Since 1977, the ultra-thin caliber 240 has shown proven performance and reliability. Over the years, Patek Philippe has modified this self-winding movement with additional functions for numerous models.
Its evolution continues with caliber 240 PS CI J LU, which drives the Cubitus Instantaneous Grand Date, Day and Moon Phases.
Last October Patek Philippe launched the Cubitus collection with this model boasting a novel complication to mark the milestone.
The integration of the grand date required adding 104 parts to the base caliber. Despite its parts totalling 353 and with a height of 4.76mm, the new movement accommodates with the slender profile of the square-shaped case with rounded corners and a diameter of 45mm.
The caseback in sapphire crystal offers a view of the caliber with an off-centre gold mini-rotor adorned with the same pattern of horizontal lines as the blue sunburst dial.
Caliber 240 PS CI J LU.
Patek Philippe's engineers re-worked the base movement by adding an instantaneous-jump calendar mechanism for the large-format date, displayed by means of two coplanar disks placed on exactly the same plane.
Another mechanism makes it possible to manage the jumps from 31 to 01 while keeping the 1 digit stationary via gears with truncated teeth. An "anti-double-jump" system further prevents any change of the date in the case of a shock or during correction.
The grand date is displayed in a twin aperture at 12 o'clock while the coaxial day and moon-phase indications at 7 o'clock are complemented by a small seconds counter at 4.30.
The development of caliber 240 PS CI J LU involved the filing of six patent applications, notably relating to the complex energy management for the various displays and their simultaneous jumps.
To avoid any time lag, Patek Philippe also engineered an instantaneous-jump mechanism for the day and moon-phase indications. Accordingly, at midnight the displays simultaneously jump in 18 milliseconds, using the energy accumulated throughout the day.
The moon-phase display is so precise that it takes 122 years to deviate by a single day from the lunar cycle.
Two coplanar disks for the grand date.
The calendar, however, requires resetting on the first day of March, May, July, October and December by using correction push-pieces set into the flanks of the platinum case.
Like all Patek Philippe's platinum timepieces, this model has a diamond -- for the first time a baguette-cut stone, set into the bezel at 6 o'clock.
A strap in a navy-blue composite material with a fabric motif and contrasting cream stitching enhances the "casual chic" style of the Cubitus Instantaneous Grand Date, Day and Moon Phases.
