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. 24, 1987
Filed:
May. 15, 1984
Applicant:
Inventor:
Gunter Reich, Cologne, DE;
Assignee:
Leybold-Heraeus GmbH, Cologne, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F01D / ;
U.S. Cl.
CPC ...
415 72 ; 415 90 ; 4152 / ;
Abstract
A friction pump (molecular pump, turbomolecular pump) has pumping surfaces which include surface areas which face upstream as well as surface areas which face downstream with respect to the pumping direction. In at least a portion of the pumping surfaces, surface areas of different roughness are present, such that the roughness of the surface areas facing downstream with respect to the pumping direction is greater than the roughness of the surface areas facing upstream with respect to the pumping direction.