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:
Nov. 19, 2002
Filed:
May. 19, 2000
Louis C. Harms, Evanston, IL (US);
Parker-Hannifin Corporation, Cleveland, OH (US);
Abstract
A control valve and a method of controlling fluid flow include an input device which provides an input for moving a primary valve member an amount which is a function of the input, thereby opening flow pathways through the valve. The control valve is connected to a mechanical feedback mechanism which moves a feedback valve member an amount which is a function of the movement of a device to which the fluid flow is directed, such as a hydraulic actuator. Movement of the actuator to a desired position causes the second valve member to be moved to such a position that, in combination with the first valve member, the flow pathways through the valve are closed. The actuator is thereby moved to and maintained at the desired position without the need for the electronics feedback sensor used in prior art systems to sense actuator position.