Mechanically driven resonant drive train for a power toothbrush

摘要

The power toothbrush includes a driving assembly which in turn includes a DC motor (14) and a battery. The DC motor has a rotating drive shaft (16), supported at its free end. The drive shaft has an eccentric portion (18). Mounted on the eccentric portion is a plastic sleeve (20) having an extending portion which engages one end of a spring member (38). The other end of the spring member is secured to a yoke (36) which is secured to a brushhead shaft (32). Rotation of the drive shaft results in the extending portion of the plastic sleeve, moving the spring between a compressed state and an extended state. The action of the DC motor excites the spring to produce an oscillating action of the brushhead shaft and a brushhead assembly (40) mounted thereon.