Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6141874 | Window frame welding method | — | 2000-11-07 |
| 5779384 | Window frame welding method and product thereof | — | 1998-07-14 |
| 5582445 | Sash lock | William L. Zemke | 1996-12-10 |
| D350275 | Sash lock | William L. Zemke | 1994-09-06 |