Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4495257 | Horizontal battery holder for cylinder cells | Charles Engelstein, David Kassel | 1985-01-22 |
| 4487820 | Battery holder for coin cells | Charles Engelstein, David Kassel | 1984-12-11 |