US1861021A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Engine indicator and spark plug
Assignee: General Motors Research Corp
•
Filing: 1929-01-24
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Granted: 1932-05-31
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Expires: 1949-01-24
Abstract
No abstract record available.
Inventors
- 👤 Edward J Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:08
CPC Classifications
G; G01; G01L; G01L23/00; G01L23/08; G01L23/18
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) | 1935-05-31 | 1935-11-30 | 1936-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-05-31 | 1939-11-30 | 1940-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-05-31 | 1943-11-30 | 1944-05-31 | $7700.00 | Window Closed / Lapsed |