METHOD OF MAINTAINING AN UNMETALLED ROADWAY DURING LOAD TRANSFER AND A VEHICLE THEREFOR

Abstract

A method of maintaining a roadway (2) during transfer of a load from a first location to a second location by a motorised vehicle (1) is described. The vehicle (1) may be a dumper truck and has a retractable blade (8) movable relative to the vehicle (1) between a retracted position (FIG. 1) and a working position (FIG. 2). The load is transferred in the vehicle (1) from the first location to the second location along the roadway (2), the blade (8) is moved to the working position after dumping the load and on the return journey the vehicle (1) acts as a grader to smooth undulations and ruts. The blade (8) is pivotally mounted and located between the front axle (5) and the rear axle (6, 7) and does not extend beyond the width of the vehicle. Unmetalled roadways on construction sites, quarries and mines may be maintained in good condition without the need to employ additional vehicles or hire separate grader vehicles.

Claims

1. A method of maintaining an unmetalled roadway between two locations which roadway is susceptible to deterioration the roadway being maintained during an operation to transfer a load from a first location to a second location by a repeated transit of a motorised vehicle along the roadway which, in an outward pass from the first location to the second location is laden with a part of the load and which in a return pass from the second location to the first location is unladen wherein the motorised vehicle comprises an open box bed for carrying the part of the load and a retractable blade which is movable relative to the said vehicle between a retracted position and a working position, the method comprising: i) moving the part of the load in the said vehicle in the outward pass from the first location to the second location along the unmetalled roadway; ii) depositing the part of the load at the second location; iii) returning the vehicle in the return pass to the first location along the unmetalled roadway with the blade in the working position such that the blade is applied to the roadway during the return pass to reduce undulations or ruts and repair at least in part deterioration in the roadway; and (iv) repeating steps i) to iii) at least once so as to move the load from the first location to the second location and to maintain the roadway during the return pass.

2. A method according to claim 1 wherein the blade is in the working position during the outward pass.

3. A method according to claim 1 wherein the roadway is in a quarry or mine or on a site for the construction of a major metalled road.

4. A method according to claim 1 wherein the motorised vehicle is articulated.

5. A method according to claim 1 wherein the blade contacts the roadway so as to reshape the surface of the roadway thereby to reduce undulations or ruts and repair at least in part deterioration in the roadway; and

6. A motorised vehicle adapted for use in maintaining an unmetalled roadway between two locations during an operation to transfer a load from a first location to a second location by a repeated transit of the motorised vehicle in a series of outward and return passes in which the vehicle in the outward pass is laden with a part of the load and causes deterioration of the unmetalled roadway, the vehicle comprising an open box bed for carrying a load, a front part carrying a driver cabin and at least one front axle and a rear part linked to the front part by an articulated connection and comprising at least one rear axle and a retractable blade mounted to the vehicle such that it is movable between a retracted position and a working position, the blade being located between the front axle and the at least one rear axle and wherein the blade does not extend beyond the width of the vehicle.

7. A motorised vehicle according to claim 6 wherein in the retracted position the blade is generally parallel to a plane through the front and rear axles and in the working position the blade contacts the ground and the bottom of the grader blade is at the same level as the ground contact point of the wheels rearward of the blade

8. A motorised vehicle according to claim 6 wherein the blade is hydraulically operable.

9. A motorised vehicle according to claim 6 wherein the blade and open box bed are independently operable.

10. A motorised vehicle according to claim 6 wherein the blade is mounted on the vehicle by means of a mounting assembly.

11. A motorised vehicle according to claim 10 wherein the mounting assembly comprises a connecting part mounted on the vehicle and the blade is rotatably mounted on the connecting part for rotation about an axis which is horizontally transverse to the longitudinal axis of the vehicle, an actuation part which is pivotally connected to the blade such that upon movement of the actuation part, the blade rotates about the transverse axis of rotation and a hydraulic ram operably connected to the connecting part and the actuation part such that upon movement of the ram, the actuation part is caused to move relative to the connecting part so as to effect rotation of the blade.

12. A motorised vehicle according to claim 6 wherein the blade is mounted on the vehicle by two mounting assemblies, located either side of the longitudinal axis of the vehicle.

13. A motorised vehicle according to claims 6 which comprises a front part carrying the driver cabin and at least one axle and a rear part comprising the open box bed and at least one axle wherein the front part and the rear part are linked by an articulated connection and the rear part carries the blade which is located forward of all the at least one axle on the rear part.

14. A motorised vehicle according to claim 6 which comprises at least three axles.

15. A motorised vehicle according to claim 6 which is a dumper truck,

16. A process for maintaining an unmetalled-roadway during transferal of a load from a first location to a second location by repeated transit in a series of outward and return passes of a motorised vehicle along the roadway where the roadway is susceptible to deterioration which comprises providing a motorised vehicle comprising an open box bed for carrying the load, a front part carrying a driver cabin and at least one front axle and a rear art linked to the front by an articulated connection and comprising at least one rear axle and a retractable blade mounted to the vehicle and being located between the front axle and the at least one rear axle which vehicle, in the outward pass, is laden with a part of the load and causes deterioration of the unmetalled roadway and which comprises moving the blade to the working position for the return pass such that the blade is applied to the roadway during the return pass to reduce undulations or ruts and repair at least in part deterioration in the roadway.

Description

[0033] The invention is illustrated by the accompanying drawings in which: [0034] FIG. 1 shows a side view of a vehicle according to the invention with the blade in the retracted position; [0035] FIG. 2 shows a side view of the vehicle in FIG. 1 with the blade in the working position; [0036] FIG. 3 shows in FIGS. 3A and 3B a cross-section of a conventional road which may be subject to grading using loose surface material in a conventional grading operation; and [0037] FIG. 4 shows in FIGS. 4A to 4C an unmetalled roadway which may be repaired during an operation to move a load from a first to a second location.

[0038] FIG. 1 shows a vehicle 1 according to the invention. The vehicle passes along roadway 2 transferring a load from a first location to a second location. The vehicle 1 has a front part 3, including the driver cabin and a rear part 4 including an open box bed for carrying the load. The front part 3 and rear part 4 are linked by an articulated connection 14 and the front part is carried by wheels 5 on a single axle and the rear part 4 is carried by wheels 6 and 7, mounted on two rear axles.

[0039] The blade 8 is shown in the retracted position which suitably is higher than the differential casing (not shown). The blade 8 is mounted on the vehicle by mounting assembly 9, preferably two assemblies 9, located to either side of the central longitudinal axis of the vehicle. The mounting assembly 9 comprises a mounting point 10 for the blade 8 which allows rotatable movement of the blade 8. The mounting point 10 is located on connecting part 11 which is pivotally mounted on the rear part 4 of the vehicle 1. Actuation part 12 is linked to the blade 8 and is pivotally linked to hydraulic ram 13 and may act to rotate the blade 8 upon activation of hydraulic ram 13.

[0040] FIG. 2 shows the vehicle 1 of FIG. 1 with the blade 8 in the working position. Upon activation, hydraulic ram 13 extends and thereby moves actuation part 12 causing the blade 8 to rotate about mounting point 10. The mounting assembly 9 may be moved into the appropriate position by pivotal movement about the point at which it connects to the rear part 4 of the vehicle 1. The bottom edge of the grading blade 8 is suitably at the same level as a plane passing through the points of contact of the wheels 5, 6, 7 with the roadway 2 in the working position.

[0041] The blade 8 may be retracted into the retracted position shown in FIG. 1 independently of operation of the open box bed.

[0042] FIG. 3A shows a conventional operation to fill a pot-hole. A solid road is shown having a surface, for example gravel or asphalt 1 with a solid sublayer 2 and a pothole 3 in the surface 1. Loose material 4 for example gravel or chippings may be moved by a grader blade 5 on a conventional grader vehicle or load carrying vehicle having a grader blade.

[0043] Once the blade 5 has moved loose material 4 across pot-hole 3, the hole is filed. The bottom of the grader blade typically is above the solid surface 1 to reduce fouling and also a load-carrying vehicle with an underslung grader blade typically is not equipped with a high torque capability at low speeds.

[0044] In FIG. 4, according to the invention, unmetalled roadway 10 has a surface 11 in a serviceable state of repair to allow transit across it between location 1 and location 2 of a motorised vehicle 12 according to the invention which has an articulation 14 between a cabin and a load carrying open box and which is carrying a load. The vehicle has a retractable blade 13.

[0045] Through passing between location 1 and 2 in an outward pass with a load, by one or more vehicles, the roadway deteriorates as shown in FIG. 4B which has troughs 20 and crests 1. As the vehicle passes from location 2 to location 1, the blade 13 engages with the displaced roadway and as a consequence, smooths the roadway as shown in FIG. 4C to allow repeat passes.