Vertical axis windmill

Claim 1

A vertical axis windmill comprising in combination: a tower; an output shaft supported by said tower for rotation about a vertically disposed axis; a power conversion means coupled to said output shaft; a plurality of horizontally disposed spars fixed for rotation with said output shaft and arranged to extend radially thereof; a plurality of vertically disposed wind reaction panels carried at least one on each of said spars; a wind vane assembly freely rotatable relative to said drive shaft and said tower, said assembly including a first wind deflecting device comprised of a pair of vertically extending panels joined to define a V-shaped unit having its apex arranged to face towards the wind, wherein a first panel is arranged to direct oncoming air radially outwardly of said spars away from said wind reaction panels, during those portions of the rotational movement of said spars relatively towards the wind, a second wind deflecting device cooperating with said second panel for channeling oncoming air towards said wind reaction panels, during that portion of the rotational movement of said spars relatively away from the wind, and a wind vane cooperating with said first and second wind deflecting devices for maintaining same in desired, relatively stationary operative positions relative to the direction of the oncoming wind, and said first panel is provided with a through opening extending from adjacent the juncture of said first and second panels, an auxiliary panel supported for movement between opening closed and open conditions, and means for normally maintaining said auxiliary panel in an opening closed condition, while permitting movement thereof into open condition in response to predetermined high wind loading condition thereon to allow oncoming air to flow through said first panel into motion retarding engagement with said wind reaction panels during rotational movement of said spars relatively towards the wind.