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:
Apr. 19, 2005
Filed:
Mar. 12, 2003
Applicants:
Toshiro Hattori, Tokyo, JP;
Katsuyuki Takahashi, Tokyo, JP;
Kiyoshi Tanaka, Tokyo, JP;
Inventors:
Assignee:
Mayekawa Mfg. Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F04B049/00 ;
U.S. Cl.
CPC ...
Abstract
A multi-stage screw compressor unit and method of operation thereof are provided, which enable operation with high efficiency always even when suction or discharge pressure fluctuates widely, the compressor unit comprising a combination of a compression stage provided with an unloader slide valve and that provided with an internal volume ratio control valve, or a combination of compression stage provided with an internal volume control valve and that of fixed internal volume ratio, or a combination of compression stages each provided with an internal volume control valve.