Valved Air-Tube Dasher Churn: A Double-Acting Valve Lets Air Out of a Tube That Swings With the Dashers

"It may be seen that as the pipe revolves to the right the inner end of the valve (V,) will be pressed against the right side closing the right side of the aperture and allowing the air to pass out on the left side behind the wing of the valve by centrifugal force and when it revolves in the contrary direction the valve acts on the contrary side with similar effect."

Print the dasher arms (/uploads/blueprints/valved-air-tube-dasher-churn-dasher-arms.stl), the cross step (/uploads/blueprints/valved-air-tube-dasher-churn-cross-step.stl), the elbow with its orifice (/uploads/blueprints/valved-air-tube-dasher-churn-elbow-valve.stl), the valve flap (/uploads/blueprints/valved-air-tube-dasher-churn-valve-flap.stl), two tube clips (/uploads/blueprints/valved-air-tube-dasher-churn-tube-clip.stl) and the pulley (/uploads/blueprints/valved-air-tube-dasher-churn-pulley.stl). Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Lay the cross step in a straight-sided round food-grade container about 190 mm across and stand a 10 mm square hardwood shaft in it, the dasher arms on its foot. Pin the flap in the elbow's orifice with a 2 mm stainless pin, glue the elbow on a 20 mm food-grade pipe reaching above the cream, and tie the pipe to the shaft with the clips, between the arms.

Stand a pine post beside the churn and mount the pulley on a 10 mm rod near its top. Fix one end of a leather strap to the pulley, wind it round the pulley, take it across and wind it a few turns round the shaft, and fix it. Glue a 12 mm dowel lever into the pulley's socket.

US 16,203 drawing sheet, public domain (expired patent).

Let the heavy cream stand until it reaches about 15 °C, checked with the thermometer. Pour in 2 litres, below the pipe's top. Raise and lower the lever steadily so the shaft swings back and forth; watch for bubbles near the bottom; time until the butter comes. Pour off the buttermilk, add cold water, churn a little and pour off again until it runs clear; work in a pinch of salt and weigh the butter.

**William A. Vertrees** of Winchester, Clark County, Missouri, US 16,203, 9 December 1856. The shaft stood in a cross piece laid loosely in the bottom, easy to lift out for washing. He claimed the air tube with its double-acting valve. A container, pipe, pine and printed parts stand in for his; the notebook's speeds are estimates. FDM prints hold food in their layer lines, so wash well and replace when worn.