PURPOSE: To get a reversing device which is precise in turning angle and smooth in action with minimum impact, by fitting an input shaft and spider to an output shaft, so that the output shaft intermittently turns by 180° while the input shaft makes a turn at a uniform speed.
CONSTITUTION: After a long work at a point P is chucked and brought aside, it is turned by 180° with the center of device as a pivot. When the work is released there, it is shifted from the point P to another point Q, being turned upside down. When this device is intermittently turned by 180°, its output shaft intermittently turns by 180° while its input shaft makes a turn at a uniform speed. In other words, the input shaft 6 is turned at a constant speed by a driving shaft, but the output shaft 7 does not turn when faces 18a, 18b, 19a, 19b of cams 18, 19 are not turned and displaced, and it is turned intermittently by 180°, for sure, during a period from its engagement to disengagement.