In addition, reference numerals and in FIG 4 designate a pair of {HEAD ~ air sealing plates} which are mounted in a vertically movable manner to the bottom end portions of the left and right side walls and by means of {TAIL ~ a spacer} and a plurality of bolts , and these air sealing plates and are slidably held in contact with the canvas belt , so that the gaps between the left and right side walls , and the canvas belt can be air tightly sealed 
In addition , reference numerals and in FIG 4 designate a pair of { HEAD ~ air sealing plates } which are mounted in a vertically movable manner to the bottom end portions of the left and right side walls and by means of { TAIL ~ a spacer } and a plurality of bolts , and these air sealing plates and are slidably held in contact with the canvas belt , so that the gaps between the left and right side walls , and the canvas belt can be air tightly sealed
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 OTH OTH OTH 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH