Andreas Strehler the Sauterelle - Regulated Energy
Andreas Strehler presents his latest wristwatch, the Sauterelle. This watch features a device for the constant supply of energy to the balance.
A constant supply of the same amount of energy to the balance is the ideal case, as this is the basis for even running characteristics.
Andreas Strehler once more has gone his own way to achieve such a constant energy supply. He has done this in order to find the most technically stable solution.
Conventionally, a complication known as Force constante (constante force) acts on the escape-wheel. However, this is the point in the whole movement where the least torque is present.
For this reason, Andreas Strehler's Remontoir d'égalité is attached to the seconds wheel or fourth wheel.
Every second the visible satellite gear provides exactly the same amount of energy to the seconds wheel and at the same time displays the seconds as dead-beat seconds. The energy is accumulated by a star-shaped satellite through a spring which is re-loaded every second. Then, the satellite wheel is released and transfers its energy to the balance. The satellite wheel then rests again against the palette-stone. This planetary design of the respective wheels is a first in a wristwatch.
This solution has the advantage that the complete escapement including the escapement wheel oscillates free from any influence between the individual impulses delivered by the Remontoir d'égalité. Hence, the Swiss Anker Escapement performs without influence from the Remontoir d'égalité, with its precision perfected over the last 200 years.
Fluctuations in the energy supply as well as flaws in the functioning of the gear train (uneven working of the mainspring, the gear train or the motion-work of the hands) are filtered and equalised by the Remontoir d'égalité. In contrast to a Force constante and its fixed division ratio, which demands a frequency of 18.000 A/h, the Remontoir d'égalité can be used with any frequency. The Sauterelle therefore has a frequency of 21.600 A/h which leads to higher precision.
All watches made by Andreas Strehler show an almost linear force path as the running down of the two mainsprings is limited by a epicyclic gear. Only the optimal part of each mainspring is used where the thrust produced is constant. With the Remontoir d'égalité, Andreas Strehler now concentrates on the elimination of external factors such as temperature. Even minor changes in temperature influences the viscosity of the lubricants used in the mainspring barrels and consequently the even running down of the mainsprings.
With the Sauterelle, Andreas Stehler for the first time presents a mechanical solution which filters almost all technical and mechanical influences on the escapement.
The constant energy supply to the escapement in the Sauterelle provides a solid basis for complications with variable energy needs such as a chronograph or a minute repeater.
The name Sauterelle – registered by Andreas Strehler as a trademark since 2008 – was chosen very deliberately, as the jumping of the seconds indication is reminiscend of a grasshopper (Sauterelle in French).