I offer a collection of 157 historical patents of the firm FICHTEL & SACHS (Germany), published between 1902 and 1980.
They are from USA or Great Britain and all in English, busy mostly with parts of bicycles, especially with some kind of hubs (dual speed hub with automatic speed shift, multi-speed hub, freewheel hub...), gearings, chain shift device and some others.
All patents are complete, that means contain the full text and all drawings (see example). You will get a professional overview about some technical developments of this company which you find nowhere in the world in this good quality / completeness. You can learn a lot about the technical details of old bicycle technique.
Delivery is as a zipped file with a patent collection of pdf files (not printed, not a book). You need only the wellknown free programme Acrobat Reader or a similar one to open the files. You can also print each file.