Patent US1620987A successfully refreshed from Google Patents.
US1620987A
Expired / Lapsed
US
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System of control by impulses of predetermined different durations
Assignee: Individual
•
Filing: 1920-08-12
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Granted: 1927-03-15
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Expires: 1940-08-12
Abstract
No abstract record available.
Inventors
- 👤 Albert D Trenor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:49
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/0011
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) | 1930-03-14 | 1930-09-13 | 1931-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1934-03-14 | 1934-09-13 | 1935-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1938-03-14 | 1938-09-13 | 1939-03-15 | $7700.00 | Window Closed / Lapsed |