Dual Constant escapement
Dual Constant escapement
The escapement carries out two fundamental tasks in mechanical watches.
Firstly, it prevents unrestricted unloading of the spring mechanism. Secondly, the escapement transfers regular pulses to the oscillation system to maintain the oscillations from the balance wheel and the balance spring. With the Dual Direct escapement that was launched in 2001, Ulysse Nardin had already set new standards in efficiency. In a traditional Swiss escapement, a large amount of the energy supplied actually needs to be used by the escapement. What is more, and this was also typical of Dual Direct, the force of the impulses relayed to the escapement decreases with the decreasing torque of the main spring. As a result, this reduces the amplitude of the balance wheel which in turn has a negative effect on accuracy. This is exactly what the “Dual Constant” counteracts. It is a sophisticated constant force escapement. The small pulses that are transmitted to the balance wheel and hairspring are always equal because they are not dependent on the tension of the mainspring. This is made possible by a complex silicium structure with locking elements, which interacts with silicium escapements which are as cleverly designed in this movement as they were in the “Dual Direct”.
The key feature is the flexible silicium blades, which are initially pre-tensioned by the mechanism for each half-oscillation of the balance wheel. This means that they absorb around 150 nanojoules of energy. 60 nanojoules of this is released rapidly and highly accurately to the oscillation system during the subsequent shift from a stable to a metastable state. And this continues until the power of the watch is drained. The special feature of the blocking lever which catches hold of the escapement wheels is that it is held by the flexible blades. This removes the need for a bearing shaft; an advantage, as this would inevitably reduce friction. Therefore, the constant-force escapement, which is pending patent, has a very positive effect on isochronism. By this, watchmakers mean that every half-oscillation of the balance wheel lasts exactly the same length of time, independent of the balance wheel’s amplitude. Of course, it goes without saying that the accuracy of this thoroughly extraordinary timepiece is second to none. (2 patents issued, 1 patent pending).
Direct silicium bonding
DRIE (Deep Reactive Ion Etching) is the name of the photolithography deep etching process used by Ulysse Nardin to produce the escapement element from monocrystalline silicium. A two-part production process is required, owing to the extreme complexity and three-dimensional structure. The two parts must then be connected together. Bonding is used to achieve this, a process which dates back to 1986. However, Ulysse Nardin now uses it to manufacture relatively small watch components for the first time. The sealed bond is created by compressing hydrophobic surfaces at process temperatures of between 1800 and 2200 degrees Fahrenheit (1000 to 1200 degrees Celsius) with the addition of oxygen. What is novel here is that the process creates stable “silicium oxide” joins, which spread in all directions from the first contact point on the vertical surfaces. In this way, what was originally two becomes one. (1 patent pending).
Silicium balance wheel with gold mass elements
and stabilizing micro paddles
Anyone who wishes to measure the constant passing of time must firstly divide it into equal segments and then count them meticulously. Whether electronic or mechanical, this is exactly what watches do. In conventional timepieces, the escapement is responsible for this: in other words, the balance wheel and the balance spring working in unison.
Silicium balance wheel
In the InnoVision 2, Ulysse Nardin uses silicium for both of these components as a matter of course, owing to the material’s wide-ranging beneficial properties. It has a density which is 3.6 times lower than the Glucydur used to make conventional balance wheels. Furthermore, silicium has a high degree of homogeneity, making it very conducive to facilitating equal mass distribution. In addition, the raw material is non-magnetic, corrosion and shock-resistant and highly flexible despite its great hardness.
Now we come to the balance wheel: For engineers and watchmakers, a balance wheel must fulfill precisely defined criteria. Its center must have the lowest possible mass yet a high moment of inertia.
The InnoVision 2’s new balance wheel possesses precisely these apparently contradictory characteristics. The part that might loosely be described as the body is a real flyweight at only seven milligrams. Ulysse Nardin uses the DRIE process to form it from silicium wafers. Oxidizing the surface creates the required thermo and mechanical stability. Moreover, the oxidization process results in slightly rounded edges. The unusual shape of the regulator lever, which looks like a paddle, is no coincidence. It maintains constant oscillation by smoothing air turbulence within the casing. In addition, and even more importantly, in this watch, the different amplitudes caused by switching between horizontal and vertical positions are equalized. Ultimately, this means that the quality factor is not compromised whatever its position. This is calculated by the number of oscillations performed by the balance wheel and spring without the need for more energy. With a view to gearing control, at 8 mg cm2, the balance wheel’s remarkably high. The moment of inertia can be adjusted with small gold elements included in the outer mass sectors in order to adjust the chronometrical precision. All in all, the entire balance wheel’s mass is significantly lower than that of conventionally constructed examples. This is what watchmaking progress looks like. (1 patent pending).
Wearable timepieces have had automatic winding since around 1770. This was devised to eliminate the need for a key to tighten the mainspring. Self-winding found its way to the wrist in the 1920s. 1932 brought about the single-direction rotor with unlimited rotation.
It was another ten years before the oscillating weight delivered energy to the barrel in both rotational directions for the first time. Since then, engineers, technicians and watchmakers have been focused on finding ways to optimize the function and efficiency of the automatic winding mechanism. In particular, systems polarizing the movements of the rotor have offered and continue to offer, great potential. A part of the conventionally constructed transmission shows a noticeable loss of friction and a notable degree of inefficient idling. This was reason enough for Ulysse Nardin to radically redesign the InnoVision 2’s self-winding mechanism, following a thorough analysis. At the start of the chain of automatic energy generation there is a centrally located ball-bearing rotor. Underneath it has three further small ball-bearings, which operate on two pairs of leaf springs in a filigree-shaped structure. The ring attached to this has a total of four springy ratchets. Its small, hook-shaped free end engages with the angular serrated winding wheel centered above the barrel. Each rotation of the oscillating weight makes the structure and the ring oscillate. This makes one or two of the four ratchets move the winding wheel in the clockwise direction, as viewed from the rear.
Finally an elaborate, two-stage satellite-reduction gear is needed. This transforms the relatively quick but low-energy actions of the innovative excenter changer into slow and therefore more powerful actions capable of tightening the centered mainspring.
“Grinder,” which is the name of the innovative self-winding mechanism, justifiably makes one think of high-performance yachting, with which Ulysse Nardin is closely associated through the Swedish Artemis team. This automatic winding system embodies the efficiency that is necessary when setting sail on a fast-paced yacht. It transforms even the tiniest amounts of kinetic energy into potential. There is virtually no idling. If necessary, the mainspring can of course be tightened by turning the rear bezel, as is also the case for “Freak”. (1 patent issued, 1 patent pending).
Sapphire-coated silicium bridge
The various advantages of silicium in mechanical movements are now sufficiently well-known. As early as 2007, Ulysse Nardin proved that there is always room for improvement by coating silicon components with a synthetic, nanocrystalline diamond film.
With ten Mohs or 10,600 Vickers, the most precious raw material is also the hardest available. In second place come sapphire or corundum with nine Mohs or 2,200 Vickers. This is why Ulysse Nardin, in collaboration with the EPFL High School of Lausanne and Sigatec, has now developed an innovative and therefore patented method for coating silicium with a thin film of sapphire. Obviously, the thickness of the coating of around one micrometer (μm) must be taken into account during construction. The InnoVision 2’s elongated center wheel bridge is made from this innovative combination of materials. The entire component has harder surfaces and a higher mechanical stability as a consequence. (1 patent issued).
24-Karat hard gold wheels
Gear wheels in mechanical movements are conventionally made of brass. This is not so in the InnoVision 2. Ulysse Nardin very purposefully chose hard gold for these components. If the gear wheels that are conventionally used in time-keeping gear trains interact with steel pinions then friction will occur. Using gold ensures a better and therefore more efficient transfer of force. This has a positive effect on the energy consumption of the whole mechanism and ultimately on the power reserve of the watch. Once the gold gear wheels have been manufactured using the photolithographic LIGA process, it is possible to create an attractive outer surface with delicate and stable structures.
Glass bridge with integrated shock protection
for the balance wheel
Nowadays, a movement without shock protection would be unthinkable. Classic designs, such as the “Incabloc” comprise a total of five micro elements. These include the bearings, the fixed bearing jewel and the endstone jewel, and a spring. The ring jewel, which may move in its bearing if there is a large impact, is pushed back into its central position by the spring. As a result, frictional resistance must be overcome. This is not the case with the InnoVision 2’s innovative system. Ulysse Nardin manufactures the balance cock itself and the entire integrated shock protection system from glass. The system consists of a coil spring held in place by resiliently suspended balance shaft bearings and a height-restricted cover. The bearing returns to its original position without being slowed by friction thanks to this innovative monobloc construction method, as the glass spring simply moves back to its rest position. In addition to flexibility and strength, glass exhibits extraordinarily good frictional behavior. In contrast to silicium, which the 2007 InnoVision 1’s balance wheel bridge and shock protection were made from, glass is completely transparent and is nowhere near as fragile as it might appear to be at first glance. Ulysse Nardin has relevant expertise in this field, thanks to its previous experiments with glass.
Super-LumiNova filled channels integrated into the glass
balance wheel bridge
Manufacturing the InnoVision 2’s balance cock from transparent glass offered unforeseen opportunities to the engineers and material scientists. During the production of this component, they were able to create delicate channels within it. When it is dark, impressive light effects are created thanks to the use of Super-LumiNova to fill in the channels. The manufacturer has a patent pending for this sophisticated process. (1 patent pending).
Eye-catching 1 – 11 and 13 – 23 time display
It is generally known that a whole day is comprised of 24 hours, which are conventionally divided into two times twelve. When it comes to ways displaying exactly what the time is, there are some examples of hands which only rotate around their axis once every 24 hours or additional day-night indicators. Looking at what the market currently offers, Ulysse Nardin has taken an innovative, if not entirely new step with the InnoVision 2. The display represents the hours 1 to 11 first and then those from 13 to 23 digitally. The digits can be read through appropriately shaped apertures. The corresponding printed ring is moved directly by the large barrel. The respective mechanism requires 15 minutes each time it switches between midday and midnight. (The hours before (AM) and after (PM) midday appear in the windows in different colors.) Ulysse Nardin has applied for a patent for this extraordinary time display. (1 patent pending).
Three-dimensional glass minute hands
In the course of a day, many individuals look at their watch more often than they look in the mirror. Alongside the exceptional digital time display, the InnoVision 2 also has a minute hand which is unrivaled on the market. In truth, it is a three-dimensional glass sculpture, manufactured using precision laser cutting. The resolution that can be achieved through this process is in the range of three to five micrometers. To ensure that the delicate glass creation is not damaged by violent impacts, it sits on a fine metal plate.