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:
Feb. 22, 2022
Filed:
Jan. 24, 2018
Applicant:
Leybold Gmbh, Cologne, DE;
Inventor:
Dieter Kolvenbach, Cologne, DE;
Assignee:
LEYBOLD GMBH, Cologne, DE;
Primary Examiner:
Int. Cl.
CPC ...
F04C 23/00 (2006.01); F04C 18/08 (2006.01); F04C 18/12 (2006.01);
U.S. Cl.
CPC ...
F04C 23/001 (2013.01); F04C 18/084 (2013.01); F04C 18/126 (2013.01); F04C 2240/30 (2013.01);
Abstract
A multistage Roots pump comprise a plurality of pump chambers in a pump housing. They constitute respective pump stages, wherein each pump stage comprises two two-toothed rotary pistons. The pump stages are separated from each other by partition walls. In the partition walls essentially radially extending connecting ducts are arranged. The connecting ducts are connected with an inflow chamber whose inflow opening has a larger cross-section than the connecting ducts.