Patek Philippe Announces New GyromaxSi Balance and Updated Pulsomax Escapement; Endows Materials Chair

Patek Philippe Ref. 5550P

Patek Philippe today announced several developments related to the company’s efforts in the areas of advanced materials and their chronometric uses. A new GyromaxSi balance in Silinvar and gold will be coupled with a newly-updated and improved Pulsomax escapement and put to work in new limited edition reference 5550P perpetual calendar Advanced Research timepieces. Patek has also endowed a research chair dedicated to the application of new micro and nanotechnologies to watchmaking.

Launched six years ago, the Patek Philippe Advanced Research department is dedicated to creating innovative components from the latest materials using the latest technologies with the ultimate goal of producing more reliable and more accurate timepieces. In 2005, Advanced Research produced the Silinvar escape wheel which required no lubrication. In 2006 came the concentrically breathing flat Spiromax balance spring in Silinvar for improved isochronism. 2008 saw the launch of the Pulsomax escapement in Silinvar for more efficient power transmission.

Today Patek Philippe announces the GyromaxSi balance in Silinvar and gold, as well as the next evolutionary step of the Pulsomax escapement. The brand claims that the use of these new Silinvar components in the limited edition Patek Philippe perpetual calendar Ref. 5550P increased the power reserve from from 48 hours to a maximum of 70 hours – enough that it can be left on the nightstand for a whole weekend without having to be readjusted on Monday morning.

The GyromaxSi balance construction consists of two diagonally opposed circular sectors crafted from Silinvar and 24K gold. The chassis is etched out of silicon wafers with the DRIE process (deep reactive ion etching) and converted into a Silinvar component by way of oxidation. The centrifugal masses are gold inlays integrated into the chassis with a technique patented by Patek Philippe. The GyromaxSi balance also features four small slotted poising weights that can be precision-adjusted according to the Gyromax principle (variable moment of inertia). The Gyromax adjustment concept was developed by Patek Philippe in the 1940s and received patent protection in 1951. Now, at the age of 60, advanced technology has created a worthy successor.

The GyromaxSi balance exhibits an unusual “hourglass” shape. Below is a basic drawing, and on the right, one end of the balance is visible in the caliber 240 Q Si movement that powers the new reference 5550P.

GyromaxSi Balance

As explained by Patek, a balance must exhibit several precisely defined properties including light weight and as much inertia as possible. In conventional balance designs, this apparent contradiction is resolved with a full-circle rim held by a number of arms (spokes). This shifts the balance wheel’s mass out to the periphery and reduces its weight. But even then, friction losses must also be minimized. Friction is encountered in the bearing jewels that contact the arbor pivots, and aerodynamic drag must be overcome as well. The air resistance of the balance wheel alone accounts for estimated friction losses of about 60%.

To concentrate as much of the total balance mass as possible at the periphery, the mass at the arbor must be reduced to the greatest extent. Patek says that its GyromaxSi fulfills this requirement with a Silinvar structure that carries centrifugal masses at its outer ends. The use of 24K gold for the balance wheel rim (2.5 times more density than traditional balance materials) allows a perceptible reduction of volume. The low density Silinvar reduces the mass at the arbor by nearly two thirds. Patek also says its design using two diametrically opposed masses results in tangibly decreased air resistance. Dynamic measurements have confirmed that the energy bonus in comparison with an ordinary rim-type wheel is more than 20%. The GyromaxSi balance retains the familiar Gyromax poising weights, now placed in an aerodynamically optimized configuration. These poising weights make it possible to precision-adjust the watch according to the principle of variable inertia, which is to say without altering the active length of the balance spring and without upsetting the isochronism of the watch.

The new Pulsomax escapement differs from the type launched in 2008 and, according to Patek, contributes strongly to increased efficiency in the movement. Largely redesigned, especially as regards the pallets, the escapement transmits power to the balance wheel much more efficiently. The pallet ends feature a locking notch that nudges the lever into the ideal position of departure just before the next impulse occurs.

The Pulsomax escapement requires no lubrication, which simplifies maintenance and improves long-term reliability. It is crafted from Silinvar and leverages the following material properties: manufacturing precision, low density, antimagnetic characteristics, and corrosion resistance.

Oscillomax is Born

Because Spiromax, Pulsomax, and GyromaxSi interact, but in reality are independent components, Patek Philippe refers to them as an ensemble named Oscillomax. Thus, a watch with Oscillomax incorporates a Spiromax balance spring, a Pulsomax escapement, and a GyromaxSi balance. In the image below, Oscillomax is engraved on the caliber 240 Q Si balance cock:

Patek Philippe Oscillomax

The last three development steps in Silinvar technology based on silicon were translated into Patek Philippe Annual Calendar watches with the caliber 324 S IRM QA LU movement. These watches were presented in limited editions of 100 to 300 pieces as “Patek Philippe Advanced Research” models, and each edition sold out within months.

To present the complete Oscillomax ensemble, Patek Philippe has turned to the legendary selfwinding caliber 240 with a perpetual calendar. The movement incorporates the following Silinvar components: the patented Patek Philippe Spiromax balance spring, the patented Pulsomax escapement, and the patented GyromaxS balance. Patek Philippe has applied for a total of 17 patents in conjunction with the Oscillomax subassembly as a whole and also filed patent applications for its individual components.

The reference 5550P will be produced in a limited edition of 300 pieces. The images below may be enlarged significantly with a click.

Patek Philippe 5550P
Patek Philippe ref. 5550P


Patek Philippe Endows Chair at the Institute of Microengineering in Neuchâtel

Patek also announced that it has endowed the new Patek Philippe Chair. Created in collaboration with EPFL (Ecole Polytechnique Fédérale de Lausanne), the Chair will be associated with the Institute of Microengineering (IMT) and based in Neuchâtel. The Chair is dedicated to the application of new micro‐ and nanotechnologies to watchmaking. Patek Philippe’s contribution will be to fund the position of a professor and his or her research team, and EPFL will provide infrastructure.

The Neuchâtel‐based IMT, which has been part of EPFL since 2009, is growing rapidly and is becoming a center of excellence, thanks to the creation of several new research teams and a network that brings together all the major players in the Swiss microengineering industry. Neuchâtel is an advantageous location, since the Jura region is the historical seat of many watchmaking and high‐tech companies. This Chair will build a bridge between the private sector and academic research.

To maintain this position and its competitiveness, the industry must continually innovate. “There is much progress to be made, particularly in increasing the energy efficiency of the movements in order to be able to make ever smaller mechanisms and components, and in increasing reliability and the power reserve,” explains Jean‐Pierre Musy, technical director at Patek Philippe.

The research touches on all production phases: from manufacturing processes to escapement mechanisms to components such as the train and the balance‐spring that must be made more efficient, uniform, robust and easy to assemble. A particularly important area of exploration will be developing new high‐tech materials, in the continuing quest for properties that will reduce friction, add to esthetics, and improve wear resistance – much like single‐crystal silicon, which has revolutionized the industry over the past several years thanks to its elastic properties which have permitted the creation of carefully crafted geometries that allow improved watch movements.

The person nominated to this Chair will thus have as his or her objective to investigate a number of research avenues, to assemble a team and to train researchers and scientists to become experts in the field so that they can continue to improve and promote these innovations.

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