Publisher: L’Institut national de la propriété industrielle

Inventors: André Huret

Date: French application November 1936

Derailleur brands: Huret

Derailleurs: Huret

This patent describes a single pulley derailleur that uses a cog-based operating mechanism - echoing the Westminster design in French Patent 785,604. I believe that this contraption was the basis of a production model - I have seen photos of real examples of something very similar. The version I have seen in photos differs by having a shaped chain-pusher-plate on either side of the pulley wheel.