This timepiece in rose gold comprises the manufacturer’s latest innovations, and like the Type XXII chronograph, oscillates at a frequency of 10 Hz. This is the first time that such high frequency has been applied in a non-chronograph watch, since the purpose is to improve the precision and the stability of rate of a conventional mechanical watch. Increasing the frequency and the power of the mechanical oscillation improves the timekeeping performance of the balance and spring.
As a general rule, the regulating power, or the mechanical energy of a timepiece, is equivalent to less than 200 microwatts for the best performing chronometers. The regulating power of this Classique Chronométrie is around 800 microwatts. This watch is thus equipped with balance-spring, pallet lever and escape-wheel in silicon. For Breguet, high frequency does not come at the expense of the power reserve. The energy stored in the mainspring barrel of the reference 7727 and its high level of workmanship keep the watch running for 60 hours. Breguet’s advances in magnetism have also resulted in an unprecedented mechanism to improve the pivoting, rotation and the stability of the balance shaft. The company’s watchmakers unveiled a new solution based on the use of two endstones incorporating powerful micro-magnets, one for each end of the balance shaft.
As one of the magnets is stronger than the other, one end of the balance shaft is kept in permanent contact with its ruby endstone. Magnetic induction generates a magnetic flux through the balance shaft developing a force that acts with the gyroscopic inertia affecting the balance shaft. This construction thus results in a self-correcting dynamically stable system. Since the magnetic bond between the shaft and the endstone is stronger than the force of gravity, the shaft continues to pivot on the endstone irrespective of the position of the watch.
Furthermore, the system performs the role of a shock absorber. If a blow shifts the pivot out of position the magnetic attraction pulling it back increases with the extent of the pivot’s lateral displacement. The shaft thus returns automatically to its position, restoring the maximum magnetic flux. In the matter of styling, the hours and minutes are off-centre on the dial, while the small seconds at 12 o’clock recall the first eccentric dial produced by Breguet 200 years ago. A patented silicon hand indicates the tenths of a second at 1 o’clock. Ultra-light silicon reduces the rotating hand’s inertia and consequently its effect on the oscillations of the balance. The pare-chute shock absorber is also visible at 2 o’clock as a reminder of Abraham-Louis Breguet’s 1790 invention.
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