I think you need to actually read the 1940's Patent ...
Figure 6 clearly shows the comb when separated; Figure 3 shows a collection tube feeding into an external container; and so on. The Patent text discusses how the mechanism operates in some detail.
Relative to the Flow-Hive, the 1940's Patent is a far superior design. If the midrib were to be made from rubber with sufficient Shore hardness to prevent the bees from chewing it, yet soft enough to maintain a seal when synthetic combs were pressed against it, this would provide a reliable sealing mechanism which could maintain it's integrity over many years of use and, as a bonus, would also lend itself to cheap, non-precision mass manufacturing techniques.
LJ