In 1825, the famous Roret Manuel de l’horloger had this to say about oil: “Among the substances used by the watchmaker, oil is the one that occupies the primary place of importance. Regardless of the care with which the watch parts are handled, their functioning is subordinate to the continual existence of grease placed in all parts where rubbing occurs; without this precaution, the organs in contact with each other will soon deteriorate and finally become destroyed causing the device to stop… As the situation stands, there is absolutely no lubricating material that can conserve its basic qualities indefinitely; everything is changed over time. The length time that timekeepers will function is thus limited by how much time will pass before the oil will deteriorate.”
More than 180 years later, this observation is still valid. In those days, olive oil—highly recommended by the authors during that era—ceded its place to more sophisticated fine oils and grease. But the result is still more or less the same: after a certain time, oil, no matter how high-tech, will deteriorate and, under certain extreme conditions of cold, will solidify, thus blocking the operation of moving parts; under extreme heat, it can also vaporize and spread throughout the case. Since the beginning, watchmakers have dreamed of reaching the unattainable ideal, of finding the ‘Holy Grail’ of timekeeping, of creating a watch without oil, a watch that would not need to be lubricated. Yet, the elusive ‘Holy Grail’ remained a dream.
In search of the ‘Holy Grail’
However, this dream has not been forgotten. Recently, a number of steps were taken in this direction—most notably we might mention the utilization of silicon or ceramic ball bearings, used by Jaeger-LeCoultre since 2002—but these advances were only limited improvements because oil and grease still remained indispensable for the other moving parts.
Recently, however, there has been a dramatic breakthrough in terms of the oil-less watch. With the presentation of its Master Compressor Extreme LAB at the SIHH 2007, Jaeger-LeCoultre has finally found timekeeping’s ‘Holy Grail’. The brand can be duly proud to have produced the first movement that requires no lubrication. This is a historical first, a real revolution (and for once, the term is not overused).
But to eliminate all lubrication is one thing. To make this a decisive advantage, not only in terms of reliability over time but also in terms of gaining precision, is yet quite another thing. The company’s ‘laboratories’ thus worked in several directions at the same time: the research on materials and surface treatments that would allow the elimination of lubrication; and the research on new shapes, notably of the regulator, which would provide the sought-after increased precision. The researchers also did not ignore the case, whose functional design had to be on the same level as the technical challenges. It was a global project, conducted by a multi-disciplinary research team chosen especially for the task at hand.
The regulating organ
Let’s begin by detailing the procedures and the choices that led to the elimination of all lubrication, and in particular, that of the regulating organ, at the heart of the endeavour. Traditionally, the jewelled regulating organ is lubricated with a fine oil placed on five oiling points. In the new Calibre 998C, four special materials have been combined in order to eliminate the need for lubricating these points: Easium™ carbonitride, black mono-crystalline diamond, silicon, and molybdenum bisulfide.
The material Easium™, used notably in the nuclear industry, made its entry into the world of watches because of its very high degree of hardness and its exceptional tribological properties, which means the very low friction coefficient, or rubbing factor, of its surface. The use of Easium™ is the subject of the first of six patents that cover the Master Compressor Extreme LAB. This material replaces the traditional jewels, made of rubies, that require oiling. The Easium™ also works in conjunction with another material, molybdenum bisulfide, which also has a very low rubbing factor. The molybdenum bisulfide is used to coat the burnished steel pivots of the balance staff, which turn inside the Easium™ bearings, thus no lubrication is needed. The two bearings turning the tourbillon carriage are also made of Easium™.
Close by, the traditional ruby pallet stones have been replaced by another material: mono-crystalline black diamond. Composed of 100 percent carbon atoms, this synthetic diamond is the hardest material in the world, and it also has a very low rubbing factor. Thus, no lubrication is required when the diamond touches the silicon teeth of the escape wheel. Not only is the wheel lighter (this is important because of inertia since it stops and starts incessantly), but also because of its revisited shape, the silicon wheel works better when combined with the diamond.
Gear and winding systems
Let’s leave the regulating organ and take a look at the gear trains. Here, too, we see that the pivots have been coated with the molybdenum bisulfide compound. However, the jewels of the moving gears have been preserved because, with their weaker rotational speeds compared to the regulating organ, the interaction of the jewels and the molybdenum bisulfide allows optimal operation without the addition of oil.
Let’s now pass to the winding system, beginning with the barrel. Traditionally, grease is added to the barrel for two reasons: first, the grease helps to prevent the wear on the spring whose spirals rub against each other; and secondly, it lets the bride slide smoothly inside the drum.
In the Extreme LAB, it has been possible to eliminate these various grease points thanks to the use of graphite powder. Placed inside the barrel, the graphite adheres to the spring’s spirals, letting them slide smoothly against each other, without rubbing. Graphite, also made of carbon atoms, is a very stable material, whose molecular structure takes the form of a stack of micro-platelets. It has the advantage of being basically unchangeable over time, regardless of the temperature and hygrometry levels. The grease points inside the winding and time-setting mechanism have also been eliminated, since the entire mechanism has been coated with Nickel-PTFE.
Optimal performance of the oscillating weight is also assured by ceramic ball bearings (used by Jaeger-LeCoultre since 2002), while friction has been reduced even more by using new materials to create the oscillating weight itself.
In addition to new materials, the oscillating weight has been given a new geometry. With its totally new shape, it is composed of two elements: its openwork support, made of carbon fibre that was chosen for its rigidity and lightness; and the weight itself, which is made of an iridium platinum alloy, the densest non-toxic material currently in existence. With this combination, the total thickness of the mass can be reduced by 14 percent and its weight reduced by 28 percent, all while maintaining the same winding rate. It also offers better resistance to shocks and improved reliability over time. The innovative oscillating weight is the subject of the second patent registered for the Extreme LAB.
Let’s return for a minute to the regulating organ in order to have a closer look at its geometry because, here too, it has been fundamentally revisited, starting with the balance. To our surprise, we notice that the balance does not have the traditional circular shape, but is made up of two weights connected on each side of an oscillating arm. How did the researchers come up with this? By studying, at great length, the relationship between the total surface of the balance and its aerodynamic performance, the Jaeger-LeCoultre team was led to re-look at its shape. The larger the surface of the balance, the greater is the aerodynamic friction and the greater is the energy required to maintain the oscillations of the balance spring, which is detrimental to the precision. By drastically rethinking the shape of the balance, made in the very dense iridium platinum alloy in order to minimize its aerodynamic friction, the researchers were able to succeed, at a constant inertia, in creating a balance that requires significantly less energy.
The form of the arms, openings, and pointed ends of the weights all enable the mass/inertia ratio to be reduced. While a high inertia ensures a stable regulator that is not very sensitive to shocks, it nonetheless means a larger mass, resulting in higher mechanical friction and higher energy consumption to maintain the oscillations, as well as a greater difference in amplitude between the horizontal and vertical positions. The new balance of the Calibre 998C is successful in reducing the total mass without modifying the determined inertia. This low mass/inertia ratio, by reducing the amplitude variations between the different positions, allows the watchmaker to perform a more precise adjustment of the watch (the adjusting screws are also aerodynamically cast inside of two weights). This new type of balance is the subject of Jaeger-LeCoultre’s third patent on the Extreme LAB.
A concentric balance-spring
The balance-spring also helps optimize precision in the Extreme LAB. Its isochronism has been significantly improved because of an operation that can be qualified as nearly micro-surgical in nature. We know that, for a balance-spring to beat in the most concentric manner possible, the outer terminal curve of the spring traditionally gets deformed. This is what happens with a so-called Phillips terminal curve, but this curve only re-centres the outer spirals that beat in a slightly off-centred fashion. In order to also act on the inner spirals, so that the balance-spring beats in a perfectly concentric manner, the watchmakers at Jaeger-LeCoultre introduced a distortion, in the form of a ‘bend’, that modifies the rigidity of the spring at a specific point close to the collet pinning-point. This ‘bend’ improves performance by decreasing the variations between the different positions, and, inside the tourbillon, it offers better equilibrium all the way around.
The tourbillon carriage has also been revisited and corrected. Made of a magnesium alloy, it is very light, weighing 0.199 grams, and is 20 percent lighter than titanium. It also helps cut energy losses due to friction and reduces the inertia by 38 percent.
The combination of a high-inertia balance (11.5mg/cm2) and a frequency of 28,800 vibrations per hour allows the Extreme LAB to attain exceptional performance: the tolerance in the movement is -1 to +4 seconds per day (compare this to the COSC standards which are -2 to +8 seconds per day).
Researching the exterior
It would only be fitting that the case enclosing and protecting this exceptional movement be deeply and carefully considered from top to bottom and then re-designed so that its aesthetics reflect the technology as much as possible. Each component part making up the case has therefore been studied in detail, beginning with the movement’s suspension system and the necessity to avoid any metallic contact with the case, including the crown. The solution, which makes up the fourth patent covering the Extreme LAB, is a supple polyurethane seal that also surrounds the crown. This functions not only as a waterproof seal but it also protects the movement and winding stem from external shocks and vibrations by letting them ‘float’ inside the case.
The case itself is quite resistant both in terms of its materials as well as its structure. It is composed of an interior case in carbon fibre, chosen for its rigidity, which is fitted inside a titanium ring, and protected on the top by an ultra-light and highly resistant bezel made of silicon carbonitride. The structure of this case resulted in the fifth patent for the Extreme LAB.
The sixth patent covers the attachment system for the bracelet, whose perfect fit around the wrist is ensured by an original system of notched adjustments in the strap fastening. The bracelet itself is made up of a multi-layered combination of materials such as leather, ultra-strong cordura canvas on the bottom layer, and alcantara on the top.
The extreme attention paid to even the slightest details of the Extreme LAB is also seen in the transparent dial, revealing the heart of the movement. A central element of this dial is a bridge made of Ticalium®, an alloy of aluminium reinforced with particles of titanium carbide, which gives it better mechanical hardness and resistance, without increasing the density. Above is a small transparent sapphire crystal dial shaped like an arc of a circle. The black of the central bridge, the white of the numerals and hour markers, the grey of the tourbillon bridge, and the various touches of red—second time zone, date hand that jumps above the tourbillon, crown, stitching of the bracelet—all come together to create an attractive and functional design for the Master Compressor Extreme LAB, representing a new generation in timekeeping.
Creating the future
We could say that, in its own way, the Extreme LAB is the fruit of the 174-year old history of the Jaeger-LeCoultre manufacture, marked by a continual spirit of innovation as well as the integration of the various métiers and savoir-faire into a single integrated company. More directly, the Extreme LAB is the ‘daughter’ of recent innovations such as the spherical tourbillon introduced in 2004, the crystal gong in 2005, or the ellipse isometer escapement in 2006, which brought in new professions such as watchmaking analysts, computer simulation specialists, and material engineers.
Co-existing with the most traditional métiers, these new practices allow for the continuous validation of the theoretical by the practical: simulations that interact with product development, providing for progressive confirmation of procedures; measurements of all parameters such as torque, energy, friction, aerodynamics, simulations of wear and aging, etc.
These new métiers, grouped together in a specific unit that complements the existing structures of development, laboratory, and prototyping, permit Jaeger-LeCoultre to tackle new challenges, including precision and reliability, that await watchmaking in the 21st century. This spirit is summed up by the brand’s management with a quote from Steve Jobs: “The best way to predict the future is to create it.” The Extreme LAB is proof that the brand is doing just that.
Source: Europa Star August-September 2007 Magazine Issue