Tourbillon
Encyclopedia
Horology
Horology is the art or science of measuring time. Clocks, watches, clockwork, sundials, clepsydras, timers, time recorders and marine chronometers are all examples of instruments used to measure time.People interested in horology are called horologists...
, a tourbillon (icon; tuʁbijɔ̃ "whirlwind") is an addition to the mechanics of a watch escapement
Escapement
In mechanical watches and clocks, an escapement is a device that transfers energy to the timekeeping element and enables counting the number of oscillations of the timekeeping element...
. Developed around 1795 by the French-Swiss watchmaker Abraham-Louis Breguet from an earlier idea by the English chronometer maker John Arnold
John Arnold
John Arnold was an English watchmaker and inventor.John Arnold was the first to design a watch that was both practical and accurate, and also brought the term "Chronometer" in to use in its modern sense, meaning a precision timekeeper...
a tourbillon aims to counter the effects of gravity by mounting the escapement
Escapement
In mechanical watches and clocks, an escapement is a device that transfers energy to the timekeeping element and enables counting the number of oscillations of the timekeeping element...
and balance wheel
Balance wheel
The balance wheel is the timekeeping device used in mechanical watches and some clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a spiral spring, the balance spring or hairspring...
in a rotating cage, to negate the effect of gravity when the timepiece (and thus the escapement) is stuck in a certain position.
Originally an attempt to improve accuracy, tourbillons are still included in some expensive modern watches as a novelty and demonstration of watchmaking virtuosity. The mechanism is usually exposed on the watch's face to show it off.
Mechanics of the Tourbillon
Gravity has a direct effect on the most delicate parts of the escapement, namely the pallet forkPallet fork
The pallet fork or pallet lever is an integral component of the lever escapement of a typical mechanical watch. Its purpose is to release the escape wheel one tooth at a time, at each swing of the balance wheel, and also give the balance wheel small pushes to keep it going.The lever is shaped like...
, balance wheel and hairspring. Most notably is the hairspring, which functions as a regulator for the escapement and is thus the most sensitive part to any exterior effects, such as magnetism, shocks, temperature, as well as inner effects such as pinning positions (inner collet), terminal curve, and heavy points on the balance wheel.
Many different inventions have been developed to counteract these problems. Temperature and magnetism have all but been eliminated as problems with new materials. Shocks have much less effect today than at Breguet's time thanks to stronger and more resistive materials. The escapement still gets deregulated at the moment of the shock, but the hairspring does not get as easily deformed from shocks as before.
Gravity comes into play on the remaining effects, one of them is easily taken away, namely heavy point on the balance wheel. This leaves pinning point and terminal curve. Both of these add a lot of variation to the regulation of a watch, depending on how it is assembled and regulated by the watchmaker and positioned in the watch and later by the owner. As the balance wheel goes from one extreme position to the other in its swing back and forth, the hairsprings coils extend and contract a great deal, leading to problems that are extremely hard to counteract. Some have tried using hair springs that are cylindrical or even spherical instead of flat as is prominent today. Some variations of Breguet's overcoil have been developed to counteract the effects of the terminal curve. As for the pinning point, Grossmann, Berthoud, Breguet, Caspari and Leroy tried many different possibilities, but not much was gained.
The biggest obstacle for a watchmaker regulating a watch, even today, is getting a similar result from the escapement no matter the position it is kept in. This has been made infinitely easier with accurate timing machines which give instantaneous timing results, where as in Breguet's time all that watchmakers had was another watch to regulate from, so results were not very exact and it could take weeks to get them. Effects of gravity on an escapement can have quite significant effects with slight variations of position, even if a pocketwatch was most of the time in a breast pocket, the exact position could still vary over 45°. A tourbillon quite neatly takes away this problem. The watchmaker now only needs to regulate for 3 different positions, instead of 6 like before. Those are two horizontal positions, dial up and down, and four vertical positions, crown at 12, 3, 6 and 9 o'clock.
A tourbillon most often makes one complete revolution per minute, which has no effect in the two horizontal positions, but makes all the difference in the 4 vertical positions, since even if a watch is stationary in a random vertical position, the tourbillon makes the escapement spin around its own axis, effectively cancelling out the effects of gravity of each of the 4 generalized positions. Even today with new materials and improved theories, it is nearly impossible to regulate a watch so it keeps the same time in all positions. A tourbillon allows watchmakers today to obtain results that are better than normal mechanical watches. Although, this is still immensely inferior to quartz, which normally vary 3 seconds per month, where a good mechanical watch keeps 3 seconds per day.
Mechanical watches today are mostly sold to buyers who value craftsmanship and aesthetics over very accurate timing. Most tourbillons use standard swiss lever escapement
Lever escapement
The lever escapement is a key component of the typical movement found in most mechanical wristwatches, pocket watches and many small mechanical non-pendulum clocks....
s, but some have a detent escapement.
The tourbillon is considered to be one of the most challenging of watch mechanisms to make (although technically not a complication
Complication (horology)
In horology , complication refers to any feature in a timepiece beyond the simple display of hours, minutes, and seconds.A timepiece indicating only hours, minutes, and seconds is otherwise known as a simple movement...
itself) and is valued for its engineering and design principles. The first production tourbillon mechanism was produced by Breguet for Napoleon in one of his carriage clock
Carriage clock
A carriage clock is a small, spring-driven clock, designed for travelling, developed in the early 19th century in Austria. The case, usually plain or gilt-brass, is rectangular with a carrying handle and often set with glass or more rarely enamel or porcelain panels...
s (travel clocks of the time were of considerable weight, typically weighing almost 200 pounds).
Double-axis tourbillon
In 2003, inspired by the double axis tourbillon invented in the 1970s by Richard Good (see below), the young German watchmaker Thomas Prescher developed for the Thomas Prescher Haute Horlogerie the first flying double-axis tourbillon in a pocket watch and, in 2004, the first flying double-axis tourbillon with constant force in the carriage in a wristwatch. Shown at the BaselworldBaselWorld
Baselworld Watch and Jewellery Show is a trade show for the watch and jewellery industry organized annually in the city of Basel, Switzerland. The international show unites about 2,100 exhibitors from over 45 countries, including the leading watch and jewelry brands, as well as companies...
2003 and 2004 in Basel, Switzerland.
A characteristic of this tourbillon is that it turns around two axes, both of which rotate once per minute. The whole tourbillon is powered by a special constant-force mechanism, called a remontoire. Thomas Prescher invented the constant-force mechanism to equalize the effects of a wound and unwound mainspring
Mainspring
A mainspring is a spiral torsion spring of metal ribbon that is the power source in mechanical watches and some clocks. Winding the timepiece, by turning a knob or key, stores energy in the mainspring by twisting the spiral tighter. The force of the mainspring then turns the clock's wheels as it...
, friction, and gravitation. Thereby even force is always supplied to the oscillation regulating system of the double-axis tourbillon. The device incorporates a modified system after a design by Henri Jeanneret.
Double and quadruple tourbillons
Robert Greubel and Stephen Forsey launched the brand Greubel ForseyGreubel Forsey
Greubel Forsey is a watchmaking company specializing in very high-end complicated timepieces. It was launched in 2004 by Robert Greubel and Stephen Forsey and is based in La Chaux-de-Fonds, Switzerland....
in 2004 with the introduction of their Double Tourbillon 30° (DT30). Both men had been working together since 1992 at Renaud & Papi, where they developed complicated watch movements. The Double Tourbillon 30° features one tourbillon carriage rotating once per minute and inclined at 30°, inside another carriage which is rotating every four minutes.
In 2005 Greubel Forsey
Greubel Forsey
Greubel Forsey is a watchmaking company specializing in very high-end complicated timepieces. It was launched in 2004 by Robert Greubel and Stephen Forsey and is based in La Chaux-de-Fonds, Switzerland....
presented their Quadruple Tourbillon à Différentiel (QDT), using two double-tourbillons working independently. A spherical differential connects the four rotating carriages, distributing torque between two wheels rotating at different speeds.
Triple-axis tourbillon
In 2004 Thomas Prescher developed the first triple-axis tourbillon for the Thomas Prescher Haute Horlogerie with constant force in the carriage in a wristwatch. Presented at the BaselworldBaselWorld
Baselworld Watch and Jewellery Show is a trade show for the watch and jewellery industry organized annually in the city of Basel, Switzerland. The international show unites about 2,100 exhibitors from over 45 countries, including the leading watch and jewelry brands, as well as companies...
2004 in Basel, Switzerland, in a set of three watches including a single-axis, a double-axis, and a triple-axis tourbillon.
The world's unique tri-axial tourbillon movement for wristwatch with traditional jewel bearings only was invented by the independent watchmaker Aaron Becsei, from Bexei Watches, in 2007. The Primus wristwatch was presented at the Baselworld
BaselWorld
Baselworld Watch and Jewellery Show is a trade show for the watch and jewellery industry organized annually in the city of Basel, Switzerland. The international show unites about 2,100 exhibitors from over 45 countries, including the leading watch and jewelry brands, as well as companies...
2008 in Basel, Switzerland. In the three axis tourbillon movement, the 3rd (external) cage has a unique form which provides the possibility of using jewel bearings everywhere, instead of ball-bearings. This is a unique solution at this size and level of complication.
Flying tourbillon
Rather than being supported by a bridge, or cock, at both the top and bottom, the flying tourbillon is cantilevered, being only supported from one side. The first flying tourbillon was designed by Alfred Helwig, instructor at the German School of Watchmaking, in 1920.In 1993, Kiu Tai-Yu, a Chinese watchmaker who resides in Hong Kong, created a semi-flying tourbillon with only an abbreviated carriage for the escapement
Escapement
In mechanical watches and clocks, an escapement is a device that transfers energy to the timekeeping element and enables counting the number of oscillations of the timekeeping element...
wheel and pallet fork
Pallet fork
The pallet fork or pallet lever is an integral component of the lever escapement of a typical mechanical watch. Its purpose is to release the escape wheel one tooth at a time, at each swing of the balance wheel, and also give the balance wheel small pushes to keep it going.The lever is shaped like...
, the upper pivot of the balance wheel
Balance wheel
The balance wheel is the timekeeping device used in mechanical watches and some clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a spiral spring, the balance spring or hairspring...
being supported in a sapphire bridge. Some mistakenly believe this to be the world's first tourbillon watch with neither bridge nor carriage.
Modern tourbillon watches
In modern mechanical watchMechanical watch
A mechanical watch is a watch that uses a mechanical mechanism to measure the passage of time, as opposed to modern quartz watches which function electronically. It is driven by a spring which must be wound periodically...
designs, a tourbillon is not required to produce a highly accurate timepiece; there is even debate amongst horologists
Horology
Horology is the art or science of measuring time. Clocks, watches, clockwork, sundials, clepsydras, timers, time recorders and marine chronometers are all examples of instruments used to measure time.People interested in horology are called horologists...
as to whether tourbillons ever improved the accuracy of mechanical time pieces, even when they were first introduced, or whether the time pieces of the day were inherently inaccurate due to design and manufacturing techniques. Nevertheless, the tourbillon is one of the most valued features of collectors' watches and premium timepieces, possibly for the same reason that mechanical watches fetch a much higher price than similar quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
watches that are much more accurate. High-quality tourbillon wristwatches, usually made by the Swiss
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
luxury watch industry, are very expensive, and typically retail for at least thousands of dollars or euro
Euro
The euro is the official currency of the eurozone: 17 of the 27 member states of the European Union. It is also the currency used by the Institutions of the European Union. The eurozone consists of Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg,...
s, with much higher prices in the tens of thousands of dollars or euros being common. A recent renaissance of interest in tourbillons has been met by the industry with increased availability of time pieces bearing the feature, with the result that prices for basic tourbillon models have receded somewhat in recent years (where as previously they were very rare, in either antiques or new merchandise); however, any time piece that has a tourbillon will cost a great deal more than an equivalent piece without the feature.
Modern implementations typically allow the tourbillon to be seen through a window in the watch face. In addition to enhancing the charm of the piece, the tourbillon can act as a second hand for some watches as it generally rotates once per minute. However some Tourbillons spin faster (Gruebel Forsey's
Greubel Forsey
Greubel Forsey is a watchmaking company specializing in very high-end complicated timepieces. It was launched in 2004 by Robert Greubel and Stephen Forsey and is based in La Chaux-de-Fonds, Switzerland....
24-second tourbillon for example). There are many watches that feature the oscillating balance wheel visible through the watch dial that are not tourbillons. This feature is often referred to as "open heart".
In the late 20th century, the first research into multi-axis tourbillon movements was done by British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
clock makers Anthony Randall and Richard Good, eventually producing two and three-axis tourbillon movements.
Affordability crisis
Several Chinese manufacturers now produce a variety of tourbillon movements. These movements are bought as ébauches by some foreign manufacturers and incorporated into watches that meet the requirements of the Federation of the Swiss Watch Industry to be sold as Swiss watches. The availability of cheap tourbillons has led industry spectators to worry that another Quartz crisisQuartz crisis
The Quartz Crisis, also known as the Quartz Revolution is a term used in the watchmaking industry to refer to the economic upheavals caused by the advent of quartz watches in the 1970s and early 1980s, which largely replaced mechanical watches...
may occur, where the Swiss watch industry will not be able to adapt quickly to cheaper complicated mechanical watches produced in other countries.