US2439723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flowmeter
Assignee: Bituminous Coal Research Inc
•
Filing: 1946-01-12
•
Granted: 1948-04-13
•
Expires: 1966-01-12
Abstract
No abstract record available.
Inventors
- 👤 Richard B. Engdahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:43
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/28; G01F1/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1530222A
Cited
US1677691A
Cited
DE558231C
Cited
US1963011A
Cited
US2065695A
Cited
US2311848A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-04-13 | 1951-10-13 | 1952-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-13 | 1955-10-13 | 1956-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-13 | 1959-10-13 | 1960-04-13 | $7700.00 | Window Closed / Lapsed |