The Patek Philippe ‘Advanced Research’ department has been diligently researching the possibilities of introducing new materials and components to the serious business of mechanical watches. There is no escaping the wide range of modern materials or the vast possibilities they represent. Ignoring these potentials would be folly considering we live in the 21st century. In retrospect we can look back to transportation such as trains, motorcars, and airplanes to see the impact that modern materials have brought to their advancements’.

Patek Philippe is not alone in their innovative dedication to advanced technology. However they prefer to move ahead with the same steadfast dedication, no matter the time and resources required, which has made the name Patek Philippe synonymous with excellence.

The first innovation from the Patek Philippe ‘Advanced Research’ department was the Silinvar® escape wheel in 2005 that is based on the material silica. Silinvar®, developed by CSEM in Neuchatel Switzerland in exclusive collaboration with Patek Philippe, Rolex and Swatch Group, has very unique properties such as extreme hardness that reduces wear and also the need for lubrication, it is anti-magnetic, and is extremely light. But possibly the most interesting and practical advantage of Silinvar® is its ability to be manufactured using “Deep Reactive Ion Etching’ or DRIE. It is DRIE that brings new possibilities in terms of accuracy to Silinvar® components, up to 5 times the accuracy when compared to conventionally manufactured steel components.

2006 brought the introduction of the Spiromax® hairspring, another Silinvar® component. Spiromax® brings a new dimension to the art of hairsprings. Besides the important fact that it is totally non-metallic, and hence non-magnetic, the entire spring could be manufactured as a whole component using DRIE. Gone are the tedious tasks of pinning, forming, and adjusting each and every hairspring since each Spiromax® hairspring is exactly the same. And possibly more important was the ability to form a unique, and patented, terminal curve at the outer end of the spring (seen here as a bit of a bulge). It is the terminal curve and its shape that deceptively gives Spiromax® the ability to perform equally well at all power levels provided by the main spring. Spiromax® hairsprings have also been designed to compensate for the thermal expansion of the Gyromax® balance wheel. In brief; as the balance wheel expands with increased temperature, the Spiromax® becomes less flexible which enables a complimentary result maintaining a regular frequency of the oscillator. A very calculated and critical marriage of technology that would not be possible without the technology of Silinvar® and DRIE.

Manufacturing Silinvar® components to exacting standards was the highlight of 2008 when Patek Philippe introduced their new pallet fork; the final component of Pulsomax®, “The Trilogy”, as I like to call it, was complete. The precision of DRIE manufacturing shed new light on the age-old problem of proper pallet fork geometry. Ruby pallets stones are no longer required as to the hardness and greatly reduced friction of Silinvar®. Lubrication of the pallet and escape wheel, a considerable disadvantage of conventional lever escapements’, is now obsolete. Subtle, but very important, geometric forms can now be incorporated within the pallet fork as never before in order to improve its interaction with the escape wheel resulting in greater efficiency and accuracy.

Since 2005 Silinvar® components have been incorporated into several specific limited editions of Patek Philippe watches. Patek Philippe progressively introduces current Silinvar® innovations to current production, as for example Spiromax®, to the line of watches that use Cal 324 movements. This encompasses the broad spectrum of Patek Philippe men’s watches including Nautilus, Aquanaut, Calatrava and Annual Calendar models.

Not surprisingly the Patek Philippe ‘Advanced Research’ department has not been sitting idle. Bringing new innovations to time keeps minds sharp and ideas fresh. One of these sharp fresh ideas concerns the balance wheel, another integral component of the regulating mechanism. The idea for a new balance wheel design might look quite radical at first glance but there is good reason behind this development.

“Balance Wheel” is a fitting description for a wheel that oscillates radialy on a singular axle and must be perfectly balanced if it is to accomplish its duty with perfection as demanded in a mechanical watch.

Silinvar® is used to construct the skeleton of this new development while a new idea is introduced to place as much inertia (effective mass) to the outer perimeter of the wheel via a gold alloy that is incorporated with Silinvar® during the manufacturing process. The idea is to keep the balance wheel carriage (skeleton) as light as possible while placing the weight at the extreme perimeter that increases the effective mass while in oscillation. After all it is the effective mass of the balance wheel married with the consistent elastic properties of the hairspring that result in the most important aspect of precision mechanical time keeping.

Knowing full well that every mechanical mechanism is comprised of multitude components, adjustment of time is necessary. The new Patek Philippe balance wheel in development takes this into consideration via a dual set of timing weights (red) that are diametrically opposed at the exterior of the Silinvar® skeleton. These weights are the same that have been used in the patented Gyromax® balance for many years. A simple turn in one direction or another brings timing to perfection within fractions of a second per day. The road to the future of precision time is becoming wider due to advanced technology.

Pulsomax® and Spiromax® have brought forth a new frontier in materials and geometry to precision watchmaking. Modern materials such as Silinvar®, and its manufacturing methods DRIE, have helped to open these new vistas.

However the age-old struggle of controlling an oscillating balance wheel with a spiral hairspring might be the most difficult quandary in watchmaking and not to be ignored. At Patek Philippe these new challenges are being embraced with steadfast dedication and tempered by the idea that everything takes time…

Patek Philippe has a long history of being a vigilant company; carefully guarding its heritage, and most importantly its customers. Changes do not happen overnight at Patek Philippe, each one being cautiously considered taking as much time as necessary to make a well-informed decision with purpose. The words “fad and trendy” do not exist in the Patek Philippe vocabulary, instead being replaced with the words “tradition and trust”. So it is that Philippe and Thierry Stern, the Family owners of Patek Philippe, started to consider the possibility of creating their own standard of excellence several years ago that is now the “Patek Philippe Seal”. Let’s have an inside look at the purpose and benefits that this decision brings to the Patek Philippe customer.

The purpose of the Patek Philippe Seal was to create a new world recognized benchmark for Patek Philippe watches that would incorporate all of the standards that have always made a Patek Philippe watch special. This decision was not made in an egotistical manner but rather was aimed at formalizing and communicating what stands behind the Patek Philippe quality, internally and outside the company, and to bring a stronger guarantee of excellence to their customers. The directives of the Patek Philippe Seal are very strict, stronger than any other benchmark from any other watch company and most importantly envelop the watch in its entirety. And so after more than 120 years Patek Philippe has started to replace the long standing Geneva Seal with the Patek Philippe Seal beginning in mid 2009. This change over will take approximately 2 years to complete and like the Geneva Seal will only apply to mechanical watches.

The Geneva Seal was established in 1886. The main purpose was to certify the quality of origin for watches being manufactured within the Canton (State) of Geneva Switzerland and could not be used by watch companies located outside of Canton of Geneva. The criteria of the Geneva Seal are pointed to the quality and finish of the movement parts only, governing the visual presentation of all components and their mechanical functionality. Time keeping accuracy, cases, dials, and all other aspects of a finished watch are not included in this criterion. The Patek Philippe Seal is not meant to replace the Geneva Seal, many other quality watches from other brands will continue with the Geneva Seal while only watches manufactured by Patek Philippe will be endowed with the Patek Philippe Seal.

How, and why, does the Patek Philippe Seal differ from the Geneve Seal? Firstly the Patek Philippe Seal encompasses the entire watch that is being delivered to the customer as whole, not fractional pieces of the finished product. Of course all watches will continue to respect the exact standards of fit and finish that have always existed at Patek Philippe such as to meet a timing rate of -3/+2 seconds per day for watches with mechanical movements of more than 20 mm in diameter. This timing test is administered on the finished/complete watch in a dynamic manner that more accurately resembles real wearing conditions as compared to the current industry standard (COSC) that is carried out in static positions for the movement only. The reasoning here is simple, a customer purchases a watch, not only a movement, and expects his/her watch to keep accurate time. It is a well known fact that once a movement is fit into its case the overall accuracy will inevitably change, so guaranteeing the finished product accuracy is very important.

The Patek Philippe Seal goes far beyond the time keeping accuracy of every Patek Philippe watch. Each and every component is controlled numerous times prior to being assembled to create a watch, and controlled again as a completely finished Patek Philippe watch. By the time a Patek Philippe watch is completed there have been hundreds of quality assurance inspections carried out, and each inspection must meet the directives mandated by the Patek Philippe Seal, without exception. Even the precious gems used as adornments are not immune to the scrutiny of the Patek Philippe Seal as they must be of the highest quality (Top Wesselton) in all aspects and must be set to very exacting specifications. Never are adhesives used, and all gems are set in either radial, or linear positions in order to amplify their cut and brilliance

Service is the final, and possibly most important, guarantee of the Patek Philippe Seal. To create a fine watch is only half the story especially if there is nothing standing behind it after the sale. Patek Philippe has always stood behind every watch they have produced, no matter the age. The Patek Philippe Seal guarantees, in writing, that every aspect of your watch will be serviceable for many future generations. Great after sales service requires a strong and tight-knit structure between the manufacture, distributors, and retailers. Every watchmaker who services a Patek Philippe watch must complete continuous and vigorous training, which guarantees that every watch can be returned to the customer meeting original factory specifications.

It is the discipline of the Patek Philippe manufacture, and the personal guarantee of Mr. Philippe Stern, and Mr. Thierry Stern, that puts weight behind the Patek Philippe Seal. They are the guardians of the Seal collectively. It is not by accident that your Patek Philippe watch keeps perfect time, your minute repeater sounds perfect, the case is of the highest quality in terms of finish and material content, and the movement parts are all hand-finished to the highest standards in the industry. There is no substitute for respect. Respect for watchmaking, respect for the customer, and most importantly, respect for the longevity of your watch and its relationship with the parent company, Patek Philippe.

In this edition of Rendezvous we will discover the art of gem setting, or stone setting as it is sometimes referred. The gem setter has a very risky job in that they are responsible for the final adornment of jewelry that are made of gold or platinum and which already have many hours of work invested via other craftsmen. A fine eye for geometry and nerves of steel are required since one tiny mistake will ruin all the many hours of previous work sending the object to the melting pot. In this particular watch there are more than 1,000 diamonds within the dial, case, and bracelet, all which are set entirely by hand.

Quality gems are essential to any fine piece of jewelry. Selecting a reputable gem supplier is of paramount importance, someone who is totally trustworthy and will deliver the best gems as agreed. Sub quality gems are very common in today’s market and so at Patek Philippe only flawless top Wesselton diamonds are used, with each gem being subjected to quality control at the Patek Philippe internal gemology department for absolute quality assurance, nothing is left to chance. Once the gems are delivered it is not as simple as opening the package and setting them to the jewelry object. First the gems are sorted by size to exacting measurement to assure uniformity. Next the gems are carefully examined by the gemologist for any inclusions before being sent to the gem setting expert. And again it is the gem setter who, via years of experience, control the quality as each gem is set by his/her hand and eye.

Round cut gems are the most commonly used in jewelry pieces and therefore we will examine the art of setting them firstly. In this example the gems have been set in the upper half of the Twenty~4 earring. While at the bottom the stones have not yet been set. The gem setter must first make small pockets with a drill, or burr, that will receive the gem. This is totally done by eye using only a drawing for comparison and reference. A keen eye for the size of each gem to be set is of paramount importance.

Now that the pockets have been established the gem setting begins. Each stone is set in an appropriately sized pocket given its diameter (girth). Along the perimeter of each stone a very sharp cutting tool, or -graver- as it is known in the trade, is used to raise a series of pips in the precious metal. In most cases 4 pips are raised that will act as “claws” to be gently pulled over the edge of the stone to secure it in place. In some circumstances, such as corner stones, only 2 or 3 pips will be raised as space may be at a minimum. Most importantly is that the claws are of ample strength to hold the gem securely, and the setter must not break this delicate spur of metal while performing the intricate task of gently bringing it up and over the edge of the gem forming the claw. Imagine making as many as 4,000 claws to hold 1,000 stones without breaking one single claw in the process!

Random, or mixed, setting of diamonds is another form of gem setting but with a twist. In this example you will notice that the diamonds along the straight edges of the bracelet and case are placed in rows of equal size stones. However the diamonds set in the dial and bracelet links are of many different sizes and placed in a random pattern. The idea of random setting is to create a surface either flat or curved with as much brilliance as possible, something that cannot be achieved with row set diamonds due to the symmetrical spaces required between the stones. This technique is only suitable for large surfaces and is rarely used due to the technical difficulty required. The gem setter must first survey the surface to be set as well as the collection of diamonds at his/her disposal. There is no drawing to work from and therefore requires an expert eye to see clearly all the possibilities and to fill the space as completely as possible. Think of it as snowflakes of different sizes that eventually cover an entire surface, and like snowflakes each random set jewelry piece is a totally unique piece of gem setting art with no two ever being the same.

Diamonds are not the only gems of distinction. Colored stones such as rubies and sapphire are sometimes mixed in settings to create arrays of color and contrast that can mimic nature or be total fantasy. In this instance a deep pocket with five leaves, representing a rose is first formed by the engraver. A bouquet of red rubies are set in the petals while a diamond is set in the middle of the flower representing the heart. I should note that in my efforts to show you the “real deal” the article shown here was still in the process of setting, hence there are minute marks that will be perfectly polished away at the next step.

Blind setting has its origins in more modern times thanks to innovations in case fabrication and gem technologies. The idea is to create a seamless series of gems, without the conventional claws that hold them in place and the separations between the stones. In theory you might think it to be an easy way of setting the gems, but looks can be misleading. The bezel of this gents watch has 52 baguette diamonds set in a circular pattern. There are no spaces between the stones since each stone has been lapped to an angle of exactly 6.5 degrees. Think of it like a pie with each piece forming an angle that completes the circle. Squares or rectangles can never form an uninterrupted circle. The buckle is no exception: each stone has been lapped to very specific angles in order to complete the intricate pattern.

Key to blind setting is the use of a shallow groove that runs the length of the gem just below the girth. If more than one row of diamonds will be set side-by-side there would be a groove on two sides of the stone. The groove cut in the gem is fit into a channel with a corresponding nib fabricated in the gold or platinum object that holds the stones in place without the need for claws or spacing between the stones. There is -zero- room for error in this process, the groove in the diamond must be absolutely perfect in its depth and location in relationship to the girth, and the nib of the channel must be just as accurately fabricated. Otherwise the stones might be either too tightly compressed creating the possibility of breakage, or too loosely spaced making a sloppy set. Minute fractions of a millimeter must be observed when blind setting is employed.

The art of setting gems is not for the faint hearted, the risk is high, the tools are sharp, and an eye for accuracy is absolutely mandatory. Of course a watch isn’t the only accessory that benefits from quality gems. These ring and earrings are set with diamonds as the ultimate accessories to a fine watch. In this particular example the pattern of diamonds is passed along from the watch to different entities, such as earrings and finger ring accessories, like a constellation of stars in the winter sky.

In this edition of Rendezvous we wish to take you on a guided tour of “The Art of Cloisonné”. There are many skills required to bring a fine timepiece to life. The precision-mechanic who makes the small intricate bits and pieces, the watchmaker who assembles and adjusts the mechanism, the case maker who fabricates a home for the mechanism, and various other skilled artists who contribute their skills and professionalism to the completed object of art. The enamelers who produce such fantastically beautiful cloisonné enamel work are often overlooked artists in this chain of professionals since their work is quite rare and exclusive.

The enameler is an artist in every sense of the word. Having the eye of a classical artist who must survey the “canvas” they will adorn is paramount and being capable of working with brushes as thin as a human hair is necessary. Knowing your materials of composition such as enamels (glazes), as well as metals, critical temperatures cannot be understated. There is little margin for error in enameling since once the object is fired in the kiln it is permanent and there is no way to erase an error to start again.
Cloisonné comes from the word cloister; meaning separation. Starting with a subject the idea must be brought to the proper size. In most cases the enameler is working from a larger visual such as a painting, photograph, or totally free hand. A sketch is usually produced either on the work piece itself, or on paper that can be directly transfered to the work piece in the appropriate size. The objective at this point is to set the outline for each cloister of color that will adorn the object.

Many different metals can be used for the base (platform) of a cloisonné watch dial, however gold is the platform material of choice for all cloisonné dials at Patek Philippe. Whatever the choice of platform material the next step is to lay extremely fine strips of gold wire thus forming the shapes required to produce the cloisters. This is an extremely time consuming process since the gold wire is very delicate and the shapes can be very difficult to form. In the example shown here the platform has been chased/engraved prior to the gold wire setting to create subtle textures that will be visible through the translucent glaze. In case you are wondering, the wire is initially attached to the platform via a mild adhesive that will burn away during the firing process.

Having shaped the wires and set them the next step is to select the color and type of glaze that will fill the individual cloisters of the object. Early enameling, thousands of years ago, was merely a matter of fusing rough pieces of glass to a metal surface. Over many centuries the art of enameling has evolved giving the enameler more direct involvement in the final result. Today it is common amongst the best enamelers that they mix their own glazes using a combination of ground glass and other components to get the exact color and transparency they feel is required. Think of glazes as “secret recipes”, each unique to the artist.

The “canvas” has been set with the cloisters being established via a gold wire grid, and the colors selected. At this point the enameler will fill each cloister with the exactly selected glazes that have been so carefully mixed and prepared. This particular process may sound simple but in reality there may be several applications of color, each being fired briefly in the kiln with overlapping layers, before a final product is established. In this instance the prepared glazes are being held on a small pallet in one hand while the other hand is carefully filling the cloisters with a very fine brush. Notice the color chart and sketch in the foreground.

At the side of every good enameler is a color chart that they have personally mixed and fired in their individual kiln in order to ensure that each color is to their exact specification needed for the project at hand. In this particular case the enameler has mixed different combinations of components to his/her preference as a reference they will use in the next step of cloisonné. Keep in mind that the initial mixture of components in the raw form of powders will not necessarily show the end result, it -must- be fired in the kiln to prove the colors required will indeed bring a fantastic subject to life.

After firing in the kiln 6 or 7 times, possibly more, as layers of glaze are built within the cloisters the final piece of art is discovered exposing its magnificent rainbow of color. As with all other aspects of the enameling art the firing process is very important. The artist must understand and observe the critical (melting) temperatures of each and every material involved, otherwise the result will be a molten glob of metal and glass with no artistic value. Typically the kiln is set to a temperature of about 1450F (800C) degrees but this might very well be adjusted a bit higher or lower depending on the combination of materials being incorporated. In this example of cloisonné there are a varied effect of colors and textures thanks to the combination of engraving and chasing that underlies the translucent glazes selected by the artist to realize a greater amount of detail to the subject.

Paillons are another technique used by the enameler to add a greater sense of depth and detail to their work. Starting with a sheet of gold leaf, gold that has been rolled very thin, a special punch is fabricated that will produce the tiny paillons that can be made to fly over the underlying enamel. The gold leaf is a very thin sheet of almost pure gold, 22/24K, 5 times thinner than a typical sheet of writing paper! Using the tiny punch by hand the enameler needs only to push slightly on the gold leaf to produce the tiny objects they will use as adornment. However it is very important to keep in mind the extremely delicate nature of these tiny objects. They are so delicate that the only way to transfer them to the work is by using a very tiny brush that the gold leaf will attach. Once transfered the paillons are touched gently to ensure they are set well upon the enameled surface. Another trip to the kiln is required to meld the paillons permanently with the enamel. Notice how the tiny birds seem to fly in front of the clouds not within them.

A wonderful cloisonné watch dial like this is truly a miniature work of art which will endure many generations and can be enjoyed everyday if you wish. In this case the main features are formed via the cloisonné method in a mosaic of interwoven colors cast over a chased/engraved platform that brings contrast, definition, and a sense of reality to the bird and its surroundings. Whether your personal taste in art may be realism, abstract, or fantasy, it is the enamelers' special relationship with the art of glass, metals, and fire that bring us the fantastic objects we know as cloisonné.

Welcome back to Rendezvous. As promised in my previous edition I will take you on a guided tour of the newest technological development from Patek Philippe, the Pulsomax® escapement. As a refresher let me bring you up-to-date. Beginning in 2005 Patek Philippe introduced the first in a series of technological innovations from their Advanced Research department, the Ref 5250 featuring a Silinvar® escape wheel. Again in 2006 another Silinvar® innovation the Ref 5350 featuring the Spiromax® hairspring. In 2008 a trilogy of innovations culminating in the Ref 5450, featuring a Silinvar® lever, was realized. Should I mention that the Ref 5450 is a limited edition of 300 pieces in Platinum for the discerning collector. For those who may have missed the previous edition of Rendezvous we invite you to read “Pulsomax®, Ref. 5450” first, this may shed a bit more light on the subject we are about to explore.

It is a trilogy of innovations that brought Patek Philippe to the completion of their evolutionary Pulsomax® escapement. In order to begin the evolution I will start you off with an animation of a typical Swiss escapement. In the middle of the screen is a lever, or anchor, that is moving left to right and limited in each direction by mechanical banking stops. At the top is a D shaped rotating ruby jewel that engages a finely tuned slot in the lever several times per second (don’t be misconceived by the animation, it has been slowed dramatically for visual purposes). You will also notice the two ruby pallet stones inserted into the lever that dispense a small amount of energy to the lever, via the escape wheel at the bottom of the screen, each time it moves from left to right. This small, but very important, transfer of energy is what keeps a mechanical watch ticking. I should point out that the components of a typical Swiss lever escapement are made of steel with a few rubies inserted.

Now the Pulsomax® escapement. Most notable is the dramatic change in the geometric shape of the lever as compared to the typical Swiss lever. But more importantly is the fact that it is made of Silinvar®, a highbred component of Silica that has 1/3 the mass of steel. The escape wheel that provides the impulse to the lever and thus to the balance wheel, or oscillator that we will discuss a bit later, is also made of Silinvar®. The combination of Silinvar® to Silinvar® has very low friction and eliminates the need for oil. What does this mean and how does it improve my watch. Well first we should remember what happens to oil when it gets a bit old, sticky and mucky, requiring someone to clean and re-oil. And secondly when there is less friction the components wear less. Sounds simple, so why isn’t every watch equipped with a Pulsomax® escapement...

Deep Reactive Ion Etching (DRIE) is the manufacturing method that makes super precision Silinvar® components possible with each component being completely made as a singular component compared to the typical Swiss lever that is a composite of steel and ruby parts requiring numerous adjustments to operate correctly. Looking closely at these two photos you will see that the escape wheel is held via notches formed in the lever pallets, eliminating the need for mechanical banking stops as required in the typical Swiss lever escapement. Although these photos where made using a large scale Pulsomax® model, the DRIE process is the only manufacturing method capable of forming watch sized Silinvar® components to the required accuracy, up to 10 times more accurate than conventional machining methods.

So far we’ve examined two of the Pulsomax® components, the lever and escape wheel. But Pulsomax® being a trilogy consisting of three Silinvar® components it is time to examine the hairspring. Here we can see a conventional steel hairspring as it breaths while being wound and unwound via the small energy impulses provided by the escape wheel and transferred via the lever to the balance wheel. Look closely and you will see that the coils of the hairspring are not breathing in a concentric manner. In other words the coils gather up in a rather unsymmetrical pattern, wasting energy and causing undue friction upon the balance wheel.

In this example we can see the Spiromax® hairspring in action, very slow motion video. Notice how much more concentric the coils of the hairspring wind and unwind in a very symmetrical manner. This symmetry is made possible via a Patek Philippe patented terminal curve (outer coil) of the spring that could only be produced using Silinvar® and the DRIE manufacturing process. The Spiromax® hairspring plays a very important role in the trilogy of Pulsomax®.

Let me say that there are a multitude of advancements in the Pulsomax® escapement that would require a book, and a high level of watchmaking knowledge to understand completely, including the newly designed pallet geometry that has greatly improved the efficiency of the entire escapement. There are nay-sayers that discount the idea of bringing innovations into the world of watchmaking, I disagree. Until recently there was a 50+ year vacuum of new and innovative ideas in the world of mechanical watches and this might explain the resistance to the introduction of new ideas and technology. But rest assured there are watch manufacturers that have the vision, stamina, and resources to bring mechanical watches to a whole new level in the 21st century. The Pulsomax® and Spiromax® are proof of these intentions.

In conclusion let me point out some of the major advantages of the Pulsomax® escapement and Spiromax® hairspring:

As a trilogy of Silinvar® components working together they afford a much greater degree of accuracy, both in terms of mechanical accuracy and precision time keeping.

Silinvar® being of Silica is totally anti-magnetic and is thus immune to magnetic influence, a major disturbance of precision time keeping.

The manufacturing method Deep Reactive Ion Etching (DRIE) brings the most accurate components and complex geometric shapes to reality eliminating the need for hard banking pins that cause undue shock to the mechanics.

DRIE also enables the ultra precision manufacture of the lever pallets, that interact with the escape wheel, affording a much greater degree of efficiency to the watch. This results in longer running time and a more stable rate of accuracy.

Pulsomax® being of Silinvar® materials exhibits great anti-friction properties and requires no oil, lengthening the time intervals between servicing.

Thank you for visiting -Rendezvous- at patek.com. Please continue to the next page to give us your comments and critique as they are important in our pursuit of excellence.

The “Trilogy” is complete. In 2008 Patek Philippe unveils the Ref 5450 Annual Calendar wristwatch featuring the latest development from the Patek Philippe Advanced Research department, the Pulsomax® escapement. I say “Trilogy” since in 2005 Patek Philippe launched the Ref 5250 Annual Calendar watch featuring their first high tech innovation the Silinvar® escape wheel, and again in 2006 launched the Ref 5350 Annual Calendar incorporating the Spiromax® hairspring, also a Silinvar® innovation, in conjunction with the Silinvar® escape wheel.

The “missing” link. As it is with watch escapements being the regulatory heart of the watch, there are three major components of importance; the escape wheel, the hairspring, and the ancre (pallet fork). I’ve written previous articles on the Patek Philippe Ref. 5250 and Ref. 5350, and waited with anticipation the past two years for the third innovation, the missing link, to be released. Now with the Ref. 5450 this missing link, the ancre, has been incorporated using Silinvar® and in my opinion the trilogy has been completed.

Escapements are peculiar beasts that strike fear into hearts of watchmakers and have been the subject of more debate and experiments than possibly any other subject in watchmaking. Allow me to explain. All mechanical watches need a power source, the mainspring, and as its name implies is the main source of power which keeps your watch ticking away. At the opposite end of the watch mechanism is the balance wheel that by virtue of the hairspring (which is directly attached) oscillates at a certain frequency (rate) acting as the heart beat of the watch.

The tricky part of the escapement function is the transfer of power to the oscillating balance wheel. In the lever escapement, which is incorporated within virtually every wristwatch of the past 100 years, it is the ancre (pallet fork) that is responsible for this very important “connection”. How the ancre receives power from the escape wheel, and how efficiently it makes the transfer of power to the balance wheel, is a key factor in the overall accuracy of the watch performance.

The conventional Swiss lever escapement shown here is comprised mostly of steel components including the escape wheel and pallet fork. It is the rotating escape wheel that provides energy from the mainspring to the pallet fork which in turn gives a small impulse to the balance wheel several times per second that keeps it oscillating. Two ruby, or in some cases sapphire, pallet jewels are fixed into the pallet fork to reduce friction with the escape wheel. For more than 100 years this combination of steel and ruby has changed little, until now.

The differences are obvious. Immediately you might notice that the Pulsomax® escapement in this drawing looks more robust and you might assume that it is more massive in terms of weight. Quite the contrary since the Pulsomax® escapement is fabricated from Silinvar® which is 1/3 the density of the same steel components used in the conventional Swiss lever escapement. Also noticeable is the radical geometric design of the pallet fork, but we will save this geometry lesson for a future edition of -Rendezvous- when we can explore its technical merits in greater detail.

Speed is of essence. The Pulsomax® escapement components being so much lighter than conventional steel components are able to react much faster than their steel counterparts of the past and thus the transfer of power between themselves and ultimately to the oscillating balance wheel is greatly improved. As well as being lighter and faster, the Pulsomax® escapement made of Silinvar® shares excellent anti-friction properties negating the need for lubrication (oil) that has been the detriment of all lever escapements of the past.