This 1976 patent covers an early version of MAVIC's signature 800 design. It differs from the first production versions in a number of vaguely interesting ways:

• The inner parallelogram plate shown is made up of two independant parts, rather than one, artily drilled, large plate.
• The cable is clamped using a grub screw.
• There is an adjustable outer cable stop.
• The pulley cage plates are shown as curved, rather than modernistically angular.
• There is a whole lot of complexity going on at the p-pivot, which did not make it onto the production version.

The patent is issued to Georges Bloy. There is no mention of MAVIC. Georges Bloy also appears to hold only two other patents, one for a front derailleur and the other for a similar rear derailleur design - which may indicate that he was not a regular MAVIC designer.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: Georges Bloy
• Country: France
• Date: Priority date August 1976
• Derailleur brands: MAVIC
• Derailleurs: MAVIC 800