Today in 1956, US Patent 2756917 A was issued, an invention of John T. Kline, for his “Valve For Counter Pressure Filling Apparatus.” There’s no Abstract, although in the description it includes this summary:

Briefly outlined they are as follows: The charged liquid is supplied to a reservoir by piping connected to a continuous source of supply forming a closed circuit; air or gas under pressure, such as carbon dioxide, is also supplied to the reservoir by suitable piping leading from a continuous source forming a closed circuit, thereby providing a head above the liquid in the reservoir; and a plurality of filling heads, each one of which contains a rotary fiat valve and means to temporarily seal the containers, is joined to the bottom of the reservoir and connected with the interior thereof by suitable piping to permit removal of the liquid and/ or the air or gas confined therein. By positioning the valve in each filling head in a predetermined pattern, a filling sequence is accomplished which permits the filling of the containers without excessively foaming or effervescing the liquid. This sequence consists of temporarily sealing the container to the filling head; then positioning the valve to permit the air or gas under pressure in the reservoir, commonly called counter pressure, to enter into the container to equalize the pressure between them; then positioning the valve to permit the liquid in the reservoir to enter into the container under its normal hydrostatic pressure and to return the air or gas (counter pressure) in the container back to the reservoir as it is being displaced by the liquid; then positioning the valve to out off the flow of the liquid and the air or gas (counter pressure) to and from the container; then exhausting any air or gas remaining in the container and finally permanently sealing the container.

My invention, while relating generally to apparatus for transferring gaseous liquids from a source of supply to containers, specifically relates to the rotary fiat valve employed by such apparatus and is specifically directed to the method employed in conveying the liquid and air or gas from the reservoir to the container.