A retractable cover system for a tipper trailer body of a truck includes a cover for the top of the trailer body , and {HEAD ~ a winder pulley} for controlling {TAIL ~ the movement} of the cover across the top of the trailer body  
for controlling
A retractable cover system for a tipper trailer body of a truck includes a cover for the top of the trailer body , and { HEAD ~ a winder pulley } for controlling { TAIL ~ the movement } of the cover across the top of the trailer body
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH