The genesis of a new classic
The Watch Quote™ - March 26th, 2010
All good things take time. And if it has to be perfect, it might take some more time. After all, the ambition with the new CH 29-535 PS chronograph caliber for the Ref. 5170J was not just to present a classic manually wound chronograph movement with a column wheel and a horizontal clutch built entirely in-house. The objective was also to outperform its predecessor, the CH 27-70 PS, which was based on a Lémania movement blank extensively reengineered and modified by Patek Philippe to create one of the most beautiful chronograph calibers ever made. When the new chronograph movement premièred last November with the launch of the Patek Philippe Ladies First Chronograph, the CH 29-535 PS caliber was discussed in-depth by many journalists and found to fulfill the loftiest expectations.
It has been worth the wait
Patek Philippe spared no effect to exceed all expectations with its new classic wrist chronograph. Indeed, the development of the CH 29-535 PS movement took more than five years, spanning several stages that also embraced further chronograph calibers including, in 2005, the CHR 27-525 PS with a height of just 5.25 mm: it holds the world record as the thinnestAll good things take time. And if it has to be perfect, it might take some more time. After all, the ambition with the new CH 29-535 PS chronograph caliber for the Ref. 5170J was not just to present a classic manually wound chronograph movement with a column wheel and a horizontal clutch built entirely in-house. The objective was also to outperform its predecessor, the CH 27-70 PS, which was based on a Lémania movement blank extensively reengineered and modified by Patek Philippe to create one of the most beautiful chronograph calibers ever made. When the new chronograph movement premièred last November with the launch of the Patek Philippe Ladies First Chronograph, the CH 29-535 PS caliber was discussed in-depth by many journalists and found to fulfill the loftiest expectations.
It has been worth the wait
Patek Philippe spared no effect to exceed all expectations with its new classic wrist chronograph. Indeed, the development of the CH 29-535 PS movement took more than five years, spanning several stages that also embraced further chronograph calibers including, in 2005, the CHR 27-525 PS with a height of just 5.25 mm: it holds the world record as the thinnest split-seconds chronograph movement with column-wheel control. The new chronograph movement inherited its chronograph wheels with the patented tooth profiles. In 2006, the workshops presented the self-winding Annual Calendar chronograph with a disk clutch that delivered further important insights regarding power flows and amplitude characteristics in chronographs. Finally, five further inventions were incorporated in the new caliber CH 29-535 PS to achieve the desired degree of perfection.
Traditional movement architecture
The CH 29-535 PS caliber is controlled by a column wheel that according to proven traditions rotates beneath a polished cap. While the cap hides the refined details of the column wheel, it also firmly secures the chronograph levers in their positions – even in the event of sharp jolts – so it enhances functional reliability, a top priority at Patek Philippe. The movement features a large chronograph hand, a seconds subdial, and an instantaneously jumping 30-minute counter. Its prominent four-arm Gyromax balance wheel breathes with a frequency of 4 hertz (28,800 semi-oscillations/hour). The power reserve of the watch is 65 hours (over 58 hours when the chronograph is running), and a stop-seconds mechanism simplifies the exact synchronization of the watch with a time signal.
A tradition of ongoing innovation
Even though the CH 29-535 PS caliber is based on the classic column wheel and horizontal clutch architecture, it stands out with six patented innovations that manifest the unfaltering ingenuity of the Geneva-based manufacture.
Further ingenious features
- Optimized tooth profile
Suppression of hand bounce or rebound when starting. Vibration-free chronograph hand movement. Improved efficiency and reduction of mechanical wear.
- Precision adjustment of wheel mesh at the column wheel
The large eccentric polished column wheel cap allows the very precise adjustment of mesh depth of the chronograph wheels at the outer end of the clutch lever.
- Optimized synchronization of the clutch and brake levers
The clutch lever and the brake lever are directly synchronized with a finger at the clutch lever. The complicated involvement of the column wheel is not necessary.
- Slotted minute-counter cam
Thanks to a slot in the minute-counter cam, the chronograph counter can gently come to a standstill when reset.
- Self-setting hammers
Self-setting return to zero hammers improve functional reliability and dependability.
- Hammers pivoted between jewel bearings
The two hammers that reset the chronograph hand and the minute counter are independently and coaxially suspended between jewel bearings. Each hammer is pressed against its respective heart cam with its own spring. This system optimizes the precise alignment of the hammers and the kinetics of the mechanism.
The CH 29-535 PS movement has a number of additional features that improve reliability and performance. For example, the instantaneous 30-minute counter is much more complicated than a semi-instantaneous or continuous counter. Its elaborate construction assures that the small hand jumps within a fraction of a second, enhancing precision and legibility. The driving wheel of the chronograph is another example: it is directly integrated in the wheel train and does not need to be subsequently assembled by the watchmaker.
The beauty of mechanical engineering
As befits the heritage of Patek Philippe, the CH 29-535 PS caliber is not only extremely precise and reliable, it is also a masterpiece of aesthetics and supreme workmanship. It has strikingly elegant form parts and old-style bridges that are painstakingly chamfered, polished, and decorated with Geneva striping. Every surface, no matter how small, is finished in numerous consecutive steps, in most cases by hand. In compliance with the Patek Philippe Seal criteria, these movement decorations in no way impair the caliber’s functional integrity. Like all other steel parts, the classic S-shaped clutch lever has manually chamfered and polished edges, straight-grained flanks, and meticulously polished surfaces.
For this movement as well, all teeth of the steel wheels and all pinion leaves are individually polished by hand with a rotating hardwood disk to optimize power transmission and reduce wear.
The perfect manifestation of the Patek Philippe Seal
From its underlying concept to the artistic finissage, the new CH 29-535 PS is a perfect reflection of the quality stipulated by the Patek Philippe Seal. The philosophy behind it focuses on convenience, functionality, and long-term reliability. The shapes and configuration of the bridges serve a single purpose: to assure efficient power transmission from the mainspring barrel to the escapement with minimized friction losses in the interest of amplitude stability and rate accuracy. Every movement part was examined by the Comité de surveillance (Supervisory Authority) of the Patek Philippe Seal to make sure it complies with the manufacture’s strict technical and aesthetic directives. As proof of conformity, the minute-counter cock of every CH 29-535 PS movement exhibits the gold-filled, engraved Patek Philippe Seal: a coat-of-arms silhouette with the intertwined PP initials that stand for Patek Philippe.
A movement with so many ancestral features of haute horlogerie deserves the regalia reserved for classic traditions. With Patek Philippe’s new Ref. 5170J chronograph, this begins with the 39-mm round case in 18K yellow gold. Its sleek shape follows the same principle of gestalt that the manufacture adopted in 1932 when it created the legendary Calatrava design, quasi inventing the modern round men’s wristwatch. Its physique is devoted entirely to functionality, endowing it with tangible elegance. With a gentle flourish, the lugs extend from the caseband, imbuing the watch with dynamic poise. The chronograph is operated with pushers at 2 and 4 o’clock. Their rectangular shape has been a typical attribute of Patek Philippe wrist chronographs for seventy years. Particularly for a manually wound watch, the crown is also an important element. It is knurled for convenient winding with two fingers but small enough not to jab the wrist when the hand is bent back. The chronograph case is produced with a traditional cold-forming process in which small solid-gold bars are gradually swaged into cases in high-precision dies using heavy-duty presses. After each cycle, the case parts are heated to relieve internal stresses. Once the case blanks have been formed, they are deburred, ground, and polished in several consecutive phases with successively finer abrasives. The result of this time-consuming series of processes is a mirror-polished case that from then on is handled only with gloves to eliminate even the slightest blemish.
Elegance paired with functionality
The Ref. 5170J chronograph is a consummate statement of timeless elegance. The silvery white dial has slender applied hour markers as well as yellow-gold applied Roman numerals at 12 and 6 o’clock and black transfer-printed scales. The logarithmic pulsimeter scale on the outermost perimeter is calibrated to 15 heartbeats, revisiting the traditional doctor’s watch. The railway track minute scale features slightly compressed Breguet numerals. The seconds subdial at 9 o'clock and the 30-minute counter at 3 o'clock are recessed in the main dial and arranged somewhat below the horizontal center axis to balance the maker’s signature and the pulsimeter scale inscription in the upper half of the face. The hour, minute, and seconds hands that indicate legal time are crafted from yellow gold to match the hour markers and Roman numerals, while the chronograph seconds and minute hands are black. The counterbalanced trotteuse is black oxidized, and the instantaneously jumping 30-minute counter is made of black nickel-plated yellow gold. Unquestionably, the face of the Ref. 5170J can hardly be excelled as regards elegance, beauty, and legibility.
By adding the new Ref. 5170J wrist chronograph to Patek Philippe’s men’s collection, the Geneva-based manufacture has made a wish come true for many watch collectors and connoisseurs.