US2786552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrodynamic brakes
Assignee: Parkersburg Rig and Reel Co
•
Filing: 1952-03-20
•
Granted: 1957-03-26
•
Expires: 1972-03-20
Abstract
No abstract record available.
Inventors
- 👤 Mater Robert Griffin De La
- 👤 Edgar F Speiden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:58
CPC Classifications
F; F16; F16D; F16D57/00; F16D57/005; F16D57/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US838765A
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US1024982A
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US2170128A
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US2280042A
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US2250885A
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US2336838A
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US2349921A
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US2388112A
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US2570768A
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US2634830A
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US2672953A
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US2672954A
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US2537800A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-03-25 | 1960-09-24 | 1961-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-03-25 | 1964-09-24 | 1965-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-03-25 | 1968-09-24 | 1969-03-26 | $7700.00 | Window Closed / Lapsed |