Today in 1891, US Patent 452609 A was issued, an invention of James C. Magee, for his “Beer-Pump.” There’s no Abstract, though it’s described this way in the application:

My invention relates to an improvement in a tap or pump for beer, &e., the same having a plug which may be inserted in a keg, barrel, &c., and a tube adjustably fitted in such plug, an air-space existing between said tube and plug, so that the beer or fluid may be subjected to pressure, the tube being connected with a discharge-pipe.