US Patent 8089227 Electrically operated, continuously adjustable personal hygiene device

A toothbrush has a removable end cap at its free end area directed away from the bristles, which end cap closes off an inner space of a grip element. The end cap accommodates an electrical control element, in particular a potentiometer, which can be adjusted via an adjustment element arranged rotatably on the end cap. The toothbrush also comprises an electrical power consumption unit, in particular an electric motor, which is designed to set the bristles in vibration. The energy supply from an energy reservoir arranged in the interior to the electrical power consumption unit can be adjusted continuously by means of the control element, as a result of which the vibration intensity of the bristles can be steplessly adjusted.