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Patent US2819845A successfully refreshed from Google Patents.
US2819845A
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Draft regulator with downdraft safety means
Assignee: WALKER Manufacturing AND SALES CORP
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Filing: 1955-06-13
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Granted: 1958-01-14
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Expires: 1975-06-13
Abstract
No abstract record available.
Inventors
- 👤 Andrew H Ziph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:25
CPC Classifications
F; F23; F23L; F23L11/00; F23L11/02; F23L13/00; F23L13/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1963073A
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US2130491A
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US2242183A
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US2261586A
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US2682299A
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US2761494A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-13 | 1961-07-15 | 1962-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-13 | 1965-07-15 | 1966-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-13 | 1969-07-15 | 1970-01-14 | $7700.00 | Window Closed / Lapsed |