A tray housing driving mechanism 18, further comprising a switch engaging said first drawer to terminate movement at {TAIL ~ an extreme limit} of movement of {HEAD ~ said first drawer} 
A tray housing driving mechanism 18 , further comprising a switch engaging said first drawer to terminate movement at { TAIL ~ an extreme limit } of movement of { HEAD ~ said first drawer }
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 OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD