Today in 1895, US Patent 541831 A was issued, an invention of John Fredrick Beyerlein, for his “Beer Pump Attachment.” There’s no Abstract, although in the description it includes this summary:

My invention relates to means of connection between a source of air pressure and the beer barrel, its object being Vto prevent the fouling of such connection by the beer and froth settling back into it from the beer barrel, as well as to eliminate from the air any dust which it may contain.

The invention consists essentially of a trap of peculiar form introduced into such connecting pipe, and of the various details of construction hereinafter fully pointed out.