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:
Nov. 02, 1999
Filed:
Oct. 24, 1997
Suzuki Shokan Co., Ltd., Tokyo, JP;
Abstract
A pulse tube refrigerator which can generate cryogenic temperatures of below 10 K includes first and second refrigeration stages. Each stage includes a pulse tube and an associated regenerator provided at the low temperature side of the pulse tube. A pressure fluctuation generator having a compressor and a first to a fourth valve is provided at the high temperature side of each regenerator. The high temperature sides of each pulse tube are connected by a continuous channel while the high temperature side of each pulse tube and the high temperature side of each regenerator are connected by a by-pass channel. A magnetic material having a rare-earth element and a transition metal is used as a regenerative material for the regenerator. When pressure fluctuation is generated in each pulse tube at the phase difference angle of 180.degree., respectively, a working gas is transferred between the high temperature sides of each pulse tube, therefore, the phase angle between the pressure fluctuation in each pulse tube and the displacement of the working gas is optimized. Further, the flow amount of the operating gas sent to each regenerator is limited using a by-pass channel.