Today in 1892, US Patent 473248 A was issued, an invention of Moses Bensinger, for his “Valve For Beer-Coolers.” There’s no Abstract, although in the description it includes this summary:

My invention relates to valves for closing the opening provided in beer-coolers for the reception of the cock of a beer-keg after it has been introduced into the cooler. In beer coolers provided with an opening of the above description, when the keg has been removed from the cooler, the opening is uncovered and warm air may readily pass to the inside of the refrigerator, causing a great Waste of ice.

The object of my invention is to provide a valve for use upon refrigerators which will automatically operate to close the opening above referred to whenever the keg is removed. I accomplish this object as hereinafter specified and as illustrated in the drawings.