Therefore, with the lateral articulated joints of blade 2 following a circular path, and its rear section articulated joint following an elliptical path, the desired effect is obtained in the form of {HEAD ~ cyclical changes} in {TAIL ~ the blades pitch angle} as it travels in the closed cylindrical path 
in
Therefore , with the lateral articulated joints of blade 2 following a circular path , and its rear section articulated joint following an elliptical path , the desired effect is obtained in the form of { HEAD ~ cyclical changes } in { TAIL ~ the blades pitch angle } as it travels in the closed cylindrical path
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH