a plurality of secondary hopper door members slidably mounted in side by {HEAD ~ side} relation and parallel with said hopper door for selectively closing off {TAIL ~ a portion} of the discharge slot formed when said hopper door is open 
a plurality of secondary hopper door members slidably mounted in side by { HEAD ~ side } relation and parallel with said hopper door for selectively closing off { TAIL ~ a portion } of the discharge slot formed when said hopper door is open
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH