Roller 60 is movable along {TAIL ~ a surface} 62 of the front section 11b of {HEAD ~ the fixed frame} 11 
Roller 60 is movable along { TAIL ~ a surface } 62 of the front section 11b of { HEAD ~ the fixed frame } 11
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH