Patent US3529659A successfully refreshed from Google Patents.
US3529659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Defrosting system for heat pumps
Assignee: Individual
•
Filing: 1968-04-17
•
Granted: 1970-09-22
•
Expires: 1988-04-17
Abstract
No abstract record available.
Inventors
- 👤 Allen Trask
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:27
CPC Classifications
F; F25; F25B; F25B13/00; F25B47/00; F25B47/02; F25B47/022; F25B47/025; F25B2313/00; F25B2313/025
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1821754A
Cited
US2474304A
Cited
US2919558A
Cited
US2970816A
Cited
US3189085A
Cited
US3219102A
Cited
US3318372A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-09-21 | 1974-03-23 | 1974-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-09-21 | 1978-03-23 | 1978-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-09-21 | 1982-03-23 | 1982-09-22 | $7700.00 | Window Closed / Lapsed |