Today in 1893, US Patent 505424 A was issued, an invention of Gustav Kruse, for his “Beer Tempering Device.” There’s no Abstract, although in the description it includes these claims:

The object of my invention is to provide a beer tempering device in which the difficulty of cleaning the pipes, or worm, thereof shall be reduced to a minimum and in which, at the same time, it may be done to perfection.l As heretofore constructed these devices were uncleanly and, consequently, unhealthful because there was no known means of cleaning them thoroughly, and; hence, where the government looks after the sanitary properties of such devices, their use has been prohibited, generally, because; even after a thorough cleansing with known methods, their cleanliness was either doubtful, or: ultimately, could be proved to be unsatisfactory. To overcome said difficulties I have devised a `new mechanism which, when used according to my direction will overcome all objections and be perfectly clean.