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:
Jul. 25, 2000
Filed:
Jan. 28, 1998
Applicant:
Inventors:
Shigekazu Yamamoto, Kawasaki, JP;
Tetsuma Ikegami, Yokohama, JP;
Hiroshi Sobukawa, Fujisawa, JP;
Shun-ichi Aiyoshizawa, Tokyo, JP;
Toshiharu Nakazawa, Chigasaki, JP;
Yoshinori Ojima, Kamakura, JP;
Assignees:
Ebara Corporation, Tokyo, JP;
Ebara Densan Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ; F01C / ;
U.S. Cl.
CPC ...
417 53 ; 4182013 ;
Abstract
A screw pump includes a casing having inlet and outlet ports and a pump rotor rotatably mounted in the casing and having screw threads communicating with said inlet and outlet ports. The pump rotor is rotated by a reversible speed-controllable motor, typically a DC brushless motor, mounted in the casing to deliver a liquid such as a chemical solution from the inlet port through a liquid passage defined by the screw threads to the outlet port.