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Patent US3767930A successfully refreshed from Google Patents.
US3767930A
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Radioisotopic heat source
Assignee: United States Atomic Energy Commission
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Filing: 1972-06-21
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Granted: 1973-10-23
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Expires: 1992-06-21
Abstract
Abstract A radioisotopic heat source which includes a core of heat productive, radioisotopic material, an impact resistant layer of graphite surrounding said core, and a shell of iridium metal intermediate the core and the impact layer. The source may also include a compliant mat of iridium between the core and the iridium shell, as well as an outer covering of iridium metal about the entire heat source.
Inventors
- 👤 E Sayell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:28
CPC Classifications
G; G21; G21H; G21H1/00; G21G; G21G4/00; G21G4/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
29 words
The source of claim 1 wherein said core is of plutonium-238 dioxide and the shell is comprised of hemispherical elements with abutting marginal edges joined together about said edges.
Claim 2
Dependent Claim
43 words
The source of claim 1 including a gas venting passageway extending from said core to an interior surface of said impact resistant layer through said shell and means in said passageway for impeding flow of said radioisotopic material through said gas venting passageway.
Claim 3
Dependent Claim
36 words
The source of claim 1 including a woven wire screen mat intermediate said shell and core of from about 0.003 to 0.010 inch thick, said wire being of iridium from about 0.001 to 0.005 inch diameter.
Claim 4
Dependent Claim
18 words
The source of claim 1 including an outermost additional enclosing shell of iridium disposed about said graphite layer.
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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |