Today in 1935, US Patent 2001040 A was issued, an invention of David Sweeney, for his “Beer Dispensing Equipment.” There’s no Abstract, but it’s described as an “invention relat[ing] to beer dispensing equipment, and more particularly to equipment for handling, cooling, and dispensing, beer or other liquids.” And this appears to be the main feature.

One feature of my invention is that it is adapted for easy handling of quantities of liquid up to ten gallons or more. Another feature of my invention is the provision of means for expelling liquid, for example, beer, from a container without exposing the liquid remaining in the container to air. This is especially useful in dispensing beer where one container may be more or less infrequently used. In the ordinary case, for example, if a beer container is partially emptied, and air allowed to enter the container to fill up the space previously occupied by the liquid drawn off, the liquid remaining in the container is likely to become spoiled by contact with the air, especially if not used rather promptly. All these objections are overcome by my inventions I apply an inert gas, for example, carbon dioxide gas, (or some gas which will not spoil the beer or other liquid in the container) to the top of the container under suitable pressure. This gas then serves not only to expel the liquid from the container as it is used, but also fills up the space in the container occupied by the liquid drawn off, so that no spoilage results to the liquid remaining in the container. Still another feature of my invention is the elimination of cooling coils with their tendency to spoil beer standing in them.