Today in 1963, US Patent 3103297 A was issued, an invention of George H. Taft, for his “Combination Can Opener and Drinking Cup.” There’s no Abstract, although in the description it includes this summary:

This invention relates to a combination can-piercing device and drinking cup.

One of the principal objects of the invention is the provision of :a drinking cup provided with can-piercing instrumentalities depending from its bottom wall, guide means for attaching the cup to the top of a beverage can and sealing means associated with the cup and guide means to prevent leakage between the top of the can and the outside of the cup after the top of the can has been pierced.