A sprocket 64 having {HEAD ~ a plurality} of {TAIL ~ teeth} 66 is fixedly attached to an outer surface of the first plate 56 , the sprocket 64 having a diameter smaller than a diameter of the first plate 56 
of
A sprocket 64 having { HEAD ~ a plurality } of { TAIL ~ teeth } 66 is fixedly attached to an outer surface of the first plate 56 , the sprocket 64 having a diameter smaller than a diameter of the first plate 56
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH OTH OTH OTH OTH OTH OTH