Today in 1969, US Patent 3473556 A was issued, an invention of Edward G. Akers, Keith M. Johnson, and Robert P. Marine, for their “Beer Keg Tapping Device and Seal.” There’s no Abstract, although in the description it includes this summary:

The disclosure herein describes a novel seal and more particularly a new beer keg tapping device. The beer keg tapping device described herein includes a tapping valve and an outer fitting with the tapping valve having a beer passageway extending therethrough. The passageway has an outwardly flared portion adjacent the outlet thereof. The tapping valve is releasably secured to the beer keg and a valve element is movable axially within the beer passageway to selectively open and close the beer passageway. The outer fitting includes an elongated probe receivable within the outwardly flared portion of the passageway and engageable with the valve element to move the valve element to open the beer passageway. The probe has a beer passageway therein and a skirt-type seal adjacent the inner end of the probe. The seal is engageable with the outwardly flared portion of the beer passageway of the tapping valve and as the probe is moved axially, the skirt seal is cammed radially inwardly to form a very tight probe-to-tapping valve seal before the beer passageway is Opened. The tapping valve is secured to the beer keg by cooperating lug members on both of the keg and the outer fitting and by a pair of tabs driven through apertures in the tapping valve and engageable with projections or ribs on the keg.