Breguet Classique Chronométrie 7727 - 10 Hz


Breguet Classique Chronométrie 7727 - 10 Hz

Classique Chronométrie 7727 - 10 Hz

Where amazing inventions meet traditional skills
La Cote des Montres - November 11th, 2014

On Friday, October 31st, 2014, at the Grand Prix d’Horlogerie de Genève, GPHG (Geneva Watchmaking Grand Prix), Breguet won the most prestigious prize of “Aiguille d’Or” for the Classique Chronométrie during the annual awards ceremony held at Geneva’s Grand Théâtre.

The innovative spirit of the Breguet brand has contributed to a number of inventions that have improved time measurement. But far from resting on its laurels, Breguet pursues its quest for precision and invests in the research and development of new technologies and materials. The brand has thus been able to file more than 100 patents in the last 10 years, especially concerning improved timekeeping and striking mechanisms. But with its patent of November 7, 2010 for a magnetic pivot, the brand has set another milestone in watchmaking history by harnessing magnetism to the service of precision and reliability. The Breguet Classique Chronométrie 7727 model shows that the company has reached its objectives and set a new level in the search for perfection.

The watch, in rose or white gold is fitted with the new Hand-wound calibre 574DR, which takes advantage of the latest developments from the workshops to deliver impressive rating results. This achievement was mainly due to its balance frequency of 10Hz. When it was applied for the first time in the Type XXII chronograph, this frequency was shown to have improved the time-keeping performance of the balance and spring. Breguet’s mastery of silicon enables the Classique Chronométrie to be fitted with a double balance-spring, pallet lever and escape wheel, all in specially prepared silicon that reaches the high frequency necessary for optimum precision.

The result is a regulating power equivalent to around 830 microwatts, an achievement when one considers that the regulating capacity of the best chronometers is between 300 and 400 microwatts. Despite its high frequency, the reference 7727 has a power reserve of 60 hours thanks not only to the energy stored in its barrels, but also to the very high quality of its balance.

However, the major innovation of this Classique Chronométrie model is without doubt the use of magnetic pivots. It is likely that the impact of this invention will not be felt for a few years yet. With the magnetic pivot, Breguet not only controls the negative effects of magnetism in a watch, but also uses magnetic force to improve the pivoting, rotation and stability of the balance staff. Breguet’s watchmakers have designed a stable system using two endstones incorporating powerful micro-magnets (approx. 1.3 teslas) that keep the balance staff centred and self-adjusting.

Magnetic pivot - Brevet du 7 novembre 2010
One of the magnets is stronger than the other to create a magnetic gradient. A magnetic flux, generated within the balance-staff induces a magnetic attraction that keeps the end of the pivot in contact with the endstone.

Held in an artificial gravitational force, the balance staff is unaffected by the different positions of the watch and the conditions at each pivot remain unchanged. If a shock knocks the balance staff sideways, the system acts like a pare-chute to return it to its position, except that magnetic forces re-centre the staff to regain maximum magnetic flux.

Force d’attraction Un axe de balancier plus stable grâce à la force d’attraction - Avec le brevet du 7 novembre 2010 consacré au pivot magnétique, Breguet établit un nouveau jalon dans l’histoire de l’horlogerie.

The result is a balance that is insensitive to gravity, more stable and resistant to shocks. These innovations bring the reference 7727’s average rate to -1/+3 seconds a day, well within the COSC chronometer standard of -4/+6 seconds a day. More importantly, the difference in rate between the six positions has been brought down to -2/+4 seconds a day (maximum wind).

No fewer than six patents protect these technical achievements, which represent the excellence of Breguet’s watchmaking.

In tribute to the major inventions realised in the calibre 574DR, a great deal of attention has been given to the appearance of this Classique Chronométrie watch. The dial shows an off-centre chapter of hours and minutes, small seconds at 12 o’clock, a power-reserve indicator at 5 o’clock and a tenth-of-a-second indicator at 1 o’clock having a patented lightweight silicon hand with low inertia that doesn’t affect the balance. The pare-chute is visible at 2 o’clock, both as a reminder of A-L Breguet’s 1790 invention and to make the timepiece slimmer.

Stylistic details unfailingly denote a work by Breguet. The dial is engine-turned in six patterns: “Geneva waves” in the centre, a hobnail pattern for the small seconds, sunrays on the tenth-of-a-second dial and chevrons for the power-reserve indicator. The hours chapter is cross-hatched while a barleycorn pattern decorates the outer edge. The hands are in polished steel with the Breguet open tip, while the case in rose or white gold displays delicate fluting. The welded lugs, the unique number and the secret signature complete the marks of the watch’s pedigree. The case, on a leather strap is water resistant to 3 bar (30m) and has a sapphire-crystal back to display the fine workmanship of the movement.

Breguet Classique Chronométrie 7727 - 10 Hz

Technical description

References :7727BR/12/9WU Rose gold
7727BB/12/9WU - White gold
Case:18-carat rose gold with a finely fluted caseband
Caseback :Sapphire-crystal
Diameter :41mm
Lugs :Welded lugs with screw bars.
Water resistant :3 bar (30m)
Dial:18-carat gold, silvered and engine-turned in six different patterns
Individually numbered and signed Breguet
Numerals :Hours chapter with Roman numerals
Small seconds :At 12 o'clock
10ths of a second :At 1 o'clock
Hands :Breguet open-tipped hands in polished steel
Movement :Hand-wound movement with stop seconds
Numbered and signed Breguet. Cal. 574DR
Diameter :14 lignes
Jewels :45
Power reserve :60 hours with an indicator at 5 o'clock
Barrel :Double barrel
Escapement:In-line Swiss lever escapement in silicon
Balance-springs:Double silicon at 180°
Pivots :Magnetic
Adjusted in six positions
Strap :Leather
Clasp :Triple-blade folding clasp