Patent US2439748A successfully refreshed from Google Patents.
US2439748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat engine
Assignee: Individual
•
Filing: 1944-08-05
•
Granted: 1948-04-13
•
Expires: 1964-08-05
Abstract
No abstract record available.
Inventors
- 👤 Nettel Frederick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:50
CPC Classifications
F; F02; F02B; F02B45/00; F02B45/02; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE199205C
Cited
US1099862A
Cited
US1106115A
Cited
US1334446A
Cited
US1387848A
Cited
US1377989A
Cited
FR560178A
Cited
GB245752A
Cited
US2155776A
Cited
US2177840A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-04-13 | 1951-10-13 | 1952-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-13 | 1955-10-13 | 1956-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-13 | 1959-10-13 | 1960-04-13 | $7700.00 | Window Closed / Lapsed |