An ultrasonic atomizing device includes an ultrasonic oscillator system and a housing. The oscillator system comprises a conic-frustum shaped coupler having a projection at the central portion of its large cross-sectional portion, a circular piezoelectric plate provided with electrode plates and having...http://www.google.es/patents/US4474326?utm_source=gb-gplus-sharePatente US4474326 - Ultrasonic atomizing device
