If you’re a fan of split-seconds chronographs, and you take a look at the B15 caliber, you might be surprised by what you see (or don’t see) through its exhibition caseback. Namely, where are the clamps? Traditionally, a rattrapante mechanism works with a pair of pincers that are actuated by the split-seconds pusher, to physically stop the delicate, fine-toothed rattrapante wheel and freeze the first central seconds hand in its position on the dial.
Breitling uses a proprietary gasket that decompresses on the split-seconds wheel when the pusher is actuated. The second major – and patented – innovation that Breitling has is a unique isolating system that removes the cylindrical pin typically seen in split-seconds chronographs and replaces it with a lever that separates the stopped wheel from the rest of the (uninterrupted) gear train, increasing efficiency and offering less friction when the chronograph is running.
