| 4634844 |
Electroweldable socket and a device of manufacturing such a socket |
Bernhard Lodder, Hans Overeijnder |
1987-01-06 |
| 4566704 |
Sealing body for a pipe connection |
— |
1986-01-28 |
| 4492867 |
Method of and apparatus for determining the state of ageing of plastic products |
Johannes J. Laarhoven, Hendrik de Wit, Louis Marie SMEETS |
1985-01-08 |
| 4440195 |
Plastic tube with longitudinal channels in the wall |
— |
1984-04-03 |
| 4390383 |
Method of making plastic pipes having walls with lengthwise extending channels |
— |
1983-06-28 |
| 4362323 |
Pipe part with a socket end |
Bernhard Lodder, Gerard A. E. Blok |
1982-12-07 |
| 4341392 |
Plastics pipes having walls with lengthwise extending channels |
— |
1982-07-27 |
| 4323339 |
Device for manufacturing plastics pipes with oblong channels |
Johan de Kok |
1982-04-06 |
| 4305899 |
Method of manufacturing a plastic tube with longitudinal channels in the wall |
— |
1981-12-15 |
| 4280534 |
Plastics pipes having walls with lengthwise extending channels |
— |
1981-07-28 |