by pressing {HEAD ~ the pusher} by the operating portion to cause the spool to slide, liquid pressure from the pump port is supplied to {TAIL ~ the output port} 
by pressing { HEAD ~ the pusher } by the operating portion to cause the spool to slide , liquid pressure from the pump port is supplied to { TAIL ~ the output port }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL