Press Release - October 2007 v.2

BASELWORLD 2006


Patek Philippe Geneva - October 2007 v.2

Patek Philippe presents the Spiromax® balance spring – a patented invention that improves the isochronism of mechanical watches.

A year after the launch of the first Swiss lever escapement with a silicon escape wheel (patent application No. EP05006186), Patek Philippe presents an additional fundamental innovation: the Spiromax® balance spring made of Silinvar™. It is an epochal step forward in the constant quest for isochronism in portable mechanical watches. On the occasion of Baselworld 2006, the Geneva workshops will showcase the first watch with this innovation in a second limited “Patek Philippe Advanced Research” edition: the Ref. 5350 with a Spiromax® spring and a silicon escape wheel.

Isochronism is the key to every measurement of time based on any form of vibration. The greater the regularity of the vibration, the better the movement can be adjusted to achieve a high rate accuracy. If the source of the vibration is perfect, it is called isochronous. The key factors that disrupt isochronism are:


Ever since the spiral balance spring emerged, countless attempts have been made to eliminate its anisochronism. The history of the so-called hairspring is characterized by four milestones:


A new milestone: the Spiromax® spring by Patek Philippe

Spiromax® is a totally new type of balance spring made of Silinvar™, a revolutionary material based on monocrystalline silicon. It was developed jointly with two partners in the Swiss watch industry and a leading research institute. But it is not the material that prevents the asymmetric development of the spring. To make it breathe concentrically, the fundamental research department at Patek Philippe developed a new terminal “curve” design. The patented “Patek Philippe terminal curve” (patent application No. CH 20030749/03 & No. EP 03009603.6) exhibits a discernibly thicker region at the outer end, forcing a concentric development upon the Spiromax® spring. This causes the expansion and contraction of the spring to be symmetric relative to its center over the entire plane of oscillation. And because the “Patek Philippe terminal curve” lies within this plane, the Spiromax® spring can be crafted three times thinner than a spring with a Philips or Breguet overcoil, thus facilitating the construction of ultra-thin movements.


The Spiromax® spring exhibits additional important design features. In the center, it has an integral self-centering balance staff collet with which it is attached to the balance staff. At the outer end, it has an integral stud attachment geometry (patent application No. CH 01711/05 & No. EP 03020394.7) which precisely defines the active length of the spring.


With its revolutionary Spiromax® spring, Patek Philippe has created an oscillating element that unites several decisive advantages. The active length of the Spiromax® spring does not need to be painstakingly adjusted for each individual movement. The Spiromax® spring vibrates with ideal concentricity even without an overcoil. It is designed to be isochronous regardless of the temperature, the orientation of the movement, or the presence of magnetic fields.


Spiromax® springs: consistently identical quality

As is the case with the silicon escape wheel, the Spiromax® spring is manufactured with the photolithographic Deep Reactive Ion Etching (DRIE) process. The material exhibits a contiguously homogeneous monocrystalline structure and can be machined to tolerances in the micrometer range. Accordingly, all Spiromax® springs are of consistent, extremely high quality, a fact reflected by the remarkable rate accuracy of movements equipped with them.


The Patek Philippe Spiromax® spring at a glance
The first Patek Philippe watch with a Spiromax® spring: the Ref. 5350 Annual Calendar in a limited “Patek Philippe Advanced Research” special edition

A pioneering invention like the Spiromax® spring deserves to be showcased. A second limited “Patek Philippe Advanced Research” edition of the self-winding Annual Calendar Ref. 5350 in 18K rose gold is therefore being launched on the occasion of Baselworld 2006.


Its caliber 324 S IRM QA LU is the first movement fitted with a Spiromax® spring made of Silinvar™. As a further exclusive feature, it is also equipped with a silicon escape wheel. To do justice to these technical innovations, the movement has a specially shaped balance cock that reveals a large portion of the Spiromax® spring and the going-train bridge is milled so that the mysterious blue-violet sheen of the nearly black silicon escape wheel is more readily visible. Additionally, the sapphire-crystal back has an integrated loupe and bears the inscription “Patek Philippe Advanced Research.” The solid 21K gold winding rotor features a zirconium ball bearing. Like the silicon escape wheel, the balls run dry and never need to be lubricated. The edition of this “Patek Philippe Advanced Research” model, the Ref. 5350R, is limited to three hundred watches.



For further information, please contact:

PATEK PHILIPPE S.A.

International Public Relations Dpt.

P.O. Box 2654

1211 Geneva 2

Switzerland

Tel.: + 41 22 884 20 20

Fax: + 41 22 884 25 47

Or visit our Web site: www.patek.com



Technical data


Patek Philippe Ref. 5350 in rose gold

Movement: Caliber 324 S IRM QA LU

Self-winding mechanical movement, Annual Calendar, moon phase and power-reserve indicator

Diameter: 32.00 mm

Height: 5.30 mm

Number of parts: 355

Number of jewels: 36

Power reserve: Max. 45 hours

Winding rotor: 21K gold central rotor, unidirectional winding

Balance: Gyromax

Frequency: 28,800 semi-oscillations per hour (4 Hz)

Balance spring: Spiromax® – (2 Patek Philippe patent applications)

Escape wheel: Silicon

Functions: Two-position crown:

- Pulled out: to set the time

- Pushed in: to wind the watch

Displays:

- Hours, minutes, and sweep seconds

- Power-reserve indicator at 12 o’clock

- Subsidiary dials: Day of week at 9 o’clock and month at 3 o’clock

Apertures: Date at 12 o’clock, moon phase display at 6 o’clock

Corrector buttons:

- At 10 o'clock: day-of-week correction

- At 2 o'clock: month correction

- At 4 o'clock: date and month correction

- At 8 o'clock: moon-phase correction

Included: correction stylus in ebony and 18K rose gold

Milled balance cock and going-train bridge


Features

Case: Case in 18K rose gold

Water-resistant to 30 meters

Special feature: Screwed sapphire-crystal case back, with an integrated loupe and engraved “Patek Philippe Advanced Research” inscription

Case dimensions:

- Diameter: 39 mm

- Thickness: 11.70 mm

- Width between lugs: 20 mm

Dial:

- Silvery gray

- 3 applied Breguet-style numerals in 18K rose gold, at 3, 9, and 12 o’clock

- Eight applied baton hour markers in 18K rose gold

- Leaf-shaped hour and minute hands in 18K rose gold with luminescent coating

- Leaf-shaped day-of-week, month, and power-reserve hands in 18K rose gold

- Counterbalanced seconds hand in 18K rose gold

- Railway track minute scale transfer-printed on dial perimeter

- 12 luminous pearldrop hour markers

Strap: Alligator with large scales, matt dark brown, hand-stitched, with fold-over clasp in 18K rose gold.