US3885939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cryostat control
Assignee: Hughes Missile Systems Co
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Filing: 1974-04-25
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Granted: 1975-05-27
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Expires: 1994-04-25
Abstract
Abstract Flow control for a cryostat in which the refrigerant flow rate is controlled by adding a contaminant to the refrigerant.
Inventors
- 👤 Arvel Dean Markum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:06
CPC Classifications
F; F25; F25J; F25J1/00; F25J1/02; F25J1/0243; F25J1/0257; F25J1/0275; F25J1/0276; F25B; F25B9/00; F25B9/02; F25B2400/00; F25B2400/12; F25J2205/00; F25J2205/20; F25J2280/00; F25J2280/40; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0391
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
IN COMBINATION: A CRYOSTAT INCLUDING A COILED TUBE HEAT EXCHANGER, A HIGH PRESSURE REFRIGERANT GAS SUPPLY TO PROVIDE A REFRIGERANT TO SAID CRYOSTAT, SAID REFRIGERANT COMPRISING A MIXTURE OF 16% FREON-14 AND 84% FREON-23, AND MEANS TO INTRODUCE A CONTAMINANT INTO THE REFRIGERANT FOR SAID CRYOSTAT, SAID CONTAMINANT COMPRISING 10 PARTS PER MILLION BY WEIGHT WATER VAPOR, SAID CONTAMIANT HAVING A SOLIDIFICATION POINT ABOVE THAT OF THE REFREGERANT TO ALTERNATELY FREEZE AND MELT IN THE COILED TUBE HEAT EXCHANGER OF SAID CRYOSTAT TO REDUCE THE FLOW OF REFRIGERANT THROUGH SAID CRYOSTAT.
Claim 2
Dependent Claim
91 words
IN COMBINATION: A CRYOSTAT INCLUDING A COILED TUBE HEAT EXCHANGER, A HIGH PRESSURE REFRIGERANT GAS SUPPLY TO PROVIDE A REFRIGERANT TO SAID CRYOSTAT, SAID REFRIGERANT COMPRISING A MIXTURE OF 16% FREON-14 AND 84% FREON-23, AND MEANS TO INTRODUCE A CONTAMINANT INTO THE REFRIGERANT FOR SAID CRYOSTAT, SAID CONTAMINANT COMPRISING 10 PARTS PER MILLION BY WEIGHT WATER VAPOR, SAID CONTAMIANT HAVING A SOLIDIFICATION POINT ABOVE THAT OF THE REFREGERANT TO ALTERNATELY FREEZE AND MELT IN THE COILED TUBE HEAT EXCHANGER OF SAID CRYOSTAT TO REDUCE THE FLOW OF REFRIGERANT THROUGH SAID CRYOSTAT.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |