A hidden clasp is a folding (deployant) clasp built to conceal most of its mechanism, so the bracelet looks like one unbroken piece. The release usually sits in the bracelet itself. Its lock rests on the inner side, against the wrist, so it is less likely to be knocked open by accident.
How does a hidden clasp open?
The release is built into the bracelet rather than into a separate, visible buckle. On some designs it is a push-button centre link. On Rolex bracelets, the wearer lifts the crown emblem. The butterfly version opens when two push buttons are pressed together. Its two halves then spread out symmetrically, like a pair of wings, which is how the butterfly clasp got its name. When it is locked, both folding parts tuck away inside the bracelet.
Does every hidden clasp have a butterfly mechanism?
No. Some hidden clasps have no butterfly mechanism at all. The Rolex President bracelet is one example. When it is closed, only the crown logo shows, and that logo is what helps open it. Other bracelets do use a butterfly. On the Cartier Panthère, the folding butterfly mechanism disappears completely from view once the bracelet is shut. Either way, the aim is the same: most of the mechanism stays out of sight.
Which watches use a hidden clasp?
Hidden clasps are common on ladies’ watches and on watches made of precious metals. The hidden clasp is one sub-type within the broader family of deployant, or folding, clasps. What sets it apart from the rest of that family is how much of its mechanism stays out of sight, so the bracelet reads as one continuous run of links rather than links joined by a visible fastening.
What does the Interdica patent describe?
A US patent filed by Daniel Lauper for Interdica SA, with French priority from February 1985, describes a clasp for a bracelet or wristwatch. The clasp is entirely concealed when shut. Its side legs are hinged to a central body, and they latch onto studs. So once it is closed, none of the clasp is meant to be seen, which is the aim of a hidden clasp taken all the way.
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