When the knob is pressed in {HEAD ~ a direction} indicated by {TAIL ~ an arrow Pf}, the press switch 8 makes a stroke 
When the knob is pressed in { HEAD ~ a direction } indicated by { TAIL ~ an arrow Pf } , the press switch 8 makes a stroke
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