Issued Patents All Time
Showing 25 most recent of 29 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5729507 | Directional energy receiving systems for use in the indication of the direction of arrival of the received signal | Donald P. Massa | 1998-03-17 |
| 4909266 | Ultrasonic cleaning system | — | 1990-03-20 |
| 4859897 | Directional waterproof ultrasonic transducer for operating in air | — | 1989-08-22 |
| 4769795 | Method of making an underwater electroacoustic transducer with long-lasting high leakage resistance | Donald P. Massa | 1988-09-06 |
| 4763307 | Wide-range audio frequency underwater transducer | — | 1988-08-09 |
| 4745586 | Electromagnetic transducers for underwater low-frequency high-power use | — | 1988-05-17 |
| 4736350 | Electromagnetic transducers for underwater low-frequency high-power use | — | 1988-04-05 |
| 4700333 | Hydrophone design to overcome reduction in leakage resistance between electrode surface of transducer element assembly and the water in which the hydrophone is immersed | Donald P. Massa | 1987-10-13 |
| 4660186 | Electromagnetic transducers for underwater low-frequency high-power use | — | 1987-04-21 |
| 4641290 | Low frequency portable lightweight sonar systems and their method of deployment for greatly increasing the efficiency of submarine surveillance over large areas | Donald P. Massa | 1987-02-03 |
| 4469175 | Mechanoacoustic transducer for use in transmitting high acoustic power densities into geological formations such as oil-saturated sandstone or shale | — | 1984-09-04 |
| 4439847 | High efficiency broadband directional sonar transducer | — | 1984-03-27 |
| 4433399 | Ultrasonic transducers | — | 1984-02-21 |
| 4428206 | Means for detecting the accumulation of frost in a low temperature refrigeration system | — | 1984-01-31 |
| 4348869 | Means for detecting the accumulation of frost in a low temperature refrigeration system | — | 1982-09-14 |
| 4342229 | Apparatus and method for the non-destructive testing of the physical integrity of a structural part | — | 1982-08-03 |
| 4332017 | Mechanoacoustic transducer for use in transmitting high acoustic power densities into geological formations such as oil-saturated sandstone or shale | — | 1982-05-25 |
| 4305140 | Low frequency sonar systems | — | 1981-12-08 |
| 4305141 | Low-frequency directional sonar systems | — | 1981-12-08 |
| 4297538 | Resonant electroacoustic transducer with increased band width response | — | 1981-10-27 |
| 4281484 | System for precisely and economically adjusting the resonance frequence of electroacoustic transducers | — | 1981-08-04 |
| 4231112 | High-power underwater transducer with improved performance and reliability characteristics and method for controlling said improved characteristics | — | 1980-10-28 |
| 4210969 | Sonic ranging systems to eliminate errors due to variations in the sound velocity in the medium | — | 1980-07-01 |
| 4198705 | Directional energy receiving systems for use in the automatic indication of the direction of arrival of the received signal | — | 1980-04-15 |
| 4191904 | Electroacoustic transducers of the flexural resonant vibratile type | — | 1980-03-04 |