a peripheral surface for engaging {HEAD ~ a pulley cable} for causing {TAIL ~ said pulley} to rotate 
for causing
a peripheral surface for engaging { HEAD ~ a pulley cable } for causing { TAIL ~ said pulley } to rotate
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH