This patent is for a double-action hydraulic cylinder. I believe that it relates to the actuating cylinder in Christoph Muthers ‘s 5rot hydraulic derailleur.

• Publisher: Deutsches Patent- und Markenamt
• Inventor: Christoph Muthers
• Country: Germany
• Date: German application filed August 2006
• Derailleur brands: 5rot, Acros
• Derailleurs: 5rot