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US2304783A
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Pressure responsive ratio relay
Assignee: JOHN M HOPWOOD
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Filing: 1940-06-10
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Granted: 1942-12-15
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Expires: 1960-06-10
Abstract
No abstract record available.
Inventors
- 👤 Robert R Donaldson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:25
CPC Classifications
F; F15; F15B; F15B9/00; F15B9/02; F15B9/08; Y; Y10; Y10S; Y10S236/00; Y10S236/01; Y10T; Y10T137/00; Y10T137/2278; Y10T137/2409
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) | 1945-12-14 | 1946-06-15 | 1946-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-12-14 | 1950-06-15 | 1950-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-12-14 | 1954-06-15 | 1954-12-15 | $7700.00 | Window Closed / Lapsed |