Patent ID: 7425168
Filing Date: 2008-09-16
Classification: A63H

Abstract:
1. A remote control toy helicopter comprising a body with a tail; a motor and a battery for the motor, the motor being controllable by a controller remote from the helicopter body; a main rotor with at least two propeller blades, wherein the propeller blades define a plane of rotation of the main rotor, wherein the main rotor is driven by a rotor shaft, on which the propeller blades are mounted; a tail rotor driven by a second rotor shaft directed transversly to the rotor shaft of the main rotor; an auxiliary rotor driven by the rotor shaft of the main rotor in the rotational sense of the main rotor, the auxiliary rotor being mounted such that a first longitudinal axis of the auxiliary rotor, in the sense of rotation, is situated in an acute angle relative to a second longitudinal axis of one of the propeller blades of the main rotor, the auxiliary rotor having a further plane of rotation being spaced from the plane of rotation, the auxiliary rotor being mounted in a swinging relationship on an oscillatory shaft provided essentially transversely to the rotor shaft of the main rotor and the swinging motion being relatively upwards and downwards around the oscillatory shaft, such that the swinging motion of the auxiliary rotor controls an angle of incidence of the propeller blades of the main rotor, each of the propeller blades having a substantially convex upper surface along the second longitudinal axis, the upper surface being convex from a leading edge to a trailing edge of the blade, wherein each propeller blade has a substantially concave lower surface along the second longitudinal axis and the lower surface being concave from the leading edge to the trailing edge of the blade throughout a substantial portion of the second longitudinal axis of the blade, wherein the propeller blades of the main rotor are essentially in line with each other, wherein the concave lower surface of each of the blades is complementary in shape to the convex upper surface of each of the propeller blades, wherein the propeller blades of the main rotor are mounted pivotably on a joint formed by a spindle which is fixed on the rotor shaft of the main rotor, and the spindle is substantially parallel to the longitudinal axis, wherein the main rotor is a unitary body, and wherein the propeller blades are essentially rigidly connected with each other and wherein each propeller blade has an upper surface formed in the form of an upwardly convex curve running from a free end of the propeller blade toward the rotor shaft.