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:
Jun. 11, 2002
Filed:
Jul. 02, 1999
Hitachi, Ltd., Tokyo, JP;
Abstract
Oil from an oil source is introduced into an inside of a reciprocal oil hydraulic pressure cylinder through a port, and a lock shaft is pushed against a lock plate by the oil pressure to restrict movement of a tilt table. A cylindrical portion made of a material having a large friction coefficient to the lock plate is attached to a top end of the lock shaft so as to contact with the lock plate in a surface contact state. Releasing of stage locking is performed by introducing the oil into the inside of the reciprocal oil hydraulic pressure cylinder through another port to draw back the lock shaft by the oil pressure. Thereby, the stiffness of the sample stage lock mechanism in the x-direction becomes large and the friction force in the y- and z-directions also becomes large. Therefore, vibration of the tilt table in the x-, y- and z-directions can be effectively suppressed.