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. 24, 1991
Filed:
Apr. 25, 1990
Toshio Kamimura, Iwate, JP;
Teijin Seiki Company Limited, Osaka, JP;
Abstract
A hydraulic actuator comprising a cylinder formed with an axial cylinder chamber, a main piston provided in the cylinder chamber and dividing the chamber into a first chamber and a second chamber and further formed with a locking chamber, an annular locking groove formed in the cylinder, a locking member cooperating with the annular locking groove to lock the main piston in a predetermined position, the locking member movable between an unlocking position and a locking position, a locking-unlocking piston for moving the locking member into the locking and unlocking positions, and a pressure introducing passageway for selecting the first or second chamber that is higher in pressure and introducing the higher pressure in the selected chamber into the locking chamber of the main piston. The locking-unlocking piston is moved by the pressure introduced by the pressure introducing passageway to move the locking member into the locking and unlocking positions.