Patent US4765153A successfully refreshed from Google Patents.
US4765153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cryostat with radiation shields cooled by refrigerator
Assignee: Toshiba Corp
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Filing: 1987-02-09
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Granted: 1988-08-23
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Expires: 2007-02-09
Abstract
Abstract A cryostat with two radiation shields cooled by a two stage helium refrigerator which can be easily and quickly removed for maintenance. The inner radiation shield is thermally connected with the second stage of the refrigerator by gaseous convection, while the outer radiation shield is connected with the first stage by metal-to-metal surface contact. The refrigerator is removably installed in a gas-tight receptacle, which forms an annular region around the refrigerator.
Inventors
- 👤 Yoshihiro Wachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:16
CPC Classifications
F; F17; F17C; F17C3/00; F17C3/02; F17C3/08; F17C3/085; F25; F25D; F25D19/00; F25D19/006; F17C2221/00; F17C2221/01; F17C2221/016; F17C2221/017; F17C2270/00; F17C2270/05; F17C2270/0509
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
A cryostat comprising: (a) a reservoir for holding cryogenic liquid; (b) double radiation shields, each of which surrounds said reservoir; (c) a vacuum vessel surrounding said double radiation shields; (d) a refrigerator removably mounted on said vacuum vessel, having two different temperature heat stages, one of which is in thermal contact with one of the radiation shields, while the other of which is in thermal contact with the other radiation shield; (e) a receptacle covering said refrigerator heat stages gas-tightly; (f) means for introducing uncondensible gas into said receptacle; and (g) means for evacuating gas from said receptacle.
Claim 2
Dependent Claim
98 words
A cryostat comprising: (a) a reservoir for holding cryogenic liquid; (b) double radiation shields, each of which surrounds said reservoir; (c) a vacuum vessel surrounding said double radiation shields; (d) a refrigerator removably mounted on said vacuum vessel, having two different temperature heat stages, one of which is in thermal contact with one of the radiation shields, while the other of which is in thermal contact with the other radiation shield; (e) a receptacle covering said refrigerator heat stages gas-tightly; (f) means for introducing uncondensible gas into said receptacle; and (g) means for evacuating gas from said receptacle.
Claim 3
Dependent Claim
106 words
A cryostat comprising: (a) a reservoir for holding cryogenic liquid; (b) double radiation shields, each of which surrounds said reservoir, one of the shields comprising a contact block of high thermal-conductivity having a tapered hole; (c) a vacuum vessel surrounding said double radiation shields; and (d) a refrigerator removably mounted on the vacuum vessel, having two different temperature heat stages, wherein one of said heat stages is tapered so as to fit in said tapered hole and to obtain metal-to-metal surface contact with the contact block, and the other of said heat stages is in thermal contact with the other of said shields by gaseous convection.
Claim 4
Dependent Claim
106 words
A cryostat comprising: (a) a reservoir for holding cryogenic liquid; (b) double radiation shields, each of which surrounds said reservoir, one of the shields comprising a contact block of high thermal-conductivity having a tapered hole; (c) a vacuum vessel surrounding said double radiation shields; and (d) a refrigerator removably mounted on the vacuum vessel, having two different temperature heat stages, wherein one of said heat stages is tapered so as to fit in said tapered hole and to obtain metal-to-metal surface contact with the contact block, and the other of said heat stages is in thermal contact with the other of said shields by gaseous convection.
Claim 5
Dependent Claim
17 words
A cryostat according to claim 1, wherein the tapered heat stage is coated wtih an indium foil.
Claim 6
Dependent Claim
20 words
A cryostat according to claim 1, wherein the tapered hole in the contact block is coated with an indium foil.
Claim 7
Dependent Claim
111 words
A cryostat comprising: (a) a reservoir for holding cryogenic liquid; (b) double radiation shields each of which surrounds said reservoir, one of the shields comprising a non-contact block of high thermal-conductivity; (c) a vacuum vessel surrounding said double radiation shields; (d) a refrigerator removably mounted on the vacuum vessel, having two different temperature heat stages, wherein one of the heat stages comprises fins of high thermal-conductivity facing said non-contact block across a gap, and the other of the heat stages is in thermal contact with the other of the shields by metal-to-metal surface contact; and (e) means for introducing uncondensible gas into the gap between said fins and said non-contact block.
Claim 8
Dependent Claim
111 words
A cryostat comprising: (a) a reservoir for holding cryogenic liquid; (b) double radiation shields each of which surrounds said reservoir, one of the shields comprising a non-contact block of high thermal-conductivity; (c) a vacuum vessel surrounding said double radiation shields; (d) a refrigerator removably mounted on the vacuum vessel, having two different temperature heat stages, wherein one of the heat stages comprises fins of high thermal-conductivity facing said non-contact block across a gap, and the other of the heat stages is in thermal contact with the other of the shields by metal-to-metal surface contact; and (e) means for introducing uncondensible gas into the gap between said fins and said non-contact block.
References Cited (Backward Citations)
US3611746A
Cited
US3609992A
Cited
US4279127A
Cited
US4218892A
Cited
JPS5932758A
Cited
JPS6069540A
Cited
US4535595A
Cited
US4543794A
Cited
US4484458A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |