WO2000046095A1

WO2000046095A1 - Articulated vehicle with height adjustable load receiving body

Info

Publication number: WO2000046095A1
Application number: PCT/AU2000/000065
Authority: WO
Inventors: Jeffrey Kendall
Original assignee: Razorback Vehicles Corp Ltd
Current assignee: Razorback Vehicles Corp Ltd
Priority date: 1999-02-03
Filing date: 2000-02-03
Publication date: 2000-08-10
Anticipated expiration: 2001-08-03
Also published as: AUPP846199A0

Abstract

Articulated vehicle (10) includes prime mover (11) with drive wheels (23) and trailer (12) and is intended to collect and transport shopping trolleys. Prime mover (11) is connected to trailer (12) by means of pivot couplings to permit relative pivoting movement between prime mover (11) and trailer (12) about a vertical axis and a generally horizontal transverse axis. A resilient means (such as a spring or an air-bag) extends between prime mover (11) and trailer (12) and urges prime mover (11) and trailer (12) to be generally horizontally aligned. Trailer (12) includes U-shaped chassis (13) and a vertically movable load receiving tray. Hydraulic cylinders arranged in series raise the load receiving tray to a transport position or to lower the tray so that shopping trolleys may be loaded or unloaded.

Description

ARTICULATED VEHICLE WITH HEIGHT ADJUSTABLE LOAD RECEIVING BODY

Technical Field

The present invention relates to vehicles and more particularly, but not exclusively, to vehicles used to collect shopping trolleys.

Background of the Invention

Typically, trolleys are collected from car parks and surrounding residential areas by tractors to which there is attached a trailer which receives the shopping trolleys.

When tractors are employed, the cost is substantial as tractors provide facilities and power well beyond the demands required to haul a trailer which receives shopping trolleys. Still further, tractors are reasonably complex to operate.

Object of the Invention

It is the object of the present invention to overcome or substantially ameliorate at least one of the above discussed disadvantages.

Summary of the Invention There is disclosed herein a vehicle including:

a chassis, a driven dirigible wheel supporting the chassis, and a load receiving body supported on the chassis for generally vertical movement relative thereto between a lowered position and a raised position, and a hydraulic circuit operatively associated with the driven wheel and load receiving body, said hydraulic circuit including:

a pump which can be driven by a motor to provide hydraulic fluid under pressure;

a hydraulic drive motor to rotatably drive the wheel;

a steering motor operatively associated with the wheel to direct the wheel;

height adjustment hydraulic cylinders to raise and lower the load receiving body; a drive valve operable to deliver hydraulic fluid to said drive motor to cause operation thereof to drive the wheel, said valve also being operable to have hydraulic fluid bypass said drive motor when said wheel is to remain stationary;

a steering valve to receive hydraulic fluid from said drive valve and to deliver hydraulic fluid to said steering motor to cause operation thereof to direct said wheel;

a delivery valve to provide for the delivery of hydraulic fluid to said height adjustment cylinders, said delivery valve delivering hydraulic fluid to said height adjustment cylinders upon a predetermined hydraulic pressure being exceeded;

a height adjustment valve to receive hydraulic fluid from said delivery valve and deliver hydraulic fluid to said height adjustment cylinders to cause said height adjustment cylinders to raise or lower said load receiving body; and

means to return hydraulic fluid from said height adjustment cylinders to said reservoir.

There is further disclosed herein a vehicle including:

a prime mover including a driven dirigible wheel;

a trailer coupled to the prime mover for pivoting movement relative thereto about a horizontal axis generally transverse of the vehicle; and

a resilient means extending between the trailer and prime mover, urging the prime mover and trailer to be generally horizontally aligned.

There is also disclosed herein a vehicle including:

a chassis, a plurality of wheels supporting the chassis and a load receiving body supported on the chassis for generally vertical movement thereto between a lower position and a raised position, and a hydraulic circuit operatively associated with the wheels for the purposes of driving the vehicle and steering the vehicle and also being operatively associated with the load receiving body to raise and lower the body, said hydraulic circuit including:

a pump to be driven by a motor to provide hydraulic fluid under pressure;

a hydraulic drive motor to rotatably drive at least one of the wheels; a steering motor operatively associated with at least one of the wheels to direct the vehicle;

height adjustment hydraulic cylinders to raise and lower the load receiving body;

a first valve to which hydraulic fluid under pressure is delivered from the pump, the first valve being operable to deliver hydraulic fluid to the cylinders or to deliver hydraulic fluid to the drive motor and steering motor;

a second valve, the second valve being connected to the first valve so as to receive hydraulic fluid therefrom when fluid is to be directed to said drive motor and said steering motor, said second valve being a proportional flow control valve manipulated by the user of the vehicle to control the speed of the vehicle;

a third valve, said third valve being connected to said second valve so as to receive hydraulic fluid therefrom, said third valve being operable by the user for determining forward and reverse direction by being operatively associated with said drive motor to deliver hydraulic fluid thereto; and

a steering valve operably associated with the third valve to receive hydraulic fluid therefrom returning from said drive motor, said steering valve being operable to control said steering motor.

Brief Description of the Drawings

A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:

Figure 1 is a schematic side elevation of a vehicle to collect shopping trolleys;

Figure 2 is a schematic top plan view of the vehicle of Figure 1 ;

Figure 3 is a schematic hydraulic circuit employed in the vehicle of Figures 1 and 2;

Figure 4 is a schematic alternative hydraulic circuit to be employed in the vehicle of Figures 1 and 2; and

Figure 5 is a schematic perspective view of the rear portion of the vehicle of Figure 1. Detailed Description of the Preferred Embodiment

In the accompanying drawings there is schematically depicted a vehicle 10 to transport shopping trolleys. The vehicle 10 includes a prime mover 11 and a trailer 12. More particularly, the trailer 12 has a chassis 13 which receives a load carrying tray vertically movably supported between the arms 14 of the trailer 12.

The chassis 13 is of a "U-shaped" configuration so as to have a base 15 from which the arms 14 rearwardly extend. The tray (body) 43 is supported by means of four hydraulic cylinders 16 extending between the arms 14 and tray. Hydraulic fluid under pressure delivered to the cylinders 16 causes the tray to raise and lower. In the lowered position, shopping trolleys may be removed or located on the tray 43. Preferably, the arms 14 would be provided with adjustable abutments 17 to retain the shopping trolleys in position. The abutment 17 would be movable to permit movement of the trolleys there passed.

The chassis 13 is provided with supporting wheels 18 which are rotatable about an axis generally transverse of the vehicle 10.

The prime mover 11 includes a chassis 19 which would receive in a compartment 20 a motor 21 to drive a hydraulic pump 22. The motor 21 may be electrically driven or it may be an internal combustion engine.

The chassis 19 is supported by, in this embodiment, a single driven dirigible wheel 23. Associated with the wheel 23 would be a hydraulic motor 24 which drives the wheel 23. The wheel 23 is controlled in its directional movement by a hydraulic cylinder 27.

The prime mover 1 1 would seat a driver and would provide a steering wheel operatively associated with a steering valve 25 which controls the cylinder 24 to direct the vehicle 10.

As best seen in Figure 5. the hydraulic cylinders 16 are located on the outside of the arms 14 and are attached thereto so as to extend downwardly to brackets 44 attached to the load receiving tray 43.

The vehicle 10 includes a hydraulic circuit 26 which includes the pump 22, motor 24, valve 25, ram 26 and hydraulic cylinders 16.

The hydraulic circuit 26 further includes a reservoir 28 from which the pump 22 draws hydraulic fluid via a filter. Hydraulic fluid under pressure is delivered from the pump 22 to a drive valve 30. The drive valve 30 is a spool valve having a valve portion 31 which directs hydraulic fluid to the motor 24 so that the wheel 23 drives the vehicle 10 in the forward direction. The spool valve 30 includes a further portion 32 which delivers hydraulic fluid to the motor 34 so that the vehicle 10 moves in a reverse direction. The valve 30 has a further portion 33 which prevents the hydraulic fluid under pressure through the motor 24. The valve portion 33 prevents hydraulic fluid moving to or from the motor 24 and therefore, in cooperation with the brake valve 34 acts as a brake.

The valve 34 is operable to allow the motor 34 to "free wheel", together with the wheel 23. This would be achieved in conjunction with the valve portion 33. This is provided for the purpose of towing.

Hydraulic fluid leaving the valve 30 is delivered to the steering valve 25. The steering wheel of the vehicle 10 causes operation of the valve 25 and delivery of hydraulic fluid to the cylinder 27 to directionally control the wheel 23. The valve 25 is of a conventional structure in that it includes a rotary meter which ensures the hydraulic fluid supplied to the cylinder 27 is proportional to the angular displacement of the steering wheel.

Hydraulic fluid under pressure leaving the valve 30 is also delivered to a delivery (check) valve 35 which permits delivery of hydraulic fluid to the cylinders 16 upon pressure within the hydraulic fluid exceeding a predetermined pressure. More particularly, when the valve 25 is operated, this predetermined pressure is exceeded to cause hydraulic fluid to be delivered to a height control valve 36.

The height control valve 36 determines the direction of movement of the cylinders 16 and whether the load receiving tray is raised or lowered. The cylinders 16 are arranged in series and are configured such that the four cylinders 16 move in unison and retain the tray in the raised position during movement of the vehicle 10.

Hydraulic fluid leaving the cylinders 16 is returned to the reservoir 28 via a filter 37.

There is further provided a pressure relief valve 38.

In operation of the above-described vehicle 10, the load receiving tray would be raised and lowered to enable shopping trolleys to be collected by or delivered from the vehicle 10. A driver of the vehicle 10 manipulates the valves 30, 25 and 36 to give the vehicle 10 motion, to steering the vehicle 10 and to raise and lower the load receiving tray. When the motor 21 is operable and the pump 20 delivering the hydraulic fluid to the valve 30, the operator manipulates the valve 30 so that hydraulic fluid is delivered to the motor 24 to cause the vehicle 10 to go in a forward or reverse direction. When hydraulic fluid is not delivered to the motor 24 via the valve 30, the valve 34 acts as a brake in that it prevents the movement of hydraulic fluid to or from the motor 24. Hydraulic fluid under pressure leaving the valve 30 is delivered to the valve 35 which in turn, controls the hydraulic cylinder 27. An operator manipulating the steering wheel controls the position of the cylinder 27 and therefore the direction in which the vehicle 10 moves. Whenever the steering wheel is operated, the valve 25 causes pressure within the hydraulic circuit 10 to rise so that hydraulic fluid passes through the check valve 35 to be delivered to the valve 36. The valve 36 in turn delivers hydraulic fluid under pressure to the cylinders 16 to raise or lower the load receiving tray.

When the vehicle 10 is stationary, the operator merely manipulates the steering wheel to raise the pressure within the circuit 26 and therefore operation of the rams 16. Furthermore, when the vehicle 10 is in motion and the operator using the steering wheel, the rams 16 are urged to a position at which the load receiving tray is raised. The valve 36 would be configured so as to be urged to deliver hydraulic fluid to the cylinders 16 to raise the load receiving tray. This would only be overridden by the operator when the cylinders 16 are to be operated to lower the load receiving tray.

Arranged in parallel with the motor is a pressure relief valve 39.

The valve 40 is a solenoid valve operable to fix the portion of the steering cylinder 27 by inhibiting fluid therethrough.

The valves 41 enables the motor to draw fluid from the tank 28 to eliminate cavitation during motor "free wheeling".

The valve 25 includes a spool valve 42 which is connected to the cylinder 27 to control the flow of fluid thereto. The valve 42 has a "back pressure" facility to assist in creating a load sensitive steering arrangement proportional to the load on the cylinder 16. This arrangement also enables leakage to be made up.

The prime mover 1 1 is connected to the trailer 12 by means of pivot couplings 39 which are spaced on opposite sides of the vehicle 10 and permit relative pivoting movement between the prime mover 1 1 and trailer 12 about a generally horizontal transverse axis 40. Extending between the prime mover 11 and trailer 12 is a "leaf spring 41 which urges the trailer 12 to be generally horizontally aligned with the prime mover 11 as best seen in Figure 1. It should be appreciated that the spring 41 may be replaced with other resilient means such as an "air-bag".

The above-mentioned leaf spring 41 also provides the vehicle 10 with a resilient suspension as pivoting movement will occur between the prime mover 1 1 and trailer 12 during operation.

In Figure 4 an alternative hydraulic circuit 50 is illustrated. In this circuit a pump 51 draws hydraulic fluid from a reservoir and delivers the hydraulic fluid under pressure to a spool valve 52. The valve 52 in a first position (as illustrated) delivers hydraulic fluid under pressure for the purposes of driving the vehicle 10. and to a steering mechanism. In a second position the valve 52 delivers hydraulic fluid to the four cylinders 16. The cylinders 16 are arranged in parallel and receive hydraulic fluid under pressure via hydraulic line 53. Return line 54 communicates with a further hydraulic line 55 via the valve 52.

In the abovementioned first position of the valve 52, the valve 52 directs the hydraulic fluid under pressure only to the hydraulic line 55, with no fluid being directed to the hydraulic cylinders 16.

The line 55 delivers hydraulic fluid to a proportional flow control valve 56. The valve 56 is operable to determine the flow delivered to the operator manipulated valve 57. The operator manipulated valve 57 in a first position allows the drainage of hydraulic fluid from the drive sub-circuit 58. This is the position illustrated in Figure 4. In a second position, hydraulic fluid is delivered under pressure to the drive motors 59. Incorporated in the drive circuit 58 is a valve 60. The valve 60 enables a high and low speed to be selected. In a first position, the motors 59 are arranged in series while in a second position of the valve 60, the motors 59 are arranged in parallel. When arranged in series the motors 59 operate at twice the speed as when they are arranged in parallel. The valve 60 is connected to the line 63 via the valve 57. The line 63 delivers hydraulic fluid under pressure to the steering circuit 50. This circuit 50 includes a steering valve 64 which delivers hydraulic fluid to a steering cylinder 65. The valve 64 would be operated by a user manipulating the steering wheel of the vehicle 10. The hydraulic cylinder 65 directs the direction of the wheel 23.

Each of the motors 59 would be drivingly associated with one of the wheels 18. The valve 56 would be operated by the accelerator pedal of the vehicle 10. By operation of the accelerator pedal, more fluid is allowed to pass to the valve 57. Associated with the valve 56 is a pressure compensated flow control valve 66. The valve 66 governs the pressure delivered to the valve 56 so that the pressure is generally constant.

Located in the line 63 is a relief valve 67 which determines the pressure maintained in the line 63. For example the valve 67 may be set at 300 PSI.

The valve 57 is also operable to reverse the flow through the motors 59 for the purposes of selecting reverse.

One-way valves 68 allow the motors 59 to draw fluid from the line 63 to aid in avoiding cavitation.

The pump 51 would be driven by the motor 21 as previously discussed. In the embodiment of Figure 4 it should be appreciated that the wheel 23 is not driven, merely the rear wheels 18. The wheel 23 is used only to direct the vehicle.

The valve 52 is operable to cause the cylinders to extend and retract. For example in a first position (as illustrated) the fluid under pressure is delivered to the valve 56. In a second position the fluid under pressure is delivered to the cylinders 16 to cause the cylinders to retract.

In a third position the hydraulic fluid is delivered to the cylinders 16 to cause the cylinders 16 to extend.

In the above described preferred embodiments the tray 43 is supported by the cylinders 16 being located at the four corners of the tray.

Claims

1. A vehicle including: a prime mover including a driven dirigible wheel; a trailer coupled to the prime mover for pivoting movement relative thereto about a horizontal axis generally transverse of the vehicle; and a resilient means extending between the trailer and prime mover, urging the prime mover and trailer to be generally horizontally aligned.

2. A vehicle including: a chassis, a plurality of wheels supporting the chassis and a load receiving body supported on the chassis for generally vertical movement thereto between a lower position and a raised position, and a hydraulic circuit operatively associated with the wheels for the purposes of driving the vehicle and steering the vehicle and also being operatively associated with the load receiving body to raise and lower the body, said hydraulic circuit including: a pump to be driven by a motor to provide hydraulic fluid under pressure; a hydraulic drive motor to rotatably drive at least one of the wheels; a steering motor operatively associated with at least one of the wheels to direct the vehicle; height adjustment hydraulic cylinders to raise and lower the load receiving body; a first valve to which hydraulic fluid under pressure is delivered from the pump, the first valve being operable to deliver hydraulic fluid to the cylinders or to deliver hydraulic fluid to the drive motor and steering motor. a second valve, the second valve being connected to the first valve so as to receive hydraulic fluid therefrom when fluid is to be directed to said drive motor and said steering motor, said second valve being a proportional flow control valve manipulated by the user of the vehicle to control the speed of the vehicle; a third valve, said third valve being connected to said second valve so as to receive hydraulic fluid therefrom, said third valve being operable by the user for determining forward and reverse direction by being operatively associated with said drive motor to deliver hydraulic fluid thereto; and a steering valve operably associated with the third valve to receive hydraulic fluid therefrom returning from said drive motor, said steering valve being operable to control said steering motor.

3. The vehicle of claim 2 wherein said hydraulic cylinders are arranged in series.

4. The vehicle of claim 3 further including a pressure compensated control valve operably associated with the second valve to aid in maintaining a constant pressure delivered to said second valve.

5. The vehicle of claim 2 or 3 wherein said hydraulic circuit includes two hydraulic drive motors each operably associated with a respective one of the wheels, and said circuit further includes a fourth valve operably associated with the two motors to selectively arrange the two motors in series or parallel.

6. The vehicle of claim 3 wherein the vehicle includes a prime mover with a chassis, and a trailer with a chassis, the trailer being coupled to the prime mover for pivoting movement relative thereto about a horizontal axis generally transverse of the vehicle, with the vehicle further including a resilient means extending between the trailer and prime mover urging the prime mover and trailer to be generally horizontally aligned.

7. A vehicle including: a chassis, a driven dirigible wheel supporting the chassis, and a load receiving body supported on the chassis for generally vertical movement relative thereto between a lowered position and a raised position, and a hydraulic circuit operatively associated with the driven wheel and load receiving body, said hydraulic circuit including: a pump which can be driven by a motor to provide hydraulic fluid under pressure; a hydraulic drive motor to rotatably drive the wheel; a steering motor operatively associated with the wheel to direct the wheel; height adjustment hydraulic cylinders to raise and lower the load receiving body; a drive valve operable to deliver hydraulic fluid to said drive motor to cause operation thereof to drive the wheel, said valve also being operable to have hydraulic fluid bypass said drive motor when said wheel is to remain stationary; a steering valve to receive hydraulic fluid from said drive valve and to deliver hydraulic fluid to said steering motor to cause operation thereof to direct said wheel; a delivery valve to provide for the delivery of hydraulic fluid to said height adjustment cylinders, said delivery valve delivering hydraulic fluid to said height adjustment cylinders upon a predetermined hydraulic pressure being exceeded; a height adjustment valve to receive hydraulic fluid from said delivery valve and deliver hydraulic fluid to said height adjustment cylinders to cause said height adjustment cylinders to raise or lower said load receiving body; and means to return hydraulic fluid from said height adjustment cylinders to said reservoir.

8. A vehicle substantially as hereinbefore described with reference to Figures 1 to

3 of the accompanying drawings or Figures 1, 2 and 4 of the accompanying drawings.