A few years ago I bought this bike at an antiques shop in Bayreuth, Germany. I have been searching for information about this brand, but did not find much so far.
It seems that Anker produced bicycles until 1948 according to this source,
or 1953 according to this source, but there is not much information about the type of bikes they produced, components, and whether the bikes were used by German professional cyclists.
If you have information, I’d appreciate your comments.