Airscrew for Toy Helicopter

Abstract

The present invention relates to an airscrew for a toy helicopter, comprising a rotating shaft directly connectable to a driving mechanism of the helicopter, two airscrew blades, a balance mechanism, said two airscrew blades respectively hinged to the rotating shaft so that a blade angle of the airscrew blade is able to change during the flight. In an embodiment, a middle portion of the balance mechanism is hinged to the rotating shaft, and each of two airscrew blades has an extending member, the balance mechanism is contacted with the extending member during the swing motion, such that the blade angle of the airscrew blade is changed. The present invention has a compact structure and a stable balancing capability, therefore, the disadvantages such as easy breakage of the link is avoided and the package volume is also reduced. The connecting member between the airscrew blades as well as the balance rod and the rotating shaft is thicker and has a bigger intensity, so it is not easy to be broken due to the falling of the helicopter, therefore, it can be used in a flyable toy or a prototype aircraft, and a vertical lift aerocraft.

1 . An airscrew for a toy helicopter, comprising:
 a rotating shaft directly connectable to a driving mechanism of the helicopter, two airscrew blades, a balance mechanism, said two airscrew blades being hinged to the rotating shaft respectively so that a blade angle of the airscrew blade is able to change during the flight, characterized in that, a middle portion of the balance mechanism being hinged to the rotating shaft, each of two airscrew blades has an extending member, the balance mechanism is contacted with the extending member during the swing motion, such that the blade angle of the airscrew blade is changed.   
   
   
       2 . The airscrew for the toy helicopter according to  claim 1 , characterized in that, said extending member is hung on the balance mechanism. 
   
   
       3 . The airscrew for the toy helicopter according to  claim 1 , characterized in that, said balance mechanism is a balance rod which the weight of an end portion is larger than a middle portion thereof. 
   
   
       4 . The airscrew for the toy helicopter according to  claim 1 , characterized in that, said balance mechanism is an auxiliary rotating wing having a blade-shaped wing panel at the end portion thereof. 
   
   
       5 . The airscrew for the toy helicopter according to  claim 1 , characterized in that, a hinge shaft sleeve at the middle portion of the balance mechanism is coplanar with the hinge shaft of the airscrew blade. 
   
   
       6 . The airscrew for the toy helicopter according to  claim 5 , characterized in that, an angle in a range of 20-90° is formed between the axes of the hinge shaft sleeve at the middle portion of the balance mechanism and the axes of the hinge shaft of the airscrew blade. 
   
   
       7 . The airscrew for the toy helicopter according to  claim 1 , characterized in that, a connecting member is provided between two of airscrew blades, both ends of said connecting member are respectively provided with a tenon and a fork lever, and the airscrew blade has a hole corresponding with said tenon, the tenon is inserted into the hole, and the fork lever is wedged below the airscrew blade.