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:
Jan. 28, 1992
Filed:
Jan. 17, 1990
Norihide Saho, Tsuchiura, JP;
Taisei Uede, Hitachi, JP;
Yoichi Ono, Hitachi, JP;
Hisanao Ogata, Ibaraki, JP;
Takeo Nemoto, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A cryopump for effecting a cooling operation by a freezing medium such as liquid helium. A plurality of radiation-heat shield plates for protecting cryopanels against an external heat radiation are provided in opposed relation to a gas inlet of the cryopump. Particularly, a plurality of groups of such radiation-heat shield plates are provided in such a manner that the radiation-heat shield plates of each group are arranged in a multi-stage manner in registry with one another in the direction of the depth of the cryopump and are disposed in parallel relation to one another. Each of the cryopanels is disposed adjacent to a rear surface of respective radiation-heat shield plates facing away from the gas inlet. With this construction, the gas molecules reflected by those radiation-heat shield plates and by a rear wall of the cryopump, are less liable to reach the gas inlet, and tend to be condensed at an increased rate on those cryopanels.