Patent ID: 8104377

Claim:
An index table in which a rotating table is rotatably supported at a frame by a rotating shaft, a setting surface is provided at the frame orthogonal to a rotating table surface of the rotating table, a motor is disposed at one surface among two surfaces of the frame that are orthogonal to the rotating table surface and the setting surface, a worm shaft is disposed orthogonal to the two surfaces of the frame, a worm wheel that engages a worm provided at the worm shaft is provided at the rotating shaft, an output shaft of the motor is connected to an end portion of the worm shaft at a side of the one surface through transmitting elements, and the motor drives the rotating table through the transmitting elements, the worm of the worm shaft, and the worm wheel, wherein a tooth thickness of the worm gradually increases or decreases along an axial direction, wherein the motor is mountable to the one surface and to the other surface among the two surfaces, wherein, when mounting the motor to the other surface by removing the motor from the one surface, the worm shaft is mounted to the frame in an opposite direction with left and right sides of the worm shaft being reversed, and the worm wheel is reversed to mount the worm wheel to the rotating shaft in an opposite direction, and wherein the output shaft of the motor is connected to an end portion of the worm shaft at a side of the other surface through the transmitting elements.