Patent ID: 6984110

Claim:
A windmill blade comprising: blade bodies mounted to a rotating shaft to form a blade assembly, each of the blade bodies receiving pressure of wind while being provided with a plurality of wind pressure adjusting holes; a plurality of wind pressure adjusting plates coupled to each of the blade bodies while being connected together to an associated one of wires, each of the wind pressure adjusting plates being slidable along guides respectively arranged at opposite sides of an associated one of the wind pressure adjusting holes provided at an associated one of the blade bodies, thereby adjusting an opening degree of the associated wind pressure adjusting hole; elastic members each adapted to connect one end of an associated one of the wires to one side portion of an associated one of the blade bodies; winches each adapted to connect the other end of an associated one of the wires to the other side portion of an associated one of the blade bodies, the winches being mounted to a single shaft to simultaneously wind or unwind the wires; and means for driving the winches.