Ventilating Paddle Rocking Churn: Hinged Paddles That Strike One Way and Slip the Other

Cook set out to let "a current of fresh air" into the churn "to hasten the production of the butter and to improve its quality." George W. Cook of Schenectady, New York, received US 3,460, dated 28 February 1844, for "Cook's Ventilating Churn": a semi-cylinder balanced on pivots so it rocks easily, its top closed by thin boards except a narrow opening in the middle. Inside, two frames at about 45° from the vertical, inclined opposite ways, carry perforated paddles hung on gudgeons. As the vessel is canted, one set swings square to its frame and strikes the cream while the other turns flat against its stops. This rung works out how the paddles hang, then prints the ends, frames and paddles, bends a stainless semi-cylinder, and makes butter.