Hinged-Arm Frame Churn: An Arm That Swings Back Holds the Dasher's Top, Its Forked Brace Holds the Cover Down

"By means of the forked brace bar the churn is held in position in the frame without other fastening and the cover firmly fastened thereon, thus preventing the cream from being thrown out by the action of the beaters. The brace bar also serves to steady the end of the arm in which the beater shaft is stepped."

Glue up a hardwood base B 400 x 600 x 30 mm. Mortise four hardwood uprights C 40 x 40 mm, 603 long, into it at the back, 220 mm apart side to side, in pairs 100 mm apart front to back, 230 mm behind where the churn's centre will be. Join each side pair at the top with a cross tie D 40 x 30, 160 long, bored 20.6 mm across 40 mm from its front end for the cross bar's journals; join the front pair with a cross tie D' 260 long, 30 below the top; and join each pair 430 mm up with a cross tie D'' 260 x 40 x 20 for the crank shaft's boxes.

Run a 20 mm stainless rod 270 mm long as the cross bar F through both cross ties D. Cut a hardwood arm G 40 x 30 mm, 310 long, bore it across 20.4 mm 20 mm from its back end, and pin it on F so it reaches forward over the churn's centre resting on the tie D'. Glue a hardwood block 40 x 40 x 40 under its front end, bored 16.6 mm 30 deep from below for the staff's top. Screw two hardwood buttons O, O' on the tie D' either side of the arm, to turn over it. For the brace bar M, cut two hardwood legs 20 x 20 mm, 250 long, and a foot bar 110 x 20 x 12 notched for the staff, and hang the legs either side of the arm on a 12 mm stainless pin through it above the staff, so the foot presses the cover.

Use a 20-litre food-grade bucket as the churn A on the base in front of the frame, with the step in its bottom. Cut a 12 mm HDPE cover to it and saw it in two halves through a 17 mm centre hole. Cut a 16 mm stainless staff L 586 mm long, screw two crossed hardwood slats 240 x 30 x 8 mm on hubs 70 and 170 mm above its foot as the dasher, and pin the pinion b on it 420 mm above the churn's floor. Screw two hardwood boxes I, I' 50 x 24 x 47 mm on the D'' ties, bored 16.6 mm across 23 mm above them. Run a 16 mm stainless shaft H 410 mm long through them with the wheel K pinned on its front end meshing b, a shaft collar behind the front box, and a crank J of mild steel flat bar, 100 mm throw, with a hardwood handle at the back.

With the arm turned back, stand the churn on the base with the staff in its step, pour in about 10 litres of heavy cream at about 15 °C, checked with the thermometer, and lay on the half covers. Swing the arm down over the staff's top, turn the buttons over it and let the brace bar rest on the covers. Turn the crank steadily, timing it. To look in, turn the brace up and lift a half cover. When the butter comes, turn the buttons, swing the arm back, lift out the staff, 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 Stilwell** of Griffin, Spalding County, Georgia, US 32,388, 21 May 1861, "Churn". He claimed "the combination of the brace bar M, hinged arm G, buttons O, O', with a vertical barrel churn and rotary dasher shaft L". He neither drew nor described the dasher on the shaft; ours is two crossed slats. His churn was a hooped barrel and his gears bevel wheels; ours are a bucket and a printed crown wheel and pinion. The patent gives no sizes; every size here is ours.