Cartier Rotonde de Cartier Astroregulateur

This is an English translation of a story that ran in Cronos magazine in Mexico in summer 2011

Though he invented the rotating oscillating weight for pocket watches around 1770, Abraham Louis Perrelet’s concept for an automatic watch that harnesses energy from the wearer was much better suited for wristwatches, which followed more than a century later. John Harwood, a watch repairer from the Isle of Man, filed a patent for a bumper winding system in 1923, but it was Rolex that set the benchmark with 1930’s Oyster Perpetual wound by a semi-circular weight that rotated 360 degrees. “Rolex was the first to introduce 360-degree rotation, and that was probably the biggest 20th-century invention,” says John Reardon Senior Vice President and Head of Sotheby’s Watch & Clock department in New York City. “After that, there wasn’t a big bump until Patek Philippe’s 12-600 caliber and the Ref. 2526 in 1954. That was a game changer because it was the first time a very high-end company offered an automatic system. The mythology is that Patek had to wait for Rolex’s patent to expire.” While the basic premise of the automatic winding system remains the same—to generate energy from the wearer’s arm motions—watchmakers recently have been working to advance these systems with heightened efficiency, adjustable speed settings, bi-directional systems, and even peripheral oscillators that allow a full view of the movement through the case back.

Richard Mille RM030

“The state of winding in a watch has always been a priority for me, because it is one of the major areas that can affect chronometric results, a watch’s timekeeping accuracy,” says Richard Mille, who recently introduced a declutchable rotor system in the RM030 as an advancement to his earlier rotor with variable geometry, which adjusts to the wearer’s activity level. Mille spent four years developing the declutchable rotor system that automatically senses when optimal winding is reached at 50 hours power reserve, and then disconnects the gears between the rotor and winding barrel allowing the rotor to spin without winding. When the power reserve drops below 40 hours, the gears re-engage to ensure that the watch constantly operates within the optimum range. An on/off indicator at 12 o’clock shows when the system is active or disengaged. “The power reserve of the winding spring and its torque together determine the quality of power in the winding spring,” explains Mille. “If this power sags below a certain point, the balance won’t move back and forth the ideal calculated amount, and timekeeping will be affected. So you want to be sure that there are optimal hours of power in the spring.”

Perhaps the most imaginative method for regulating winding speed is Urwerk’s Twin Turbine system, which debuted in 2008. Featured in this year’s UR-110 and UR-202S, (dubbed The Hammerhead Full Metal Jacket for its specially designed metal bracelet), the twin turbine system uses air friction similar to the way 18th-century clockmakers regulated the speed of chiming clocks. But there’s nothing old fashioned about Urwerk’s system, which replaces the traditional rotating vanes with spinning miniature air compressors, which are visible through the case back. The spinning turbines force air through holes into a tiny air chamber, and a selector switch, which you adjust to your activity level, controls the amount of airflow—restricting airflow increases the air pressure and slows down the turbines that are connected to the winding rotor. When the selector is set at “vigorous,” the winding rate is reduced by about 35 percent; at “extreme” the turbines and rotor are fully blocked. “Urwerk is doing things no one has ever done before,” points out Sotheby’s Reardon. “The idea of building mini air compressors into a watch is very Formula 1, but at the end of the day, the system reduces long-term wear and increases the lifespan of the movement. Plus, it’s fun to play with.”

Urwerk’s twin turbine

In a far more traditional vein, Reardon also commends the durability and beauty of Cartier’s 1904MC, the brand’s first automatic in-house movement, which debuted in 2010’s Calibre de Cartier timepieces. Designed for exceptional chronometric stability whether you wear it for hours or days, the 1904 MC also features a stop-seconds system that allows you to set the time to the nearest second by pulling out the crown to stop the small seconds hand. The robust movement is also designed to handle shocks by employing an innovative system of ceramic ball bearings fitted at the centre of the rotor. For faster and easier winding, Cartier replaced traditional reversers with a pawl system, while a bi-directional rotor winds as it spins both clockwise and counter-clockwise.

A bidirectional rotor is also a key element of TAG Heuer’s Calibre 1887 chronograph movement, which powers 2010’s Carrera Calibre 1887 Chronograph and the 300 SLR Calibre 1887 Limited Edition Automatic Chronograph. Working from an existing platform developed by SII in the late 1990s, TAG Heuer’s engineers completely reconfigured the integrated column wheel chronograph to enhance its reliability and efficiency. What sets the Calibre 1887 apart is its capacity to store only as much power as needed rather than continually amass energy. This system reduces stress on the mechanism, and, according to TAG Heuer’s General Manager Giorgio Sarne, is 30 percent more efficient than regular automatic movements. Sarne explains that the mechanism winds much faster due to its innovative bi-directional rotor. “It makes an important difference because your chronograph is always full of energy—high-efficiency winding impacts the precision of the watch. If your watch always has the right amount of energy, the system is very reliable and strong.”

Other recent advancements in automatic movement design include peripheral winding systems, which replace central rotors with oscillators positioned on the movement’s periphery. In 2008, Carl F. Bucherer announced its first in-house movement, the CFB A1000, featuring a highly efficient shock absorption system with a peripheral rotor design featuring DLC-coated rollers equipped with ceramic ball bearings to reduce maintenance. This year’s round Patravi EvoTec Calendar is powered by the CFB A1000 Caliber outfitted with a module that indicates week numbers in addition to a big date, day indicator, and date indication.
After patenting its Automatic Sequential Winding (A.S.W.) device driven by a peripheral oscillating rotor in 2009, DeWitt followed with 2010’s in-house caliber DW8014, a complicated regulator movement integrating a tourbillon. The movement is the engine of this year’s Deco-infused Twenty-8-Eight Regulator A.S.W Horizons. The bidirectional peripheral rotor is attached to a ring with an inside sinusoidal profile. And similar to Mille’s declutchable system, it automatically engages and disengages to ensure the watch operates within an optimal range of between 92 percent and 96 percent of the mainspring torque. The system ensures that the gear train receives a constant and stable flow of energy while also eliminating the running defects that occur with slip springs in typical automatic movements. A dead-beat seconds hand, which is positioned in direct contact with the tourbillon cage, pauses with each second, illustrating the extreme precision of the oscillating balance.

A peripheral oscillating weight made of dense platinum winds Audemars Piguet’s Caliber 2897 in the new Royal Oak Offshore Selfwinding Tourbillon Chronograph, another knockout 2011 debut. The watch carries on a legacy at Audemars Piguet, which introduced the first automatic tourbillon wristwatch in 1986. Today’s incarnation makes a dramatic technical leap by combining the tourbillon with a chronograph and by utilizing advanced materials including ceramic and forged carbon. The platinum peripheral oscillating weight is mounted on ball bearings and inserted in a groove in the case’s center allowing the 180-degree oscillator to spin 360 degrees while preserving a thin profile and providing unimpeded views of the intricate mechanism with its column wheel chronograph.

Corum CO313 Movement

Platinum was also the metal of choice for a new linear oscillating weight that winds the new Corum Golden Bridge Automatic. Four years of development resulted in a novel oscillating weight that slides on rails back and forth between gaskets equipped with ceramic ball bearings. The energy generated is transmitted via a rack fixed to the oscillating weight, ensuring the movement has sufficient power.

And in characteristic over-the-top style, Jacob & Co.’s new Cyclone Tourbillon integrates the tourbillon escapement with the winding system. The limited-edition timepiece is the brainchild of a two-year collaboration with Swiss complications specialist La Fabrique de Temps. This irregularly shaped watch features a tourbillon carriage positioned on a front-mounted oscillating mass that freely spins around the dial.

Other new models that dramatically reposition the rotor on the front of the dial for a dynamic focal point include Piaget’s Emperador Coussin Tourbillon Automatic Ultra-Thin and Dior’s Chiffre Rouge with Dior Inverted Caliber. Meanwhile, Cartier’s impressive Astroregulateur, which debuted last year, seeks to defy the effects of gravity by positioning the tourbillon escapement, oscillator and pendular seconds display on the visible rotor, one element that always returns to the same position in the vertical plane. And the thoroughly unconventional (and playful) double battle-axe mystery rotor of MBF’s HM3 competes for attention with the thoroughly unconventional time display in raised domes positioned outside of the movement itself.

“Over the last 80 years, significant strides have been made in the development of a more perfect winding watch—one that is efficient, shock resistant, and thin,” says Reardon of Sotheby’s. The fact that you need a rotor is problematic as it adds to the size and thickness of the movement, and it also leads to concerns when the wearer is extremely active.  Like with a windmill, you want to use the energy, but if there is too much power going to the movement, there has to be a way to disengage the system and store that energy to keep the watch running as long as possible. It’s a balance between stopping and going, and it’s a question of efficient utilization of the energy that’s generated.”