PURPOSE: To facilitate the optimum design of transverse rigidity of a conveyer belt by incorporating an axial load cell in a trough carrier roller to be vertically moved.

CONSTITUTION: Axial load cell system rollers to which strain gauges aWf are applied are incorporated in shafts of respective carrier rollers 17W19 of a trough carrier roller 6 to measure loads applied to the rollers 17W19 through a belt 8. And on the basis of the measuring result are vertically moved the roller 6 by driving a ball screw 13 through a lifting motor 16 and a bevel gear 15 along a slide rail 14 to change the positions of the carrier rollers 5W7 and properly set convex angle changing points of a conveyer belt 8. By this constitution is facilitate the optimum design of transverse rigidity of the belt.