PURPOSE: To easily conduct adjustment, particularly, fine adjustment of cam position by properly sliding a position adjusting shaft to gear an adjusting gear part with the transmitting gear part of an optional cam, and rotating the position adjusting shaft to adjust the position of the cam.

CONSTITUTION: To adjust the position of each cam of a collected cam device 96, a nut 123 is slightly loosen to reduce elastic holding force, and then, for example, position adjustment of a cam 100 is first conducted. A lock member 151 is engaged with a ring recessed part 149 on the right end in the drawing of a position adjusting shaft 127 to gear an adjusting gear part 129 with the transmitting gear part 133 of the cam 100. The shaft 127 is properly rotated in this state to adjust the position of the cam 100. Then, an adjacent cam 103 is adjusted. In this case, the member 151 is engaged with the second recessed part 149 from the right end to gear the adjusting gear part 129 with the trans mitting the gear part 133 of the cam 103, and the shaft 127 is rotated for posi tion adjustment. In such position adjustment, a fine adjustment handle 145 is used to properly conduct fine adjustment.