Circular motion of pin in disk, which works inside of the straight, slotted yoke, produces an irregular, vertical motion of rod. Downward motion of rod is slow but has a quick return. [br][Virginia Downward and William Clark, 1930][br][br][Editor's Note: This mechanism is a form of the slider-crank with a higher-order kinematic contact pair of the pin in the slider, similar to the Reuleaux-Viogt model C-4. The slider element of Reuleaux-Viogt model C-1 is missing. FCM]