Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6585299 | Pipe connector | Erich Quadflieg, Friedrich Lenze, Martin Schluter | 2003-07-01 |
| 6513840 | Drill rod coupling | Erich Quadflieg | 2003-02-04 |
| 6511102 | Pipe connector | Friedrich Lenze, Erich Quadflieg | 2003-01-28 |
| 5048871 | Screwed pipe joint | Gerd Pfeiffer, Erich Quadflieg, Friedrich Lenze, Josef Siekmeyer | 1991-09-17 |