BREGUET Classique Chronometrie 7727

Abraham-Louis Breguet, the great horology genius who invented the tourbillon in 1801 paved the way for a legendary Swiss watch making destiny named after him. Today, driven by the a desire in innovations, Breguet continues to invest in the research and development in traditional watch making in order to improve the accuracy of time keeping instruments.

With new technologies and materials; and under the guidance of its President and CEO, Mr Marc A. Hayek, the watch making house has filed more than 100 patents over the past 10 years, most of them involving chronometry and acoustic regulators. In 2010 Breguet introduced the Type XXII reference 3880 ST, with a frequency of 10 Hz, resulting from its research into high frequencies aimed at a closer and more stable measurement of time. It was the first series-produced watch with a movement of 10 Hz.

At the same time, the brand introduced the world’s first magnetic governor for the strike in its Réveil Musical. With this alarm watch it demonstrated that instead of trying to counter the effects of magnetism, the phenomenon could be harnessed to improve the operation of watch movements. This year, Breguet presents the current results of its quest to improve time measurement with the Classique Chronométrie, reference 7727.

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. Breguet’s mastery of silicon enabled this high frequency to be reached with a conventional balance-spring.

The main advantages of silicon components are that they can be manufactured to a high precision and are extremely lightweight. Furthermore they are non-magnetic. This watch is thus equipped with balance-spring, pallet lever and escape-wheel in silicon. The balance-spring, especially developed for this model, delivers optimum precision and unequalled isochronism. 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. (This follows in the wake of Abraham-Louis Breguet, who in 1790 developed the pare-chute to prevent shocks breaking the balance shaft, as well as the tourbillon to average out the effects of gravity).

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.

Finally, the power-reserve indicator is at 5 o’clock. The dial has been the subject of much attention for it displays six engine-turned patterns. The centre is in “Geneva waves”, a clou de Paris hobnailing design adorns the small seconds dial, the tenths-of-a-second counter displays a sunburst pattern, while the power-reserve indicator is decorated in chevrons. The chapter ring for the hours has an edging decoration and the outside edge is in a barleycorn pattern.

This watch is fitted with a calibre 574 DR hand-wound movement with a Breguet magnetic balance oscillating at 10 Hz on a silicon spring, and an in-line Swiss lever escapement in silicon. A stop-seconds feature allows the watch to be set to a time signal. The rose gold case, water resistant to 3 bar (30 m), has a sapphire-crystal caseback displaying the movement.

Just as the technical aspects at the heart of this timepiece unfailingly evoke a work by Breguet, its styling also features all the attributes of a Breguet timepiece: the engine-turned dial, the delicate fluting on the caseband, the polished steel Breguet hands, the welded lugs, the unique number as well as the secret signature. The reference 7727 also comes in a white-gold case with a leather strap.

Technical details
Model: BREGUET Classique Chronometrie 7727 ( REF. 7727BR/12/9WU)

18-carat rose gold with fine fluting on the caseband. Sapphire-crystal caseback. 41 mm diameter. Welded lugs. Water resistant to 3 bar (30 m)

18-carat silvered gold, engine-turned by hand in six different patterns. Individually numbered and signed BREGUET. Off-centre chapter ring with Roman numerals. Power-reserve indicator at 5 o’clock. Small seconds at 12 o’clock. Silicon hand indicating tenths of a second at 1 o’clock. Open-tipped Breguet hands in polished steel.

Hand-wounded numbered and signed BREGUET. Cal. 574 DR. 14 lignes. 45 jewels. 60-hour power-reserve indicator at 5 o’clock. In-line Swiss lever escapement in silicon. Silicon balance-spring. 10 Hz frequency. Adjusted in 6 positions.

Leather strap.

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