US Patent 7425168 Toy helicopter

A helicopter has a main rotor with propeller blades which is driven by a rotor shaft and which is hinge-mounted to this rotor shaft. The angle between the surface of rotation of the main rotor and the rotor shaft may vary. A swinging manner on an oscillatory shaft is essentially transverse to the rotor shaft of the main rotor and is directed transversely to the longitudinal axis of the vanes. The main rotor and the auxiliary rotor are connected to each other by a mechanical link. The swinging motions of the auxiliary rotor controls the angle of incidence (A) of at least one of the propeller blades of the main rotor. There are wings from the body and a stabilizer at the tail.