BASELNEWS 2010The Breguet Tradition 7047 with tourbillon, fusee and silicon Breguet overcoil balance spring
The balance spring is a vital component of the heart of a watch movement. It is also the most decisive in terms of improving the precision of time-measuring mechanisms. Its steady oscillations give the movement its rhythm and regulate the flow of time. The balance spring is best described as a very fine spiral-shaped coil spring. Usually made of metal, it is vulnerable to shocks, magnetic fields and even the pull of gravity, which can cause warping.
Made of silicon
In 2006, Breguet launched the first wristwatches fitted with a balance spring and an escapement made of silicon, a substance with a number of advantages:
• Silicon is totally impervious to magnetic fields.
• The manufacturing process leading to a silicon balance spring yields a broad variety of configurations, facilitating its shaping in precise conformity with carefully calculated models.
• Silicon balance springs are lighter than metal ones and thus less prone to warping caused by the pull of gravity. They are also highly resistant to corrosion and friction as well as impervious to rust.
• All silicon components are subjected to a special process that markedly improves their resistance to handling and shocks.
After nearly four years of service in various watch movements, Breguet’s flat silicon balance springs have posted absolutely conclusive results, allowing the company to turn its attention to the development of springs featuring the famed “Breguet overcoil” terminal curve. Producing a curve in a sliver of silicon to give it a third dimension represents a quite considerable watchmaking exploit. Usually cut from flat silicon wafers, the springs remain simple flat strips. Silicon having none of the malleability of metal, getting it to form a bend rising up from the coil required a complete rethinking of the overall production process. The Breguet overcoil silicon balance spring will now be adding its specific advantages to those of silicon on all Breguet calibres, whatever their basic configuration.
Today the new “Breguet overcoil silicon balance spring” is found in the Breguet Tradition 7047 timepiece with tourbillon and fusee-and-chain transmission. Recalling the constructional scheme of the first tourbillon pocket watches built by Breguet, this model is presented in a platinum version with a movement treated with an anthracite-toned grey metal compound. Its surface finish results from a new and improved electrodeposition process involving an alloy of precious metals of the platinum group darker in hue than ruthenium.
The fusee-and-chain transmission connected to the barrel maintains a constant force for as long as the watch is running. A number of patent applications cover the large tourbillon resonator at one o’clock on the watch face, one for a titanium balance and three relating to Breguet silicon balance springs. A further patent was awarded for the power-reserve indicator fitted directly on the barrel.
Pride of Manufacture Breguet
Displaying impressive technical sophistication, the Breguet Tradition 7047 is the pride of Manufacture Breguet. As always an undisputed pioneer in horological research and development, Breguet’s creative achievements are soon turned into practical technical advances found in timepieces marketed promptly, without undue delays or quantitative limitations.