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. 24, 1991
Filed:
Jul. 19, 1990
Applicant:
Inventors:
Frank Fleischmann, Bergheim-Glessen, DE;
Hans-Peter Kabelitz, Cologne, DE;
Hans Kriechel, Bornheim, DE;
Martin Muhlhoff, Colonge, DE;
Assignee:
Leybold Aktiengesellschaft, Cologne, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F01D / ;
U.S. Cl.
CPC ...
415 90 ; 415914 ; 417366 ;
Abstract
A gas friction pump has an inlet arranged to be coupled to a vessel to be evacuated; an outlet and an outlet-side pumping stage formed of a helical gas pumping channel. The pump further has a scavenging gas inlet circumferentially surrounding the helical gas pumping channel for exposing the channel to a scavenging gas.