Sprockets A and B are input and output shafts, while the other four serve as idlers. Sprockets C and D are in a sliding yoke adjusted by rotating the control knob. With sprocket A stationary and the knob turned counterclockwise, the yoke travels down its threaded shaft. This means shaft B changes position relative to shaft A, with the chain from sprocket C taken up by sprocket D. If the yoke reaches its end of travel in either direction, it must be reversed to make further phase adjustments.

Sprockets A and B are input and output shafts, while the other four serve as idlers. Sprockets C and D are in a sliding yoke adjusted by rotating the control knob. With sprocket A stationary and the knob turned counterclockwise, the yoke travels down its threaded shaft. This means shaft B changes position relative to shaft A, with the chain from sprocket C taken up by sprocket D. If the yoke reaches its end of travel in either direction, it must be reversed to make further phase adjustments.

The Phase Variator from Candy Controls, Niles, Ill. (www.candycontrols.com), is a simple but effective method of adjusting the timing relationships between machines even while they are running. It operates as a 1:1 phase transmission with input and output shafts rotating in the same direction. It is made from cast aluminum with steel input and output shafts. Needle bearings with separate oil seals support the shafts and all internal sprockets. The control knob ratio is 36:1, so one full turn of the knob changes the rotational location of the output shaft by 10 relative to the input shaft.