The outcome is a travel watch whose date display is synchronized with the respective local time. It simultaneously adjusts the date when the time zone is corrected. The new self-winding caliber 31-260 PS QA LU FUS 24H movement is endowed with eight patents. To package it in style, the manufacture created a totally new Calatrava case. Its flanks are guilloched with the inimitable hobnail pattern and its dial is framed in the vintage genre inspired by old photo cameras.
The connection between the Annual Calendar and the Travel Time function involved several technical challenges. The issue wasn’t just to accommodate both mechanisms in the same case. They had to interact in such a way that the displayed date corresponded with local time, hence the time at the location of the wearer of the watch. And it may need to be adjusted when the time zone is corrected. Thus, in the new caliber 31-260 PS QA LU FUS 24H movement, the Annual Calendar is controlled by the Travel Time function and it is the local-time hour wheel that drives the calendar.
For the new Ref. 5326G-001, Patek Philippe redesigned the Travel Time function as well. While the basic principle with two hour hands from the center is retained (solid hand for local time, pierced hand for home time), the two common time zone pushers in the left-hand case flank were replaced with a winding-stem setting mechanism that has three positions. To optimized the efficiency, precision, durability, safety, and operating convenience of the caliber 31-260 PS QA LU FUS 24H movement, the engineers developed several innovations that resulted in eight patent applications.
For instance, these technical refinements make it possible to reduce the energy consumption and wear of certain components, to switch from the 30th to the 1st and from the 1st to the 30th without desynchronizing the calendar when adjusting the time zone, to prevent shifts and double jumps of the displays or avoid damaging parts of the movement if the moon phase, the month, or the day of the week are corrected in a time frame during which this is explicitly inadvisable. To accommodate this mechanical movement with its exclusive functions, Patek Philippe created a new white-gold case with a diameter of 41 millimeters. With its slightly chamfered bezel and the polished, inclined lugs, it underscores the sleek and timeless elegance of the Calatrave design yet expresses its very own distinctive personality. The case middle displays Patek Philippe’s signature hobnail motif along its entire circumference.
Another unique facet of the Ref. 5326G-001 is its vintage-style dial. It is crafted entirely by Cadrans Flückiger in Saint-Imier, a dial specialist which has belonged to Patek Philippe since 2004. It is an aspect that quickly associates with getaways, wanderlust and exploration. The time of day is shown by applied Arabic numerals in white gold with beige luminous coatings. The hours of local time and the minutes are displayed with luminous white-gold “Seringue” hands that with their long tips resemble syringes.
A pierced “Seringue” hand indicates the hours of home time. The three apertures of the Annual Calendar – day of the week and month on one line at 12 o’clock, date at 6 o’clock – show easily legible black inscriptions on white backgrounds. Two small round windows marked “LOCAL” at 8 o’clock and “HOME” at 4 o’clock are day/night indicators for local time and home time, respectively. This balanced arrangement is complemented by the subsidiary seconds that sweeps the moon-phase aperture at 6 o’clock. The calendar indications can be adjusted with the aid of small correctors in the caseband located near the respective functions: day at 10, month at 2, date at 4 and moon phases at 8 o’clock. The vintage aspect is emphasized with a slightly raised box-design sapphire-crystal glass.
The new Ref. 5326G-001 Annual Calendar Travel Time is delivered with two interchangeable straps, one beige calfskin with nubuck texture (original version), the other black calfskin with embossed textile finish and beige decorative stitching (additional strap). Both straps underscore the vintage style of the dial. They both assure comfort and safety with a fold-over clasp in 18K white gold.
The eight patents of the new caliber 31-260 PS QA LU FUS 24H movement
• Timesetting with three crown positions (Swiss patent application CH 716383 A2)
This timesetting system has a lever with three positions that can deactivate certain wheels as long as they are not performing any correction. This reduces energy consumption and wear of the respective wheels. The result is a gain for the balance amplitude (rate accuracy) and for reliability
• Forward/backward mechanism for the Annual Calendar (European patent application EP 3776095 A1)
This system relies mainly on the addition of a tooth and a spring on the month lever that allows the transition from the 30th to the 1st and from the 1st to the 30th without desynchronizing the date. Therefore, the user can easily switch the time zone forward or backward with the winding stem.
• Linear time-zones spring (European patent EP 3650953 B1)
This system consists of a star wheel and a jumper spring. It allows a strong torque increase between the local time hour wheel and the home time hour wheel and thus an acceleration of the date jumps despite the increase in energy consumption. It provides the user with more precise information.
• Pivotable holding bridge (European patent applications EP 3714336 A1 and 070431/2021)
This system keeps the day disc in position without the use of a center screw. To remove the disc, the watchmaker merely needs to pivot the bridge to the side. This releases the star without requiring the disassembly of the movement and without any modification of the settings. This timesaving and simplification is part of the improvements in watch maintenance.
• Inertial delta (European patent application EP 3822711 A1)
This mechanism offsets the inertia difference between a heavier and a lighter wheel. When the time zone is being corrected in either direction, it prevents an unintended forward or backward misalignment of the time displays (home time, local time, minutes). This increases the accuracy of the displays.
• Braking mechanism for the date disc when a correction is made (European patent application EP 3882716 A1)
This system with an additional spring (brake) is only active when the crown is pulled to the middle position. It prevents double jumps of the date disc if the user exerts too much force. It safeguards the greater reliability of the mechanism (amplitude gain and wear reduction).
• Flexible correctors (European patent application 20205322.9)
With a system of flexible leaf springs for switching protection purposes, this mechanism prevents the risk of a material failure when the user performs a correction during an unfavorable time window. This improves the reliability and longevity of the movement.