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:
Nov. 17, 1998
Filed:
Oct. 04, 1995
Applicant:
Inventors:
Teruo Maruyama, Hirakata, JP;
Yoshikazu Abe, Neyagawa, JP;
Akira Takara, Higashiosaka, JP;
Yoshihiro Ikemoto, Hirakata, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka-fu, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ;
U.S. Cl.
CPC ...
417 441 ; 417205 ; 4174234 ;
Abstract
A positive displacement vacuum pump, in which a plurality of rotors are driven into synchronous operation by independent motors, uses a rotational position sensor making use of the electromagnetic induction effect for obtaining rotational position information for the individual shafts. The rotational position sensor is cooled.