The hydraulic windmill
An hydraulic windmill is described. It pumps pressurized oil from rotor shaft level to the ground where a motor generator produces electricity. Alternatively, the useful output may be heat. Rotor speed is governed by a flow valve. Over pressure, the result of high wind velocity, rotates the tail to move the rotor blades out-of-the-wind. Loss of oil pressure causes a brake to close as well as to swing the tail to its maximum distance from the rotor plane.
Browing, J. A.↗