Rotary electric toothbrush

A rotary electric toothbrush comprising:

• a. a power handle having a foot and a motor, the motor having a rotatable power shaft;
• b. means for supplying electrical power to the motor;
• c. a longitudinally extended brush stem attached to the power handle at a point remote from the foot and extending therefrom to terminate at a stem head;
• d. a brush cartridge attached to the stem head and extending therefrom to terminate at a toothbrush head, so that "headward" indicates a direction toward the toothbrush head and "footward" indicates a direction toward the foot, the brush cartridge including at least one generally cylindrical brush the longitudinal axis of which is oriented approximately headward-to-footward;
• e. a drive shaft extending from the power handle to the brush, the headward end of the drive shaft including means for engaging the brush and transmitting to it the motion of the drive shaft;
• and
• f. transmission means for transmitting the motion of the power shaft to selectively cause the drive shaft alternatively to rotate about its longitudinal axis or to move parallel thereto in a reciprocating manner, whereby a user of the electric toothbrush may direct power from a single motor selectively to cause the brush to rotate about its longitudinal axis and, alternatively, to move in a reciprocating manner parallel thereto.