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.
That one never made any money for sure! Imagine the modifications to bottling lines necessary to make it work!