Today in 1955, US Patent 2707827 A was issued, an invention of Fred W. Petram, for his “Combined Can Holder and Opener.” There’s no Abstract, although in the description it includes this summary:

This invention relates to can openers and more particularly to a combined can opener and holder.

It is a principal object of the present invention to provide a device which may be efficiently and easily used in opening and holding a can of beer or a can of juice or similar material, the construction consisting entirely of one piece.

It is another object of the present invention to provide a combined can holder and opener of the above type which is adapted to snap on to the upper lip of the can at the end of the device remote from the can opening portion, the latter being resiliently retained against the lower lip of the can with the device intermediate its ends curving outwardly to provide a grasping portion.