Flexible multilayer tubular structure for irrigation and process for its preparation
Patent 4139159 Issued on February 13, 1979. Estimated Expiration Date: 
May 25, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 25, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References RE28095 3777987 3830067 Method of making irrigation conduits Patent #: 3989572 InventorsAssigneeApplicationNo. 05/800175 filed on 05/25/1977US Classes:239/547, DISTRIBUTOR OR NOZZLE IN CIRCUMFERENTIAL WALL OF FLEXIBLE SUPPLY LINE156/252, Perforating lamina156/290, Bonding of facing continuously contacting laminae at spaced points only239/145, POROUS OR EXTERNAL WICK DISCHARGE MEANS428/34.5, Contains fabric, fiber particle, or filament made of glass, ceramic, or sintered, fused, fired, or calcined metal oxide, or metal carbide or other inorganic compound (e.g., fiber glass, mineral fiber, sand, etc.)428/35.6, Cellular material derived from plant or animal source (e.g., wood, cotton, wool, leather, etc.)428/36.1Textile, fabric, cloth, or pile containing (e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.)ExaminersPrimary: Drummond, Douglas J.Attorney, Agent or FirmInternational ClassesA01C 23/04 (20060101)A01C 23/00 (20060101) B29C 53/00 (20060101) B29C 53/48 (20060101) F16L 11/12 (20060101) A01G 25/02 (20060101) E02B 13/00 (20060101) Foreign Application Priority Data1976-06-01 JPAbstractA 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. | |
