GB281360A - Improvements in windmills - Google Patents

Abstract

281,360. Sharp, F. L., and Bonnaud, H. M. Aug. 24, 1926. Windmills with adjustable shields, are provided with a vane or tail on the shield relatively movable thereto to cause the shield to become wholly interposed between the vanes and the wind. The shield 9, Fig. 1, rotating on a bracket 10<b> carries a tail 11 which causes it to shield half the vanes against the wind current. The vanes 7 rotate the sleeve 3 in the shaft 10 to drive the lower shaft 5. When the wind-pressure becomes excessive, the pulleys 14 rotate the governor device 13 at a speed sufficient to turn the tail 11 to a horizontal position and the supplementary tail 12 to a vertical position by means of rods 16, 17, 19, causing the shield to swing round so as to completely shield the vanes 7 from the wind until their speed of rotation falls again. In the form shown in Fig. 4, a shield a with a tail f covers half the vanes c and a second rotatable shield g normally lies within it, held by a stop j<1> engaging a pivoted catch i<1> on the shield a. When the wind pressure becomes excessive, a flap e on the shield a is tilted, releasing the catch i<1> from the projection j<1> and allowing the wind impinging on the vanes k of the shield g to move it round until the second stop j engages the second catch, i, in which position the vanes c are completely enclosed. When the wind pressure falls, a spring restores the flap to its vertical position, releasing the second catch i and stop and allowing the wind to rotate the shield g back within the shield a.