An assist mechanism aids movement of a retractable unit reciprocally moving between an open and a closed position and includes a pressing device, {HEAD ~ a stopper mechanism}, an engagement member, a catch portion, and {TAIL ~ a release member} 
An assist mechanism aids movement of a retractable unit reciprocally moving between an open and a closed position and includes a pressing device , { HEAD ~ a stopper mechanism } , an engagement member , a catch portion , and { TAIL ~ a release member }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL