DUST COLLECTOR

PURPOSE:To continue smooth operation as well as to check the by-pass flow between screen frames by protruding a plate shaped elastic member from the lowest end of a screen frame to abut against the upper portion of a screen frame in the second position. CONSTITUTION:A dust collector, which drives endless link chains 3x, 3x through a pair of upper and lower sprocket wheels, is formed by connecting a screen frame 4 having a dust collecting screen 14 to the link chains 3x, 3x aslant. A plate shaped elastic member 110, which longitudinal length is the length of the width of the screen frame 4, is protruded from the lowest bottom end of the screen frame 4 and its tip abuts against the upper portion of the screen frame 4 in the second position. While making a straight advance, the by-pass flowing water between the screen frames 4 is shut off by the elastic member 110. At the time when the upper and lower sprocket portions are turned reverse, the elastic member 110 is made only to bend or alienate but not to have the structure member of the screen frame 4 to come in contact with each other.