Power toothbrush with a tunable brushhead assembly system

A method for implementing a brushhead assembly system portion of a power toothbrush appliance to control a resonant frequency thereof, comprising the steps of:

• providing a brushhead assembly system that includes a beam portion adapted to receive a brushhead having a brush member, wherein the beam portion undergoes lateral movement about a pivot via a drive system of the power toothbrush appliance, wherein the drive system includes a drive shaft and the lateral movement is accomplished by interaction of an eccentric coupling member mounted on the drive shaft with a proximal end of the beam portion, wherein conversion of a rotational action of the drive shaft to the lateral movement of the beam portion is accomplished by a scotch yoke arrangement, and
• tuning the beam portion via one or more characteristics of the beam portion so as to maintain a sufficient difference between the resonant frequency of the brushhead assembly system and a drive frequency of the power toothbrush appliance to maintain an amplitude of motion of the brush member in operation within a range of 1.0-2.5 mm, wherein the one or more characteristics are selected from the group consisting of:
• (1) stiffness of the beam portion;
• (2) length of the beam portion;
• and (3) cross-sectional moment of inertia of the beam portion.