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:
Nov. 11, 2003
Filed:
Mar. 18, 2002
Applicant:
Inventor:
Michel Puech, Metz-Tessy, FR;
Assignee:
Alcatel, Paris, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B 2/308 ; F04B 2/312 ; F04B 1/200 ;
U.S. Cl.
CPC ...
F04B 2/308 ; F04B 2/312 ; F04B 1/200 ;
Abstract
In a vacuum pumping system according to the invention, the Roots or claw multistage dry primary pump discharges into an outlet stage including an additional piston or membrane pump connected in parallel with a preliminary evacuation pipe including a check valve. The outlet stage very significantly reduces heating of the primary pump and thereby enables the vacuum pumping system to pump efficiently and without damage gases with a low thermal conductivity, such as argon or xenon.