Today in 1970, US Patent 3527391 A was issued, an invention of Anthony George Dimuria, for his “Means for Expelling Liquid from a Container by Applied External Pressure.” There’s no Abstract, although in the description it includes these claims:

A liquid container having two generally side by side openings, one for ingress of pressure applying medium and the other for egress of liquid, valve means normally maintaining said openings closed and a unit having a connection to a source of pressure applying medium and a liquid dispensing connection adapted to be applied to the container, the unit having means for operating the valve means to open said openings and thus put said container in communication with said connections respectively. Each Opening may have a valve seat with a valve element normally maintained resiliently seated thereon and each connection is dimensioned to project through its corresponding valve seat and to unseat the valve element associated therewith when the unit is applied to the container, said connections sealingly engaging said valve seats before unseating the respective valve elements whereby each valve seat also acts as a seal for one of said connections.

This invention relates to means for expelling liquid from a container by applied external pressure. While the invention has broad application it is particularly well adapted for use in dispensing beer from a barrel or keg. For purposes of explanation and illustration the invention will be described as embodied in means for dispensing beer from a barrel, as in the dispensing of draught beer in a tavern, but it is to be distinctly understood that the invention has other applications. The dispensing container may take various forms, the liquid being expelled or dispensed from the container may be any liquid and the pressure applying medium, which is preferably carbon dioxide in the case of dispensing beer, may in other cases be compressed air or other gas.