US Patent 8123523 Prophy angle and adapter

A dental prophy angle includes a housing and a rotor. The housing defines a first bore and a second bore in communication with the first bore, and rotor is disposed within the second bore. The rotor includes a gearing system, and rotor includes a lock having a lock channel configured to receive a tip of a drive shaft. The housing includes a lock receiver for receiving the lock receiver permits rotation of the lock within the lock receiver and restrains linear movement of the lock in a direction substantially parallel to a rotational axis of the rotor.