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:
Aug. 20, 1985
Filed:
Sep. 24, 1982
Karl-Heinz Post, Kaarst, DE;
Otwin Eich, Remscheid, DE;
Barmag Barmer Maschinenfabrik Aktiengesellschaft, Remscheid, DE;
Abstract
A hydraulic throttle valve is disclosed which includes a choke piston slideably mounted in a bore for movement between an open position and a closed position. A differential piston is coaxially mounted with respect to the choke piston, and a control valve is mounted for slideable movement in a second bore which is laterally spaced from and parallel to the first bore. The control valve is operated by an electromagnet to selectively direct a control fluid to either side of the differential piston, and thereby open or close the choke piston. A feedback spring arm interconnects the choke piston and the control valve, with the spring arm resisting the opening of the choke valve and with the resisting force being a function of the force applied to the control valve by the electromagnet. A balance of forces acting on the choke piston is thereby achieved, with the choke piston being opened to an extend functionally related to the magnitude of the input current to the electromagnet. A shuttle valve is also provided which is operatively connected to each of the hydraulic inlet channel and the hydraulic outlet channel of the throttle valve, with the output of the shuttle valve being operatively connected to the control valve. The shuttle valve acts to connect that one of the inlet and outlet channels having the higher pressure, to the control valve.