Twin Loose-Dasher Churn: A Flywheel and Pitman Plunge a Rod, Two Winged Dashers Riding Loose on It Turn Opposite Ways

"The dashers being arranged thus loosely on the dasher-rod, and guided and held by means of the grooves m, m, and pins n, n, it will be seen that if they are forced down through the milk or cream, that they will have, in addition to their vertical motion, a horizontal motion imparted to them, by means of the resistance of the fluid on their inclined wings; the lower dasher turning in one direction, while the upper dasher turns in the opposite direction."

Glue up hardwood for a bed C 450 x 420 x 25 mm and two sides 310 mm deep and 900 mm tall, and screw the sides onto the bed 400 mm apart, flush at the back and open at the front. Cut a ring a 20 mm thick, 330 mm outside and 283 inside, and screw it to the bed centred 170 mm from the front, so the bucket's foot just drops into it. Join the sides at the back with a rail 50 mm deep, 400 mm up. Tenon two cross-pieces b, 40 x 50 mm, into the rail, 300 mm apart between centres, reaching forward over the bucket. Let a hex nut into the underside of each over the bucket's rim, and run an M10 threaded rod through it as a screw c, with two nuts locked on top as its head and a washer under its foot. Screw a guide bar 260 x 40 x 25 mm between the cross-pieces over the bucket's centre, with a 29 mm slot open to the front.

Use a 20-litre food-grade bucket as the body A. Cut a 12 mm HDPE cover to the bucket's top, 304 mm across, with a 32 mm hole in the middle for the rod.

Cut two hardwood bearing boards 400 x 340 x 25 mm and screw them between the sides, 80 and 200 mm behind the bucket's centre, their tops flush with the sides, so they stand 560 to 900 mm up. Bore both 16.6 mm at 725 mm up for the shaft E and at 625 mm for the shaft D, over the bucket's centre. Cut stainless rod 16 mm for E, 218 mm long, and D, 255 mm long. Pin the pinion g on E and the wheel f on D behind the back board with split pins, meshing, and hold both shafts with shaft collars. Pin a winch d of mild steel flat bar, 120 mm throw, with a hardwood handle, on D's back end. Cut a flywheel G 300 mm across from two 15 mm hardwood boards glued crossgrain, bore it 16 mm at the centre and 10.4 mm at 45, 60 and 75 mm out, and fix it on E's front end between two shaft collars.

Cut a 28 mm hardwood dowel 440 mm long for the rod I and bore it 10.4 mm across, 15 mm from the top, for the pin i. Mark a groove m 30 mm from the foot and another 120 mm from the foot. Cut each with a gouge 6 mm wide and 4 deep, a quarter of the way round the rod, rising 6 mm as it goes; the two run opposite ways from their starts. Slide the dasher K up the rod to the lower groove and L to the upper, and drive an M5 stainless screw, its point filed round, into each hub's hole until the point rides in the groove without binding: the pins n. Cut a hardwood pitman H 30 x 15 mm, 230 mm long, bored 10.4 mm at both ends 200 mm apart. Bolt its top to the flywheel's 60 mm hole as the pivot h, stand the rod in the bucket through the cover and the guide slot, and bolt the pitman's foot to it as the pin i, with lock nuts and washers.

Pour about 12 litres of heavy cream at about 15 °C, checked with the thermometer, into the bucket, set it in the ring with the dashers in, put on the cover and turn the screws c down onto it. Bolt the pitman to the rod, and turn the winch steadily, timing it; move the pivot h to the 45 or 75 mm hole for a shorter or longer stroke. When the butter comes, unbolt the pin i, slip the rod forward out of the guide slot, turn back the screws, draw the bucket out and lift out the dashers. Take out the butter, pour the buttermilk into a bowl, wash the butter in cold water until it runs clear, salt and weigh it.

**John Paff** of Eden, Erie County, New York, US 29,189, 17 July 1860, "Churn". He claimed "the dashers K, and L, provided with inclined wings l, l, as described, secured one above the other, loosely on the dasher-rod I, the connection with said dasher-rod being effected by means of the grooves m, m, and pins n, n". He knew inclined wings fixed to the rod and two fixed dashers had been used before. His body was the usual staved churn, its chimes fitting over a raised circle on the bed; ours is a bucket in a ring round its foot. The patent gives no sizes and does not say how far the grooves run; every size here is ours.