The pressing device presses {TAIL ~ the retractable unit} toward {HEAD ~ the open position} in which the unit is extended 
The pressing device presses { TAIL ~ the retractable unit } toward { HEAD ~ the open position } in which the unit is extended
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH