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US2931578A
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US
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Circulating and heating means for building
Assignee: Individual
•
Filing: 1958-03-31
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Granted: 1960-04-05
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Expires: 1978-03-31
Abstract
No abstract record available.
Inventors
- 👤 Dean L Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:24
CPC Classifications
E; E06; E06B; E06B7/00; E06B7/02; E06B7/04; E06B7/06; F; F24; F24S; F24S20/00; F24S20/60; F24S20/63; Y; Y02; Y02B; Y02B10/00; Y02B10/20; Y02E; Y02E10/00; Y02E10/40; Y02E10/44; Y10; Y10S; Y10S454/00; Y10S454/90
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-04-05 | 1963-10-05 | 1964-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-05 | 1967-10-05 | 1968-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-05 | 1971-10-05 | 1972-04-05 | $7700.00 | Window Closed / Lapsed |