Sub-soil drainage piping
Patent 4626129 Issued on December 2, 1986. Estimated Expiration Date: 
July 26, 2004. 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.
July 26, 2004. 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 1406182 2009163 2054703 2143072 2874844 3902322 3902323 Drainage field pipe Patent #: 4134268 InventorsAssigneeApplicationNo. 06/634485 filed on 07/26/1984US Classes:405/43, Porous or apertured pipe, flume, or tileway405/36, DRAINAGE OR IRRIGATION405/45PorousExaminersPrimary: Taylor, Dennis L.Attorney, Agent or FirmInternational ClassE02B 11/00 (20060101)Foreign Application Priority Data1983-07-27 ZAAbstractA sub-soil drainage pipe segment 12 comprises a first round cylindrical portion 14 forming a socket 16 and a second round cylindrical portion 18 integral with and extending from the first portion, the inside diameter of the first portion being substantially equal to the outside diameter of the second portion. In the second portion there are a plurality of circumferentially spaced, longitudinally extending slots 22. The slots are defined by longitudinally extending side walls which diverge from the outside inwardly. A plain end 20 of the second portion forms a spigot which is receivable in the socket of a similar segment, so that a number of such segments can be interconnected end-to-end to form a sub-soil drainage line. | |
