In this patent, Desider Stern writes first about Mr. Robbiati's 1946 patent for a home coffee maker ( i call the flathead) mentioning its flaws:
_ the big seal which could leak,
_ the fact that the water cooled too much while traveling to the head in the U-shaped tube,
_ the too many manufacturing steps.
So he proposes a few improvements (no seal, an inner tube and a manufacturing simplification for production in series):