Patent US1917818A successfully refreshed from Google Patents.
US1917818A
Expired / Lapsed
US
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Valve for rotary filters
Assignee: Hamilton Beauchamp & Woodworth
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Filing: 1931-11-23
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Granted: 1933-07-11
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Expires: 1951-11-23
Abstract
No abstract record available.
Inventors
- 👤 Selim E Woodworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:44
CPC Classifications
B; B01; B01D; B01D33/00; B01D33/58; B01D33/60; B01D33/06; B01D33/073; B01D33/09; B01D33/44; B01D33/46; B01D33/466; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86501
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) | 1936-07-10 | 1937-01-09 | 1937-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-07-10 | 1941-01-09 | 1941-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-07-10 | 1945-01-09 | 1945-07-11 | $7700.00 | Window Closed / Lapsed |