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