Adjustable Concave Beater Churn: Beaters You Turn to Meet the Cream at Any Level

A concave beater carries air into cream only where its face meets the cream's surface flat; fixed on its arms, that confines the churn "to a definite and unchangeable quantity of milk." Thomas G. Clinton, George H. Knight and Edward H. Knight of Cincinnati, Ohio, received US 6,764, dated 2 October 1849, for an adjustable churn-dasher: concave beaters rotating vertically, each mounted between arms so it "can lie between the arms at any desired angle," for instance by "a square mortise in the arm with an octagonal journal to the beater," so the face and the surface can be brought into the same plane at any level of milk. The dasher comes apart for scalding, and they brought no metal into contact with the milk. This rung works out the angle for a given level, then prints the arms and four concave beaters with octagonal journals, fits them in a box, and makes butter.