Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4883002 | Furnace closing mechanism for industrial furnaces | — | 1989-11-28 |
| 4869470 | Vacuum furnace for heat treatment of metallic workpieces | Paul Heilmann, Fritz Kalbfleisch, Friedrich Preisser | 1989-09-26 |
| 4870256 | Graphite holding elements for heating bars in industrial furnaces | Wolfgang Heise, Georg Kell | 1989-09-26 |
| 4867808 | Heat treating a metallic workpiece by quenching under cooling gas under above atmospheric pressure and specified circulation rate | Paul Heilmann, Friedrich Preisser | 1989-09-19 |