US3773874A
Expired / Lapsed
US
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Method for lining a continuous concrete pipe
Assignee: FULLERFORM COMPNY A ARIZONA LP
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Filing: 1971-07-20
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Granted: 1973-11-20
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Expires: 1991-07-20
Abstract
Abstract A METHOD FOR FORMING A CONTINUOUS CONCRETE PIPE HAVING AN INTEGRALLY FORMED LINING EXTENDING OVER PART OR ALL OF THE SURFACE OF ITS BORE. THE INVENTION RELATES TO A CONTINUOUS CONCRETE PIPE LAYING MACHINE WHICH TRAVELS ALONG IN A TRENCH AND WHICH WRAPS A CONTINUOUS SHEET OF IMPREVIOUS LINER MATERIAL ABOVE AN INFLATABLE CORE AND THEN CONTINUOUSLY DEPOSITS CEMENTIOUS MATERIAL INTO THE TRENCH TO SURROUND THE LINER AND CORE. WHEN THE CEMENTITIOUS MATERIAL HAS SET, THE CORE IS DEFLATED AND REMOVED LEAVING A FORMED CONCRETE PIPE WITH LINER IN PLACE IN THE TRENCH.
Inventors
- 👤 J Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:02
CPC Classifications
B; B28; B28B; B28B21/00; B28B21/92; B28B21/94; E; E21; E21B; E21B43/00; E21B43/02; E21B43/10; F; F16; F16L; F16L1/00; F16L1/024; F16L1/028; F16L1/038
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |