US2623390A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential hydrostatic pressure type device
Assignee: Shell Development Co
•
Filing: 1948-11-01
•
Granted: 1952-12-30
•
Expires: 1968-11-01
Abstract
No abstract record available.
Inventors
- 👤 Robert E Speckmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:09
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/14; G01F23/16; G01F23/164
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US668514A
Cited
US1682602A
Cited
US1661995A
Cited
GB292859A
Cited
FR761812A
Cited
GB484764A
Cited
US2548960A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-12-30 | 1956-06-30 | 1956-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-12-30 | 1960-06-30 | 1960-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-12-30 | 1964-06-30 | 1964-12-30 | $7700.00 | Window Closed / Lapsed |