Abstract: Provided are an arm, a tool magazine, and a machine tool capable of suppressing interference between tool storage arms and suppressing an increase in size in the direction parallel to an axis of rotation. The arm is provided in the tool magazine of the machine tool and configured to grip a tool. The arm includes a support plate configured to be fixed to the tool magazine and two support rods configured to rotate on both sides of the support plate. The positions of the tool grip side end portions of the two support rods are different in the rotation center axis direction of the tool magazine.

Abstract: Provided are a tool changer and a machine tool having a plurality of tool storage magazines and capable of suppressing the generation of vibration. The tool changer performs tool change between first and second tool storage magazines. The center of gravity of the second magazine is disposed below the tool change positions of the first and second magazines. Preferably, the second magazine is inclined with respect to a horizontal plane.

Abstract: The present invention relates to a rotation crusher which treats refuse and seeks to prevent explosions by controlling the volume of steam fed into the crusher to keep the temperature inside a main body of the crusher between about 70.degree. C. to 100.degree. C. so that the steam content may be regulated to exceed a certain value to keep the oxygen content below an explosion preventive critical value, thereby preventing completely explosions inside the crusher.

Abstract: An electric melting furnace is provided with an exit comprising an overflow dam and a downwardly extending unmolten-substances blocking plate placed inwardly of the overflow dam. The exit is positioned on or near an extension of a line connecting the center O of a furnace body and one of the furnace electrodes, the distance L in centimeters between the electrode and the overflow dam being determined by the equation: ##EQU1## where P is the electric furnace load (w) and K is a constant in the range of 16 to 25. Lighter molten substances are continuously discharged over the dam under the weight of the combustion residue. Heavier molten metals accumulate on the furnace floor and are discharged over dam by tilting the furnace body in the direction of the exit.