Though it won’t be officially launched until Basel 2013 we thought this was too interesting to keep to ourselves –it’s the latest take on the Zenith “Christophe Colomb” series of watches (part of the Zenith Academy collection.)
The Christophe Colomb watches place the escapement and balance in a gimbaled cage, so that no matter what position the watch is in , the balance is always parallel to the ground –as it’s always in one position, there are no positional variations in rate.
This variation on the theme includes one of the oldest of constant-force mechanisms in watchmaking –a chain-and-fusée. A feature in the past of many high precision watches, including most marine chronometers and many pocket watches (English watchmakers were very fond of them) the chain-and-fusée compensates for the variation in torque produced by the mainspring as it unwinds by creating a gradually greater mechanical advantage for the barrel as its torque decreases.
Incidentally, due to some accidents of history and nomenclature, there’s still some confusion about these watches –the Christophe Colomb watches are not tourbillons, although they are another way of going at the problem of variations in rate due to the effects of gravity in different positions. The use of the gimbal system and differential gearing to transfer power from the going train to the escapement and balance has no relationship to the tourbillon technically –though like the tourbillon it has its own special visual fascination.