Rotary motion electric toothbrush - has reversible motor drive and bristles mounted in Archimedean screw pattern on head

摘要

The electric tooth-brush has a rotary movement to clean the teeth and massage the gums. It has a 12 volt synchronous motor in the handle and operated by a three way button which can reverse its rotation. A cylindrical brush which is removable and interchangeable is fixed to the axle of the motor. The motor can be supplied by mains current passed through a transformer in the carrying case or by batteries either in the case or in the handle. The bristles are preferably implanted in an Archimedes screw terminated by a spherical tuft.