Here is a project spanning five years of development work where I crafted test fixtures, concept models, and working prototypes. Working with William T. Beale an innovative mechanical engineer, we built & experimented with multiple versions for “proof of concept” and ultimately a patented device making messy bicycle derailleurs & chains obsolete.
The transmission may have applications beyond bicycles. For example, Winches and Electric motor drive vehicles where a continuous speed is desired by the input.
https://www.google.com/patents/US7011322