Issued Patents All Time
Showing 1–16 of 16 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6496448 | Transducer receiving voltage inputs, such as square waves, rich in harmonics | — | 2002-12-17 |
| 6491095 | Transducers, and methods of producing transducers, with cryogenically treated transducer members | — | 2002-12-10 |
| RE37204 | Transducer assembly | — | 2001-06-05 |
| 5592359 | Transducer | — | 1997-01-07 |
| 5122992 | Transducer assembly | — | 1992-06-16 |
| 5020035 | Transducer assemblies | — | 1991-05-28 |
| 4878057 | Typewriter keyboard | Rickey H. Ming | 1989-10-31 |
| 4737767 | Solid state keyboard | James R. Ligman | 1988-04-12 |
| 4658897 | Downhole transducer systems | James R. Ligman, Eric D. Plambeck | 1987-04-21 |
| 4651044 | Electroacoustical transducer | — | 1987-03-17 |
| 4512402 | Casing tuned downhole tool | James R. Ligman, Eric D. Plambeck | 1985-04-23 |
| 4257482 | Sonic gravel packing method and tool for downhole oil wells | — | 1981-03-24 |
| 4220887 | Prestressed, split cylindrical electromechanical transducer | — | 1980-09-02 |
| 4206491 | Entry system | James R. Ligman, Peter N. Kaufman, David K. Carlson | 1980-06-03 |
| 4193010 | Sensor device using piezoelectric coating subjected to bending | — | 1980-03-11 |
| 4190785 | Pressure sensitive signal generator using piezoelectric coating | — | 1980-02-26 |