The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 27, 1999
Filed:
Feb. 09, 1998
David J Anderson, Plymouth, MN (US);
Jason Danner, Eagan, MN (US);
Commercial Intertech Corp., Minneapolis, MN (US);
Abstract
A power-assist hydraulic system for use in connection with a linkage extending through a housing and mechanically coupled to an actuated member. The power-assisted hydraulic system includes a double-acting hydraulic cylinder having a rod configured for interconnection to the actuated member, an accumulator for storing pressurized hydraulic fluid and a rotary valve. The rotary valve has a valve interface for selectively connecting the hydraulic cylinder to the accumulator. The rotary valve has at least one valve piston for receiving pressurized hydraulic fluid to maintain a hydraulic balance at the valve interface. A sleeve having a bore through which the linkage can extend is mechanically coupled and movably mounted with respect to the rotary valve for moving the rotary valve between a neutral position and first and second rotated positions in response to forces between the linkage and housing. The sleeve and rotary valve cooperate to drive the hydraulic cylinder in a first or a second direction in response to the rotary valve being in the first or the second rotated position, respectively.