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:
Mar. 03, 1981
Filed:
Jul. 06, 1979
Eckehart Schulze, Weissach-Flacht, DE;
Hartmann & Lammle GmbH & Co., Rutesheim, DE;
Abstract
An electrohydraulic follow-up amplifier comprises a hydraulically operated prime mover constituted by a cylinder and a piston axially movable therein and fixedly connected to a connecting member. The arrangement includes further an electronically controlled motor, for instance a direct current servomotor driving for instance a nut meshing with the threaded spindle carrying a control member cooperating with valves for control flow of pressure fluid into and out from cylinder chambers to opposite sides of said piston of said prime mover. The spindle is connected to the connecting member over a coupling comprising a cylinder fixed to the connecting member and a piston fixed to the spindle. The piston of the coupling is movable between two abutments, one of which is adjustable by feeding pressure fluid into cylinder chambers to opposite sides of said piston of the coupling and flow of such pressure fluid is controlled by an additional valve which in turn in controlled from a cam disk which is turned in dependence on the movement of the connecting member.