PURPOSE: To effectually drop and remove a material clinging to an endless conveyor belt, by providing two pairs of pinch rollers at both the ends of a lower portion of the belt, and providing vertically-curved rollers for belt inversion guiding, between the pairs of pinch rollers.

CONSTITUTION: An endless belt is wound on a drive roller and a driven roller 3 provided at both the ends of a frame 1, so that the belt is supported on the bottoms of the upper and lower portions 4, 5 by idle rollers 6, 7. Two pairs of pinch rollers 9, 10 are provided on the low portion 5 near the drive roller and the driven roller 3 to pinch the lower portion 5 vertically. Vertically curved rollers 11 for guiding the 180° inversion of the belt portion 5 between the pairs of pinch rollers 9, 10 are provided in such a manner that the directions of the inverting actions of the rollers 11 between the pairs of pinch rollers are inverse to each other. As a result, the belt portion 5 is effectually inverted so that a material clinging to the belt portion is smoothly dropped.