Slotted Bell Crank Drive
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.
[Virginia Downward and William Clark, 1930]
[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]