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:
Jun. 27, 1978
Filed:
Aug. 24, 1976
James K Yip, Richfield, MN (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A closed-center controller is disclosed, especially of the type utilized in hydrostatic power steering systems. The controller includes valving which, in the neutral position, defines a bypass passage communicating inlet fluid through the interior of the hollow, primary valve member to the tank port of the controller. The bypass passage includes a variable bypass orifice having a maximum flow area in the neutral position of the valving and decreasing to zero as the valving is displaced from the neutral position. The variable bypass orifice permits the passage of just enough fluid, typically in the range of about 0.25 gpm to about 0.5 gpm, to minimize the temperature difference between the controller valving and the remainder of the hydraulic system, thus minimizing the possibility of thermal seizure of the valving within the controller.