Today in 1966, US Patent 3251386 A was issued, an invention of Frank A. Bellato, for his “Filler Valve Assembly.” There’s no Abstract, but in the description it states that the “invention relates to container filling apparatus, and particularly to what is known as a racker assembly used to fill beer kegs and the like.” But it’s primarily this.

The major object of the invention is to provide a racker assembly by means of whicha beer keg may be quickly and easily filled with a free unobstructed flow, while at the same time a supply of a gas under pressure (such as CO is being introduced into the keg to minimize turbulence and foaming of the beer as delivered into the keg.