Button-Set Hinged-Slat Dasher Churn: Slats Deflect the Cream, a Button on the Rod Holds Them Open or Lets Them Shut

"This dasher is constructed with movable slats H, H, which, when open, rest upon stop pins a, and serve the office of deflectors, and as the dasher is drawn up the cream is thrown below the slats and to the sides of the churn and as the dasher is pressed down the cream will be forced up and toward the center of the churn, and against a cross piece J, secured to the center of the dasher."

From 20 mm hardwood make a box 400 x 300 mm and 380 mm deep inside, on four legs 50 mm square and 300 mm long. Screw a post 50 x 40 mm, 860 mm long, up the middle of the back. Cut a lid with a 32 mm hole in its middle. Bolt a lever 30 x 30 mm, 640 mm long, to the post's top so it reaches over the lid's middle to the front. Fill the box with water overnight so it swells tight, then empty it.

Make two end bars 296 x 40 x 20 mm and join them with the cross piece J, 396 x 40 x 30 mm, bored 31 mm in its middle. Cut two inner slats H 380 x 63 x 12 mm, each with a tab 20 x 9 mm on its inner edge 10 to 30 mm from the middle, and two outer slats H' 380 x 52 x 12 mm. Bore each along its length for a 6 mm stainless hinge pin, H 3 mm in from its inner edge and H' 4 mm in, and hang them between the end bars on pins 392 mm long, H 32 mm and H' 98 mm each side of the middle. Fix 6 mm stop pins, 20 mm long, into the end bars under the slats: 80 mm out and 27 mm below the hinges for H, 130 mm out and 21.5 mm below for H'. Glue posts 20 x 10 x 19 mm on the slats, 120 mm each side of the middle, 40 mm out from each hinge, and join each pair with a piece L 76 x 20 x 6 mm on pins.

Turn a hardwood rod F 30 mm across and 440 mm long, with a cross handle at its top to turn it. Pass it down through J and glue the button on its foot, below J, so that in one position its inclined surfaces lie under the slats' tabs and hold the slats open on their pins. Join its top to the lever with a pin in a slot. Set the dasher in the box and the lid on.

Pour about 20 litres of heavy cream at about 15 °C into the box, checked with the thermometer, and put the lid on. Work the lever up and down, timing it. For thin cream keep the button holding the slats open; if the cream thickens, turn the rod half round so the slats shut on each down stroke. When the butter comes, lift the dasher out, drain the buttermilk, wash the butter in cold water until it runs clear, salt and weigh it.

**S. N. Campbell** of Elgin, Kane County, Illinois, US 25,804, 18 October 1859, "Churn". He claimed "the arrangement and combination of the button K, dasher rod F, movable slats H, H', pieces L, and bar J". The patent gives no sizes and does not say where the slats are hinged, how the button's surfaces bear on them, or how the pieces L join H' to H: the hinge lines, the tabs, the button's surfaces, the links and every size here are our reading.