In biology, the concept of a single heart is deeply ingrained, and this concept also extends to the watchmaking industry. In order to survive, human beings only need a beating heart; in order to show the time accurately, the watch only needs a power core. However, there are a few multi-hearted creatures in nature. For different reasons, more and more watches are equipped with multiple speed governing mechanisms. So what are the advantages of this configuration?
Most mechanical watches operate on the same principle: a single energy source, a single gear train, and a single speed regulation mechanism. The speed regulation mechanism is usually regarded as the core of the watch. The energy stored in the clockwork is released in an orderly manner by the speed regulation mechanism, thereby determining the speed of the watch. The speed governing mechanism includes an escapement and a balance wheel, and the two components work together. The escapement pushes the balance wheel, otherwise it is adjusted by the balance wheel.
Differential gear train improves accuracy
Some watchmakers equip their watches with two or more speed regulators to increase their accuracy. The first solution is to use two oscillators and a differential gear train to average the speed. Thanks to this precise transmission, the balance can compensate for each other’s errors, so the time displayed is the average of the speed.
The Philippe DufourDuality watch and the MB & FLegacyMachine2 watch are both equipped with two speed governing mechanisms and differential gear trains, which improve accuracy by averaging the speed of two balance wheels.
The Philippe DufourDuality (1996), inspired by the double balance pocket watch, is a hallmark of this concept. Since then, more and more watches have used differential gear trains.
Roger Dubuis ExcaliburQuatuorCarbon carbon fiber watch with four hairsprings and its four speed adjustment mechanisms visible to the naked eye, each of which can make up for other errors.
Some watchmakers even build movements with more than two oscillators. For example, the Roger Dubuis Excalibur QuatuorCarbon carbon balance watch with four hairsprings is equipped with four balance wheels, which are connected by a set of differential gear trains. Theoretically, the more balance wheels, the more accurate the time display is, because the averaging operation based on multiple displays reduces the overall error range. In addition, the four balance wheels are placed in different orientations, which also balances the effect of gravity.
Improving accuracy through resonance
Like the differential gear train, the purpose of resonance is to improve accuracy with two oscillators. Of course, there is no differential gear train in this case, but rather the well-known resonance phenomenon is used.
The Haldimann H2 FlyingResonance watch has a central double escapement and relies on resonance effects.
The resonance principle is that two oscillating bodies close to each other affect each other and finally achieve synchronization. In 1665, Christian Huygens took the lead in recording this phenomenon, and he found that no matter where or when the two pendulums began to swing, the final frequency would tend to be the same. Since then, only a few watchmakers have successfully applied the principle of resonance to watchmaking. Two centuries ago, Astide Janvier and Abraham-Louis Breguet created the ‘Sympathetic Clock’. Recently, François-Paul Journe, BeatHaldimann, and Antoine Preziuso sought to take advantage of the synchronism of the oscillators in the watch to achieve better stability and thus improve accuracy.
ArminStromMirroredForceResonance watch, the brand’s first use of the concept of resonance, with dual balance wheel and resonance clutch spring.
In 2016, ArminStrom presented the public with an interesting way to use resonance with its MirroredForceResonance watch. This watch is equipped with two barrels, two gear trains and two speed control mechanisms. The two balance wheels are connected by steel resonance clutch springs fixed on the studs, which are synchronized by the small vibrations transmitted by them.
Dual architecture independent functions
Another reason for using two speed control mechanisms is to drive different functions. Some watchmakers have designed chronographs with dual speed control mechanisms.
For example, the Breguet Tradition Chronographe Indépendant Ref. 7077 chronograph uses an original dual architecture. Most chronographs have a single architecture, relying on a second gear train that meshes with the travel time system to drive the chronograph function. When the timing function is activated, the balance amplitude will decrease (driving more gear trains will increase friction).
The timing mechanism of Breguet Ref.7077 chronograph is independent. In fact, the watch is equipped with two separate ‘child movements’-each equipped with an energy source, a gear train and an oscillator. There is no interaction between the travel time display and the timing function. Therefore, when the timing function is activated, the energy consumption does not interfere with each other, and the speed of the movement is not affected.
Zenith DefyElPrimero21 chronograph is also equipped with two ‘child movements’ and two speed control mechanisms. One is used for travel time, with a frequency of 5 Hz; the other is used for timing, with a frequency of 50 Hz (to make the timing accuracy to one hundredth of a second). The ultra-high vibration frequency is impressive. Of course, the timing function can only run for about 50 minutes. This is why the travel time display and timing function cannot be adjusted by the same oscillator.
Energy-saving standby mode / active mode
As long as the watch is continuously running, the perpetual calendar function records the time without adjustment. But if you store your watch for a while, things are different, especially in safes where it is difficult to place the winder.
At the SIHH in Geneva this year, the Vacheron Constantin TwinBeat watch gave an ingenious solution. This is a perpetual calendar watch equipped with two gear trains and two speed regulating mechanisms.
When worn, the watch vibrates at a high frequency of 5 Hz, making it ideal for modern active lifestyles. When not wearing, switch the mode from Active to Standby (and vice versa) with the button. In the standby mode, the watch relies on a second speed governing mechanism (1.2 Hz frequency). The lower vibration frequency allows this watch to run continuously for up to 65 days, which is impressive. (Photo / text watch home compiled by Xu Chaoyang)