The use of hydraulic motors allows {HEAD ~ a simple system} of {TAIL ~ electrically controlled valves} 406 to be used to control these functions 
of
The use of hydraulic motors allows { HEAD ~ a simple system } of { TAIL ~ electrically controlled valves } 406 to be used to control these functions
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH