US3788088A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double acting expander ending and cryostat
Assignee: Raytheon Co
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Filing: 1972-11-29
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Granted: 1974-01-29
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Expires: 1992-11-29
Abstract
Abstract Double-acting expander engine minimizes shuttle losses by having a cylinder at low temperature along its entire length, and minimizes pumping losses by requiring only a thin piston and minimizes conduction losses by providing a thin piston rod. Refrigeration capacity is approximately doubled by the doubleacting configuration.
Inventors
- 👤 A Dehne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:54
CPC Classifications
F; F02; F02G; F02G1/00; F02G1/04; F02G1/043; F02G1/044; F02G1/0445; F25; F25B; F25B9/00; F25B9/14; F02G2244/00; F02G2244/50; F02G2250/00; F02G2250/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
216 words
A cryogenic refrigerator comprising: a cylinder to receive a heat load; a piston reciprocably mounted within said cylinder to divide said cylinder into a first expander space and a second expander space; a first regenerator having a warm end and a cold end, said cold end of said first regenerator being connected to said first expander space so that gas flow into and out of said first expander space flows through said first regenerator; a second regenerator having a cold end and a warm end, said cold end of said second regenerator being connected to said second expansion space so that gas flow into and out of said second expander space flows through said second regenerator; means for supplying refrigerant gas at high pressure; means for supplying refrigerant gas at low pressure; valve means connected to both said refrigerant gas means and to both said regenerators for alternately supplying low pressure and high pressure refrigerant gas to said warm end of said second regenerator and for oppositely alternately supplying high pressure and low pressure refrigerant gas to said warm end of said first regenerator, the improvement comprising: said valve means being coupled to said piston to be directly actuated by piston motion; said piston and said valve means being influenced only by gas pressure and friction.
Claim 2
Dependent Claim
216 words
A cryogenic refrigerator comprising: a cylinder to receive a heat load; a piston reciprocably mounted within said cylinder to divide said cylinder into a first expander space and a second expander space; a first regenerator having a warm end and a cold end, said cold end of said first regenerator being connected to said first expander space so that gas flow into and out of said first expander space flows through said first regenerator; a second regenerator having a cold end and a warm end, said cold end of said second regenerator being connected to said second expansion space so that gas flow into and out of said second expander space flows through said second regenerator; means for supplying refrigerant gas at high pressure; means for supplying refrigerant gas at low pressure; valve means connected to both said refrigerant gas means and to both said regenerators for alternately supplying low pressure and high pressure refrigerant gas to said warm end of said second regenerator and for oppositely alternately supplying high pressure and low pressure refrigerant gas to said warm end of said first regenerator, the improvement comprising: said valve means being coupled to said piston to be directly actuated by piston motion; said piston and said valve means being influenced only by gas pressure and friction.
Claim 3
Dependent Claim
28 words
The expander of claim 1 wherein said valve means is operated so that gas conditions in said first and second expander spaces are substantially on the Stirling cycle.
Claim 4
Dependent Claim
40 words
The expander of claim 1 wherein said valve means is connected so that when high pressure gas is connected to said warm end of said first regenerator, low pressure gas is connected to said warm end of said second regenerator.
Claim 5
Dependent Claim
43 words
The cryogenic expander of claim 3 wHerein said valve means comprises valve ports connected to said high and low pressure refrigerant gas supplies and a valve spool coupled to said piston and acting in conjunction with ports connected to both of said regenerators.
Claim 6
Dependent Claim
82 words
The cryogenic expander of claim 1 wherein said valve means is a valve spool connected to said piston for control by said piston and is operated by said piston as said piston moves in said cylinder while permitting expansion of refrigerant gas in said spaces in said cylinder, said valve being included in said means for supplying refrigerant gas to said warm end of said first regenerator and said means for supplying refrigerant gas to said warm end of said second regenerator.
Claim 7
Dependent Claim
55 words
The cryogenic expander of claim 5 wherein said means for alternately supplying high and low pressure refrigerant gas to said warm end of said first regenerator is a valve port and said means for alternately supplying low pressure and high pressure refrigerant gas to said warm end of said second regenerator is a valve port.
Claim 8
Dependent Claim
47 words
The cryogenic expander of claim 6 wherein a cover encloses said cylinder, a window in said cover, a device to be cryogenically refrigerated mounted on said cylinder and having a view out of said window, said cover providing a vacuum space between said cylinder and said cover.
Claim 9
Dependent Claim
47 words
The cryogenic expander of claim 1 wherein a cover encloses said cylinder, a window in said cover, a device to be cryogenically refrigerated mounted on said cylinder and having a view out of said window, said cover providing a vacuum space between said cylinder and said cover.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |