When it comes to double-chaser chronograph, you can not but mention Rolex Ref.4113. There is no doubt that it is the most talked about, most sought after, but also the Valjoux 55 family's most expensive double-chase chronograph. Ref.4113, once the only Rolex watch with a $ 1 million price tag in a public auction ($ 1.17 million in 2013), has today raised it to $ 2 million (May 2016 Rich Ensemble "start-stop-reset" auction auctioned 2.4 million Swiss francs). Ref.4113 is Rolex's only double-chaser chronograph, came out in 1942, the output is only 12 pieces. This watch is huge, up to 44 mm in diameter. Equipped with Valjoux 55 VBR movement, it is also the most advanced configuration. Rolex Ref.4113 Rolex Ref.4113 double chase chronograph Rolex Ref.4113 is no longer a single button design - the central button is responsible for starting the timing, the button at 2 o'clock is responsible for activating the double chase needles, 4 o'clock position button is responsible for resetting the timing. Please note that the previous version of the Valjoux 55 VBR was not "paused" (as with all single-button double-needle chronographs), but the Rolex Ref. 4113 has this feature. The Rolex Ref. 4113 is likely to be the only dual-button double-chase chronograph equipped with the Valjoux 55 VBR movement. Compared with other versions of the Valjoux 55 VBR movement, the Rolex Ref.4113 adds extra functionality and a relatively thin case. Rolex Ref.4113 Why is Rolex Ref.4113 built? This particular model has never been released for sale nor appears in any of the brand's ads. But we know that this watch from 1942, a total of 12, from 051313 to 051324 serial number. Interestingly, most examples of surfacing are inextricably linked to Sicily. For example, in May 1991, Christie's Ref. 4113 (deal price 82,500 Swiss francs) was auctioned at Geneva on 051313 and the client was the family of the famous driver Stefano La Motta. As another example, in October 1991 Christie's London auctioned Ref. 4113 (deal price £ 27,500) under number 051318. The client was a widow, and her husband worked for the fleet. As a result, many people speculate that this rare and famous double-chaser chronograph has deep roots in motorsports. Today, Rolex Ref.4113 is one of the most popular antique watches, as evidenced by historical and recent auction results. Butex double chase chronograph, Landeron double chase chronograph movement Butex double chase chronograph Shown on the picture is a Butex dual chase chronograph, the overall layout of the lever can be inferred, the movement should come from Landeron factory. The watch's double-pin mechanism is activated by a pushbutton at 10 o'clock. This design is completely different from the Venus and Valjoux movements, but coincidentally similar to the modern double-chaser chronograph by IWC and Lange . This type of watch, like a traditional chronograph, is not just a wrist-to-hip decoration, it's more about functionality and really timekeeping. Butex double chase chronograph movement In addition, the mechanical complexity of the movement is amazing. They belong to the history of the most amazing and the most sophisticated watch movement ranks, and even called the two mass production of the ultimate retro collection chronograph movement one, the other is the Longines 13ZN. Without regard to retouch, 13ZN may be aesthetical and design dominance, but the complexity of the Venus 185 / Valjoux 55 VBR absolutely superior life expectancy. Serena Valjoux 84 Mono-Rattrapante There is a real need for double-chaser chronographs, but the conventional double-chaser chronograph can not benefit the general public due to the cost price. Moreover, the mechanical mechanism of the double chase chronograph is very complicated, the difficulty of maintenance services can be imagined. As a result, industry participants began to think about making a more economical and easier-to-calibrate movement. The first is Valjoux 84 movement on the 1940s broadcast watch. Serena Valjoux 84 Mono-Rattrapante As mentioned earlier, both the mechanical mechanism of the Venus 185 caliber and the Valjoux 55 VBR caliber are equipped with double chasing needles. In 1936, Charles Jeanrenaud-Bovet of Fleurier obtained a chronograph patent (patent no. 185,465) equipped with only a second hand, but with functionality similar to the two-chaser chronograph. It is called "Mono-Rattrapante" and "Mono" refers to a single second hand. Valjoux 84 movement At first glance, the look of the Valjoux 84 and the earlier one-button version of the Valjoux 22 movement are very similar. However, it is easy to notice the extra helical spring at 9 o'clock (left), which is the key element that allows the chronograph movement to give the second hand the "catch-up" mechanism. Serena Valjoux 84 Mono-Rattrapante Press the button at 2 o'clock, the timer mechanism starts; then press the button at 4 o'clock, the second hand pauses, but the timing mechanism is still working. During this period, the coil spring gradually accumulated tension. Release the button at 4 o'clock, release the tension coil spring, the second hand will "catch up" on the actual passage of time. However, since the catch-up mechanism is basically connected to the small studs that pull the coil spring, the time to press and release the button at 4 o'clock is limited to 60 seconds (ie, the time it takes for the seconds wheel to make a revolution). Long time, small stud will stop gear operation, the entire movement will also stop working. Lowenthal Mono-Rattrapante Why is this mechanism effective? Because it allows users to record the time of an event, while the timing mechanism can still keep track of elapsed time. The mechanics of this mechanism are comparable to those of double chasing needles, but without the need for a second hand, simpler and easier to produce, adjust and service. In addition, this mechanism can also be used for other single-button movement. For example, some watches manufactured by Lowenthal have a similar mechanism. Dubey & Schaldenbrand Index-Mobile mechanism The creative application of tension springs by Brembo is an interesting innovation in watchmaking, and the watchmaking world is equally excited about the production of a double-chained chronograph with similar technology. In 1948, Georges Dubey and Rene Schaldenbrand won a patent (patent no. 253051), also using studs and tension springs, mounted on the Valjoux 77 movement with the addition of a second hand, under the central chronograph gear Tension spring that functions like the tension spring on the Valjoux 84. The two were then granted two more patents, each of which simplified the original system and the second and final one, making it possible to implement a double-chasing mechanism with a single-button chronograph movement. The patent eventually evolved into the Dubey & Schaldenbrand Index-Mobile mechanism. Dubey & Schaldenbrand Index-Mobile How Does It Work? The Index-Mobile is equipped with an additional coil spring, mounted above the dial and connected to the second hand. In general, the conventional double-chase chronograph movement needs to be mass-transformed within the movement, while the Dubey & Schaldenbrand Index-Mobile mechanism shifts most of the retrofitting work to the outside of the movement, to the dial, to the inside of the movement Modification is just an extra addition of a central gear and lever. The gear is connected to a second second hand and to the original central gear via a spring. Press and hold the button at 3 o'clock, the lever will stop the gear and the second second hand, then you can read the time of the first event. The button can be released as needed, and the second second hand can "catch up" with the spring still on the dial to the still running first pointer. The basic principle is very similar to broadcast Granville, but it realizes the real double chase needle timing function. Index Mobile mechanism patents This mechanism, even compared to the Valjoux 84, is undoubtedly more cost-effective as it adds extra elements to the basic movement without the need to revamp the entire movement. Compared to the traditional double-needle chronograph movement, the Index Mobile mechanism has lower production costs and the Index Mobile mechanism has almost no loss of functionality compared to the Valjoux 84 movement, although the latter is subject to the same 60 second Within the constraints. Index Mobile mechanism patents Interestingly, most of the broadcast Granville Valjoux 84 watch with chromium case, the steel will be less. A small portion of the Mono-Rattrapante watches made by Lowenthal use a solid gold case and, although very rare, the value of these watches depends very much on the condition of care. Curiously, there seems to be no particular reason, but demand for the D & S Index-Mobile mechanism is significantly lower than for the Valjoux 84, probably due to the large number of gold-plated D & S watches. In any case, Index Mobile mechanism is a charming watch invention, worthy of attention and recognition. This article is reprinted from the watch house, if you have any questions, please send an email to wbsj@wbiao.cn to contact us.