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. 07, 1997
Filed:
Nov. 16, 1995
Ike C Hsu, Los Altos, CA (US);
Jay H Ambrose, Los Gatos, CA (US);
Lockheed Missiles and Space Company, Inc., Sunnyvale, CA (US);
Abstract
A stacked multistage Joule-Thomson (J-T) cryostat is described in which each stage comprises a thermally conducting material plate member with fluid passages formed therein and in which the stages are stacked one above the other but separated from each other by thermally insulating standoff supports. Each successive stage in the stack is cooled to successively lower temperature zones by J-T expansion and liquefaction of different coolant gases. Each stage has a restricting passageway connected to a different high pressure gas coolant supply and forming a throttle valve opening into two-phase (liquid-vapor) coolant reservoir passages. The reservoir passages in all but the coldest stage are in heat exchange relation with the high pressure supply passages of the lower boiling temperature coolant gases. The coldest stage is in heat exchange relation with a cold surface on which a device to be cooled can be mounted. Because the stages are constructed of thermally conductive material, there is substantially no thermal gradient within a given stage, and because the stages are thermally isolated from each other, substantial parasitic loads by the heat exchanger section on the cold reservoir for a given coolant is avoided.