Today in 1969, US Patent 3464435 A was issued, an invention of Kay R. Lamb and Charles R. Mandeville, for their “Quick Keg Tap with Self-Sealing Connection.” Here’s the Abstract:

A keg-tapping assembly consisting of a collar installed in an opening of a keg. A bushing assembly carrying a sleeve is fastened on the collar with the sleeve extending through the collar with clearance for gas to pass into the keg. A normally closed pressure-responsive gas admission valve of the type used in pneumatic tires is provided on the bushing assembly. The bushing assembly also includes a normally collapsed live rubber axial conduit. A removable draft tube assembly can be mounted on the bushing assembly, the draft tube assembly including a rigid draft tube which is forced through the live rubber conduit and is contained coaxially in the sleeve, the draft tube extending into the keg to a considerable depth so that beverage can be forced out through the draft tube responsive to the admission of gas under pressure through the gas-admission valve. When the draft tube assembly is withdrawn, the live rubber conduit collapses, sealing otf the assembly so that foreign material cannot enter the keg.