Patent ID: 7436088

Claim:
An electromagnetic exciter comprising: a magnetic circuit device including an outer yoke having a cylindrical side wall and a bottom wall connected to one end of said side wall, a magnet disposed within and arranged on the bottom wall of said outer yoke, and an inner yoke mounted on said magnet, said magnetic circuit device defining a magnetic gap between said inner yoke and said side wall of said outer yoke; a voice coil inserted into said magnetic gap; a casing dimensioned to contain said magnetic circuit device and said voice coil, said casing having a cylindrical wall disposed around said magnetic circuit device; a suspension connected between said cylindrical wall of said casing and said magnetic circuit device; and a weight extending from said side wall of said outer yoke, wherein said suspension includes an inner section secured to said side wall of said outer yoke, an outer section secured to said cylindrical wall of said casing, and a connecting section for interconnecting said inner and outer sections, said suspension including at least one opening among said outer section, said inner section and said connecting section; and wherein said weight includes at least one projection extending through said suspension and loosely fitted within said at least one opening.