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:
May. 05, 1998
Filed:
Jun. 06, 1995
Applicant:
Inventors:
Katsuya Okumura, Pouhkeepsie, NY (US);
Yuuichi Mikata, Kanagawa-ken, JP;
Manabu Tsujimura, Kanagawa-ken, JP;
Yoshio Ando, Kanagawa-ken, JP;
Assignees:
Ebara Corporation, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki-shi, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ; F04B / ;
U.S. Cl.
CPC ...
417-2 ; 417 42 ; 417 43 ; 417 442 ; 417 53 ;
Abstract
A method and apparatus for evacuating a vacuum system which includes an evacuating portion comprising first and second vacuum pumps which are connected in series. The method and the apparatus are characterized in that the first vacuum pump is operated in a range from reverse rotation to forward rotation, and the second vacuum pump is rotated unidirectionally, thereby enabling pressure control of the vacuum system over a wide range.