GB2129662A - A spreading apparatus to be placed on a vehicle - Google Patents

Abstract

A spreading apparatus to be placed on a vehicle and comprising a container, from which the spreading material can be distributed through a dosing device, and velocity sensing driving wheel (3) placed at the rear end of the vehicle. The driving wheel may be lowered into contact with the roadway and is adapted to drive the dosing device and possibly also a spreading disc through an energy transferring device. The energy transferring device is provided by means of a hydraulic wheel pump (4) coupled to the wheel (3), said hydraulic wheel pump feeding pressurized liquid through a liquid conduit to one or more hydraulic motors (11) driving a plurality of stirrer and delivery rolls. The pressurized liquid is also fed to a piston (12) in a cylinder, which when the pressure in the conduit has been reduced to a predetermined value due to an empty material container, or as a consequence of the spreading being decoupled, reduces the pressure of the wheel (3) against the roadway. <IMAGE>

Description

SPECIFICATION A spreading apparatus to be placed on a vehicle The invention relates to a spreading apparatus to be placed on a vehicle and comprising a container from which the spreading material isfedthrough a dosing device and possibly also a spreading disc hydraulicly driven, and a velocity sensing driving wheel placed at the rear end of the vehicle and capable of being pressed againstthe roadway by adjustable hydraulic power, said driving wheel being carried at one end by a suspension arrangement, the opposite end of which is connected to the lower end of a substantially vertically displaceable column connected to the frame of the apparatus.

Such a spreading apparatus with a velocity sensing driving wheel is knownforinstancefrom German Offenlegungsschrift No.2,830,056.

When the material container no longercontains material, it is desired that the driving wheel is automatically raised.

Aspreading apparatus ofthetype mentioned in the introduction to the specification is according to the invention characterised by the hydraulic power for the hydraulic motors of the dosing device and the spreading disc as well as the pressure for a hydraulic cylindervaryingthe pressure ofthe driving wheel againstthe roadway being produced by a wheel pump coupled tothe driving wheel, and bythe hydraulic cylinder being adapted to reduce the wheel pressure against the roadway and optionally to liftthe driving wheel off said roadway as a consequence of a reduction in pressure in the hydraulic system by relieving the hydraulic motors. In this mannerthe pressure is reduced when the delivery rollers are no longer loaded.As a resultthe wheel can be raised automatically relative to the roadway when the spreading is disengaged orwhen the material container is empty. An unnecessary operation ofthe machinery is thereby automatically avoided.

According to a particularly advantageous embodi mentthesuspension arrangementforthewheel may comprise a parallelogram suspension, in which the cylinder with a displaceable piston is placed as a diagonal.

The invention will be described below with refer ence to the accompanying drawing, in which Fig. 1 illustrates a spreading apparatus to be placed on a vehicle and comprising a velocity sensing driving wheel, Fig. 2 illustrates a particularly advantageous suspension arrangementforthe driving wheel, Fig. 3 illustrates a hydraulic system coupled to the driving wheel, Fig. 4 illustrates the hydraulic circuits of a spreading apparatus with two hydraulic motors, Fig. 5 illustrates a hydraulic circuit with three hydraulic motors, and Fig. 6 illustrates a hydraulic circuit with four hydraulic motors.

Fig. 1 illustrates a spreading apparatus which as indicated may be placed on a truck. A material container 1 is situated on permanent frames.The material from the container 1 is distributed by means of a stirrer roll in the container, whereafter it proceeds to a dosing device situated underneath it. From the dosing device the material is fed to a conveyor 14 transporting ittothe rear end oftheframe,from which it is distributed through a spreading disc 2.

A driving wheel 3 drives the stirrer roll, the dosing device, and the spreading disc 2, said driving wheel being placed at the rear end ofthe vehicle and being capable of being pressed againsttheground (roadway). At one end the driving wheel 3 is carried by a suspension arrangement, the opposite end ofwhich is connected to the lower end of a substantially vertically displaceable column 13 communicating with the frame of the apparatus.

A hydraulic wheel pump 4, cf. Fig. 3, is connected to the driving wheel of the apparatus according to the invention. This wheel pump feeds an amount of liquid pertime unitwhich is proportional to the driving velocityto a hydraulic motor 5, which in turn drivesthe spreading disc 2 through chain wheels 6, a pump 7 having a variable displacement, an adjustable valve 8, and a motor9, ata velocity which should be independent of the velocity of the vehicle, and which as far as possible should be constant. Furthermore, the liquid is fed to a multiwayvalve 10 driving one or several hydraulic motors 11. These hydraulic motors drive the delivery roller and the stirrer roll at a velocity proportional to the velocity of the vehicle.If the container 1 is empty, the motors are almost unloaded, and the liquid pressure is thereby reduced correspondingly. The principle is nowthatthis liquid pressure is alsofedto a piston in a cylinder 12, which as long as the pressure exists presses the driving wheel 3 towards the roadway. This cylinder 12 may optionally implythatthewheel 3 is raised relativetothe roadway when the pressure is reduced to a predetermined value.

According to a particularly advantageous embodimentthe suspension arrangement for the wheel 3 comprises a parallelogram suspension, cf. Fig. 2, in which the cylinderwith the piston at least partially is situated as a diagonal.

Measures have, of course, been taken to ensure in any case that the wheel 3 at start is pressed towards the roadway until the pressure is established as a consequence ofthe load at the rotation of the wheel.

A hydraulic wheel pump 24 is connected to the driving wheel 23, cf. Fig. 4 illustrating a hydraulic circuit. This wheel pump 24 communicates through a rectifier valve 25 with a cylinder 35 capable of keeping the driving wheel 23 in contact with the roadway.

Furthermore a pressure valve 26, a manual decoupling valve 27, and a decoupling valve 28 controlled by a solenoid are provided. 29 is a unit providing a constantflow, said unit feeding the first nine litres of oil to the valve 30 which does not tolerate too much oil.

From the valve 30, oil is fed to the spreading disc motor 31.36 is filling up valve. If the user drives relatively fast in the direction of a corner and stops, no more oil is fed. The inertia in the disc and the valve 36 then implies that it does not suck itself dry. The total amount of oil from the two branches is then fed to valves 37 controlled by a plurality of solenoids, said valves in turn controlling their respective hydraulic motors38. Two motors appear from the Figure. These motors are interconnected through chain wheels, the wheels comprising teeth 32 and 39, respectively. The principle is nowthat it is possible to change gear either by coupling one, the other or both motors. The rate of rotation may thereby be varied in the ratio 1:1.58:2.58.

According to an alternative embodiment, cf. Fig. 5, three hydraulic driving motors 38 may be used, the motors being interconnected by means oftoothed wheels comprising the stated number of teeth. In response to the selection of valves 37 to be opened it is possible to change the numbers of rotation in the ratios 1: 1.58 :2.58:3.85:4.85:5.43 6.43.

According to a third embodimentfour hydraulic motors 38 may be interconnected by means of toothed wheels comprising the stated number of teeth, cf. Fig. 6. By means of these four hydraulic motors it is possible to obtain fifteen different combinations corresponding to a ratio between the numbers of rotation of :1.41 1.41: 1.71: 2.41: 2.71: 3.12: 4.12:6.72 :7.72 :8.13 :8.43:9.13 :9.43:9.84:10.84.

According to the invention a hydraulic gear is thus provided which includes a large number of variations and which is relatively easy to control.

The term "roadway" is to be interpreted throughout this documentas including any surface upon which a vehicle carrying the spreading apparatus may travel.

The following Table illustrates the solenoids which must be provided with electric current in order to achieve the different gears. By supplying electric currenttothe solenoid, thevalve interrupts the supply of oil to the motor in question.

Table of Gear Possibilities 2 motors 3 motors 4 motors Electric current to the solenoid Electric current to the solenoid Electric current to the solenoid associated with the motor 80. associated with the motor No. associated with the motor No.

1:2.58 1. 1:6.43 1. 1:10.84 1:1.58 I 2. 1:5.43 I 2. 1: 9.84 1 1:1 II 3. 1:4.85 II 3. 1: 9.43 II 4. 1:3.85 I II 4. 1: 9.13 III 5. 1:2.58 III 5. 1: 8.43 I II 6. 1:1.58 I III 6. 1: 8.13 1 III 7. 1:1 II III 7. 1: 7.72 II III 8. 1: 6.72 I II III 9. 1: 4.12 IV 10. 1: 3.12 1 iv 11. 1: 2.71 II IV 12. 1: 2.41 III IV 13. 1: 1.71 I II IV 14. 1: 1.41 I III IV 15. 1: 1 II III IV

Claims (6)

1. A spreading apparatus to be placed on a vehicle and comprising a containerfrom which the spreading material is fed through a dosing device and possibly also a spreading disc hydraulicly driven, and a velocity sensing driving wheel placed at the rear end of the vehicle and capable of being pressed againstthe roadway by adjustable hydraulic power, said driving wheel being carried at one end by a suspension arrangement, the opposite end of which is connected to the lower end of a substantially vertically displaceable column connected to the frame of the apparatus, characterised by the hydraulic powerforthe hydraulic motors of the dosing device and the spreading disc as well as the pressure for a hydraulic cylindervarying the pressure ofthe driving wheel against the roadway being produced by a wheel pump coupled to the driving wheel, and by the hydraulic cylinder being adapted to reduce the wheel pressure againstthe roadway and optionally to liftthedrivingwheeloff said roadway as a consequence of a reduction in pressure in the hydraulic system by relieving the hydraulic motors.

2. Aspreading apparatus as claimed in claim 1, characterised by the suspension arrangementforthe wheel comprising a parallelogram suspension, in which the cylinder with a displaceable piston is placed as a diagonal.

3. Aspreading apparatus as claimed in claim 1, characterised by the hydraulic energy for a plurality of hydraulic motors forthe dosing device and spreading disc being produced by a hydraulic wheel pump coupled to the driving wheel, a controllable valve being present in front of each hydraulic motor optionally interconnected through gears.

4. Aspreading apparatus as claimed in claim 1, characterised by comprising three driving motors coupled through gearsforthe establishment of up to seven different gears.

5. A spreading apparatus as claimed in claim 1, characterised by comprising four driving motors coupled through gearsforthe establishment of up to fifteen different gears.

6. Aspreading apparatus substantially as described above and with reference to the accompanying drawing.