US 12,214,478 B2
Hydraulic power tool
Eric D. Norquist, Brookfield, WI (US); James G. Ballard, Waukesha, WI (US); Kris J. Kanack, Whitewater, WI (US); Luke J. Skinner, West Bend, WI (US); Robert Jensen, Brookfield, WI (US); Marc S. D'Antuono, Whitefish Bay, WI (US); and Peter Davies, Brookfield, WI (US)
Assigned to Milwaukee Electric Tool Corporation, Brookfield, WI (US)
Filed by Milwaukee Electric Tool Corporation, Brookfield, WI (US)
Filed on Nov. 28, 2023, as Appl. No. 18/521,571.
Application 18/521,571 is a continuation of application No. 16/745,688, filed on Jan. 17, 2020, granted, now 11,878,402.
Claims priority of provisional application 62/819,790, filed on Mar. 18, 2019.
Prior Publication US 2024/0091924 A1, Mar. 21, 2024
Int. Cl. B25F 5/00 (2006.01); B21D 39/04 (2006.01); B25F 5/02 (2006.01)
CPC B25F 5/005 (2013.01) [B21D 39/048 (2013.01); B25F 5/02 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A hydraulic tool including a fluid reservoir, a pump, an electric motor, an outer cylinder, and a piston dividing the outer cylinder into a first chamber and a second chamber, the hydraulic tool comprising:
a pressure rail fluidly coupled to the pump;
a sequence valve fluidly coupled to the pressure rail and the outer cylinder;
a shuttle valve in fluid communication with the sequence valve, the pressure rail, and the fluid reservoir;
an inner cylinder affixed to the outer cylinder, the piston sliding along an external surface of the inner cylinder, the piston moving at a high speed and a slow speed;
a first longitudinal channel fluidly coupled to the fluid reservoir and the first chamber; and
a first bypass check valve disposed in the first longitudinal channel;
as the piston moves at the high speed, a first pressure level in the first chamber being reduced below a second pressure level so that hydraulic fluid is drawn from the fluid reservoir through the first longitudinal channel and the first bypass check valve into the first chamber.