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