Power driven rotary toothbrush

Claim 1

A tooth-brushing device comprising a brushing unit having a pair of shafts, means rotatably supporting said shafts in laterally spaced, parallel relation to each other, flexible bristles projecting radially outwardly from each shaft, said bristles being arranged in a series of clusters spaced from one another along the length of each shaft, there being a plurality of bristles in each cluster distributed in a circular array about the shaft axis and projecting radially outwardly therefrom, and means for counter-rotating said shafts in directions to brush the teeth away from the gums, said clusters on each shaft being spaced apart so that the ends of the bristles in each cluster are separated from the ends of the bristles in adjacent clusters by a distance approximating the width of a tooth, some of the bristles in each cluster being longer and more flexible than others in the same cluster, the longer more flexible bristles being more effective to brush between the teeth.