Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4550228 | Ribbon speaker system | Leo Spiegel, Anthony J. Shuman, James L. Kirtley, Jr. | 1985-10-29 |
| 4537067 | Inertial borehole survey system | Harper E. Sharp, Leo Spiegel, Richard M. Masters, Elmer J. Frey, John R. Howatt | 1985-08-27 |
| 4454756 | Inertial borehole survey system | Harper E. Sharp, Leo Spiegel, Richard M. Masters, Elmer J. Frey, John R. Howatt | 1984-06-19 |