Counter-Turning Hooped Beater Churn: One Bevel Wheel Turns a Spindle and a Hollow Shaft Opposite Ways, Spiral Hoops Sweep the Wall

"The hoops n n ... not only maintain the relative position between k and m, but have a specific effect in displacing and agitating that portion of the milk or cream which would, by the operation of the two sets of beaters, be forced and impacted against the walls of the vessel, where they would, if allowed to remain, escape the action of the beaters, to a considerable extent."

Use a 20-litre food-grade bucket as the body A and set the printed step in the middle of its floor. Cut a 12 mm HDPE cover B to its top, bore it 23 mm at the centre, and saw it across through the hole into two halves.

Cut a 12 mm stainless spindle G 580 mm long. Plane two hardwood slats j 220 x 30 x 8 mm, bore each 12.2 mm at the middle with a hardwood hub, and pin them on the spindle 30 and 130 mm above its foot, a quarter turn apart, each tilted 20 degrees about its length.

Cut a 22 mm stainless tube H 270 mm long. Plane two hardwood slats k and m 250 x 30 x 8 mm, tilted 20 degrees the other way. Fix k on the tube's foot with a hardwood hub. Bore m 13.2 mm at its hub so it turns loose on the spindle, and slide it on between the two j slats. Bend two strips of stainless strip 20 mm wide into hoops n that run a quarter turn round at 124 mm radius while dropping 100 mm, and screw each from an end of k down to the end of m a quarter turn round, so m lies at right angles to k. Slide the tube down over the spindle.

Screw two hardwood posts 30 x 40 mm, 195 tall, to the cover either side of its centre, 150 mm apart over their inner faces, and join their tops with a top bar bored 12.6 mm over the centre. Screw two hardwood bearing blocks 50 x 25 mm, 120 tall, to the cover 60 and 125 mm in front of the centre, bored 16.6 mm across 96 mm above the cover. Pin the pinion f on the hollow shaft 40 mm above the cover and the pinion e on the spindle 105 mm above f, teeth facing each other. Run a 16 mm stainless shaft 150 mm long through the blocks with the crown wheel C pinned on its inner end between the two pinions, meshing both, a shaft collar, and a crank D of mild steel flat bar, 100 mm throw, with a hardwood handle.

Pour about 10 litres of heavy cream at about 15 °C, checked with the thermometer, into the bucket with the beaters in, lay on the cover halves and seat the gearing. Turn the crank steadily, timing it. When the butter comes, lift off the cover and gearing, lift out the beaters, take out the butter, pour the buttermilk into a bowl, wash the butter in cold water until it runs clear, salt and weigh it.

**Wm. Bently Hopkins** of Oakfield, Genesee County, New York, US 31,806, 26 March 1861, "Churn". He claimed "the beaters j j and k, m, the latter provided with spiral arms, n n", and did not claim beaters on separate shafts turning opposite ways as such. His text says the hoops run a quarter of the circle, putting m at right angles to k, and also that m is forty-five degrees in advance of k; we follow the hoops. His gearing was a bevel wheel between two bevel pinions; ours is a printed crown wheel. The patent gives no sizes; every size here is ours.