Hydraulic actuator control system for refuse collection vehicle

1. A system for controlling motion of a hydraulic actuator on a refuse collection vehicle, the system comprising:

(i) an operator input device configured to produce a proportional electrical signal that is proportional to the degree of motion of the operator input device;

(ii) a proportional pneumatic control valve configured to produce a pressurized air control signal in proportion to the proportional electrical signal; and

(iii) a hydraulic control valve configured to selectively control flow of hydraulic fluid to a hydraulic actuator in response to the pressurized air control signal.

2. The system of claim 1 , where the proportional pneumatic control valve increases the pressure of a supply of pressurized air in proportion to the proportional electrical signal.

3. The system of claim 1 where the hydraulic control valve has a centering spring to spring-bias the hydraulic control valve to a neutral position in which no hydraulic fluid flows to the hydraulic actuator.

4. The system of claim 3 where the hydraulic control valve further comprises a pneumatic actuator configured to move the hydraulic control valve in response to the pressurized air control signal.

5. The system of claim 4 where air pressure acting on the pneumatic actuator causes the hydraulic control valve to move against the force acting on the hydraulic control valve from the centering spring, and where the distance the hydraulic control valve moves is proportional to the pressurized air control signal.

6. The system of claim 1 , where the operator input device is further configured to produce two or more digital signals that correspond to the direction of motion of the operator input device.

7. The system of claim 6 , further comprising a plurality of pneumatic control valves, where each pneumatic control valve is configured to operate in response to one of the digital signals produced by the operator input device.

8. The system of claim 7 , where each pneumatic control valve receives pressurized air from the proportional pneumatic control valve and selectively transmits pressurized air to a pneumatic actuator on the hydraulic control valve.

9. The system of claim 1 , further comprising a fluid passageway for transmitting pressurized air from the proportional pneumatic control valve to the hydraulic control valve.

10. The system of claim 9 , where the length of the fluid passageway is less than 15 feet.

11. The system of claim 9 , where the length of the fluid passageway is less than 10 feet.

12. The system of claim 9 , where the length of the fluid passageway is less than 5 feet.

13. A mobile refuse collection vehicle system comprising:

(i) a source of pressurized hydraulic fluid and a source of pressurized air;

(ii) a lifter apparatus configured to interface with a refuse container;

(iii) a hydraulic actuator configured to move the lifter apparatus through a range of operation;

(iv) an operator input device configured to produce a proportional electrical signal that is proportional to the degree of motion of the operator input device and one or more digital signals that correspond to the direction of motion of the operator input device;

(v) a proportional pneumatic control valve configured to produce a pressurized air control signal from the source of pressurized air in response to the proportional electrical signal;

(vi) one or more pneumatic control valves that are configured to selectively transmit the pressurized air control signal to a pneumatic actuator in response to a digital signal; and

(vii) a hydraulic control valve configured to be selectively actuated by the pneumatic actuator to control flow of a hydraulic fluid from the source of pressurized hydraulic fluid to a hydraulic actuator.

14. The system of claim 13 where the hydraulic control valve has a centering spring to spring-bias the hydraulic control valve to a neutral position in which no hydraulic fluid flows to the hydraulic actuator.

15. The system of claim 14 where air pressure acting on the pneumatic actuator causes the hydraulic control valve to move against the force acting on the hydraulic control valve from the centering spring, and where the distance the hydraulic control valve moves is proportional to the pressurized air control signal.

16. The system of claim 13 , further comprising a fluid passageway for transmitting pressurized air from the proportional pneumatic control valve to the hydraulic control valve.

17. The system of claim 16 , where the length of the fluid passageway is less than 5 feet.

18. The system of claim 16 , where the length of the fluid passageway is less than 10 feet.

19. A mobile refuse collection vehicle system comprising:

(i) a source of pressurized hydraulic fluid and a source of pressurized air;

(ii) a lifter apparatus configured to interface with a refuse container;

(iii) a hydraulic actuator configured to move the lifter apparatus through a range of operation;

(iv) an operator input device configured to produce a proportional electrical signal that is proportional to the degree of motion of the operator input device and two or more directional digital signals that correspond to the direction of motion of the operator input device;

(v) a proportional pneumatic control valve configured to produce a pressurized air control signal from the source of pressurized air in response to the proportional electrical signal;

(vi) two or more pneumatic control valves that are configured to selectively transmit the pressurized air control signal to a pneumatic actuator in response to the directional signals, wherein each pneumatic control valve responds to one of the directional digital signals; and

(vii) a hydraulic control valve configured to be selectively actuated by the pneumatic actuator to control flow of a hydraulic fluid from the source of pressurized hydraulic fluid to a hydraulic actuator.