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. 08, 1980
Filed:
Jun. 30, 1977
Hugo A Panissidi, Peekskill, NY (US);
Glenmore L Shelton, Jr, Carmel, NY (US);
Peter M Will, Norwalk, CT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A servo-control valve for a linear hydraulic motor wherein the control valve piston is isolated from the side loading of a cam and roller by employing a cam follower plunger, as a separate detached element coaxial with the piston. The valve piston and the cam follower plunger are maintained in intimate contact due to the constant back pressure applied by the hydraulic system. The plunger is encased in a cylindrical array of balls which are preloaded between the plunger and the piston chamber walls such that the plunger experiences essentially only rolling friction, but no sliding friction, as the plunger moves. This form of preloading of the balls eliminates the backlash associated with clearance around the plunger.