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:
May. 24, 1988
Filed:
Feb. 27, 1987
James R McBurnett, Corinth, MS (US);
James M Eley, Corinth, MS (US);
Kuldip Raina, Corinth, MS (US);
Dana Corporation, Toledo, OH (US);
Abstract
A dry valve for a gear pump includes a piston having a valve head and a piston head mounted on the opposite ends of a piston rod. The piston is selectively movable between an opened position, wherein hydraulic fluid is permitted to flow from a reservoir to a pumping chamber of the gear pump, and a closed position, wherein such flow is obstructed. A source of pressurized air exerts a biasing force against the piston head to selectively move the piston. An outlet port of the gear pump is connected through a feedback passageway to the dry valve. The feedback passageway communicates with the side of a chamber in which the piston rod of the dry valve reciprocates between the opened and closed positions. When the dry valve is in the opened position, the pressurized fluid from the outlet port of the gear pump exerts a side-loading pressure against the piston rod, causing a frictional force to be generated between the piston rod and the piston rod chamber which resists relative movement.