a variable throttle mechanism installed in {HEAD ~ said pump} to change {TAIL ~ a flow rate} of said discharged oil from said pump to said hydraulic device 
to change
a variable throttle mechanism installed in { HEAD ~ said pump } to change { TAIL ~ a flow rate } of said discharged oil from said pump to said hydraulic device
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH