| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlling a turntable which is not affected by a tooth-skip of a timing belt or a backlash of gears. SOLUTION: Rotation and temporary positioning of a turntable is effected by an electric control and electric braking based on a servomotor 42. Normal positioning following the temporary positioning is effected by fitting a wedge member 32L or 32R in a recess 43 to mechanically couple a turntable with a base. For effecting the normal positioning, the servomotor 42 is set free to release electric braking, whereby the mechanical coupling may not be hindered. Thus, even if errors are generated in a transmission member due to a tooth-skip of a timing belt or a backlash of gears, there is no problem so that operations can be continued to improve productivity. In addition, positioning by means of servo control can be effected in a rough manner, and hence loads on the servo control are reduced so that costs for the servo control can be reduced.
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