Today in 1972, US Patent 3687340 A was issued, an invention of Remes E. De La Hunt, for his “Tapping Device For Beer Kegs.” Here’s the Abstract:

A keg tapping device is provided in which a pressure hose and a liquid discharge hose are connected to a common connector member connectable to a keg fitting on a keg to automatically open valving means in the keg fitting and the common connector to permit discharge of liquid from the keg and pressurization of the keg in response to the connection of the connector to the keg; seal and valve means are automatically closed upon disconnection of the connector from the keg and the keg includes a substantially permanently installed drain pipe so that there is no insertion of any member into the internal confines of the keg during the tapping operation with the connection of the connector and the pressure and lager discharge hoses being made by a simple push down and twisting movement.