Surface Dash-Wheel Churn: A Fast Fan Skims the Cream Over a Partition on a Parallel-Rule Frame

"... the rest o, o, w, v, v, is raised or lowered until when b is placed on it the buckets or fans will dip about one-eighth of an inch into the cream and the crank is turned rapidly in such manner that the wheel shall impel the milk or cream which it strikes in the direction of w".

From 18 mm pine make an oblong box open at the top, 600 x 300 mm and 320 mm deep inside: floor 636 x 336 mm, sides 636 x 320 mm, ends 300 x 320 mm, glued and screwed.

Cut two hardwood uprights o 30 x 13 x 190 mm and pin each to a side of the box with an 8 mm bolt 22 mm above the inside floor, 100 mm from the right end. Cut a pine division board w 228 x 170 mm and pin its foot to two hardwood blocks on the floor 200 mm from the left end, so it stands 16 mm clear of the floor. Cut two hardwood bars v 20 x 20 x 340 mm and pin them to the uprights' tops and w's top corners, 300 mm apart, with 160 mm between each foot and top pivot, so the bars stay level as the frame leans. Screw a hardwood handle h i 30 x 12 mm to the left end of one bar, long enough to stand 100 mm above the rim, and bend a flat-bar frame e over the rim to hold it with a pin through holes drilled every 20 mm in the handle.

From pine make chamber b open below: two sides 360 x 270 mm, two ends 234 x 270 mm and a top 360 x 270 mm, 270 mm wide outside so it sits on the bars inside a. Drill both sides 12.5 mm for the fan shaft 40 mm up from b's lower edge and 230 mm from its left end, and one side again 170 mm above that for the crank shaft. Cut the 12 mm stainless rod to 285 mm for the fan. Push eight hardwood arms 18 x 18 x 69 mm into the hub's sockets, screw a bucket across each pair of arm ends, slide the hub onto the shaft inside b and fix it with an M4 screw across.

Cut a pulley f 240 mm across and a pulley c 60 mm across from 12 mm plywood, each with a 3 mm flange glued on the outer face, and file a groove round each rim for the cord. Fix c on the fan shaft outside b. Run a 12 mm stainless stub shaft through b's side 170 mm above, fix f on it and a hardwood crank arm 24 x 10 x 112 mm with a 24 mm dowel handle 80 mm long beyond it, out over the side of a. Tie a loop of 6 mm cotton cord round both pulleys.

Pour in about 14 litres of heavy cream at about 15 °C, checked with the thermometer. Set chamber b on the bars and move the handle until the buckets just dip into the cream, about 3 mm, then pin it in frame e (the notebook gives the lean for other quantities). Turn the crank fast and time it: the fan throws cream over the division board and it returns under it. When the butter comes, lift b off, pour off the buttermilk, wash the butter in cold water until it runs clear, work in a pinch of salt and weigh it.

**Andrew Patterson** of Birmingham, Allegheny County, Pennsylvania, US 23,111, 1 March 1859, "Churn". He held that a fast fan at the surface does more than a submerged wheel, which has to lift the whole cream, and that it also gathers the butter on the far side of the partition. He claimed box a with chamber b serving as its lid and as the frame for the dash wheel and crank. His only figure is the 1/8 in. dip; every size and material here is ours.