For example, as generally illustrated in FIGS 5A, 5B and 8, {HEAD ~ the exterior blade surface} 204B may comprise a tapered surface which may be disposed at {TAIL ~ an angle} to the blade axis of rotation AB and be generally parallel to a surface 110 of a cooperating mounting rail 102 
For example , as generally illustrated in FIGS 5A , 5B and 8 , { HEAD ~ the exterior blade surface } 204B may comprise a tapered surface which may be disposed at { TAIL ~ an angle } to the blade axis of rotation AB and be generally parallel to a surface 110 of a cooperating mounting rail 102
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH