As you may know, you can have free access to patents via the European Patents Office's website:
(btw this site is a huge source of technical information for any watches enthousiast!)
If you do search with "Applicant" = Vacheron Constantin, you'll be able to browse and download all patents related to our favorite brand.You can find patents for "Richemont" as well; and some Richemont's patents are illustrated with VC watches, other with different brands from the group.
So I wonder how the split between VC and Richemont is done (if there is any); if the patent is applied by Richemont, does that mean that every brand of the group may use the patent?
Thanks to enlighten me. ;o)