Electro acoustic transducers comprising a flexible and sealed transmitting shell

摘要

The invention relates to electro-acoustic transducers comprising a flexible and sealed transmitting shell referred to as flextensional transducers. A transducer according to the invention comprises one or more electro-acoustic drivers, e.g., a stack of piezoelectric plates 1a, 1b . . . 1n, located inside a flexible and sealed shell. Each piezo-electric driver comprises, at both its ends, a counter-mass coupled mechanically and acoustically with the stack and the ends of the shell by means of an axial threaded rod and two nuts screwed on the ends of the rod. The mass of the two counter-masses and the dimensions of the stack are determined so that the fundamental frequency of the axial oscillations of this mechanical assembly will be close to the natural frequency of the bending oscillations of the shell. An application of the invention is the construction of sonar transmitters.