US Patent 7679240 Vibration motor

A vibration motor having an eccentric weight 20 includes a tubular metal holder frame 30 with a flat bottom part 31 and a wall surface 32, the flat bottom part 31 having an inner projection 31f with a bottom-up recess part W, the upper wall surface 32 being domed; a pair of external terminal pieces 14 and 15 attached to a plastic end cap 13, wherein the plastic end cap 13 has spacer projections 13b and 13c inserted between the motor case 11 and the flat bottom part 31.