Issued Patents 1989
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4877474 | Process for the production of a hollow chamber plate of synthetic material | — | 1989-10-31 |
| 4861536 | Method for manufacturing a sealing ring | Gunter Graf, Stefan Sponagel | 1989-08-29 |
| 4850097 | Method for the manufacture of a sealing ring with a sealing lip having hydrodynamically acting return elements | Gunter Graf, Stefan Sponagel | 1989-07-25 |
| 4827099 | Method and apparatus for continuous production of tubular bodies by means of laser longitudinal seam welding | Rolf Krebs, Otto Welsing, Friedhelm Retzlaff, Friedhelm Gunter, Hans-Jürgen Wahl +1 more | 1989-05-02 |
| 4797173 | Apparatus for face welding bundles of thermoplastic moldings under pressure | Klaus E. Pohlmann, Harmut Schikowsky | 1989-01-10 |