Cabaret Tourbillon

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Cabaret Tourbillon - A. Lange & Söhne
How to stop a Whirlpool?**

Designed to improve watches’ accuracy, the tourbillon had never been coupled with a stop-seconds mechanism – until A. Lange & Söhne’s Cabaret Tourbillon came along. But just how does one stop a tourbillon?

As watchmakers A. Lange & Söhne researched the idea of creating a tourbillon with a stop-seconds mechanism, the first thing they had to rule out was any approach that involved stopping the tourbillon cage directly. This would have been quite simple from a mechanical point of view; but if only the cage is halted, the balance wheel remains free, and its oscillations will decrease in amplitude until they eventually cease and it comes to rest. Once the brake has been released, the restart phase might thus require external input for oscillation to resume. Instead, the mechanism eventually patented by A. Lange & Söhne stops the balance itself, thus allowing it to conserve its potential energy – and deliver a perfect restart.

The next challenge for the Saxony-based Manufacture was therefore to design a system that could stop the balance, bearing in mind that the latter sits in the middle of a moving cage with three pillars, each of which represents an obstacle to any brake mechanism. The watchmakers developed a stop lever consisting of a V-shaped spring, with two arms exerting pressure on the outer rim of the balance to bring it to a halt. The spring is assembled on a hinge, so that if one of the arms strikes one of the cage pillars, the second will still strike the balance – and still be able to stop it on its own. The curve on the tip of each of the arms was carefully studied with this in mind, and finalised after a great many tests, thereby ensuring optimum action in any configuration. When the brake is released, the balance instantly starts oscillating again.

Cabaret Tourbillon

This ingenious mechanism has been fitted into a magnificent rectangular movement, the manual-winding L042.1 calibre, with a large date and power-reserve indicator. It beats at 21,600 vibrations per hour, with two barrels providing a substantial five days’ worth of autonomy. The L042.1 calibre features a design that remains true to A. Lange & Söhne’s hallowed tradition, with impeccable finishes to match. The three-quarter nickel silver base plate sports six gold bezels, held in place by blue-tinted steel screws. Three more bezels grace the hand-engraved bridges on the intermediate wheel, the tourbillon, and the black polished tourbillon bridge on the dial side. The balance oscillates between two diamond endstones. The movement measures 22.3mm x 32.6mm x 6.35mm; in all, it comprises a total of 373 components, 84 of them for the tourbillon alone.

The L042.1 calibre is housed in the elegant, Art Deco-style rectangular case from the Cabaret collection and can be admired through the transparent sapphire crystal caseback. Available in 18K gold or 950 platinum, it measures 29.5mm by 39.2mm. The silver- or rhodium-plated dial is made from solid silver, and features applied Roman numerals and diamond-shaped hour-markers. Its calculated symmetry results in distinctive visual harmony. The large date indicator at 12 o’clock provides a pleasing counterpoint to the tourbillon, which is flanked by the seconds and power-reserve indicators. The elegant, faceted hands are rose gold or rhodium-plated gold. The final touch is the brown or black alligator strap, with a rose gold or platinum folding clasp.

 

*Written by Xavier Markl
*This year GMT Magazine and WorldTempus have embarked on the ambitious project of summarising the last 20 years of the Tourbillon in  The Millennium Watch Book - Tourbillons, a big, beautifully laid out coffee table book. This article is an extract. The Millennium Watch Book - Tourbillons is available on www.the-watch-book.com, in French and English.

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