Patent US3926223A successfully refreshed from Google Patents.
US3926223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Large diameter hollow bodies of helical thermoplastic strip
Assignee: Individual
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Filing: 1973-06-19
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Granted: 1975-12-16
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Expires: 1993-06-19
Abstract
Abstract A large-diameter hollow body, especially pipe such as waste or sewage pipe, consisting of a multiplicity of helical turns of an extruded thermoplastic synthetic-resin hollow strip heat-sealed together in laterally abutting relationship. The thermal butt welds are provided in planes transverse to the axis so that the inner surface has turns which are flush with one another. The turns themselves are hollow and of a generally rectangular profile with a substantially round (preferably circular) inner cross-section.
Inventors
- 👤 Aristovoulos George Petzetakis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:29
CPC Classifications
F; F16; F16L; F16L9/00; F16L9/18; B; B29; B29C; B29C65/00; B29C65/02; B29C48/00; B29C48/03; B29C48/09; B29C48/11; B29C48/12; B29C48/13; B29C48/131; B29C48/25; B29C48/88; B29C48/911; B29C48/9115; B29C53/00; B29C53/56; B29C53/58; B29C53/78; B29C53/80; B29C53/82; B29C53/821; B29C53/825; B29C53/827; B29C53/84; B29C53/845; B29C65/022; B29C65/028; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/114; B29C66/1142; B29C66/50; B29C66/51; B29C66/52; B29C66/522; B29C66/5227; B29C66/70; B29C66/71; F16L9/16; B29C65/04; B29C65/14; B29L; B29L2009/00; B29L2009/005; B29L2023/00; B29L2023/005; B29L2023/22; B29L2024/00; Y; Y10; Y10S; Y10S138/00; Y10S138/11
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
145 words
A LARGE-DIAMETER DUCT CONSISTING OF A MULTIPLICITY OF GENERALLY HELICAL TURNS OF A HOLLOW-PROFILE STRIP, THE STRIP BEING OF SUBSTANTIALLY SQUARE OUTER CROSS-SECTION AND SUBSTANTIALLY CIRCULAR INTERNAL CORSS-SECTION, SAID STRIP HAVING A PAIR OF LATERAL PARALLEL FLANK WALLS AND A PAIR OF FREE WALLS BETWEEN SAID FLANKS, THE FLANK WALLS OF ADJOINING TURNS BEING BUTT-WELDED TOGETHER WHEREBY SAID FREE WALLS DEFINE INNER AND OUTER SURFACES OF THE DUCTM SAID STRIP BEING COMPOSED OF POLYVINYLCHLORIDE OR POLYETHYLENE THERMOPLASTIC SYNTHETIC-RESIN MATERIAL ENABLING ELASTIC DEFORMATION OF SAID FREE WALLS UPON BENDING OF SAID DUCT AND RELAXATION OF THE DEFORMATION STRESSES IN SAID FREE WALLS WITH TIME, SAID STRIP HAVING A MINIMUM WALL THICKNESS AT SAID LATERAL FLANKS WHICH IS APPROXIMATELY 50% OF THE MINIMUM WALL THICKNESS AT SAID FREE WALLS, EACH PAIR OF ADJOINING TURNS DEFINING ACCUMULATIONS OF THE THERMOPLASTIC MATERIAL OF V-SECTION AT THE BUTT-WELD BETWEEN THEM.
Claim 2
Dependent Claim
145 words
A LARGE-DIAMETER DUCT CONSISTING OF A MULTIPLICITY OF GENERALLY HELICAL TURNS OF A HOLLOW-PROFILE STRIP, THE STRIP BEING OF SUBSTANTIALLY SQUARE OUTER CROSS-SECTION AND SUBSTANTIALLY CIRCULAR INTERNAL CORSS-SECTION, SAID STRIP HAVING A PAIR OF LATERAL PARALLEL FLANK WALLS AND A PAIR OF FREE WALLS BETWEEN SAID FLANKS, THE FLANK WALLS OF ADJOINING TURNS BEING BUTT-WELDED TOGETHER WHEREBY SAID FREE WALLS DEFINE INNER AND OUTER SURFACES OF THE DUCTM SAID STRIP BEING COMPOSED OF POLYVINYLCHLORIDE OR POLYETHYLENE THERMOPLASTIC SYNTHETIC-RESIN MATERIAL ENABLING ELASTIC DEFORMATION OF SAID FREE WALLS UPON BENDING OF SAID DUCT AND RELAXATION OF THE DEFORMATION STRESSES IN SAID FREE WALLS WITH TIME, SAID STRIP HAVING A MINIMUM WALL THICKNESS AT SAID LATERAL FLANKS WHICH IS APPROXIMATELY 50% OF THE MINIMUM WALL THICKNESS AT SAID FREE WALLS, EACH PAIR OF ADJOINING TURNS DEFINING ACCUMULATIONS OF THE THERMOPLASTIC MATERIAL OF V-SECTION AT THE BUTT-WELD BETWEEN THEM.
Claim 3
Dependent Claim
20 words
The duct defined in claim 1 wherein said strip is coated alone one of said walls with a different material.
Claim 4
Dependent Claim
31 words
The duct defined in claim 1 wherein the free walls of said turns defining the inner surface of said duct are flush with one another whereby said inner surface is continuous.
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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |