Patent ID: 7296511

Claim:
A rice hulling roll driving apparatus in a rice huller wherein, a first roll shaft is provided with a first small-diameter pulley, a second roll shaft is provided with a first large-diameter pulley, and the first small-diameter pulley, the first large-diameter pulley, and a driving pulley for a first motor are connected together by a first endless belt, so that a first and second rice hulling rolls, which constitute paired rice hulling rolls, rotate at different peripheral speeds in directions opposite to each other; the first roll shaft is provided with a second large-diameter pulley in addition to said first small-diameter pulley, the second roll shaft is provided with a second small-diameter pulley in addition to said first large-diameter pulley, and the second large-diameter pulley, the second small-diameter pulley, and a driving pulley for a second motor are connected together by a second endless belt; the first small-diameter pulley and the second large-diameter pulley are attached to the first roll shaft so that each of the pulleys may rotate with respect to the first roll shaft, and the first large-diameter pulley and the second small-diameter pulley are attached to the second roll shaft so that each of the pulleys may rotate with respect to the second roll shaft; transmission switching means is provided between the first small-diameter pulley and the second large-diameter pulley, which are attached to the first roll shaft, and between the first large-diameter pulley and the second small-diameter pulley, which are attached to the second roll shaft, so as to transmit rotation of the pulleys to the corresponding roll shafts; and said transmission switching means comprises a slidable cylinder provided so as to be movable in a direction of each roll shaft, a large diameter portion provided around an outer periphery of the slidable cylinder, a spline shaft formed on the large-diameter portion in order to fit into a boss portion of each of the pulley, a spring that always urges the slidable cylinder toward the pulley attached to the roll shaft at the end thereof, and an air chamber into which compressed air is fed to cause the slidable cylinder to slide against an urging force of the spring.