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US 12,202,117 B2Granted
Tool with hydraulic system for regenerative extension and two-speed operation
AssigneeMilwaukee Electric Tool Corporation
InventorJames G. Ballard
Life of this patent
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Abstract
Embodiments of the invention provide a hydraulic tool including a hydraulic actuator cylinder, a piston, a fluid reservoir, a pump, a regeneration check valve, and a pilot-operated valve. The regeneration check valve is disposed in a regenerative extension fluid path that fluidly couples a first and second chamber of the hydraulic actuator cylinder. The pilot-operated valve is disposed in a power extension fluid path that fluidly couples the second chamber to a fluid reservoir.
Claims20
A hydraulic tool comprising:
- a hydraulic actuator cylinder;
- a piston within the hydraulic actuator cylinder, the piston including a piston head, the piston head dividing an internal space of the hydraulic actuator cylinder into a first chamber and a second chamber;
- a fluid reservoir;
- a pump configured to draw fluid from the fluid reservoir and provide fluid to the first chamber via a hydraulic supply line;
- a regeneration check valve disposed in a regenerative extension fluid path that fluidly couples the second chamber to the first chamber;
- and
- a pilot-operated valve disposed in a power extension fluid path that fluidly couples the second chamber to the fluid reservoir, the pilot-operated valve comprising:
- a first port fluidly coupled to the second chamber;
- a second port directly fluidly coupled to the fluid reservoir;
- and
- a pilot port fluidly coupled to the hydraulic supply line via a pilot line.
8 more elements
A method of operating a hydraulic tool, the method comprising:
- providing fluid from a pump via a hydraulic supply line to a first chamber of a cylinder of the hydraulic tool;
- moving a piston at a first speed within the cylinder when a pressure in the first chamber is less than a first threshold pressure so that fluid exits a second chamber of the cylinder as the piston moves within the cylinder;
- blocking fluid flow through a powered extension fluid path when the pressure in the first chamber is less than a second threshold pressure;
- and
- opening a pilot-operated valve to fluidly couple the second chamber to a fluid reservoir to allow fluid flow through the powered extension fluid path as the pressure at a pilot port of the pilot-operated valve exceeds the second threshold pressure so that the piston moves at a second speed that is less than the first speed, wherein the pilot-operated valve comprises a first port directly fluidly coupled to the second chamber and a second port directly fluidly coupled to the fluid reservoir.
2 more elements
A hydraulic tool comprising:
- a hydraulic actuator cylinder;
- a piston that actuates a tool portion of the hydraulic tool, the piston disposed within the hydraulic actuator cylinder, the piston dividing an internal space of the hydraulic actuator cylinder into a first chamber and a second chamber;
- a regenerative extension fluid path that directly fluidly couples the second chamber to the first chamber;
- and
- a pilot-operated valve disposed in a power extension fluid path that fluidly couples the second chamber to a fluid reservoir, the pilot-operated valve comprising:
- a first port directly fluidly coupled to the second chamber;
- a second port directly fluidly coupled to the fluid reservoir;
- and
- a pilot port fluidly coupled to a hydraulic supply line via a pilot line;
- fluid flow through the regenerative extension fluid path causing the piston to move at a first speed, and
- fluid flow through the powered extension fluid path causing the piston to move at a second speed that is less than the first speed.
8 more elements
Dependencies are inferred from the claim text.