Patek Philippe Perpetual Calendar Chronograph Ref. 5270G

In 1925, Patek Philippe created the world’s first wristwatch with a perpetual calendar: the Ref. 97’975. It always correctly displayed day of the week, the month, and the date for months with 31 and 30 days and, depending on the leap-year cycle, February with either 28 or 29 days.

The brand started regular production of perpetual calendars only in 1941. Created before 70 years, these Ref. 1518 chronographs with perpetual calendars featuring display apertures for the day and month as well as rectangular pushers are now favorites in international auctions by fetching top prices and still repeatedly breaking world records.

While Patek Philippe concentrated on the launch of new chronographs from November 2009 to the end of 2010, the emphasis is now on other complications. But to the delight of many watch lovers, the year of chronographs has not quite ended yet. One example is the new Ref. 5270, which for the first time combines the functionality of a perpetual calendar with the new classic chronograph caliber that is crafted entirely in-house and had its global debut in 2009.

This year, on the occasion of the 70th anniversary of its first wristwatch with a perpetual calendar and a chronograph, Patek Philippe unveils a new complicated wristwatch: Perpetual Calendar Chronograph Ref. 5270.

Patek Philippe Perpetual Calendar Chronograph Ref. 5270

The new manually wound chronograph caliber with a perpetual calendar CH 29-535 PS Q; probably incorporates more innovative optimization features than any other traditional chronograph mechanism. For example, the engagement and disengagement action takes place in the traditional manner with the driving, clutch, and chronograph wheels, but instead of the conventional triangular teeth, these wheels have newly calculated and patented toothing profiles that reduce wear, boost efficiency, and prevent tooth tip collisions.

Moreover, the engagement of the wheels is not adjusted with customary eccentrics but instead with the slightly eccentric shape of the polished column-wheel cap that very precisely defines the position of the clutch lever at its outermost point. Further optimization features include self-setting hammers pivoted between jewel bearings, the synchronization of the brake lever with the clutch lever, and the slotted minute-counter cam that prevents the excessively abrupt deceleration of the wheel in response to a reset command.

Thanks to this group of six patent-pending inventions, the new caliber is decidedly the most advanced of all traditional chronograph movements. It is also the perfect choice for driving the perpetual calendar, one of the most popular Patek Philippe complications. Indeed, the eternal calendar is of particular significance for the workshops in Geneva.

Patek has developed a totally new mechanical calendar module to add the perpetual calendar complication to the manually wound basic chronograph caliber CH 29-535. It took two years to perfectly match the 1.65-mm high traditional cam-controlled calendar mechanism with 182 parts to the chronograph ensemble.

Thus, the perpetual calendar of the Ref. 5270 demonstrates Patek Philippe’s competence in dealing with complex components such as large levers, date, day and month stars, and year cams with planetary leap-year wheels, jumper springs, and other intricate parts. Additionally, the many steel parts in the going train and the calendar mechanism stand out not only as regards their precision but also with respect to the artistic finishing that turns them into tiny, aesthetic masterpieces.

They exhibit manually satin-finished flanks and straight-grained surfaces as well as carefully chamfered and polished edges – and as opposed to plain flat 45° bevels, the chamfers are slightly convex, a typical Patek Philippe detail. The steel wheels and pinions are also meticulously finished: all teeth and leaves are individually polished by hand using a rotating hardwood disk.

This work is done not just for the sake of beauty. Smoothly polished surfaces generate less friction, reduce wear, and transmit kinetic energy more efficiently.

Patek Philippe Perpetual Calendar Chronograph Ref. 5270G white gold

Dial of the new Perpetual Calendar Chronograph Ref. 5270 reflects the genetic code of the original model that was launched in 1941. These family ties are apparent in the aperture displays for the day of the week and the month at 12 o’clock. The analog date dial at 6 o’clock features an integrated moon-phase display which is so precise that it deviates from the true lunar cycle by merely one day every 122 years.

The seconds subdial on the left and the instantaneously jumping 30-minute counter on the right are slightly below the horizontal centerline: this is a characteristic feature of the new manufacture caliber. As was the case 70 years ago, the black-oxidized gold hands for standard time are leaf-shaped, as in the Ref. 1518 presented in 1941, while the chronograph hand with its counterweight has a slender lancet-style silhouette.

The applied baton hour markers in black-oxidized gold are framed by a railway-track minute scale and the chronograph scale. The two small, round apertures for the day/night indication (between 7 and 8 o’clock) and for the leap-year indication (between 4 and 5 o’clock) are hallmarks of the modern perpetual calendar.

The fact that the silvery opalescent dial with a visible diameter of 32.4 mm accommodates a total of eleven indications in a well-organized and legible way, testifies to the unique competence and uncompromising timepiece design philosophy of Patek Philippe.

The case of the Ref. 5270 sets a worthy stage for the complicated caliber CH 29-535 PS Q movement and the clear dial. With a diameter of 41 mm, it is distinctly larger than its predecessors and radiates contemporary generosity and elegance.

Crafted from 18K white gold, it is a classic three-part construction manufactured in-house with the traditional cold-forming technique. Placed in high-precision dies, the solid white-gold blanks assume their final shape while being subjected to the force of heavy-duty, high-tonnage presses.

Cold-forming is followed by many hours dedicated to machining the bores for the crown, chronograph pushers, correction push pieces, and strap bars as well as for deburring, precision grinding, and mirror polishing; after these operations, the case with the concave bezel and the elegantly curved lugs is finished. The 18K white-gold chronograph pushers exhibit the same slightly rounded rectangular shape as those that adorned the first Patek Philippe wristwatch chronographs with perpetual calendars of the 1940s and 1950s.

The strap lugs with the slightly concave flanks were also inspired by these earlier models. The screwed display back with the sapphire-crystal window showcases some of the most attractive elements of mechanical watchmaking artistry: the large Gyromax balance as well as the key levers and wheels of the chronograph mechanism.

These beautifully crafted movement parts are among those that can be admired in action. The watch is worn with a hand-stitched matt black alligator strap secured with an 18K white-gold foldover clasp.

Technical details

Model: Patek Philippe Perpetual Calendar Chronograph Ref. 5270G

– Caliber CH 29-535 PS Q
– Manually wound mechanical movement, column-wheel chronograph, chronograph hand, instantaneously jumping 30-minute counter, and subsidiary seconds. Perpetual calendar with day, month, leap-year cycle and day/night indication in apertures, analog date. Moon phases.
– Diameter: 32 mm
– Height: 7 mm (of which 1.65 mm for the perpetual calendar)
– Number of parts: 456 (of which 182 for the perpetual calendar)
– Number of jewels: 33
– Power reserve: 65 hours
– Balance: Gyromax®
– Frequency: 28,800 semi-oscillations/hour (4 Hz)
– Balance spring: Breguet

Two-position crown
– Pushed in: To wind the watch
– Pulled out: To set the time and stop the seconds hand

Center hour and minute hands
Chronograph hand (trotteuse) from the center
Subsidiary dials:
– 30-minute counter between 3 and 4 o’clock
– Subsidiary seconds between 8 and 9 o’clock
– Date at 6 o’clock
– Day and month on an axis beneath 12 o’clock
– Moon phase at 6 o’clock
– Day/night indication between 7 and 8 o’clock
– Leap year cycle between 4 and 5 o’clock

Corrector push pieces:
– Day corrector between 1 and 2 o’clock
– Month corrector between 12 and 1 o’clock
– Moon-phase corrector between 6 and 7 o’clock
– Date corrector between 11 and 12 o’clock
Delivered with correction stylus in ebony and 18K white gold

Chronograph pushers: 
– Start and stop at 2 o’clock
– Reset at 4 o’clock

Patek Philippe Seal

18K white gold, sapphire crystal, screwed display back with sapphire crystal window
Water-resistant to 30 meters
Case dimensions: Diameter: 41 mm
Height: 12.40 mm
Width between lugs: 21 mm

Silvery opalescent
Twelve applied hour markers in black-oxidized gold
Leaf-shaped hour and minute hands in black-oxidized gold
Counter-balanced chronograph hand from the center
Subsidiary dials, off-center, circular guilloché pattern
– Subsidiary seconds between 8 and 9 o’clock. Leaf-shaped hands in black-oxidized gold
– 30-minute counter between 3 and 4 o’clock: Leaf-shaped hands in blackoxidized gold

Alligator leather with square scales, hand-stitched, matt black, foldover clasp in 18K white gold.

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