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:
Mar. 13, 2001
Filed:
Aug. 12, 1998
Applicant:
Inventor:
Barrie Dudley Brewster, Brighton, GB;
Assignee:
The BOC Group plc, Windlesham, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B 3/00 ;
U.S. Cl.
CPC ...
F04B 3/00 ;
Abstract
A vacuum pumping system for use with a process chamber. The pumping system has a first vacuum pump whose inlet is adapted for communication via a first line with a chamber outlet and a second vacuum pump whose inlet is adapted for communication via a second line with a first pump outlet. A third line containing a throttle valve is linked to the first and to the second lines in parallel to the first vacuum pump to enable variable amounts of gas to flow through the throttle valve from the second line to the first line depending on the position of the throttle valve.