Balance-Wheel Churn Frame: A Weighted Wheel Drives the Dash Up and Down and Its Pitched Blades Make It Revolve

"The nature of my invention consists in lengthening or shortening the stroke and lowering and raising the dash so as to give it the right position in the churn at the same time giving the dash an independent revolving motion to the right and left and giving the operator power over the work to be done."

From 51 mm square timber (the patent's two inches) cut two front posts about 1.83 m long and two back posts about 0.91 m. Set the feet about 0.91 m apart; lean the front posts in so they meet at the top, and the back posts at the same angle. Join front and back posts on each side with two side cross pieces about 0.81 m between shoulders, at 300 and 860 mm up, and front and back with cross pieces at the same heights, cut to the bevel. On the top of the long posts fix a cap G reaching 410 mm forward, bored 32 mm near its end for the staff, and brace it with two timbers down to near the tops of the short posts.

Bolt a hardwood bearing block bored 26 mm to the middle of each top front and back cross piece, and pass a 25 mm mild steel shaft K through them (the patent's about one inch). Glue two 18 mm plywood discs into a wheel 600 mm across with a rim 50 mm wide and four arms, and screw a ring of 60 x 12 mm mild steel flat bar round it so it weighs about 14 kg, near the patent's 30 pounds. Cut a slot 13 mm wide from 60 to 140 mm out along one arm for the wrist, a 16 mm bolt with a nut. Fix the wheel on the shaft's front end. On the back end fix a crank F of flat bar with three holes for the handle, so it can be lengthened or shortened.

Cut a 32 mm hardwood staff D about 1.25 m long and pass it up through the cap. Make a hardwood socket I to slide on it, with a lug for the rod and a thumb screw (threaded rod, nut and wing nut) to fix it. Cut a hardwood rod E 730 mm between holes, from the wrist to the lug. Fit a hardwood socket H on the staff's foot, bored 16.5 mm, with a thumb screw through its side; turn the top of the churn handle L down to a 16 mm pin with a groove, so the thumb screw rides in the groove and the handle turns freely: the swivel J.

Cut a 28 mm hardwood handle 420 mm long. For each dasher halve together two hardwood pieces 38 x 19 mm (the patent's 1 1/2 x 3/4 inch), 260 long, at right angles, and plane each blade on both sides down to about 6 mm at its edges, every blade bevelled the same way so they all stand on one angle, about 30 degrees. Fix two such dashers on the handle's foot, 60 mm apart.

Pour about 10 litres of heavy cream at about 15 °C, checked with the thermometer, into the bucket, stand it under the staff with the handle through its lid, and join handle and staff at the swivel. Set the socket I on the staff so the dash just clears the bottom at the low point, and the wrist for the stroke you want. Turn the crank F, timing it; the wheel carries the stroke round and the dash turns as it goes. When the butter comes, loosen the swivel's thumb screw, lift the handle out, take out the butter, pour the buttermilk into a bowl, wash the butter in cold water until it runs clear, salt and weigh it.

**Nathan D. Ross** of Braintrim, Wyoming County, Pennsylvania, US 28,607, 5 June 1860, "Churn". He did not claim the up-and-down motion of dasher and handle, but the revolving of the dashers and handle by the series of dashers and blades. The frame, shaft, wheel and dasher-piece sizes are his, given as "about"; he gives the wheel's size and weight but not its material; ours is plywood with a steel ring; the bucket, stroke, rod and blade angle are ours.