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:
May. 18, 1993
Filed:
May. 17, 1991
Applicant:
Inventors:
Allen J Bartlett, Milford, MA (US);
Douglas F Aitken, Bedford, NH (US);
Assignee:
Helix Technology Corporation, Mansfield, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
62 555 ; 55269 ; 417901 ;
Abstract
A cryopump is capable of pumping a process chamber at a process pressure and differentially pumping a second chamber such as an RGA independently at a substantially lower pressure. A member extends through the cryopump housing into a low pressure region disposed within the second stage array. The member comprises a port for accessing the low pressure region, thus providing an independent differential pumping source. No physical seal is required between the member and the main cryopump volume to maintain the pressure differential.