These tray locking members 50 wedge against the flat side 51 of the extrusion 37 to secure {HEAD ~ the tray} 15 in {TAIL ~ position} and prevent it from sliding from side to side 
These tray locking members 50 wedge against the flat side 51 of the extrusion 37 to secure { HEAD ~ the tray } 15 in { TAIL ~ position } and prevent it from sliding from side to side
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH