Further, because of the pair of levers 14, 14 having independent both ends, {HEAD ~ the spring forces} at {TAIL ~ both ends} are equalized, and so the shutter plate 15 can be moved in such a manner as to automatically eliminate the formation of clearance in the transverse direction 
Further , because of the pair of levers 14 , 14 having independent both ends , { HEAD ~ the spring forces } at { TAIL ~ both ends } are equalized , and so the shutter plate 15 can be moved in such a manner as to automatically eliminate the formation of clearance in the transverse direction
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL 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