Amerikáner is a hand-cranked drill, usually with a "transmission", some with two gears. Also called furdancs (from the verb fúr = bore/drill). From the -er one can easily tell Amerikáner is a word of German origin, and it means "American". After short consulting with German Wikipedia, I could not find this expression there, just Bohrkurbel or Brustleier.
What is so American about this machinery? I've no idea. Even electric drill is an invention of the (late) 19th century - and it comes from Australia. There must be something in the system how it works that compelled craftsmen to call it like that, lots of craftsmen here were German in origin I suspect it was in their slang.