Patent ID: 7815482
Filing Date: 2010-10-19
Classification: A63H

Abstract:
1. A rotor assembly for a remote control toy helicopter, comprising a motor and a battery for the motor, the motor being controllable by a controller remote from the helicopter body; a main rotor having two propeller blades mounted on a rotor shaft for rotation with the rotor shaft, an auxiliary rotor mounted on the rotor shaft for rotation in the sense of rotation of the main rotor, the auxiliary rotor being mounted in a swinging relationship on an oscillatory shaft provided essentially transverse to the rotor shaft of the main rotor and the swinging motion being relatively upwardly and downwardly about the oscillatory shaft, the main rotor and the auxiliary rotor having planes of rotation spaced from each other and being linked with each other by a mechanical linkage, such that the swinging motion of the auxiliary rotor controls an angle of incidence of the propeller blades of the main rotor, and wherein the main rotor is pivotably mounted with a spindle which is fixed on the rotor shaft, and wherein each blade includes a convex curve in a profile on its top face from a position towards a leading edge towards a position towards a trailing edge, the convex curve preferably being present over a portion of the generally longitudinal length of the blade, and wherein the blade has a width between the leading edge and the trailing edge, and a length from a tip of the blade to the rotor shaft, the blade being rigid in a direction from the tip of the blade to a position where the blade is mounted with the spindle, and a fastening point on the main rotor being situated at a first distance from an axis of the spindle of the propeller blades of the main rotor, and a fastening point on the auxiliary rotor being situated at a second distance from the axis of the oscillatory shaft of the auxiliary rotor, and the first distance being larger than the second distance, and wherein the first distance is about double of the second distance, and the fastening point with the auxiliary rotor being removed from the auxiliary rotor by an arm extending from the auxiliary rotor and the first distance and the second distance being such that the mechanical linkage between the fastening points is located in a substantially parallel relationship relative to the rotor shaft.