Today in 1939, US Patent 2165684 A was issued, an invention of Frederick A. Struck, for his “Portable Liquid Container and Means For Filling the Same.” There’s no Abstract, although in the description it includes this summary:

This invention relates to a portable beer dispenser and has for its principal object the provision of a portable container in which, from the time the container is filled until the last drink r is drawn, the beer will be constantly and uniformly maintained under the same pressure it was in the original barrel.

Draft beer is packed by the breweries in kegs or barrels. If this beer is drawn from the barrel 10 in bulk into a container it soon loses its richness and flavor due to the escape of the gas therefrom, and if allowed to stand in the container for any length of time it will become stale, flat and undrinkable. With. the use of this invention, how- 1 ever, the beer is maintained under pressure while it is being transferred to the portable container and while it is being dispensed from the container so that at no time is it possible for the gas to escape from the beer and the flavor is maintained exactly as it was in the original barrel.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency.