Rotary implement

Claim 1

A hand-held rotary dental appliance comprising: an elongated housing, a motor mounted within said housing having a rotatable shaft disposed in axial alignment with the longitudinal axis of said housing, a balanced, weighted flywheel nonrotatably mounted on said shaft, a first end of said flywheel formed with a flat surface disposed normal to the axis of said shaft and a pair of pins projecting outwardly therefrom normal to said surface, a coupling member mounted on the first end of said flywheel having a surface formed with a flat face having a diameter the same as the first end of said flywheel disposed in juxtaposition with the surface on the first end of said flywheel, a pair of grooves formed in said coupling member in registration with said pins to allow torque transfer of said pins to said coupling member while allowing said coupling member to be free to move longitudinally relative to said flywheel, an implement-engaging cup mounted rigidly on said coupling member in axial alignment with said motor shaft, a dental working instrument having a shaft longitudinally mounted relative to said housing and axially aligned with the shaft of said motor to frictionally engage with said cup member for transference of torque.