Issued Patents All Time
Showing 1–10 of 10 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5340232 | Manhole cover | Hansruedi Spiess | 1994-08-23 |
| 5160213 | Covering for a ground opening | Hansruedi Spiess | 1992-11-03 |
| 5071177 | Locking device for the positive holding of a cover or grate in a frame | Hansruedi Spiess | 1991-12-10 |
| 5056955 | Locking device for coverings for manholes and other ground openings | Hansruedi Spiess | 1991-10-15 |
| 5017039 | Covering for a ground opening | Hansruedi Spiess | 1991-05-21 |
| 4952094 | Ground water drain | Hansruedi Spiess | 1990-08-28 |
| 4925337 | Manhole covering | Hansruedi Spiess | 1990-05-15 |
| 4909664 | Arrangement for draining liquid collecting on a ground surface | Hansruedi Spiess | 1990-03-20 |
| 4904120 | Frame for forming coverings on ground openings | Hansruedi Spiess | 1990-02-27 |
| 4873795 | Covering for a ground opening | Hansruedi Spiess | 1989-10-17 |