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. 21, 1996
Filed:
Jan. 18, 1995
Bruce R Andeen, Boxborough, MA (US);
Gerald J Fortier, Plainville, MA (US);
Allen J Bartlett, Milford, MA (US);
Michael J Eacobacci, Randolph, MA (US);
Philip C Lessard, Boxborough, MA (US);
Helix Technology Corporation, Mansfield, MA (US);
Abstract
In a subatmospheric regeneration process, a relief valve and a roughing valve are coupled in parallel to a common roughing pump. During regeneration, the cryopump is warmed to release gases from cryopump stages. The relief valve opens at a first cryopump pressure level less than a predetermined maximum pressure. The maximum pressure is subatmospheric. The relief valve closes when the cryopump pressure drops below a second cryopump pressure level. Pressure in a line between the relief valve and the roughing pump is monitored to control the opening of the roughing valve to the roughing pump.