Today in 2010, US Patent 7819286 B2 was issued, an invention of William L. Antheil and Nelson Bolton, assigned to Kegx LLC, for their “Beer Keg and Method Of Assembly.” Here’s the Abstract:

A container, or keg, for storing, shipping, and dispensing a bulk quantity of a fluid, for example, beer or like malt beverage, is provided. The container/keg includes a flaccid bag (56) for containing the fluid and a substantially rigid, pressure-tight, plastic vessel (10) within which the bag (56) is contained. The bag (56) has a mouth (58) secured with a locking ring or the like to an opening in the vessel (10) via which the mouth (58) is accessible externally of the vessel (10) for purposes of filling the bag (56) with the fluid and/or dispensing the fluid from the bag (56). Preferably, the shape of the vessel (10) permits it to be efficiently stacked and shipped when in a full or empty condition. Methods for assembling, filling and shipping kegs are also provided.