Rotary hydraulic valve
AssigneeMilwaukee Electric Tool Corporation
InventorsJames G. Ballard, Benjamin J. Tretow
Life of this patent
Estimating the term…
Abstract
A hydraulic tool can include a hydraulic cylinder, a piston within the hydraulic cylinder, and a rotary valve. The piston can be configured to move between a retracted position and an extended position. The piston can include a piston ram and a piston rod that define a ram side and a rod side inside the hydraulic cylinder. The rotary valve can be moved between a first position and a second position. The first position can be configured to direct flow at a first variable speed and a first variable force to the ram side of the hydraulic cylinder and the second position can be configured to direct flow at a second variable speed and a second variable force to the rod side of the hydraulic cylinder.
Claims15
A hydraulic tool, comprising:
- a hydraulic cylinder;
- a piston within the hydraulic cylinder configured to move between a retracted position and an extended position, the piston including a piston ram and a piston rod that define a ram side and a rod side in the hydraulic cylinder;
- and
- a rotary valve moveable between a first position and a second position, the first position configured to direct flow at a first variable speed and a first variable force to the ram side of the hydraulic cylinder and the second position configured to direct flow at a second variable speed and a second variable force to the rod side of the hydraulic cylinder,
- the rotary valve including a first pair of teeth and a second pair of teeth.
A method of operating a hydraulic tool having a load ram and a rapid advance cylinder within a load cylinder, the load cylinder defining a rod end and a cylinder end, the load ram configured to extend and retract within the load cylinder, the method comprising:
- rotating a drive assembly via a motor, the drive assembly having a drive sprocket with a plurality of radially extending pawls;
- and
- rotating a rotary valve from a first position to a second position via one of the radially extending pawls engaging one tooth of a pair of teeth that extend radially from the rotary valve, the pair of teeth in axial alignment along a body of the rotary valve,
- the body of the rotary valve defining a first port in fluid communication with the rapid advance cylinder and the cylinder end of the load cylinder, a second port in fluid communication with the rod end of the load cylinder, a pressure port fluidly coupled to a pump and a reservoir, and a tank port fluidly coupled to a tank reservoir.
A method of operating a hydraulic tool having a load ram and a rapid advance cylinder within a load cylinder, the load cylinder defining a rod end and a cylinder end, the load ram configured to extend and retract within the load cylinder, the method comprising:
- rotating a drive assembly via a motor, the drive assembly having a drive sprocket with a plurality of radially extending pawls;
- and
- rotating a rotary valve from a first position to a second position via one of the radially extending pawls engaging one tooth of a pair of teeth that extend radially from the rotary valve, the pair of teeth in axial alignment along a body of the rotary valve,
- the body of the rotary valve defining a first port in fluid communication with the rapid advance cylinder and the cylinder end of the load cylinder, a second port in fluid communication with the rod end of the load cylinder, a pressure port fluidly coupled to a pump and a reservoir, and a tank port fluidly coupled to a tank reservoir;
- and
- rapidly advancing the load ram by directing hydraulic fluid into the rapid advance cylinder and fluidly coupling via rotation of the rotary valve:
- i) the first port to the pressure port, and ii) the second port to the tank port.
Dependencies are inferred from the claim text.