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:
Sep. 16, 1986
Filed:
Oct. 15, 1985
Vinod K Nanda, Rochester, MI (US);
Henry D Taylor, Pontiac, MI (US);
Vickers, Incorporated, Troy, MI (US);
Abstract
A hydraulic control system comprising a hydraulic actuator having opposed openings adapted to alternately function as inlets and outlets for moving the element of the actuator in opposite directions and a variable displacement pump with loading sensing control for supplying fluid to said actuator. A pilot pressure operated meter-in valve is provided to which the fluid from the pump is supplied and pilot pressure is applied to the meter-in valve for controlling the direction and displacement of movement of the meter-in valve and the direction and velocity of the actuator. A pair of lines extends from the meter-in valve to the respective openings of the actuator and a pilot pressure operated meter-out valve is associated with each line of the actuator for controlling the flow out of the actuator when that line to the actuator does not have pressure from from the pump applied thereto. A spring loaded poppet valve is associated with each line and a passage extends from at least one of the poppet valves to the meter-out valve and operable, when the meter-out valve is closed after being open, to reduce the pressure holding the spring loaded poppet valve closed, thereby permitting the spring loaded poppet valve to open at a relatively low pressure developed in one of the lines associated with the one meter-out valve, thereby allowing the one meter-out valve to open.