Flexible multilayer tubular structure for irrigation and process for its preparation
US4139159A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1977 |
| Grant date | Feb 13, 1979 |
| Priority date | — |
| Expiry date | May 25, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1362
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A plastic tubular irrigating structure is provided for agricultural and other irrigation systems. The structure comprises (A) a flexible outer layer of a thermoplastic synthetic resin tube having at least one continuous fin-like heat-sealed portion along its length and watering orifices, and (B) a flexible inner layer, as a filter, of a water-permeable, water-insoluble sheet, preferably a nonwoven fibrous sheet, fixed partly to the inside of the outer layer (A), the inner layer (B) being permeable to a larger amount of water than the outer layer (A). In the absence of water supply, the structure is a flattened tube, but upon supply of water therethrough, it assumes an expanded tubular shape.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.