Today in 1958, US Patent 2842293 A was issued, an invention of Robert S. Knapp and Richard B. Nebinger, for their “Dispensing Apparatus.” There’s no Abstract, although in the description it includes this summary:

The present invention relates generally to a dispensing device, and more particularly to an apparatus for pressurizing a liquid container and regulating eduction flow therefrom.

The sale of beer and similar ebullient liquids in relatively large containers, particularly gallon size, for home use necessitates the provision of a simple, efficient and reliable dispensing means for providing a constant pressure on the beer within the container and for regulating eduction flow therefrom. It is desirable to provide dispensing means of this type wherein carbon dioxide pressurization by means of a sparklet bulb may be employed. Several difficult problems arise, however, in attempting to adapt an efficiently operating apparatus to the use of sparklet bulb pressurization. In particular, it is necessary to maintain a constant pressure on the beer throughout the dispensing life of the container, so that the last volume of beer Withdrawn will be received at substantially the same flow rate and pressure as the first volume. It is of further importance to prevent foaming of the beer as a result of agitating and mixing by the pressurizing gas. In addition, the use of carbon dioxide as the pressurizing gas also presents the problem of parts freezing within the bulb mechanism.

it is a primary object of this invention, therefore, to provide a dispensing device of the type described having novel pressure regulator means for providing a constant dispensing pressure.

It is another object to provide a dispensing device of the type described, wherein the pressurizing gas is released above the top. surface of the liquid Within the container in a manner which eliminates the possibility of agitation and consequent foaming of the liquid.

It is a further object to provide a dispensing device of the carbon dioxide type having novel means for preventing freezing within the carbon dioxide release mechanism.

It is still another object to provide a dispensing device of the type described having a self-closing, manually actuated push button type of valve for regulating dispensing flow through a spigot.

It is still a further object to provide a dispensing device of the type described having safety relief valve means to prevent excessive internal container pressure in the event of accidental malfunction of the pressure regulating or dispensing valve means.