Issued Patents All Time
Showing 1–24 of 24 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5976298 | Method of producing multilayer thermoplastic pipe | Ralph-Peter Hegler | 1999-11-02 |
| 5953974 | Apparatus for cutting slots in corrugated and twin-wall pipes | Ralph-Peter Hegler | 1999-09-21 |
| 5560941 | Apparatus for the manufacture of corrugated pipes of thermoplastic plastics | Ralph-Peter Hegler | 1996-10-01 |
| 5511964 | Apparatus for the production of plastic pipes | Ralph-Peter Hegler | 1996-04-30 |
| 5489403 | Method for welding pipe pieces made of thermoplastics | Ralph-Peter Hegler | 1996-02-06 |
| 5472659 | Method for continuously manufacturing compound corrugated pipe having smooth portions | Ralph-Peter Hegler | 1995-12-05 |
| 5393211 | Apparatus for the manufacture of a plastic pipe having transverse profile features | Ralph-Peter Hegler | 1995-02-28 |
| 5346384 | Apparatus for the production of plastic pipes | Ralph-Peter Hegler | 1994-09-13 |
| 5320697 | Method for welding together pipes consisting of thermoplastic plastics | Ralph-Peter Hegler | 1994-06-14 |
| 5320797 | Method and apparatus for the continuous manufacture of a compound pipe with a pipe socket | Ralph-Peter Hegler | 1994-06-14 |
| 5141427 | Apparatus for the production of plastic pipes | Ralph-Peter Hegler | 1992-08-25 |
| 5071173 | Plastic pipe for sewer pipe reconstruction | Ralph-Peter Hegler | 1991-12-10 |
| 4930936 | Partial-seepage drainage pipe with mating sleeve | Ralph-Peter Hegler | 1990-06-05 |
| 4915425 | Pipe connecting element | Ralph-Peter Hegler | 1990-04-10 |
| 4900503 | Method and apparatus for producing a finned tube from synthetic plastics material | Ralph-Peter Hegler | 1990-02-13 |
| 4779651 | Plastic corrugated tube with integrally molded sleeve coupler | Ralph-Peter Hegler | 1988-10-25 |
| 4773451 | Double tubing comprising two protective tubes integrally joined to one another by a web | Ralph-Peter Hegler | 1988-09-27 |
| 4513787 | Corrugated sheathing hose | Ralph-Peter Hegler | 1985-04-30 |
| 4492551 | Apparatus for the production of plastic pipes with transverse grooves | Ralph-Peter Hegler | 1985-01-08 |
| 4488467 | Apparatus for cutting openings in pipes | Ralph-Peter Hegler | 1984-12-18 |
| 4381276 | Process and apparatus for the fabrication of a flat-shaped hollow body | Ralph-Peter Hegler | 1983-04-26 |
| 4303104 | Double-wall plastic tubing in which the outer wall has transverse corrugations and the inner wall is smooth | Ralph-Peter Hegler | 1981-12-01 |
| 4212618 | Apparatus for the manufacture of transversely contoured tubing from thermoplastic material | Ralph-Peter Hegler | 1980-07-15 |
| 4184831 | Apparatus for producing plastic drain pipes | Ralph-Peter Hegler | 1980-01-22 |