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. 06, 1982
Filed:
Jul. 15, 1980
Oliver W Johnson, Chaska, MN (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A system is disclosed for controlling the flow of fluid from a pair of pumps (15,15') to a steering system (11) and a pair of auxiliary load circuits (13,13'). The steering system includes valving (43) defining a variable flow control orifice (45), and the steering system normally operates with a pressure differential X across the variable orifice, and provides load pressure signals (47,49,49',53,53') representative of demand for fluid by the steering system. Fluid flow from the pumps is controlled by a pair of priority flow control valves (21,21') including a pair of valve members (27,27') each of which is biased by a spring (29,29') toward a position permitting flow to the steering system. The spring (29) exerts a biasing force equivalent to the pressure differential X while the spring (29') exerts a biasing force equivalent to a pressure differential Y, which is less than X. When the output of the pump (15) is unable to maintain the pressure differential X across the flow control orifice, the differential across the orifice drops to Y, at which point the valve member (27') is biased by the spring (29') to permit flow from the pump (15') to the steering system.