Today in 1939, US Patent 2165605 A was issued, an invention of John C. Baker, for his “Beer Drawing Apparatus.” There’s no Abstract, although in the description it includes this summary:

This invention relates to a method and pressure being reduced gradually as the beer apparatus for drawing beer and other brew. The flows through the draft tube at full flow, the rate invention aims generally to provide a method and of flow is reduced much below the full flow rate apparatus whereby the beer may easily and of the tube and nearly the Whole pressure drop 5 quickly be drawn from the keg or other container occurs at the restriction, and, in addition, by 5 and discharged into a glass or other receptacle reason of the diverging walls of the space imto fill the glass with quiescent clear live beer mediately beyond the restriction, the beer is having substantially all the dissolved gas which suddenly subjected to a sub-atmospheric pressure as it contained in the keg and surmounted by a it leaves the restriction flowing at high velocity, collar, or head, of the desired amount of creamy so that the dissolved gas in the beer is caused 10 fine-texture foam; and whereby this may be done suddenly to expand and form minute bubbles at without waste, and without requiring special skill a multiplicity of points, thereby changing a. large on the part of the bartender or other attendant. part, or even substantially all, of the flowing With the dispensing apparatus now generally cooled liquid beer in to a fine-texture creamy foam.