Patent attributes
A self-righting toothbrush includes a head section mounting a set of frontwardly extending bristles and a tail section having a rearwardly extending lateral asymmetry. A medial section has a pivot surface that allows the toothbrush to pivot and roll on a horizontal support surface. The head and tail sections have respective centers of mass. In a non-bristles up position, one or both of the head and tail section centers of mass are spaced from a vertical plane that includes a pivot point where the pivot surface contacts the support surface and is perpendicular to a toothbrush rolling direction. Due to a moment imbalance dominated by the tail section center of mass, a rotational moment induces the toothbrush to pivot about the neutral pivot axis to a bristles up position in which both centers of mass are aligned in the vertical plane.
