Patent US3552129A successfully refreshed from Google Patents.
US3552129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High pressure resistant cofferdam
Assignee: Individual
•
Filing: 1968-01-26
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Granted: 1971-01-05
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Expires: 1988-01-26
Abstract
Abstract A COFFERDAM OF SIMPLE, GENERALLY CIRCULAR CONFIGURATION, ADAPTED TO WITHSTAND POWERFUL EXTERNAL PRESSURES AT CONSIDERABLE DEPTHS. THE COFFERDAM COMPRISES CONCENTRIC SPACED CYLINDRICAL STRUCTURES OF GRADUATED HEIGHTS, BEING PROGRESSIVELY LESS HIGH AT THE INSIDE. SEEPAGE WATER IN THE SPACES IS CONTINUOUSLY PUMPED OUT, AND THE WEIGHT OF SUCH WATER COUNTERACTS THE POWERFUL OUTSIDE PRESSURES AT THE INTERVALS WHERE THE CYLINDERS ARE NOT BRACED, THEREBY OBVIATING THE NECESSITY FOR CONTINUOUS MASSIVE BRACING AND STRUCTURAL ELEMENTS AT THE LOWER PORTIONS OF THE DAM.
Inventors
- 👤 George H Hooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:18
CPC Classifications
E; E02; E02D; E02D19/00; E02D19/02; E02D19/04
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) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |