Hemispherical-Dasher Bowl Beater: An Open Half-Sphere Spun Close to Its Bowl Throws the Froth Into a Cup

"The dasher being then rotated, the eggs are subjected to such attrition between the sides of the bowl and the closely adjacent surface of the dasher as to be rapidly reduced to the desired frothy state."

Print the bowl foot down, the cup closed end down, six hoops flat, two hubs, the pinion, the crank gear and the crank. Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Cut a 10 mm dowel 188 mm long as the shaft and sand it. Put the six hoops' tabs into one hub's slots, press the second hub onto their other ends, and slide both hubs onto the shaft, its short end standing 10 mm out of one hub's boss. Drill 2.5 mm through the shaft at each hub's cross hole and fix them with M3 screws.

Set the shaft's short end in the dimple in the bowl's side and lower the long end into the notch opposite. Fit the pinion on the long end outside the bowl with an M3 screw through the shaft. Put the crank gear inside the cup's bracket with its axle through the plate, and fix the crank on the axle's flat with an M3 screw and washer.

Lift off the cup, pour 4 egg whites into the bowl and replace the cup so its gear meshes the pinion. Turn the crank briskly and time it: the froth is thrown up into the cup and the liquid runs back to the bowl. Lift the cup and scrape the froth out with the spatula. To churn, use 300 ml of heavy cream at about 15 °C instead.

**William Borrman** of Cincinnati, Hamilton County, Ohio, US 20,032, 27 April 1858. His bowl was earthenware or the like, his cup tin, and the top of the cup, or all of it, could be glass to watch the work. His dasher was wire or the like open work, and its shaft could cross the dasher or not. He claimed the half-sphere open-work dasher with a bowl of the same form and size, and the inverted cup that keeps the beaten matter beyond the dasher's reach. Our hoops, hubs, sizes and gearing are ours. FDM prints hold food in their layer lines, so wash well and replace when worn.