{TAIL ~ A projection} 18 is provided in the chains 17 to push the rear end of {HEAD ~ the base frame} 5 
{ TAIL ~ A projection } 18 is provided in the chains 17 to push the rear end of { HEAD ~ the base frame } 5
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH