Transformed stress direction acoustic transducer
US4999819A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1990 |
| Grant date | Mar 12, 1991 |
| Priority date | — |
| Expiry date | Apr 18, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K9/121
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This invention describes an acoustic transducer assembly wherein an extremely high figure of merit (d.sub.h g.sub.h) is obtained as a result of converting incoming acoustic axial stress into radial extensional stress thereby multiplying its effect. The piezoelectric active element is encased in a metal sandwich enclosing two semilunar air spaces which allow the device to withstand extremely high hydrostatic pressure yet still respond to low level sound waves when acting as a hydrophone. The mechanical prestress induced by the differential coefficients of expansion between the metal case and the piezoelectric ceramic element also serves to prevent depolarization aging.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.