Today in 1969, US Patent 3454199 A was issued, an invention of Dell M. Malick, for his “Keg Tapping Structure.” There’s no Abstract, although in the description it includes this summary:

A complete tapping structure is disclosed. This tapping structure consists of a keg unit or keg valve and a tapping unit which is adapted to be coupled to the keg unit so that the contents of the keg may be exhausted. The keg unit is adapted to be held upon a conventional keg neck structure by cam means so as to be secured against undesired rotation by ratchet means. The tavern unit is adapted to be coupled to the keg unit by being located upon it and twisted. The tavern unit may be removed from the keg unit by being twisted without causing the keg unit to be uncoupled from the keg neck.