Today in 1987, US Patent 4653290 A was issued, an invention of Shelley R. Byrne, for his “Beer Keg Ice Sleeve and Method of Making Same.” Here’s the Abstract:

An ice sleeve cooler for beer kegs or other beverages comprising a slip-over ice sleeve open at the bottom and open at the top and having inner and outer sleeve members with an ice pocket therebetween. The bottom of the sleeve members are joined in sealed relation and have a draw-string for attachment around the lower side wall of the keg, and both inner and outer sleeve members have top draw-strings for individually attaching these members to the keg. The method of fabricating the ice sleeve cooler from a one-piece sheet of plastic stock involves the steps of folding and sealing the sheet to form the double sleeve members with an integral bottom edge.