Ultrasonic transducer with temperature stability due to selected damping materials and/or assembly methods
US4163917A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 25, 1977 |
| Grant date | Aug 7, 1979 |
| Priority date | — |
| Expiry date | Nov 25, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49945
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic transducer and a method for manufacture thereof in which a piezoelectric crystal is bonded to a flat diaphragm with the neutral bending axis of the crystal/diaphragm combination being within the bonding agent. The diaphragm is then pressed into the open end of a hollow shell. The resonant frequency of the shell, diaphragm and crystal combination is determined by the extent to which the diaphragm is pressed into the shell and, in the preferred example disclosed, is set at about 19.8 KHz. The shell cavity is then filled with a mixture of RTV and a nonconductive particulate material at a weight ratio between 5/1 and 20/1. This mixture lowers the Q of the transducer while also raising its resonant frequency to the desired 20 KHz.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.