Issued Patents All Time
Showing 1–9 of 9 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 11634949 | Percussion boring device and method for reversing a percussion boring device | Gerhard Völkel | 2023-04-25 |
| 10480246 | Percussion boring device | Franz-Josef Puttmann, Gerhard Völkel | 2019-11-19 |
| 7874382 | Pneumatically reversible ram boring device | Franz-Josef Puttmann | 2011-01-25 |
| 6406215 | Positive connection between a pipe and a ring inserted into the pipe | Franz-Josef Puttmann | 2002-06-18 |
| 6267187 | Boring apparatus with coupling for rapid connection of drill string segments | Franz-Josef Puttmann | 2001-07-31 |
| 6244783 | Widening apparatus | Franz-Josef Puttmann | 2001-06-12 |
| 5960892 | Automatically driven pile driver drilling device | Franz-Josef Puttmann, Alfons Hesse | 1999-10-05 |
| 5954145 | Reversible percussion piston drill apparatus | Alfons Hesse, Franz-Josef Puttmann | 1999-09-21 |
| 5148878 | Ram boring machine | Paul Wayne Schmidt, Alfons Hesse, Franz-Josef Puttmann | 1992-09-22 |