F.P. Journe Souverain Tourbillon "Ruthenium" Limited Edition of Only 99 Pieces, Tourbillon "Invenit et Fecit" with D'egalite Constant Force Remontoir and Dead Seconds - This watch features a stunning Ruthenium-plated Brass Movement and solid Ruthenium-plated 18kt Gold Dial. This watch is encased in the larger 40mm Platinum case and has a black crocodiel strap with classic buckle.
Tourbillon Souverain - Remontoir d’Egalité
Invented by Breguet over 200 years ago, the tourbillon is a rotating cage that houses the escapement and oscillating balance. At that time, pocket watches were generally to be
found in a vertical position in a gentlemen’s fob pocket. In that vertical plane, however, the watch could be orientated: crown up, crown down, crown left or crown right, and in each of those positions gravity pulled on the balance and escapement from a different angle, causing the watch to slightly speed up or slow down. This made it difficult to regulate the watch to keep accurate time: especially in those days of split, bi-metallic balances and steel hairsprings.
The tourbillon: note the cock (one-arm bridge).
By putting the escapement (balance, hairspring, pallet and escape wheel) in a rotating cage, the positionally induced errors (in the same plane as the tourbillon) are averaged out,
thus making the watch a better timekeeper.
Ideally, there would be no positional errors and so no need for a tourbillon to average them out. While manufacturing techniques and material technology have come a long way in
reducing those errors since Breguet's day, positional errors do still exist.
The tourbillon first made an appearance in a wristwatch over 50 years ago when Andre Bornand made a one-off for Patek Philippe in 1945 . A few years later Lip put a tourbillon in a wristwatch, then Omega made twelve wristwatch tourbillons; however, it was Audemars Piguet in 1985 who gave the world the first serially produced wristwatch tourbillon.
This was also the first automatic tourbillon and the smallest and thinnest tourbillon ever produced - and as far as Iknow, it still is.
If we are becoming blasé today regarding tourbillons, we should remember their very recent history in production wristwatches: even today it is rare to see a tourbillon wristwatch with additional complications - and they do not come much rarer than . . .
The Remontoir d’Egalité.
For a watch or clock to tell the time accurately, we need two important mechanisms: one to provide power to run the movement and hands, and a second (the escapement) to distribute that the power in very precisely measured intervals. With a tower or tall pendulum clock, weights were pulled up and provided power to run the movement. The constant period of the pendulum regulated the escapement, which released power at precise intervals. Because the weight does not change on its downward path, the flow of
power to the escapement and movement was very smooth - well it would have been if the inefficiencies in the drive train caused by poorly shaped tooth profiles in the gears,
sloppy tolerances between parts and even the effect of strong wind on the hands of tower clocks did not all play a detrimental role - and they all did.
The remontoire was designed to combat these problems. This clever complication was invented by Jobst Bürgi in the 15C to smooth out fluctuations in the power transmission to the escapement due to inefficiencies in the gear train. As gear tooth profiles became more refined and gears and parts were made to tighter tolerances, this became less of an issue; however, in the 19C, the remontoire made a comeback; it was used in tower clocks to counter the effects of strong wind on the large exterior hands from finding its way to the gear train and escapement.
The Dead-Beat Seconds.
At the end of the 17C, clocks were becoming increasingly accurate, so watchmakers took advantage of this to add a second hand. Many of these clocks were equipped with a Huygen pendulum which had a natural period of one second due to a one meter long pendulum. This had the effect of the second hand advancing, then stopping dead for one second before advancing again – much like the second hand on a quartz watch today. Second hands on mechanical watches by contrast, generally move in fractions of a second.
When the first watches were made with second hands, watchmakers attempted to create that same stop/start second effect. A few different approaches were tried, however, most of these had either a detrimental effect on timekeeping or the added complexity did more harm than good to a stable rate.
In the Tourbillon Souverain, Journe has very cleverly mounted a natural dead-beat seconds system off the release mechanism of the remontoir d’égalité. This method means that the dead second system has no adverse effect on the precision of the watch and allows the wearer to see the seconds tick off one by one.