Patent ID: 7992244

Claim:
An electric toothbrush comprising: an electric motor; a first brush head that is disc-shaped comprising a first pivot pin extending substantially perpendicular to a face of the first brush head, the first pivot pin having a first longitudinal axis extending substantially perpendicular to the face of the first brush head, the first brush head mounted for rotational movement about the first longitudinal axis; a second brush head having a second pivot pin extending substantially perpendicular to a face of the second brush head, the second pivot pin having a second longitudinal axis extending substantially perpendicular to the face of the second brush head, the second brush head mounted for rotational movement about the second longitudinal axis; a rotatable driving structure operatively connecting said motor to the first brush head and comprising a crankshaft defining a central axis of rotation, the crankshaft having a free end including a straight portion oriented parallel to and offset from the central axis of the crankshaft and an elbow connecting the straight portion to the crankshaft, the straight portion terminated with a spherical ball engaging a first guide slot defined in the first brush head, wherein rotation of the crankshaft through 360 degrees imparts oscillating motion to the first brush head about its first longitudinal axis; and a drive pin having a first end and a second end, the drive pin extending between said first brush head and said second brush head, wherein the first end of the drive pin is connected to one of said first brush head and said second brush head, and the second end of the drive pin is pivotably received in a second guide slot within one of the other of said first brush head and said second brush head, wherein said drive pin is independent of the driving structure and connected to said first brush head at a location displaced from the connection of the driving structure to said first brush head, wherein a ball joint is defined between each of the free end of the crankshaft of the driving structure and the first brush head, and the first brush head and the second brush head, said second guide slot having an arcuate surface for receiving the ball joint, wherein said first brush head rotates about said first longitudinal axis of said first pivot pin and said second brush head rotates about said second longitudinal axis of said second pivot pin.