Today in 1876, US Patent 184795 A was issued, an invention of Herman F. Peter, William A. Klinge, Paul Assman, and George Schweikert, for their “Improvement in Vent-Valves For Casks.” There’s no Abstract, although in the description it includes these claims:

Our invention relates to an improved vent-valve for casks, &c.

The invention consists, first, in the combination, with a perforated valve seat, formed on the end of a screw-threaded stem, of an elastic valve and strap or holder, to admit air to a cask, barrel, or other receptacle; second, in the combination, with the valve seat and its stem, of a guard or cap, removably secured to the stem of the valve-seat by a set-screw, whereby the valve is protected and its displacement prevented third, in the combination, with the stem of the valve-seat, constructed. with a conical bearing, of a nut having a conical bearing and an interposed elastic ring, whereby the ring may be set out by forcing the conical bearings toward each other.