Perforated drainpipe and method of making same
Patent 4421810 Issued on December 20, 1983. Estimated Expiration Date: 
December 20, 2000. 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.
December 20, 2000. 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 3281897 3499822 3505162 3565744 3632711 3677873 3753352 Irrigation device Apparatus for producing tubes by helically winding sheets Method of making a tubular collagen casing InventorApplicationNo. 06/177807 filed on 08/13/1980US Classes:428/109, With additional layer(s)156/176, To web of indefinite length156/187, Tubular core156/195, Longitudinally progressive helical winding156/244.13, Hollow article or lamina264/171.28, Polyamide (e.g., nylon,, etc.) or addition polymer of at least one monoethylenically unsaturated monomer (e.g., polyethylene, polypropylene, polystyrene, etc.) containing layer264/171.29, Including rotation of shaping surface or material being shaped264/172.1, Having particular noncircular cross-section (e.g., T-configured, etc.)405/43, Porous or apertured pipe, flume, or tileway405/48, Open seam or shielded outlet428/113, Fibers428/222, Embodying intertwined or helical component(s)428/36.3Fiber or fibers wound around each other or into a self-sustaining shape (e.g., yarn, braid, fibers shaped around a core, etc.)ExaminersPrimary: Dixon, William R. Jr.Attorney, Agent or FirmInternational ClassesB29C 43/30 (20060101)B29C 55/02 (20060101) B29C 43/22 (20060101) B29C 47/04 (20060101) B29C 47/00 (20060101) B32B 37/00 (20060101) B32B 27/08 (20060101) B32B 27/28 (20060101) B32B 27/00 (20060101) Foreign Application Priority Data1975-02-12 GBAbstractA perforated drainpipe in which at least one sheet comprised of polymeric material is shaped in generally tubular configuration with adjacent edges thereof being slightly spaced apart to define therebetween a gap extending along the tubular sheet, and at least one ribbon comprised of polymeric material, which can be the same or different as that in the tubular sheet, helically wound around the tubular sheet, preferably by extrusion, and integrally bonded thereto so as to reinforce the same and maintain the shape of the same. The sheet or sheets can extend longitudinally, being bent or curved width-wise so as to have such tubular shape, with the gap extending longitudinally. | |
