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. 28, 1993
Filed:
Aug. 26, 1992
Yuji Kamikawa, Uto, JP;
Mitsuo Nishi, Kumamoto, JP;
Tokyo Electron Limited, Tokyo, JP;
Tokyo Electron Kyushu Limited, Kumamoto, JP;
Tokyo Electron Saga Limited, Tosu, JP;
Abstract
A driving device comprises a first cover, a second cover telescopically engaging with the first cover, and a third cover surrounding the first and second covers. Part of a driving member for moving the second cover in relation to the first cover is arranged in a first space defined in the first cover. The first space is supplied with nitrogen, and pressure in the space is kept at a positive value. Gas is fed into and exhausted from a second space defined between the first and second covers, in accordance with a change in the volume thereof, whereby pressure in the second space is kept at a substantially constant value. Gas contained in a third space defined between the third cover and the first and second covers is exhausted, and pressure in the third space is kept at a negative value. Thus, the first space is completely isolated from a space around the driving device.