Patent US3452723A successfully refreshed from Google Patents.
US3452723A
Expired / Lapsed
US
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Rotary piston internal combustion engine,especially circular piston internal combustion engine
Assignee: Kloeckner Humboldt Deutz AG
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Filing: 1967-03-15
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Granted: 1969-07-01
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Expires: 1987-03-15
Abstract
No abstract record available.
Inventors
- 👤 Johann Keylwert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:43
CPC Classifications
F; F02; F02B; F02B53/00; F02B2053/005; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027; F02B2730/00; F02B2730/01; F02B2730/018; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 0
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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) | 1972-06-30 | 1972-12-30 | 1973-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-30 | 1976-12-30 | 1977-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-30 | 1980-12-30 | 1981-07-01 | $7700.00 | Window Closed / Lapsed |