US2438720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Deep well circuit for heat pumps
Assignee: MUNCIE GEAR WORKS Inc
•
Filing: 1947-02-19
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Granted: 1948-03-30
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Expires: 1967-02-19
Abstract
No abstract record available.
Inventors
- 👤 Marvin M Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:00
CPC Classifications
E; E21; E21B; E21B36/00; E21B36/003; F; F24; F24T; F24T10/00; F24T10/30; F28; F28D; F28D20/00; F28D20/0052; Y; Y02; Y02E; Y02E10/00; Y02E10/10; Y02E60/00; Y02E60/14; Y10; Y10S; Y10S159/00; Y10S159/902
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1981730A
Cited
US2167878A
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 |