Today in 1952, US Patent 2605949 A was issued, an invention of Gustave Stern, for their “Control Head for Devices for Filling Bottles Under Counterpressure.” There’s no Abstract, although in the description it includes this summary:

The, object of the present invention is a control head for devices for filling bottles or other like (containers, with gaseous or nongaseous liquids, under counter-pressure), said head previously placing the bottles under compressed air.

The purpose of the invention is essentially to increase the automatic operation of the device, thereby enabling the rate of filling to be considerably accelerated, thus increasing the efficiency.

invention ensures the. satisfactory operation of the device when the pressure. of the supply of. compressedV air. is higher than the pressure in the filling tank which contains the liquid to be drawn out. Owing to this fact, it permits the elimination of the complicated and costly apparatus intended to ensure, the regularity of the air pressure.

Finally, tile invention relates to the provision of means of enabling the level of the liquid inside the bottles to be adjusted accurately.