Star Valve-Dash Churn: A Lever Drives a Close-Fitting Perforated Dash, Its Centre Valve Shuts Going Down and Opens Coming Up

"... provided with a valve as at G which closes the aperture L, Fig. 2, upon the downward pressure of the lever C, Fig. 1, which causes the cream to be forced up through the perforations m in the dash and valve and upon the upward motion of the lever C the cream passes freely down through the aperture L and is again forced up through the perforations m, &c., which creates a violent agitation of the cream."

Use a straight-walled stainless stockpot about 280 mm across inside and 300 deep as the body A: the patent asks for one "of a uniform size inside from top to bottom". Bend a 3 mm stainless strip 25 mm wide into a hoop that clamps round the pot 20 to 45 mm below its rim, closed with a bolt and lock nut. Bolt to it an arm B of the same strip rising 290 mm beside the pot and bent out 35 mm to the pivot, 165 mm from the pot's centre, bored 8.4 mm for the pin I.

Cut a 6 mm HDPE dash F 278 mm across, 1 mm smaller than the pot inside, with a 120 mm aperture L at its centre. Bore 18 mm holes m in two rings, 14 on a 176 mm circle and 20 on a 236 mm circle. Bend four strips of stainless strip 20 mm wide into bows E rising 76 mm, screw their feet to the dash just outside the aperture, and screw their tops to a hardwood collar 48 mm across glued on the stem 70 mm above the dash.

Cut a 28 mm hardwood dowel 480 mm long as the stem D and flatten its top 55 mm to a tongue 12 mm thick, bored 8.4 mm across 25 mm from the top for the pin j. Slide on the dash's collar, then from below the valve G, sleeve upward, and drive a 6 mm stainless pin h through the stem 40 mm under the dash, so the valve can drop about 30 mm open and rise to shut the aperture.

Cut a hardwood lever C 40 x 30 mm and 615 mm long, rounded at one end. Bore it 8.4 mm across 20 mm from that end for the pin I. Chisel a mortise 13 mm wide and 42 long through it, 150 to 192 mm from the pin hole, for the stem's tongue, and a slot 8.4 mm wide, 160 to 184 mm, through its sides for the pin j. Pin the lever to the arm B with an 8 mm stainless pin I and split pins, the tongue up through the mortise, and the 8 mm pin j through the slot and tongue.

Pour about 13 litres of heavy cream at about 15 °C, checked with the thermometer, into the pot, lower the dash in, and pin the lever. Work the lever down and up through its full stroke, briskly, timing it. When the butter comes, unpin the lever, lift the dash 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.

**J. V. Stevens** of Pomeroy, Meigs County, Ohio, US 31,338, 5 February 1861, "Churn", which he called "J. V. Stevens's Star Churn". He claimed "the perforated valve dash to be worked with or without a lever", and wrote that it produced butter "under favorable circumstances in one and a half minutes by the clock"; we have not tested that. He preferred stoneware for the body, with a recess at the top for the hoop; ours is a stainless stockpot with a clamped hoop. His text says the body is of a uniform size inside, though Fig. 1 draws it tapering; we follow the text, which the close-fitting dash needs. The patent gives no sizes; every size here is ours.