Method for joining plastic pipes, a joint ring used in the joining and a pipe joint provided with the method
US6149756A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 24, 1998 |
| Grant date | Nov 21, 2000 |
| Priority date | — |
| Expiry date | Aug 24, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C66/71
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method for joining a first tubular member to a second tubular member. The method provides a stretchable and compressible welding ring having a flexible inner ring, a resistance coil wound around the inner ring and at least one layer of plastic coating the resistance coil. The method includes the step of arranging the first and second tubular members in overlapping relation with an end of the first tubular member inserted into an end of the second tubular member and with the welding ring encircling the first tubular member and compressed between the first and second tubular members. The method also includes the step of applying electric energy to the resistance coil to melt the at least one layer of plastic so that, upon cooling, the respective ends of the first and second tubular members are welded to the welding ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.