Plastic pipe comprising an outer corrugated pipe and a smooth inner wall
US4754781A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 22, 1986 |
| Grant date | Jul 5, 1988 |
| Priority date | — |
| Expiry date | Aug 22, 2006 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16L55/1652
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A plastic pipe consisting of an outer corrugated plastic pipe and an inner smooth wall consisting of a wear resistant elastomer, particularly a thermoplastic rubber fixed in the inner bottoms wave valleys to said outer corrugated pipe. The inner wall consists of a pipe which has been coextruded with the outer corrugated pipe so that the inner and outer pipe are heat welded to each other. The cavities between the inner pipe and the corrugations may be filled with a foam plastic. This plastic pipe is used for repairing or renewing a sewage pipe by installing such a pipe from a vertical shaft of the sewage system into the sewage pipes. The interstices between the outer side of the corrugation and the inner side of the sewage pipe may be filled with a mortar.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.