PURPOSE: To make smooth continuous operation without repeating the starting and stopping of a bedding system by automatically controlling the speed of a reversible conveyor until the bedding raw materials in a bedding hopper are made constant according to the operating speed of a sintering machine.

CONSTITUTION: The main raw materials in a charging hopper 1 are sintered, ground and cooled by the conventional practice and are fed to the reversible conveyor 41 which is constructed to permit speed control. The reversible conveyor 41 and a reversible motor thereof are run forward upon turning on of a limit switch 40 to make a product feed operation and are run backward upon turning off of said switch to make a bedding feed operation. The electric current outputted by a speed detector 42 of the sintering machine 2 increases to increase the variable instruction signal of a speed control circuit to increase the amt. of the bedding if a large amt. of the raw materials for the bedding are required as the speed of the sintering machine 2 is large. On the other hand, the current outputted by the speed detector 42 decreases to decrease the speed of the reversible motor so as to slow down the bedding feed if there is no need for a large amt. of the raw materials for bedding.