Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5841343 | Buzzer with rotary volume adjustment | Kenyon A. Hapke, Spencer C. Schantz | 1998-11-24 |
| 4312201 | Cylinder lock with force-immune knob | — | 1982-01-26 |
| 4262507 | Cylinder lock with hotel function | Max L. Flack | 1981-04-21 |