Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| D856918 | Floatation device for solar panels | Soren Lunoe, Daniel John REDDEL | 2019-08-20 |
| 7290346 | Extension set for spirit levels | Stephen Sweet, Mordechai Schwartz | 2007-11-06 |
| 7117608 | Spirit level | Duane William Zugel | 2006-10-10 |
| 7047654 | Retainer clips for securing a cylindrical level vial | — | 2006-05-23 |
| 6748666 | Spirit level | Duane William Zugel | 2004-06-15 |
| 6449859 | Spirit level | Duane William Zugel | 2002-09-17 |
| 6418634 | Spirit level with hand grips | — | 2002-07-16 |
| D451831 | Carpenter square | — | 2001-12-11 |
| D451040 | Ruler with sliding bubble vials | — | 2001-11-27 |
| 6209211 | Spirit level with multiple bubble vials | — | 2001-04-03 |
| 6029359 | Post, pipe, and sign level | — | 2000-02-29 |