US3217451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prestressed concrete structures
Assignee: Preload Co
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Filing: 1961-01-27
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Granted: 1965-11-16
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Expires: 1981-01-27
Abstract
No abstract record available.
Inventors
- 👤 John J Closner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:31
CPC Classifications
E; E04; E04H; E04H7/00; E04H7/02; E04H7/18; E04H7/20; E04G; E04G21/00; E04G21/12; E04G2021/127
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
95 words
A SUBSTANTIALLY CYLINDRICAL CONCRETE TANK STRUCTURE COMPRISING AN ANNULAR CORE WALL PRESTRESSED WITH A FIRST LAYER OF A HIGH TENSILE STRENGTH TENDON, A FIRST ROW OF UPRIGHT SEPARATORS CIRCUMFERENTIALLY SPACED ABOUT THE WALL AND CONTACTING HE FIRST TNEDON LAYER, A SECONDLAYER OF PRESTRESSING TENDON TENSIONED ABOUT THE WALL AND OVER THE FIRST ROW OF SEPARATORS, ADDITIONAL ALTERNATE ROWS OF SEPARATORS AND TENDON LAYERS, SAID SEPARATORS IN EACH ROW BEING IN RADIAL ALIGNMENT WITH THE RESPECTIVE SEPARATORS IN EACH OTHER ROW, AND A PROTECTIVE COVER COATING OVER THE LAYERS OF PRESTRESSING TENDONS AND THE UPRIGHT SEPARATORS.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-15 | 1969-05-17 | 1969-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-15 | 1973-05-17 | 1973-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-15 | 1977-05-17 | 1977-11-16 | $7700.00 | Window Closed / Lapsed |