Patent US1654052A successfully refreshed from Google Patents.
Patent US1991540A successfully refreshed from Google Patents.
US1991540A
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US
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Frost prevention system
Assignee: Standard Oil Co
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Filing: 1932-01-13
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Granted: 1935-02-19
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Expires: 1952-01-13
Abstract
No abstract record available.
Inventors
- 👤 Clifford C Buchler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:19
CPC Classifications
B; B01; B01D; B01D25/00; B01D25/12; B01D25/164; B01D25/21; B01D25/215; B01D25/28; B01D29/00; B01D29/39; B01D29/41
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) | 1938-02-18 | 1938-08-20 | 1939-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-02-18 | 1942-08-20 | 1943-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-02-18 | 1946-08-20 | 1947-02-19 | $7700.00 | Window Closed / Lapsed |