US3269424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prestressed concrete conduit and method
Assignee: Individual
•
Filing: 1963-07-30
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Granted: 1966-08-30
•
Expires: 1983-07-30
Abstract
No abstract record available.
Inventors
- 👤 John F Fisher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:43
CPC Classifications
E; E01; E01F; E01F5/00; E01F5/005; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/49947; Y10T29/49948; Y10T29/49952; Y10T29/49959; Y10T29/49961
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
57 words
A CONDUIT COMPRISING (A) A PAIR OF CONCRETE MEMBERS WITH OPPOSED EDGES SHAPED, WHEN SAID EDGES ARE BROUGH TOGETHER TO FORM A SECTION OF CONDUIT, (B) CONCRETE PRESTRESSING CABLES EXTENDING SUBSTANTIALLY LONGITUDINALLY THROUGH THE TWO CONDUIT MEMBERS AND NORMALLY HOLDING THE SAID MEMBERS IN CURVED CONDITION AND WITH EDGES OF THE MEMBERS HAVING OPPOSITE CURVILINEAR RELATION, AND
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) | 1969-08-29 | 1970-02-28 | 1970-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-08-29 | 1974-02-28 | 1974-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-08-29 | 1978-02-28 | 1978-08-30 | $7700.00 | Window Closed / Lapsed |