Considering its advantages, the Geneva manufacturer developed Silinvar®, a patented material obtained through oxidation in a vacuum causing molecular modification of the surface of the pure silicon components. One of the main advantages of the components resulting from this technology is due to the fact that they allow compensation for thermal variations, a quality essential to the stable running of the oscillator. Another important point: since it is not a surface coating, they are not altered over time due to their operations.
On the strength of this technological breakthrough, the Advanced Research workshop of Patek Philippe immediately focused on the regulating organ of timekeepers that is essential to their precision. In 2005, the company inaugurated the approach with the first component made of Silinvar®, the pallet wheel for the Swiss lever escapement. One year later, it unveiled the Spiromax®, a Patek Philippe spring with a terminal curve, and did it again this year with the Pulsomax® equipped with the Silinvar® pallets and pallet wheel. For Patek Philippe, “each of these new developments brought a significant and measurable improvement to the performance of the mechanical movement.”
Movement improvement and optimisation
“The Pulsomax® is still a Swiss lever type of escapement,” the manufacturer explains. This escapement, used in almost all mechanical watches, has been recognised for nearly 180 years for its reliability, sturdiness and performance. Thanks to the precision of the machining, the new Silinvar® pallets no longer have ruby pallet-stones. The pallets have been resized in order to increase the performance of this escapement. Thus, the pallets transmit an increased driving power to the balance. Moreover, these pallets work with a new pallet wheel that has 16 teeth instead of the usual 20. “A decisive factor in its production: the progress made in the DRIE (Deep Reactive Ion Etching) plasma engraving process now enables the silicon components to be machined on a second horizontal level by machining a second time. For the Pulsomax®, this has enabled a completely new shape of the palette fork extremities to be created, eliminating the use of a guard pin.
According to Patek Philippe, applied to the Annual Calendar Ref 5450, this new escapement combined with Spiromax® improves the escapement’s reliability because it operates without lubricant, optimises its operations by reason of a better isochronism and improves the performance of the Swiss lever escapement, thereby allowing a 30% gain in the autonomy of the movements operations.