Control of a feed system of a grinding machine
AssigneeVermeer Manufacturing Company
InventorsMichael C. Byram, Dennis K Gabler, John A Carlson
Life of this patent
Estimating the term…
Abstract
A horizontal grinder is disclosed herein. The grinder includes a grinding structure and upper and lower feed conveyors for feeding material toward the grinding structure. The upper feed conveyor is positioned above the lower feed conveyor such that the material fed toward the grinding structure travels between the upper and lower feed conveyors. The grinder also includes a power source for rotating the grinding structure. A controller is provided for controlling the speed of at least one of the lower and upper feed conveyors in proportion to an operating characteristic of the power source.
Claims23
A horizontal grinder comprising:
- a grinding structure;
- upper and lower feed conveyors for feeding material toward the grinding structure, the upper feed conveyor being positioned above the lower feed conveyor such that the material fed toward the grinding structure travels between the upper and lower feed conveyors;
- a power source for rotating the grinding structure, the power source defining an operating characteristic when generating power to rotate the grinding structure;
- and
- a controller which controls the speed of the lower and upper feed conveyors in proportion to the operating characteristic of the power source;
- wherein the upper feed conveyor is controlled by first pulse-width modulated signals generated by the controller, and the lower feed conveyor is controlled by second pulse-width modulated signals generated by the controller, the first signals and the second signals having different duty cycles.
A horizontal grinder comprising:
- a grinding structure;
- upper and lower feed conveyors for feeding material toward the grinding structure, the upper feed conveyor being positioned above the lower feed conveyor such that the material fed toward the grinding structure travels between the upper and lower feed conveyors;
- first and second hydraulic motors for driving the upper and lower feed conveyors, respectively;
- pulse-width modulated control valves for controlling fluid flow to the first and second hydraulic motors;
- a power source for rotating the grinding structure;
- a controller which controls the speed of the lower and upper feed conveyors by sending pulse-width modulated signals to the pulse-width modulated control valves;
- and
- memory in which first and second different stepped, pulse-width control curves are stored, wherein the controller uses the first control curve to determine the pulse-width modulated signals for controlling the speed of the upper feed conveyor, and the controller uses the second control curve to determine the pulse-width modulated signals for controlling the speed of the lower feed conveyor.
A method of using a horizontal grinder of a type having, a frame, a grinding rotor operatively rotatably attached to the frame, a chamber for receiving material to be ground into small pieces, a lower feed conveyor forming a floor to said chamber, one end of said lower feed conveyor being disposed adjacent to said rotor, an upper feed conveyor disposed in said chamber above said one end of the lower feed conveyor for cooperating with said lower feed conveyor to move said material from the chamber to the rotor, and a power source operatively attached to said grinding rotor, said method comprising:
- rotating the grinding rotor using the power source;
- moving the lower and upper conveyors in a direction to cause the material to be ground to move toward said grinding rotor;
- and
- causing said upper and lower feed conveyors to move toward said grinding rotor in proportion to the load on the power source while the power source is generating power to rotate the grinding rotor, said upper feed conveyor moving in response to first control signals, said lower feed conveyor moving in response to second control signals, said first control signals and the second control signals having different duty cycles.
A horizontal grinder comprising:
- a grinding structure;
- upper and lower feed conveyors for feeding material toward the grinding structure, the upper feed conveyor being positioned above the lower feed conveyor such that the material fed toward the grinding structure travels between the upper and lower feed conveyors;
- a power source for rotating the grinding structure, the power source defining an operating characteristic when generating power to rotate the grinding structure;
- a controller which controls the speed of at least one of the lower and upper feed conveyors in proportion to the operating characteristic of the power source;
- and
- memory in which first and second different control curves are stored, wherein the controller uses the first control curve to control the upper feed conveyor and the second control curve to control the lower feed conveyor.
A horizontal grinder comprising:
- a grinding structure;
- upper and lower feed conveyors for feeding material toward the grinding structure, the upper feed conveyor being positioned above the lower feed conveyor such that the material fed toward the grinding structure travels between the upper and lower feed conveyors;
- a power source for rotating the grinding structure, the power source defining an operating characteristic when generating power to rotate the grinding structure;
- and
- a controller which controls the speed of the lower and upper feed conveyors in proportion to the operating characteristic of the power source;
- wherein the upper feed conveyor is controlled by first control signals generated by the controller, and the lower feed conveyor is controlled by second control signals generated by the controller, the first signals and the second signals having different duty cycles.
A horizontal grinder comprising:
- a grinding structure;
- upper and lower feed conveyors for feeding material toward the grinding structure, the upper feed conveyor being positioned above the lower feed conveyor such that the material fed toward the grinding structure travels between the upper and lower feed conveyors;
- first and second hydraulic motors for driving the upper and lower feed conveyors, respectively;
- a power source for rotating the grinding structure;
- a controller which controls the speed of the lower and upper feed conveyors by generating electrical signals;
- memory in which first and second different control curves are stored, wherein the controller uses the first control curve to determine the electrical signals for controlling the speed of the upper feed conveyor, and wherein the controller uses the second control curve to determine the electrical signals for controlling the speed of the lower feed conveyor;
- and
- variable control valves that control fluid flow to the first and second hydraulic motors in response to receipt of the electrical signals generated by the controller.
Dependencies are inferred from the claim text.