Patent US3793411A successfully refreshed from Google Patents.
US3793411A
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US
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Method for making insulated pipe
Assignee: ROVANCO CORP I-55 & FRONTAGE ROAD JOLIET ILLINOIS A CORP OF
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Filing: 1971-04-20
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Granted: 1974-02-19
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Expires: 1991-04-20
Abstract
Abstract An insulated flow conduit construction having one or more flow conduits centered within a tubular outer casing with unitary monolithic insulating urethane foam means disposed between the conduits and the outer casing. A centered fixture is employed to initially center the flow conduits within the outer casing and urethane foam is then introduced into the casing in a controlled manner, the centering fixture being removed prior to completion of filling with urethane foam.
Inventors
- 👤 L Stonitsch
- 👤 R Stonitsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:30
CPC Classifications
F; F16; F16L; F16L59/00; F16L59/04; B; B29; B29C; B29C44/00; B29C44/02; B29C44/12; B29C44/1228; B29C44/1242; F16L59/14; F16L59/143; Y; Y10; Y10S; Y10S138/00; Y10S138/09
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) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |