Today in 1884, US Patent 307412 A was issued, an invention of Henry A. Rueter, for his “Ale or Beer Cask.” There’s no Abstract, although in the description it includes these claims:

My invention relates to the tap-hole bushing and the stopper and packing used in it; and it consists in the form given to the inside of the tap-hole bushing, and in the use of a stopper to close the tap-hole, which fills about half the length of the bushing at the inner end thereof, and a plug which fills about half the length of the bushing at the outer end, having a central chamber through it to receive the entering end of the faucet, which will form a packing around the faucet between it and the bushing when the faucet is driven in to its place.