US2808813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary positive displacement engine with helically grooved cooled rotors
Assignee: Svenska Rotor Maskiner AB
•
Filing: 1952-05-21
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Granted: 1957-10-08
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Expires: 1972-05-21
Abstract
No abstract record available.
Inventors
- 👤 Lindhagen Teodor Immanuel
- 👤 Nilsson Hans Robert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:07
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/02; F01D5/08; F05; F05D; F05D2250/00; F05D2250/20; F05D2250/25; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1146533A
Cited
US1556315A
Cited
US1601402A
Cited
US1702264A
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GB242652A
Cited
CH136470A
Cited
US1957699A
Cited
GB464475A
Cited
US2243874A
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US2159006A
Cited
US2248639A
Cited
US2103632A
Cited
US2136117A
Cited
DE696640C
Cited
US2122521A
Cited
US2169092A
Cited
US2181744A
Cited
US2247125A
Cited
US2278304A
Cited
US2369795A
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US2471428A
Cited
US2656096A
Cited
US2511441A
Cited
US2611241A
Cited
US2618120A
Cited
US2457073A
Cited
US2530173A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-10-07 | 1961-04-08 | 1961-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-07 | 1965-04-08 | 1965-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-07 | 1969-04-08 | 1969-10-08 | $7700.00 | Window Closed / Lapsed |