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:
Aug. 14, 2001
Filed:
Dec. 09, 1999
Applicant:
Inventors:
Heiner Kösters, Itzehoe, DE;
Christian Dahmlos, Kremperheide, DE;
Assignee:
Sterling Fluid Systems (Germany) GmbH, Itzehoe, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F01C 1/16 ;
U.S. Cl.
CPC ...
F01C 1/16 ;
Abstract
Screw-spindle vacuum pump with at least three closed-off feed chambers located one behind the other along each rotor and method for operating this compressor. The chamber which is last on the delivery side is brought virtually to the compression limit pressure by means of pre-admission, shortly before it opens towards the delivery side, by supplying a pre-admission stream which is at least five times as great as the intake mass stream. A precondition, in this case, is a minimum ratio of external compression to internal compression of five.