{TAIL ~ The sleeve} has {HEAD ~ a sprocket} affixed to it, and the sprocket is caused to rotate by an endless chain  
{ TAIL ~ The sleeve } has { HEAD ~ a sprocket } affixed to it , and the sprocket is caused to rotate by an endless chain
TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH