PURPOSE: To easily make the moving speed of a driven matter high and low by connecting rotators provided with a pin hole in which a connecting pin is inserted and a slit to each other inform of a chain, and providing an operation rail which comes into contact with the rotators.

CONSTITUTION: A rotator 1 having a pin hole 2 and a slit 3 is formed, and the rotator is formed in such a manner that an angle between a line connecting the pin hole 2 and an arbitrary point on the slit 3 is always 90° or more. The outside surface 5 of the rotator 1 is formed in such a manner that when the space between the pin hole 2 and the slit 3 is maximum, the space between a line connecting between the tip (a) of the slit 3 and the pin hole 2 and a parallel line circumscribed with the outside surface 5 is made maximum, and when the space between the pin hole 2 and the slit 3 is minimum, the space between a line connecting the lower end (b) of the slit and the pin hole 2 and the parallel line is made minimum. Many such rotators 1 are connected to each other by a chain, and pulled to for example, the speed is gradually increased according to the guide of an operation rail 6.