Method for relining an underground gas line or the like without excavation
Patent 4394202 Issued on July 19, 1983. Estimated Expiration Date: 
January 22, 2001. 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.
January 22, 2001. 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 ReferencesInventorsAssigneeApplicationNo. 06/227336 filed on 01/22/1981US Classes:156/94, Reclaiming, renewing or repairing articles for reuse138/97, REPAIRING156/250, With cutting, punching, tearing or severing156/252, Perforating lamina156/287, To the lining of hollow body156/294, Core within tube156/83, With swelling of material of lamina156/84, With shrinking of material of lamina264/230, UTILIZING HEAT RELEASABLE STRESS TO RESHAPE SOLID WORKPIECE (E.G., ELASTIC MEMORY, ETC.)264/36.16, Pipes or tubes29/234, Tube and coextensive core29/235, To apply or remove a resilient article (e.g., tube, sleeve, etc.)29/402.09By attaching repair preform, e.g., remaking, restoring, or patchingExaminersPrimary: Dawson, Robert A.Attorney, Agent or FirmInternational ClassesF16L 55/165 (20060101)F16L 55/162 (20060101) AbstractA method and apparatus for repairing or relining an underground pipeline without having to excavate the pipe is enabled by attaching an expandable sealing unit to the end of a predetermined length of flexible tubing and feeding it through the pipeline. The flexible tubing is fed through the existing pipeline from a point beyond where the existing pipeline exits the earth, usually within the basement of a building. Once positioned in the desired location, the expandable sealing unit is expanded to form a tight seal at the desired location within the pipe by means of heating the expandable sealing unit by a heating unit connected to the source of energy through electrical conductors which pass through the flexible tubing. | |
