Air-Chest Spiral Agitator Churn: A Disk That Draws Air Down Its Agitator Into the Cream

Webster shaped the agitator so the turning disk breathes air into the cream. Hazen Webster of Ogdensburg, St. Lawrence County, New York, received US 12,370, dated 6 February 1855, for a "Machine for Producing Butter, called 'Webster Air-Chest Agitator'": a round open disk A with openings a, b, c, turning at the bottom of a square or circular box, carrying "a spiral inclined air agitator" B whose sides run from near the centre and diverge "with a curve or circle toward the circumference," surmounted toward the rim by vertical breakers. Turning, it "opens a passage for the air down through the opening a, and so discharges from the bottom of the churn ... up through the agitator B, up through the letter b." This rung works out the speed the air passage needs, then prints the air chest (disk, agitator and breaker in one), the step and gears, builds the churn, and makes butter.