Movement No. 88 converts continuous rotary motion into intermittent rotary motion using an eccentric cam and a disk-wheel with stops. The cam (A) rotates continuously about its own center. The disk-wheel (B), which carries two stops (C and D), is mounted on a center that is eccentric to the cam. As the cam rotates, its offset profile engages one of the stops and pushes the wheel (B) through a partial rotation. At every half-revolution of the cam, the stop is released from the cam’s offset, and the wheel comes to rest. The wheel remains stationary until the cam completes its full revolution and engages the next stop, repeating the cycle. This mechanism produces a reliable step-and-pause motion widely used in indexing, timing, and counting machinery.
88. Continuous rotary converted into intermittent rotary motion. The disk-wheel, B, carrying the stops, C, D, turns on a center eccentric to the cam, A. On continuous rotary motion being given to the cam, A, intermittent rotary motion is imparted to the wheel, B. The stops free themselves from the offset of the cam at every half-revolution, the wheel, B, remaining at rest until the cam has completed its revolution, when the same motion is repeated.