 may comprise a screw conveyor or auger conveyor.

The feed mechanisms 92, 94 may be configured such that they do not convey

-15aggregate chippings into the extension hoppers 34, 36 when the extension hoppers 34, 36 are in the retracted position. The elongate hopper 32 may comprise means for blocking passage of the aggregate chippings out of the elongate hopper 32 and to the extension hoppers 34, 36 when the extension hoppers 34, 36 are in the retracted position. Alternatively or additionally, each of the extension hoppers 34, 36 may comprise means for blocking passage of the aggregate chippings into the extension hoppers 34, 36 from the elongate hopper 32 when the extension hoppers 34, 36 are in the retracted position.

When one of the extension hoppers 34, 36 is in a position other than the retracted position, the respective feed mechanism 92, 94 conveys aggregate chippings from the elongate hopper 32 into that extension hopper 34, 36. To ensure that these chippings are evenly distributed along the length of the extension hopper 34, 36 the extension hopper 34, 36 preferably comprises a distribution mechanism 96. The distribution mechanism 96 preferably comprises a screw conveyor 98 or auger conveyor. The distribution mechanism 96 may extend along the length of the extension hopper 34, 36 at least substantially parallel to the longitudinal axis 62 of the extension hopper 34, 36.

The vehicle 30 of the present invention further comprises wheels 100, 102 configured to convey the vehicle 30 in a direction substantially perpendicular to the longitudinal axis 46 of the elongate hopper 32. In this embodiment the vehicle 30 comprises two pairs of wheels 100, 102; a first or front pair of wheels 100 and a second or rear pair of wheels 102. One or both of the front and rear pairs of wheels 100, 102 may be steerable. A first wheel 100’, 102’ of each of the front and rear pairs of wheels 100, 102 is connected to the first extension hopper 34 and a second wheel 100”, 102” of each of the front and rear pairs of wheels 100, 102 is connected to the second extension hopper 36.

In this way, as the extension hoppers 34, 36 move between the retracted and extended positions, a distance between the first and second wheels 100’, 102’, 100”, 102” changes. In particular, as the extension hoppers 34, 36 move from the

-16retracted to the extended position the distance between the first and second wheels 100’, 102’, 100”, 102” increases.

The vehicle 30 of the present invention is preferably configured to span predefined widths of roads. Accordingly, the extension hoppers 34, 36 are preferably moveable into predefined positions such that there are predefined distances between the first and second wheels 100’, 102’, 100”, 102”. In particularly preferred embodiments the extension hoppers 34, 36, and therefore the wheels 100’, 102’, 100”, 102”, are moveable into three discrete positions in which the distances between the first and second wheels 100’, 102’, 100”, 102” are approximately 12 feet, approximately 14 feet and approximately 16 feet.

In preferred embodiments the elongate hopper 32 has a length of between 9 feet and 14 feet, and most preferably has a length of 12 feet. Each extension hopper 34, 36 preferably has a length of between 2 feet and 4 feet, and most preferably has a length of about 3 feet.

In a particularly preferred embodiment, the elongate hopper 32 has a length of 12 feet and when the first and second extension hoppers 34, 36 are in the intermediate position there is a distance of 14 feet between the first end walls 58 of the extension hoppers 34, 36 and when the first and second extension hoppers 34, 36 are in the extended position there is a distance of 16 feet between the first end walls 58 of the extension hoppers 34, 36.

When the extension hoppers 34, 36 are in the extended position, or any intermediate positions between the retracted and extended positions, a second end region 104 (adjacent the second end wall 60) of the first extension hopper 34 overlaps or extends adjacent a first end region 106 of the elongate hopper 32 and a second end region 104 (adjacent the second end wall 60) of the second extension hopper 36 overlaps or extends adjacent a second end region 108 of the elongate hopper 32. In preferred embodiments the first feed mechanism 92 extends between the first end region 106 of the elongate hopper 32 and the

-17 second end region 104 of the first extension hopper 34, and the second feed mechanism 94 extends between the second end region 108 of the elongate hopper and the second end region 104 of the second extension hopper 36.

Each of the extension hoppers 34, 36 may comprise a mechanism that restricts the dispensing of aggregate chippings through the extension hopper dispensing aperture 68 in the second end region 104 of the extension hopper 34, 36. Alternatively, the elongate hopper 32 may comprise a mechanism that restricts the dispensing of aggregate chippings through the elongate hopper dispensing aperture 52 in the first and second end regions 106, 108 of the elongate hopper

32. These alternative mechanisms are configured such that aggregate chippings are not dispensed from both the elongate hopper 32 and the extension hopper 34, 36 in the region of overlap.

The vehicle 30 of the present invention is preferably self-powered or self-driving. Accordingly, the vehicle 30 does not need to be towed or moved using another vehicle. The vehicle 30 preferably comprises an engine or motor configured to drive the wheels 100’, 102’, 100”, 102” of the vehicle 30 to confer motion to the vehicle 30. The vehicle 30 will also comprise suitable controls to enable the vehicle 30 to be steered and to allow the speed of the vehicle 30 to be varied, for example.

Power from the engine or motor may also be used to drive the feed mechanisms 92, 94 and/or the distribution mechanisms 88, 96. Alternatively, a different power unit may be provided to supply power to one or both of these mechanisms 92, 94, 88, 96. This alternative power unit may be a battery.

In use, when the vehicle 30 arrives on site, the extension hoppers 34, 36 are moved or slid relative to the elongate hopper 32 until the distance between the first end walls 58 of the extension hoppers 34, 36 is substantially the same as the width of the road or path being resurfaced. The vehicle 30 can then move along the road or path with the wheels 100’, 102’, 100”, 102” of the vehicle 30 either side

-18of the freshly laid bitumen or asphalt. The aggregate chippings are then dispensed from the elongate hopper 32 and the extension hoppers 34, 36 such that an even layer of chippings is deposited on the layer of bitumen or asphalt.

In the illustrated embodiment the first or front pair of wheels 100 are disposed adjacent the extension hoppers 34, 36 and the second or rear pair of wheels 102 are disposed adjacent the elongate hopper 32. It will be appreciated, however, that in other embodiments the first or front pair of wheels 100 are disposed adjacent the elongate hopper 32 and the second or rear pair of wheels 102 are disposed adjacent the extension hoppers 34, 36. In this way, the vehicle 30 may be configured to travel in either of two directions, with the extension hoppers 34, 36 at a front or leading edge of the vehicle 30 or with the elongate hopper 32 at the front or leading edge of the vehicle 30.

Also, in the illustrated embodiment the vehicle 30 comprises two extension hoppers 34, 36, each one being associated with or connected to an end of the elongate hopper 32. It will be appreciated that, in other embodiments, the vehicle may comprise an elongate hopper and only one extension hopper. In these embodiments the extension hopper is disposed proximate a first end of the elongate hopper.

As described above, the extension hopper 34, 36 is moveable with respect to the elongate hopper 32 between a retracted position and an extended position to vary the width or length over which aggregate chippings are dispensed.

In embodiments in which the vehicle only includes one extension hopper, the first wheels of the front and rear pairs of wheels are attached to the extension hopper and the second wheels of the front and rear pairs of wheels are attached to the vehicle chassis at a second end of the elongate hopper. As such, the position of the second wheels with respect to the elongate hopper remains fixed while the first wheels move together with the extension hopper.

-19In other embodiments the vehicle may comprise only a single pair of wheels. This may be beneficial in embodiments in which the vehicle is not self-driving, but is towed or otherwise driven by a second vehicle. In these embodiments one of the wheels may be attached to a first extension hopper and a second one of the wheels may be attached or connected to a second extension hopper or to the elongate hopper.

Figures 8 to 10 illustrate a vehicle 130 for dispensing aggregate chippings according to another embodiment of the present invention. The vehicle of Figures 8 to 10 is similar in many respects to the vehicle 30 described above with reference to Figures 3 to 7, and only the differences will be described in detail. In particular, the vehicle 130 includes an elongate hopper 132 and two extension hoppers 134, 136 that are moveable with respect to the elongate hopper 132 to vary the width or length over which aggregate chippings are dispensed.

In the vehicle 130 of Figures 8 to 10, no separate feed hopper is provided. Instead, chippings can be directly loaded into the elongate hopper 132 through its top opening 150. In this way, chippings can be loaded into the elongate hopper 132 from either side of the vehicle 130.

As can be seen most clearly in Figures 8 and 10, the elongate hopper 132 preferably includes a distribution mechanism 188, in the form of a pair of screw conveyers 190 that distribute aggregate chippings held within the elongate hopper 132 along the length of the hopper 132 to ensure that the aggregate chippings are distributed evenly along the length of the elongate hopper 132. The screw conveyors 190 extend parallel to the longitudinal axis of the elongate hopper 132 and an inner end of each screw conveyor 190 is supported by a bracket 191.

In the illustrated embodiment, the screw conveyors 190 are arranged to move chippings from the centre of the elongate hopper 132 towards the end walls 142, 144, with the screw conveyors 190 being arranged to turn in opposite directions. Alternatively, in another embodiment, the same result is achieved by mounting one

-20of the screw conveyors 190 in the opposite sense, and turning both screw conveyors 190 in the same direction. In this case, both screw conveyors 190 may be mounted on the same shaft. In further embodiments, the screw conveyors 190 may be arranged to move chips towards the centre of the elongate hopper 132, and/or laterally across the whole hopper. The screw conveyors 190 may be independently controllable so that either conveyor 190 can move chippings in either direction.

As in the first embodiment, first and second feed mechanisms 192, 194 are provided to transfer chippings from the elongate hopper 132 to each of the extension hoppers 134, 136. The first and second feed mechanisms 192, 194 each comprise further screw conveyors mounted substantially perpendicular to the longitudinal axis 146 of the elongate hopper 132 and to the screw conveyors 190 of the distribution mechanism 188. As can be seen most clearly in Figure 8, a pair of apertures 141 are provided in the side wall 140 of the elongate hopper 132 to allow transfer of chippings from the elongate hopper 132 into the extension hoppers 134, 136 by the feed mechanisms 192, 194.

In this embodiment, the vehicle 130 is provided with a pair of tracks 200 for conveying the vehicle 130 in a direction substantially perpendicular to the longitudinal axis 146 of the elongate hopper 132. Each track 200 is driven by one of a pair of drive wheels 202 (see Figure 9) disposed on the rear side of the vehicle 130, and is supported and guided by further pairs of wheels (not shown) in a known manner. A drive unit 203 is provided to power each drive wheel 202 to cause the tracks 200 to move. The drive units 203 on each side of the vehicle can be operated independently to allow the vehicle to be manoeuvred by differential steering.

Each of the tracks 200, along with its corresponding drive wheel 202 and drive unit 203 is mounted to the extension hopper 134, 136 on the respective side of the vehicle 130. In this way, as the extension hoppers 134, 136 move with respect to the elongate hopper 132, the distance between the tracks 200 changes.

-21 As can be seen most clearly in Figures 8 and 10, each of the drive units 203 (and hence each of the tracks 200) is also connected to the elongate hopper 132 by a telescopic beam 205 that extends laterally between the elongate hopper 132 and the drive unit 203. As the extension hoppers 134, 136 move with respect to the elongate hopper 132, the beams 205 extend or retract accordingly to accommodate the movement.

The functionality, features and other components of the vehicle 130 of Figures 8 to 10, and possible modifications thereof, are as described above with reference to the vehicle 30 of Figures 3 to 7. Features of the vehicle 130 of Figures 8 to 10 may be used in appropriate combination in the vehicle 30 of Figures 3 to 7, and vice versa.

Further modifications and variations not explicitly described above may also be made without departing from the scope of the invention as defined in the appended claims.

The present invention therefore provides an improved vehicle for spreading aggregate chippings.

Claims

1. A vehicle for spreading aggregate chippings comprising:

a feed mechanism for conveying aggregate chippings from the elongate hopper to the extension hopper; and a pair of wheels arranged to convey the vehicle in a direction substantially perpendicular to the axis of the elongate hopper, the two wheels of the pair of wheels being moveable relative to each other to change a distance between the two wheels.

2. A vehicle as claimed in Claim 1, wherein the extension hopper is slidable with respect to the elongate hopper so as to increase an overall length of hopper in a direction parallel to the axis of the elongate hopper.

3. A vehicle as claimed in Claim 1 or Claim 2, wherein the elongate hopper has a first end and a second end and the axis of the elongate hopper extends between the first and second ends, the extension hopper has a first end and a second end and an axis of the extension hopper extends between the first and second ends, and wherein the axis of the extension hopper is parallel to but offset from the axis of the elongate hopper.

4. A vehicle as claimed in Claim 3, wherein the extension hopper is moveable into a position in which the extension hopper overlaps the first end of the elongate hopper.

5.

A vehicle as claimed in Claim 3 or Claim 4, wherein the extension hopper is

-23moveable between a first, retracted position in which a first end region of the extension hopper does not extend beyond the first end of the elongate hopper and a second, extended position in which a first end region of the extension hopper extends beyond the first end of the elongate hopper.

6. A vehicle as claimed in Claim 5, wherein the feed mechanism is engaged with or engageable with the extension hopper when the extension hopper is in the second position.

7. A vehicle as claimed in Claim 6, wherein the feed mechanism is engaged with the extension hopper when the extension hopper is in the first position.

8. A vehicle as claimed in any preceding claim, wherein the feed mechanism comprises a screw conveyor.

9. A vehicle as claimed in any preceding claim, wherein one of the wheels is connected to the extension hopper such that movement of the extension hopper relative to the elongate hopper changes the spacing between the two wheels.

10. A vehicle as claimed in any preceding claim, the vehicle comprising a second extension hopper moveable with respect to the elongate hopper.

11. A vehicle as claimed in Claim 10, further comprising a second feed mechanism arranged to convey aggregate chippings from the elongate hopper to the second extension hopper.

12. A vehicle as claimed in Claim 10 or Claim 11, wherein the second extension hopper is moveable with respect to the elongate hopper so as to increase an overall length of hopper in a direction parallel to the axis of the elongate hopper.

13. A vehicle as claimed in any one of Claims 10 to 12, wherein the second extension hopper has a first end and a second end, an axis of the second extension hopper extends between the first and second ends, and the axis of the second extension hopper is parallel to but offset from the axis of the elongate hopper.

14. A vehicle as claimed in Claim 13, wherein the axis of the second extension hopper is aligned with the axis of the first extension hopper.

15. A vehicle as claimed in Claim 13 or Claim 14, wherein the second extension hopper is moveable into a position in which it overlaps the second end of the elongate hopper.

16. A vehicle as claimed in any one of Claims 13 to 15, wherein the second extension hopper is moveable between a first, retracted position in which a first end region of the second extension hopper does not extend beyond the second end of the elongate hopper and a second, extended position in which the first end region of the second extension hopper extends beyond the second end of the elongate hopper.

17. A vehicle as claimed in Claim 16, wherein the second feed mechanism is engaged with or engageable with the second extension hopper when the second extension hopper is in the second position.

18. A vehicle as claimed Claim 17, wherein the second feed mechanism is engaged with the second extension hopper when the second extension hopper is in the first position.

19. A vehicle as claimed in Claim 11, wherein the second feed mechanism comprises a screw conveyor.

20. A vehicle as claimed in any one of Claims 10 to 19, wherein movement of the first and second extension hoppers is linked such that movement of the first extension hopper is matched by a corresponding movement of the second extension hopper.

21. A vehicle as claimed in any one of Claims 10 to 19, wherein movement of each of the first and second extension hoppers is independent.

22. A vehicle as claimed in any one of Claims 10 to 21, wherein one of the pair of wheels is connected to the first extension hopper and a second one of the pair of wheels is connected to the second extension hopper.

23. A vehicle as claimed in any preceding claim, wherein the elongate hopper has a length of between 9 feet and 14 feet.

24. A vehicle as claimed in any preceding claim, wherein the or each extension hopper has a length of between 2 feet and 4 feet.

25. A vehicle as claimed in any preceding claim, wherein the vehicle comprises a power unit configured to supply power to drive the wheels of the vehicle to confer motion to the vehicle, such that the vehicle is self-powered or self-driving.

26. A vehicle as claimed in any preceding claim, comprising two pairs of wheels.

27. A vehicle as claimed in Claim 26 when dependent on Claim 10 or on any claim dependent on Claim 10, wherein two wheels are connected to the first extension hopper and two wheels are connected to the second extension hopper.

28. A vehicle as claimed in any of Claims 1 to 25, comprising a pair of tracks, each track being carried by a respective one of the pair of wheels.

29. A vehicle as claimed in Claim 28, wherein each of the pair of wheels comprises a drive wheel for the tracks.

30. A vehicle as claimed in Claim 28 or Claim 29, comprising at least one further pair of wheels for guiding the tracks.

31. A vehicle as claimed in any preceding claim, further comprising a feed hopper configured to hold aggregate chippings and to dispense the aggregate chippings into the elongate hopper.

32. A vehicle as claimed in Claim 31, wherein the feed hopper is disposed above the elongate hopper.

33. A vehicle as claimed in Claim 31 or Claim 32, wherein the feed hopper is movable with respect to the elongate hopper in a direction along the axis of the elongate hopper.

34. A vehicle as claimed in Claim 31 or Claim 32, wherein the feed hopper extends along the length of the elongate hopper.

35. A vehicle as claimed in any of Claims 1 to 30, wherein the elongate hopper has an open top to allow chippings to be loaded directly into the elongate hopper.

36. A vehicle as claimed in any preceding claim, wherein the elongate hopper comprises a distribution mechanism for distributing aggregate chippings along the length of the elongate hopper.

37. A vehicle as claimed in any preceding claim, wherein the or each extension hopper comprises a screw conveyor for distributing aggregate chippings along the length of the extension hopper.