Hi Axel,

thank you very much for solving the mystery I agree with Marc: you probably nailed it! (although: Mike Der Ami was the first who came up with Meffert).

And I agree: the basic idea already was subject of German Patent # 7142 owned by Franz Feist.

Interestingly, according to the Akah catalog of 1898/99, Meffert owned a utility model (DRGM) No. 32,200.




According to the DRGM number, it was registered in 1894.


Best regards

Martin