Abraham-Louis Breguet sought constantly to improve the accuracy and reliability of his watches through numerous inventions, ranging from the perpétuelle selfwinding watch to the tourbillon. This same spirit of invention motivates the engineers and master-watchmakers of the Manufacture Breguet today. The Classique Chronométrie 7727, packed with new discoveries and technological inventions, is a prime example, as the
’’The Classique Chronométrie 7727, packed with new discoveries and technological inventions, is a prime example
achievement of several years of research into high frequency, magnetism and new materials.
The Classique Chronométrie also honours more than two centuries of Breguet’s stylistic tradition with the fluted caseband, welded lugs, engineturned dial, open-tipped Breguet hands, secret signature and unique number, all of which are the identifying features that express the essence of a Breguet timepiece.
’’With the patent of November 9, 2010 protecting
the magnetic pivot, Breguet has set a new
milestone in watchmaking history (…)
A certificate provided only as an example, since each watch is unique and its performances are individual.
This accuracy certificate attests to the individual timekeeping performance of your Breguet Classique 7727 “La Chronométrie” watch. Based on the measurements of rate and amplitude of your watch in six positions over 48 hours – equivalent to 80% of its power reserve, they constitute the last stage of our final inspection process. The accuracy of your watch is determined by how closely it keeps its rate compared to the real time,
as expressed by the seconds gained or lost per day (s/d). The amplitude, one of the movement’s technical factors, refers to the extent of the arc (in degrees) through which the balance swings as it oscillates. It shows the momentum of the balance, a key factor for a stable rate. Rate and amplitude are influenced by the position in which the watch is working. This certificate provides the average and extreme figures measured on your watch in six different positions.
Rate (s/d) and amplitude (degree) measured at full power reserve and after running for 48 hours.
|Rate at 0h||Rate at 48h||Amplitude at 0h||Amplitude at 48h|
|HH = CH = Horizontal, dial up||0.1||-0.3||298||253|
|HB = CB = Horizontal, dial down||2.1||3.7||291||248|
|VB = 9H = Vertical, 9 O’clock up||1.5||2.1||291||251|
|VG = 6H = Vertical, 6 O’clock up||1.5||3.7||276||238|
|VH = 3H = Vertical, 3 O’clock up||0.6||1.8||292||251|
|VD = 12H = Vertical, 12 O’clock up||2.7||3||291||250|
|X Average 6 positions||1.4||2.3||290||249|
|D Delta 6 positions||2.6||4.0||22||15|
Average variation of rate (s/d) and amplitude (degree) over 48 hours of running time (over the six positions).
Maximum rate (s/d) and amplitude (degree) variation between the six positions over 48 hours.
Silicon has physical properties that are useful to watchmaking in many ways. Not only can it be cut exactly into the complex shapes of balance springs, pallet-levers and escape-wheels, it is also totally immune to magnetism. This approach now makes it possible to use magnetism without this phenomenon exercising its previously detrimental effect on the ratekeeping of the watch. Furthermore, the balance spring, the pallet-lever and the escape-wheel also weigh less, thereby not only reducing inertia, but also improving the performances of the mechanical components. These silicon parts allow the frequency of the Classique Chronométrie to be increased to 10 Hz, enabling the measurement of a 20 th of a second. The Classique Chronométrie is also equipped with twin 180° symmetrically deploying balance springs, thereby balancing out their respective forces exercised on the balance-staff as well as contributing to the stability of the oscillator and hence to improved timing precision. These technical achievements, made possible by silicon, considerably improve the regulating performance of the watch.
From 1790, Abraham-Louis Breguet, working on the premise that the thin balance pivots were the most vulnerable to shocks, made them into a cone shape held in place against a corresponding cavity in a stone on a blade spring, and called it the pare-chute.
With the magnetic pivot, Breguet pays tribute to this brilliant invention, visible at two o’clock on the dial of the Classique Chronométrie. This dynamically stable system protects the balance and provides an effective response to the disturbing effects of accelerations and low-intensity shocks. Incorporated within the pare-chute, the magnetic pivot serves to safeguard the mechanical integrity of the system and to enhance its precision.