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. 27, 1994
Filed:
Jun. 03, 1993
Applicant:
Inventor:
Hajime Ishimaru, Tsukuba, JP;
Assignee:
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F01D / ;
U.S. Cl.
CPC ...
415 90 ; 415200 ; 4152171 ; 4162 / ; 4174234 ; 4174238 ;
Abstract
A turbomolecular pump comprises a casing having an inlet port at one end portion and an outlet port at another end portion, a rotor supported rotatably within the casing, and a stator fixed on an inner wall of the casing. The rotor has rotor vanes which coact with stator vanes on the stator to pump gas molecules from the inlet port to the outlet port. The rotor and stator vanes are arranged in multi-steps and have ceramic surfaces at the steps near the outlet port of the casing and have metallic surface at all other steps, so as to promote the baking efficiency and obtain extremely high vacuums.