Patent US4628966A successfully refreshed from Google Patents.
US4628966A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthetic resin pipe for underground use
Assignee: Individual
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Filing: 1985-01-30
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Granted: 1986-12-16
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Expires: 2005-01-30
Abstract
Abstract A pipe made of a synthetic resin and suitable for underground use which has an improved strength and reliability. In a first embodiment, a helical reinforcing rib is provided by extruding together with a band of resin material which forms the main body of the pipe a corrugated tube. By passing the corrugated tube through the extrusion die, the danger of the wall thickness of the main body of the pipe being reduced is eliminated. In a second embodiment, the reinforcing rib is formed by helically winding a reinforcing member having at least an outer coating of either the same material which forms the main body of a straight-wall pipe or a material having a high fusibility therewith. In this case also, the reinforcing rib can be made from a corrugated tube having a semicircular cross-section.
Inventors
- 👤 Shiro Kanao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:30
CPC Classifications
F; F16; F16L; F16L11/00; F16L11/04; F16L11/12; B; B29; B29C; B29C53/00; B29C53/56; B29C53/58; B29C53/78; B29C53/785; B29C48/00; B29C48/03; B29C48/09; F16L9/00; F16L9/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
72 words
A pipe suitable for underground use, manufactured by the process of: passing a corrugated reinforcing rib through an extrusion die used to extrude a band of material to form a main body of said pipe, and winding said band, including said rib, around a mandrel to form said pipe, said reinforcing rib comprising a corrugated pipe having a semicircular cross-section with a flat side disposed towards said main body of said pipe.
Claim 2
Dependent Claim
72 words
A pipe suitable for underground use, manufactured by the process of: passing a corrugated reinforcing rib through an extrusion die used to extrude a band of material to form a main body of said pipe, and winding said band, including said rib, around a mandrel to form said pipe, said reinforcing rib comprising a corrugated pipe having a semicircular cross-section with a flat side disposed towards said main body of said pipe.
Claim 3
Dependent Claim
12 words
The underground pipe of claim 1, wherein said band has beveled edges.
Claim 4
Dependent Claim
12 words
The underground pipe of claim 1, wherein said band has stepped edges.
Claim 5
Dependent Claim
83 words
A pipe suitable for underground use, manufactured by the process of: providing a straight-wall pipe main body made of a synthetic resin material; helically winding around said main body a reinforcing rib, said reinforcing rib comprising a corrugated tube having a semicircular cross-section with a flat side disposed towards said main body, and said rib having at least an outer layer formed around said tube, said outer layer comprising a material having a high fusibility with said resin material of said main body.
Claim 6
Dependent Claim
83 words
A pipe suitable for underground use, manufactured by the process of: providing a straight-wall pipe main body made of a synthetic resin material; helically winding around said main body a reinforcing rib, said reinforcing rib comprising a corrugated tube having a semicircular cross-section with a flat side disposed towards said main body, and said rib having at least an outer layer formed around said tube, said outer layer comprising a material having a high fusibility with said resin material of said main body.
Claim 7
Dependent Claim
12 words
The underground pipe of claim 4, wherein said flat side is smooth.
Claim 8
Dependent Claim
16 words
The underground pipe of claim 4, wherein said flat side has longitudinally extending corrugations formed therein.
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) | 1989-12-15 | 1990-06-16 | 1990-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-15 | 1994-06-16 | 1994-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-15 | 1998-06-16 | 1998-12-16 | $7700.00 | Window Closed / Lapsed |