Patent US2438834A successfully refreshed from Google Patents.
US2438834A
Expired / Lapsed
US
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Heat storing hot-air circulating apparatus
Assignee: Individual
•
Filing: 1944-12-14
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Granted: 1948-03-30
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Expires: 1964-12-14
Abstract
No abstract record available.
Inventors
- 👤 Lloyd L Wartes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:35
CPC Classifications
F; F24; F24H; F24H7/00; F24H7/02; F24H7/04; F24H7/0408; F24H7/0416
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1708580A
Cited
US1753190A
Cited
US2166509A
Cited
US2238624A
Cited
US2290402A
Cited
US2305551A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-03-30 | 1951-09-29 | 1952-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-03-30 | 1955-09-29 | 1956-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-03-30 | 1959-09-29 | 1960-03-30 | $7700.00 | Window Closed / Lapsed |