The chronograph occupies a choice position in watchmaking as a complication in its own right. Measuring elapsed times provides immediate visualisation of the desired function, but making it work is an additional mechanical challenge, because starting a chronograph disturbs the main gear trains. To alleviate this problem, Breguet has fitted its new Tradition Chronographe Indépendant 7077 model with two independent trains. This piece is truly innovative and bears the trademark of Breguet’s impressive technical expertise.
The first is the going train for the hours and minutes, regulated by a 3Hz balance and having a power reserve of 50 hours. The two trains are entirely disconnected and the movement remains unaffected when the chronograph is started. Normally, a second train implies a second barrel to provide the energy required by the chronograph. This approach nonetheless needs more space and above all means that the owner of the watch must wind up the chronograph barrel spring as well as the going barrel. With the Tradition Chronographe Indépendant 7077 model, the company’s technicians have introduced a new type of spring perfectly suited to the chronograph function. The energy required to drive the chronograph is provided by the user when operating the reset-to-zero function. This energy is stored in a flexed blade spring. This allows for greater accuracy through independent trains and the chronograph train moving at constant force.
In addition, the reference 7077 is fitted with a patented chronograph balance-wheel in titanium ensuring perfect symmetry with the movement balance-wheel. The use of a heavier material for the balance-wheel would have meant making it smaller. The overall appearance would be affected, especially since one of the features of the Tradition collection is to make the main parts of the movement visible on the baseplate.
In keeping with the rules, the style of this Breguet Tradition Chronographe Indépendant 7077 is noted for its symmetry. The engine turned dial in silvered gold showing the hours and minutes is offset at 12 o’clock, while the chronograph hand is fixed in the centre of the watch. The chronograph-activation indicator is at 6 o’clock. Directly opposite each other at 2 o’clock and 10 o’clock two retrograde hands respectively indicate the power reserve of the watch and the chronograph minutes, while the two balance-wheels beat side by side at 4 o’clock and 8 o’clock. This hand-wound timepiece is water-resistant to 3 bar (30m) and is fitted with a leather strap.
Case in 18-carat white gold with delicately fluted caseband. Sapphire-crystal caseback. 44mm diameter. Welded lugs with screw bars. Water resistant to 3 bar (30m).
Dial in silvered 18-carat gold, engine-turned and offset at 12 o’clock. Individually numbered and signed Breguet. Hours chapter with Roman numerals. Power reserve indicator at 2 o’clock and 20-minute counter at 10 o’clock. Breguet opentipped hands in blued steel.
Hand-wound chronograph movement numbered and signed Breguet. Power reserve indicator and 20-minute counter engraved on the back of the movement. Chronograph running indicator at 6 o’clock. Cal. 580DR. 16 lignes, 62 jewels. 50 hours power reserve. Symmetrical inverted in-line lever escapements with silicon pallets. Breguet balance-wheels on Breguet springs in silicon. Movement frequency 3Hz; chronograph frequency 5Hz. The two oscillators are adjusted in six positions.
Also available in 18-carat rose gold