Today in 1893, US Patent 502835 A was issued, an invention of Charles I. Snyder, for his “Porter or Beer Tap.” There’s no Abstract, although in the description it includes these claims:

Before filling the keg, was closed ordinarily by means of a cork. This latter was forced in as the tap was driven into the keg, the tap itself being provided with a stopper (to prevent the escape of the liquor) which also was forced into the keg upon the insertion of the ordinary tap rod which communicates with the bar cock or faucet the liquor being forced through said tap rod by the pressure introduced into the keg, through the air passage and chamber of the tap, from the air pump with which the tap is connected.

Now in order that the tap shall operate successfully, it is essential that the joint between it and the keg shall be perfect to prevent the escape of the air or gas which is being forced into the keg insuring the passage of the liquor through the tap rod as the faucet is turned on. To attain this air tight joint, it is customary to use a packing of paper around the tap. This packing becomes saturated with the-liquor in a very little while and exceedingly offensive; besides does not always suffice for the purpose. Further: more, every time a tap is driven into a keg, the tap hole is more and more enlarged until the tap can no longer be used, when it be comes necessary to insert anew head. All these defects are overcome by my invention which consists: in certain details of construction, arrangement and combination of parts, all of which are more fully described hereinafter.