Today in 2003, US Patent 20030075208 A1 was issued, an invention of Mason McMullin, Robert Bell, and Mark See, for their “Beerbrella.” Here’s the Abstract:

The present invention provides a small umbrella (“Beerbrella”) which may be removably attached to a beverage container in order to shade the beverage container from the direct rays of the sun. The apparatus comprises a small umbrella approximately five to seven inches in diameter, although other appropriate sizes may be used within the spirit and scope of the present invention. Suitable advertising and/or logos may be applied to the umbrella surface for promotional purposes. The umbrella may be attached to the beverage container by any one of a number of means, including clip, strap, cup, foam insulator, or as a coaster or the like. The umbrella shaft may be provided with a pivot to allow the umbrella to be suitably angled to shield the sun or for aesthetic purposes. In one embodiment, a pivot joint and counterweight may be provided to allow the umbrella to pivot out of the way when the user drinks from the container.