Wedge-Disk Rotary Churn: A Geared Disk With Wedge Teeth Throws Cream Up Into a Collar, Slanted Holes Let the Milk Back Out

"When this disk and rim, or collar are revolved rapidly the milk is cut and agitated by the projections on the disk, and also is given an upward tendency by them. It is thrown into the collar D, and passes out at the openings s, s, s. Thus a constant stream or current is produced from the out to the inside of the collar and vice versa. The butter remains and is gathered in the collar while the milk as has been stated passes out at the openings s, s, s."

Glue up a square hardwood box A 300 x 300 mm inside and 400 deep, sides and bottom 22 mm, joints sealed with silicone sealant. Cut a 12 mm HDPE lid to the outside, 344 mm square, with a 32 mm hole at the centre.

Turn a hardwood staff B 28 mm across and 400 mm long. Set a 10 mm stainless pin 14 mm out of its foot and a 16 mm stainless rod 90 mm long 20 mm into its top. Slide the disk C on so its underside is 10 mm above the staff's wooden foot, and pin it with a dowel through its hub.

Cut a hardwood upright G 40 x 40 mm and 295 mm long, with two slots 10 mm wide and 40 long through it, and fix it upright on the middle of the box's back with two carriage bolts, washers and wing nuts, so it can be raised or lowered to set the wheels' mesh. Glue and screw a hardwood arm d 50 x 25 mm, 332 mm long, across its top, reaching over the box's centre, bored 16.6 mm there for the staff. Screw two hardwood bearing blocks 50 x 25 x 108 mm on the arm, one 60 to 85 mm in front of the staff (the standard a) and one 25 to 50 mm behind it, bored 16.6 mm across 83 mm up. Stand the staff on the step through the lid and arm, pin the wheel F on its top, run a 16 mm stainless shaft H 180 mm long through the blocks with the wheel E pinned on it meshing F, a shaft collar, and a crank of mild steel flat bar, 100 mm throw, with a hardwood handle.

Pour about 12 litres of heavy cream at about 15 °C, checked with the thermometer, into the box so it stands over the collar, put on the lid and set the wheels' mesh with the upright G. Turn the crank briskly, timing it. When the butter comes, much of it lies in the collar. Lift out the staff and disk, take out the butter, pour the buttermilk into a bowl, wash the butter in cold water until it runs clear, salt and weigh it.

**D. T. Ward** of Mansfield, Richland County, Ohio, US 30,941, 18 December 1860, "Churn". He claimed "the disk or wheel C, constructed as described and in connection therewith the rim or collar D", and said currents had been made before. He does not give the number of teeth or holes, or the form of his toothed wheels; ours are 12 teeth, four round holes and a printed crown wheel and pinion. His upright G had a diagonal brace; ours is bolted through slots so it can be raised or lowered. Every size here is ours.