DRIVING DEVICE FOR PIVOT ARM

PROBLEM TO BE SOLVED: To pivotally turn a pivot arm with a small drive motor having a small capacity, in a driving device for a pivot arm performing a direction change or the like of an article by repeated pivoting in normal and reverse directions of the pivot arm.SOLUTION: A projection 9 is formed on one end of a pivot arm 4 pivoted in normal and reverse directions by 180° by a drive motor 8 connected to an arm support shaft 5. Air cylinders 10a, 10b are provided at a position facing the projection 9 while the pivot arm 4 is stopped at a reference position and a position facing the projection 9 while the pivot arm 4 is rotated by 180°. When the drive motor 8 pivotally turns the pivot arm 4, the air cylinder facing the projection 9 is extended to press the projection 9 in a rotation direction of the pivot arm 4, and the rotation of the pivot arm 4 by the drive motor 8 is assisted.