Double-Swing Churn: Swing the Platform, the Toothed Pieces Work Both Dashers

Working a dash churn means lifting the dasher, again and again. Daniel Osgood, Jr., of Bluehill, Maine, received US 831, dated 9 July 1838, for what he called "Osgood's Double-Swing Churn": two common churns on a platform swinging in a frame. The side pieces rising from the platform are cut into teeth that mesh with the teeth of two pieces hung above, so as the platform swings backward and forward a lever is alternately raised and depressed, "giving the downward and upward motion to the dashers." The power required, he wrote, "is nearly in proportion to the power required to draw a pendulum in its lateral motion compared with that of raising its weight." This rung compares the swing of his platform and ours, then prints the toothed sectors, builds a tabletop frame for two jars, and makes butter.