In a further preferred embodiment, the exit trough may be covered by an exit cover which includes {HEAD ~ a cover plate} hingedly mounted to {TAIL ~ a pivot plate} 
hingedly mounted to
In a further preferred embodiment , the exit trough may be covered by an exit cover which includes { HEAD ~ a cover plate } hingedly mounted to { TAIL ~ a pivot plate }
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 REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL