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US 12,352,294 B2Granted
Dual mode force control for surface engaging machinery
AssigneeParker-Hannifin Corporation
InventorsJacob S. Larson, David C. Schulte
Life of this patent
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Abstract
An example control system includes: a source of fluid; a cylinder actuator having: (i) cylinder, and (ii) a piston movable within the cylinder and dividing an internal space of the cylinder into a first chamber and a second chamber; a pressure control valve; a pilot-operated valve having a pilot port that is fluidly coupled to the source; and a proportional control valve configured to fluidly couple the source of fluid to the second chamber.
Claims20
A control system comprising:
- a source of fluid;
- a cylinder actuator having:
- (i) a cylinder, and (ii) a piston movable within the cylinder and dividing an internal space of the cylinder into a first chamber and a second chamber;
- a pressure control valve;
- a pilot-operated valve having a pilot port that is fluidly coupled to the source;
- and
- a proportional control valve, wherein the pilot-operated valve operates in:
- (i) a first mode of operation, wherein the source provides fluid at a pressure level above a threshold pressure value, which actuates the pilot-operated valve via a pilot signal to the pilot port, thereby fluidly coupling the source through the pressure control valve and the pilot-operated valve to the first chamber, while fluidly coupling the source through the proportional control valve to the second chamber, and (ii) a second mode of operation, wherein the source provides fluid at a pressure level below the threshold pressure value, thereby causing the pilot-operated valve to be in an unactuated state, blocking fluid flow from the source through the pressure control valve to the first chamber, while fluidly coupling the source through the proportional control valve to the second chamber.
5 more elements
A surface engaging machine comprising:
- a plurality of row units, wherein at least one row unit of the plurality of row units has a surface engaging implement;
- and
- a control system having:
- a source of fluid,
- a cylinder actuator having:
- (i) a cylinder, and (ii) a piston movable within the cylinder and coupled to the surface engaging implement, wherein the piston divides an internal space of the cylinder into a first chamber and a second chamber,
- a pressure control valve,
- a pilot-operated valve having a pilot port that is fluidly coupled to the source of fluid, and
- a proportional control valve, wherein the pilot-operated valve operates in:
- (i) a first mode of operation, wherein the source provides fluid at a pressure level above a threshold pressure value, which actuates the pilot-operated valve via a pilot signal to the pilot port, thereby fluidly coupling the source through the pressure control valve and the pilot-operated valve to the first chamber at, while fluidly coupling the source through the proportional control valve to the second chamber, and (ii) a second mode of operation, wherein the source provides fluid at a pressure level below the threshold pressure value, thereby causing the pilot-operated valve to be in an unactuated state, blocking fluid flow from the source through the pressure control valve to the first chamber, while fluidly coupling the source through the proportional control valve to the second chamber.
7 more elements
A method comprising:
- operating a control system of a surface engaging unit in a first mode of operation, wherein the control system has:
- (i) a source of fluid, (ii) a cylinder actuator having:
- a cylinder, and a piston movable within the cylinder and coupled to a surface engaging implement of the surface engaging unit, wherein the piston divides an internal space of the cylinder into a first chamber and a second chamber, (iii) a pressure control valve, (iv) a pilot-operated valve having a pilot port that is fluidly coupled to the source of fluid, and (v) a proportional control valve, wherein operating the control system in the first mode of operation comprises:
- providing fluid from the source at a pressure level above a threshold pressure value, which actuates the pilot-operated valve via a pilot signal to the pilot port, thereby fluidly coupling the source through the pressure control valve and the pilot-operated valve to the first chamber, and
- actuating the proportional control valve to fluidly couple the source of fluid through the proportional control valve to the second chamber;
- and
- operating the control system in a second mode of operation, wherein operating the control system in the second mode of operation comprises:
- causing the source to provide fluid at a pressure level below the threshold pressure value, thereby causing the pilot-operated valve to be in an unactuated state, blocking fluid flow from the source to the first chamber, and
- actuating the proportional control valve to fluidly couple the source through the proportional control valve to the second chamber.
6 more elements
Dependencies are inferred from the claim text.