US4577997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Irrigation pipe
Assignee: Individual
•
Filing: 1983-07-07
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Granted: 1986-03-25
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Expires: 2003-07-07
Abstract
Abstract An irrigation pipe, primarily for subterranean irrigation, said pipe having incisions in the longitudinal direction of the pipe, which incisions will open under the action of the pressure enabling the irrigation water to flow into the surrounding ground. It is characteristic of the pipe that a pipe made of two-layer material is used, the outer part of which is thinner than the inner part and the inner part has been cooled down during the manufacturing before the outer layer has been made, by which method the characteristic can be obtained that the incision opens more on the outside than on the inside thus preventing impurities of any kind from accumulating in the incision.
Inventors
- 👤 Eino Lehto
- 👤 Goran Moller
- 👤 Lasse Sjovall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:57
CPC Classifications
A; A01; A01G; A01G27/00; A01G25/00; A01G25/06
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
155 words
A method of irrigation which comprises the steps of: forming a two-layer irrigating pipe by producing a hot tubular first layer of polyethylene plastic, allowing said first layer to cool, then applying a second layer of polyethylene plastic so that it completely ensheathes said first layer in continuous contact with said first layer uniformly all around the periphery thereof and with a thickness less than that of said first layer but such that material of said second layer does not blend with material of the first layer, and incising through both said layers with parallel incisions extending longitudinally of the pipe and uniformly spaced apart all around the circumference of the both layers and spaced apart along the length of the resulting pipe; burying said pipe in a region irrigated; and passing irrigating water under pressure through said pipe, thereby widening said incision outwardly and permitting water to flow outwardly through the outwardly widened incisions.
Claim 2
Independent Claim
155 words
A method of irrigation which comprises the steps of: forming a two-layer irrigating pipe by producing a hot tubular first layer of polyethylene plastic, allowing said first layer to cool, then applying a second layer of polyethylene plastic so that it completely ensheathes said first layer in continuous contact with said first layer uniformly all around the periphery thereof and with a thickness less than that of said first layer but such that material of said second layer does not blend with material of the first layer, and incising through both said layers with parallel incisions extending longitudinally of the pipe and uniformly spaced apart all around the circumference of the both layers and spaced apart along the length of the resulting pipe; burying said pipe in a region irrigated; and passing irrigating water under pressure through said pipe, thereby widening said incision outwardly and permitting water to flow outwardly through the outwardly widened incisions.
Claim 3
Dependent Claim
19 words
The method defined in claim 1 wherein said incisions are provided to enable spaced annular rows along said tube.
References Cited (Backward Citations)
US2763991A
Cited
US3293861A
Cited
US3698193A
Cited
US3422626A
Cited
US4095750A
Cited
US4117685A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-24 | 1989-09-23 | 1990-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-24 | 1993-09-23 | 1994-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-24 | 1997-09-23 | 1998-03-25 | $7700.00 | Window Closed / Lapsed |