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:
Apr. 27, 1993
Filed:
Jul. 30, 1991
Tatuya Wada, Saitama, JP;
Hiroshi Hikita, Saitama, JP;
Nobutaka Machida, Saitama, JP;
Mituharu Nonami, Saitama, JP;
Yukinori Kawamura, Kanagawa, JP;
Norikatu Matumoto, Yokosuka, JP;
Yoshiyuki Ohmura, Saitama, JP;
Tetuo Nomoto, Tokyo, JP;
Fuji Electric Co., Ltd., , JP;
Abstract
Pre-loaded piezoelectric actuators provide improved work piece displacement, frequency of repetition, accuracy and repeatability. Actuators may use a coil spring providing a compressive force adequate to substantially fully compress a laminated piezoelectric element on a non-destructive basis. Upon activation, a pre-loaded actuator delivers a full workpiece drive stroke because piezoelectric element axial compression has previously occurred. Pre-loading methods and pre-loading to damp out element oscillation are also disclosed.