Patent US2070491A successfully refreshed from Google Patents.
US2070491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric heating system
Assignee: Individual
•
Filing: 1935-08-22
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Granted: 1937-02-09
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Expires: 1955-08-22
Abstract
No abstract record available.
Inventors
- 👤 Robert H Park
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:26
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/2401
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1940-02-09 | 1940-08-10 | 1941-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1944-02-09 | 1944-08-10 | 1945-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1948-02-09 | 1948-08-10 | 1949-02-09 | $7700.00 | Window Closed / Lapsed |