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:
Dec. 15, 1992
Filed:
Nov. 04, 1991
Kurt R Lonnemo, Searcy, AR (US);
Vickers, Incorporated, Troy, MI (US);
Abstract
A hydraulic control system for controlling a hydraulic actuator comprising a pump for supplying fluid to the actuator and a directional valve for controlling the flow of fluid to the actuator. The directional valve includes a poppet piston that provides a variable orifice. The position of the poppet piston is controlled by a pilot flow controlled by a pilot valve which may be controlled by a solenoid controller. The flow out of the pilot valve is connected to the outlet of the directional valve. A pressure compensator is provided between the inlet to the directional valve and the pilot valve and maintains the pilot flow to the pilot valve constant. The pressure of fluid being applied to the actuator by the directional valve is also sensed and caused to produce a force opposing the opening force applied to the pilot valve to result in a smooth and accurate control of the load.