Abstract: A sonic generator comprises a resonant bar, a housing and magnetic excitation units connected between the resonant bar and the housing. The magnetic excitation units are connected to the bar at highly stressed points using a mounting connection which is a sleeve having an inside diameter slightly greater than the outside diameter of the bar. A resilient elastomer such as urethane is mounted between the sleeve and the resonant member. The sonic generator may be used for grinding purposes and, in particular, may be used to grind material exceptionally fine with reduced power consumption. The bar is substantially unrestrained so as to allow substantially free vibration.

Abstract: A sonic generator comprises a resonant bar, a housing and magnetic excitation units connected between the resonant bar and the housing. The magnetic excitation units are connected to the bar using a mounting connection which is a sleeve having an inside diameter slightly greater than the outside diameter of the bar. A resilient elastomer such as urethane is mounted between the sleeve and the resonant member.