Introducing the Patek Philippe Ref. 5236P-001 In-Line Perpetual Calendar

The highlight of Patek Philippe’s new releases for Watches and Wonders 2021 was its new in-line perpetual calendar display, the Ref. 5236P-001.

Nearly 80 years ago, Patek Philippe introduced its first centre-seconds perpetual calendar wristwatch in the Ref. 1591. It was a revolutionary model, presented in the midst of a world crisis. As we face a different challenge today, the Maufacture once again offers us a bold new design in an inspired watch model.

The Ref. 5236P is a perpetual calendar with centre seconds, featuring an in-line aperture display that shows the day, date and month on one single plane for convenient reading. A leap year indicator sits at the 4 o’clock position while the day/night display is at 8. The seconds counter combines a moonphase display on a vivid blue dial, and the aperture discs are also printed in matching blue text.

The Ref. 5236P In-Line Perpetual Calendar by Patek Philippe is a bold new design full of innovation.

To achieve this design, while keeping the watch relatively slim, a brand new movement has been created. The caliber 31-260 PS QL is a redesign of the caliber 31-260 REG QA that was introduced in 2011 for the Ref. 5235 Annual Calendar Regulator. Powered by a platinum micro-rotor, it offers a power reserve of up to 2 days while driving the perpetual calendar.

Patents Pending

The linear calendar display is presented with 4 rotating discs to minimize energy use while maximizing legibility. The mechanism is developed as a separate module for the base movement so that the movement remains a slim 5.8mm. Requiring 118 additional parts compared with a conventional perpetual calendar, it incorporates a display that uses 2 double ball bearings on the same plane. To ensure an accident-free operation, a patented “anti-double-jump” feature keeps the discs from jumping due to shock or a manual date change.

To manage the leap month of February, a satellite cam runs separately with the 12-month cam. An intermediate wheel connects the calendar module with the base movement via the minute hand pinion and meshes with the 24-hour wheel to manage date jumps. To manage the date jump from the 31st to the 1st, a third patent locks the units disc when the tens move from ‘3’ to ‘0’.

To ensure there was enough energy to drive the perpetual calendar, the barrel spring’s torque was increased by 20%, while the winding efficiency was increased thanks to the denser platinum rotor. The display also switches slowly, rather than an instant jump, to minimize any amplitude dip in the escapement. Thanks to the micro-rotor design, parts of the gear train can be seen from the case back. On the case sides, correctors can be seen to adjust the calendar displays.

An Elegant Blue Dial

The blue lacquer with black gradation and vertical satin-finished dial features railway track indexes housed in a case with a chamfered bezel, with angled lugs for a better fit on the wrist. Baton-style hands display the time, and the calendar display sits right under the Manufacture’s name on the dial. By combining the display, it frees more space on the dial, making it incredibly legible and simple to access at a glance. The watch is paired with a navy blue alligator leather strap with platinum fold-over clasp.

For such a complicated watch, the Ref. 5236P is very discreet in style. One glance at the watch and you might not realize its full prowess. It’s hard to imagine 503 components lie within the watch. One can certainly visualize its potential with other complications, say a perpetual calendar chronograph featuring the same in-line display. The potential for this design is endless; we can’t wait for an annual calendar model to be released in the same style.

The Ref. 5236P-001 is available on request at Cortina Watch. Contact a sales representative for more information.

Discover more on Patek Philippe’s new 2021 watches.

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