Today in 1996, US Patent 5564568 A was issued, an invention of Pleasant P. Rankin, Sr., for his “Insulating Cover For Keg Beer.” Here’s the Abstract:

An insulating cover for keg beer. The cover consists of a relatively flexible insulating material which substantially surrounds one or more kegs of beer. In a first embodiment the cover closely conforms to a single keg of beer, and thus has a cylindrical shape. Handles are provided on the exterior of the cover for easier manual transport of the keg and cover combination. The insulative properties are sufficient to maintain a relatively constant cool temperature without the use of ice, although multiple-use sealed freeze packs may be placed within the cover. In a further embodiment the cover is sized to fit upon a pallet and enclose up to four kegs. A side wall and top of the cover is openable to remove one or more of the kegs.