Stephen, Melodica-Me,
By reading your posts and looking at the patent, figure 4 is very interesting to me (the air flow).
As far as I understand, the air goes inside the sealed box at the bottom, and then released through the valve to the reeds.
What I find challenging is marker 19 in this figure: the connection to the keyboard must use a moving part inside the reeds area, which must be sealed.
How is it sealed AND move AND won’t break the sealing very fast?
It is very much related to a discussion I had with Lowboy recently.