Fonte iwc.com
IWC has reinvented the chronograph
IWC Schaffhausen has taken a long time to produce a new mechanical chronograph movement. But now the time is ripe to make decisive further developments to the “watch within a watch”. The watchmakers of Schaffhausen believe that they owe this to their model, Leonardo da Vinci.
Leonardo da Vinci did not invent the wheel. But he used it in an ingenious way and constructed his fundamental rules of mechanics on it. Even the mechanical clock existed before his time. But he also developed features including new spring drives, gear trains and escapements for it, in an effort to significantly improve its accuracy. For the same reason, IWC today is building a proprietary chronograph movement for the next chapter of its Da Vinci watches. The motivation was to make this widely distributed and fascinating mechanical function even better and to increase its acceptance and its utility. The outcome of all this effort, research and testing over the years is the movement abbreviated to Cal. 89360. This is the “motor” which drives the Da Vinci Chronograph and sets new standards in the field of horological engineering. As ever, when IWC Schaffhausen places something under the microscope and asks the question, “Can we make it even better?”, the answer is, “Yes we can!”.
In the beginning there were many questions
For the manufactory calibre 89360, these questions included not only the many detailed improvements. They were actually questions of a quite fundamental nature. What should a modern mechanical chronograph do? What is it normally used for? Is it correctly designed for the purpose? Or what can be improved? These are searching questions, which Leonardo da Vinci also asked repeatedly of the engineering of his own age. This approach to work is also referred to as progress.
A little history to start with. The first known chronographs date back to around the year 1820. As the expression formed from the two Greek words for “time” and “writing” correctly states, these were small time writers. The seconds hand originally contained a tiny ink reservoir, and at the push of a button the tip of a needle descended and deposited a dot of ink on the dial. Although rather simple in mechanical terms, the procedure was also impractical. Just 30 years later, Adolphe Nicole, a watchmaker from the Vallée de Joux, invented the chronograph with a heart lever mechanism, of which the stop hand could be brought to a standstill and set back to zero. The principle has remained the same until this day. The possibility of recording the seconds and fractions of a second within a given minute was supplemented over time with additional counters for the minutes – up to 30, 45 or 60 minutes – and subsequently for the hours, up to 12 hours as a rule. The chronograph, initially intended as a measuring instrument for science and sport, also had to place its undisputed usefulness at the disposal of the military for applications in artillery, navigation and aviation.
Why is the “watch within a watch” still good to this day?
Basically, however, nothing had changed in the measurement method. It still obliged the user to add together the minutes and half hours, or the hours, and to combine the two values in his head. This was still the case when, twenty five years ago, the mechanical chronograph suddenly experienced an unexpected renaissance in which IWC Schaffhausen played a decisive role. The result was the first chronograph in a titanium case from IWC. This is now a classic, which adds to any collection.
The word chronograph has since undergone a fundamental change in meaning. It has become a synonym for the sporting watch, which has an interesting appearance and identifies its wearers as dynamic individuals. Its original significance as a measuring instrument has receded into the background, however, which also has something to do not least with the described method of indication.
The questions of the IWC constructing engineers in the team of Kilian Eisenegger were aimed at this very point. They arrived at a new answer. The mechanical chronograph as a “watch within a watch”, which utilizes the energy of the basic movement, is no longer a serious competitor when it comes to absolute short time measurement. Today, accuracies in the range of 1/1000 of a second and less, which cannot be achieved by any mechanical watch, are determined by electronic means in sport or in science – although no one would actually need them in day-to-day life. The mechanical chronograph must accordingly offer what can be of use to every individual. This view led the development team to the conclusion that the representation of lengthy measurement periods should be recorded and capable of being read off at a glance. Best of all in the universally familiar form of an analog time display with hour and minute hands. This was a small, logical step in the thought process, and perhaps a decisive one for the future of the mechanical chronograph.
IWC Automatic Double Clicks Self-winding System via a crankshaft
Horological ambition was also focused on detailed aspects of the design. The strictest quality standards were applied to the movement that had been newly developed from the ground up. Its precision, robustness and reliability would define new standards in the production of movements. Development accordingly took place on the basis of the highest industrial design standard, Design for Six Sigma DFSS, which has been applied consistently by IWC for some time.
All that was adopted from earlier IWC designs is the automatic spring bridge that had already been improved for the Cal. 80111 movement of the Ingenieur. This is a central component, which carries the rotor and absorbs impacts from all directions. The pawl winding mechanism itself, once developed by Albert Pellaton to the point at which it was ready for series production, was redesigned completely. Two double winding pawls, making four in total instead of the previous two, transmit the energy of the rotor movement to the pawl wheel through push-and-pull movements. These now no longer lie one after the other, but are arranged in pairs opposite one another on the pawl wheel. They are also no longer controlled by the previous cam disc (heart) on the rotor arbor, but by a crankshaft similar to that found in an automobile engine. A little more detail can also be provided here. Whereas, in the design by Pellaton, an extra spring was required to impart the necessary tension to the pawl, the pawls themselves are now embodied as springs and make contact with the pawl wheel with the required tension. The positioning of the total of four pawls ensures that a dead angle is eliminated during winding, and the efficiency of the winding is increased by 30%. This in turn means that a lighter rotor can be used, which reduces the forces acting on the central arbor. Every link in this chain of design decisions serves the single purpose of increasing the robustness of the design.
The predominantly decentral chronograph mechanism is also a new IWC design. Its features include the actuation of the flyback function, which permits immediate zeroing of the already added stop times and the start of a new measurement during operation of the chronograph. The chronograph is actuated via a classic column wheel. The layout of its design is such that the stop function can run permanently without negative effects on the amplitude of the balance and thus on the accuracy of the movement. This also makes the chronograph suitable theoretically for the display of a second time zone in conjunction with its innovative display of the aggregate times. The power reserve, which is stored in a large spring barrel, has been increased accordingly to 68 hours.
The index-free vibration system with a special, Nivarox balance spring, produced exclusively for IWC, exhibits oscillation characteristics clearly superior to comparable designs and even has a lower energy requirement. Fine adjustment of the escapement is effected via four precision adjustment screws on the balance wheel ring.
A so-called “robust design” according to the principle of Dr. Genichi Taguchi, in which all functions, all components and all individual parts are inspected, tested, optimized repeatedly and checked thoroughly in a networked process in order to exclude possible faults, was sought for and achieved. Even so, the Da Vinci Chronograph with the Cal. 89360 movement had to pass the most demanding impact, vibration and temperature tests in the lengthy prototype and qualification phase, without which no IWC is allowed to take its position on the start line.
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