Today in 1971, US Patent 3610478 A was issued, an invention of Mack S. Johnston, for his “Tapping Device For Beer Kegs and the Like.” There’s no Abstract, although in the description it includes only this summary:

Disclosed is a novel tapping device for beer kegs and the like including a keg adapter mounted in the opening of a keg at the brewery and a probe-type coupler secured to the keg adapter at the dispensing establishment to dispense beer.