US4611636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reinforced underground pipe
Assignee: Individual
•
Filing: 1985-01-31
•
Granted: 1986-09-16
•
Expires: 2005-01-31
Abstract
Abstract A reinforced underground pipe made of a synthetic resin having an improved strength and reduced resin requirement. The reinforcement of the pipe is constituted by a helical rib formed on the outer surface of the main body of the pipe. At least side wall portions of the rib are corrugated. The rib may be U shaped or have a semicircular cross section. The corrugations may be rectangular, sinusoidal or triangular.
Inventors
- 👤 Shiro Kanao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:03
CPC Classifications
F; F16; F16L; F16L11/00; F16L11/04; F16L11/12; F16L9/00; F16L9/12; F16L9/16
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
51 words
A reinforced underground pipe, comprising; a tubular body made of a synthetic resin, a helical reinforcing rib formed on an outer surface of said tubular body, said rib having a pair of opposed side walls, and at least both said side walls being regularly and continuously corrugated along their entire lengths.
Claim 2
Dependent Claim
51 words
A reinforced underground pipe, comprising; a tubular body made of a synthetic resin, a helical reinforcing rib formed on an outer surface of said tubular body, said rib having a pair of opposed side walls, and at least both said side walls being regularly and continuously corrugated along their entire lengths.
Claim 3
Dependent Claim
23 words
The underground pipe of claim 1, wherein said reinforcing rib is generally U shaped and has a top wall which is continuously flat.
Claim 4
Dependent Claim
31 words
The underground pipe of claim 1, wherein said reinforcing rib is generally U shaped and further includes a top wall portion which is regularly and continuously corrugated along its entire length.
Claim 5
Dependent Claim
16 words
The underground pipe of claim 1, wherein said reinforcing rib has a continuously semicircular cross section.
Claim 6
Dependent Claim
42 words
The underground pipe of claim 1, further comprising an inner wall of lesser thickness than a main wall portion of said tubular body, said inner wall generally conforming to the shape of said rib but with a gap of predetermined width therebetween.
Claim 7
Dependent Claim
12 words
The underground pipe of claim 1, wherein said rib has rectangular corrugations.
Claim 8
Dependent Claim
14 words
The underground pipe of claim 1, wherein said rib has wavy approximately sinusoidal corrugations.
Claim 9
Dependent Claim
12 words
The underground pipe of claim 1, wherein said rib has triangular corrugations.
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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) | 1989-09-15 | 1990-03-17 | 1990-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-15 | 1994-03-17 | 1994-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-15 | 1998-03-17 | 1998-09-16 | $7700.00 | Window Closed / Lapsed |