Today in 1938, US Patent 2124959 A was issued, an invention of William Martin Vogel, for his “Method Of Filling And Closing Cans.” There’s no Abstract, although in the description it includes these claims:
This invention relates to cans and a method of making and filling the same, and has for its object the provision of means whereby a maximum quantity of air may be evacuated from the can prior to the sealing operation.
At the present time beer is being packed in cans and one of the greatest difficulties encountered is that of completely or at least nearly completely evacuating the maximum quantity of air from the can. The failure to uniformly evacuate the air results in lack of uniformity of the contents of the can. In some cases an opened can produces beer of a decidedly fiat appearance and taste; while in other cases, an extremely frothy, aerated fluid emanates. Experiments have shown that this lack of uniformity in canned beer is apparently due to the failure to eliminate or evacuate the greatest possible amount of air from the can during or after the filling operation, and prior to the sealing of the can.
The primary object therefore, of this invention, is to provide a can of such a construction, together with a method of filling and sealing such a can, which will eliminate the maximum quantity of air from the can, thereby completely, or nearly completely, filling the can with the liquid contents only. More particularly, the invention contemplates the provision of a can initially formed with an outwardly distended or dished bottom,
arranged to be reversely curved or distorted under pressure after the can is filled, thereby causing the liquid contents of the can to be bodily shifted toward the top of ‘the can, causing said contents to displace and eject the air out of the can just prior to the sealing of the top of the can.