Patent US1990657A successfully refreshed from Google Patents.
US1990657A
Expired / Lapsed
US
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Apparatus for increasing the efficiency of internal combustion engines
Assignee: Individual
•
Filing: 1933-02-21
•
Granted: 1935-02-12
•
Expires: 1953-02-21
Abstract
No abstract record available.
Inventors
- 👤 James H Krieck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:03
CPC Classifications
F; F01; F01M; F01M13/00; F01M13/04; F02; F02B; F02B47/00; F02B47/02; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7869
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1938-02-11 | 1938-08-13 | 1939-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-02-11 | 1942-08-13 | 1943-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-02-11 | 1946-08-13 | 1947-02-12 | $7700.00 | Window Closed / Lapsed |