[alexiskai]

I looked up the patent and it's for the hourglass-shaped component visible in the second image attached to post #1. Apparently that's the entire product, there are no other parts. It's supposed to "break up particles of hydrocarbons and mix them with the air more thoroughly than is done in the mixing chamber of an ordinary carburetor and prevent quantities of the liquid from accumulating on the walls of the intake manifold."

You can see from the diagram and from the component photos that it's not really a Venturi-type device. The tube has a consistent I.D., it just has this hourglass device inside it. The theory apparently is that the fuel-air mixture passing through the tube would be induced to atomize more uniformly via these fins.

This was patented in '26 and, in my view, would be vulnerable to obsolescence from improvements in carburetor design. Quite likely it's unnecessary, especially if running a more advanced carb such as the Marvel.