US Patent 9439742 Electric toothbrush

An electric toothbrush includes an inner case, made up of an inner case main body and a motor holder, mounted with various components including a motor; an outer case which interiorly accommodates the inner case and which acts as a portion the user grips with hand when brushing teeth; an eccentric shaft, configured by a shaft main body and an eccentric member, which center of gravity is arranged at a position shifted from a shaft center and which rotates by a drive force of the motor; and a vibration transmitting component for transmitting the vibration generated with the rotation of the eccentric shaft to a brush portion; where the vibration transmitting component is positioned with respect to the outer case by point contacting the inner wall surface of the outer case at a plurality of locations.