Today in 1967, US Patent 3325032 A was issued, an invention of Louis A. Cormier, for his “Bottle Cap.” There’s no Abstract, although in the description it includes this summary:

It is common practice in the soft drink and beer industries to provide the bottle with a cap having a tab extending outwardly from the cap to permit its removal without the use of a bottle opener. Such a cap is shown in the patent of Cormier No. 3,200,982 which issued on Aug. 17, 196-5. Although the cap shown in that patent operates satisfactorily, some strength is required to remove the cap with one hand; this, on occasion, has made it difficult for women or children to open the caps. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the invention to provide a bottle cap which may be removed easily without the use of the auxiliary tools.