Today in 1967, US Patent 3348726 A was issued, an invention of George D. La Cross, assigned to the Continental Can Co., for his “Pull Tab.” There’s no Abstract, although in the description it includes this summary:

This invention relates in general to new and useful improvements in easy opening containers, and more particularly to a novel pull tab construction.

In accordance with this invention, it is proposed to provide a metal pull tab which is secured to the tear strip by means of nibs which pierce the tear strip and which are sealed relative thereto.

Another object of this invention is to provide a novel pull tab which is -formed of sheet metal, but which is so constructed wherein it has the necessary beam strength while at the same time may be readily secured to a tear strip in sealed relation thereto.

Another object of this invention is to provide a novel pull tab and tear strip assembly wherein both the tear strip and the pull tab are formed of metal and the pull tab is provided with a pair of nibs which pierce the tear strip and bend there beneath, the openings required in the tear strip for the passage of the nibs being sealed by completely encasing each nib in a covering of sealing compound.

Another object of this invention is to provide a novel tear strip pull tab assembly wherein the pull tab is formed of sheet metal and has a pair of depending nibs, and the tear strip has narrow slits for receiving the nibs, the metal of the tear strip adjacent each slit being slightly deformed to facilitate the passage of a nib therethrough, and the metal being returned to its normal position during the folding over of the nib beneath the tear strip with the metal, when it returns to its original position, tightly clamping and forming interlock with the nib.