Patek Philippe, the Swiss watchmaker, has launched the stunning Calatrava Weekly Calendar timepiece (Ref. 5212A-001), which displays the week number, in addition to the day of the week and the date, making this a new function for calendar watches.
With a diameter of 40 mm and a thickness of 11.18 mm, the stainless steel Calatrava case, a rare feature for Patek Philippe, also stands out thanks to the finesse of the bezel that extends over the two-tiered, gently curved strap lugs. The case is cold-formed in the manufacture’s ateliers with high-tonnage presses, and is then meticulously hand-polished by experienced artisans, a highly complex undertaking given the many sharp edges and angles.
Its aesthetic appeal is inspired by the Ref. 2512, a one-of-a-kind piece made in 1955 and held in safekeeping by the Patek Philippe Museum. This kinship is emphasised by the reference number of the new Calatrava Weekly Calendar that consists of the same numerals in a different order. The vintage aspect is amplified by a box-type sapphire-crystal glass with a slightly cambered profile. The stainless steel snap back has a sapphire-crystal inset that allows the movement to be observed at work.
To display the day of the week and the number of the current week, Patek Philippe developed a totally new semi-integrated mechanism with a height of 1.52 mm, containing 92 additional parts. Thanks to a special plate that was developed and produced for this specific mechanism, the movement remains very svelte. A seven-point star on the hour wheel in the centre of the movement controls the day-of-week display. Via a lever, a second seven-point star with an extended Sunday tip drives the 53-tooth week wheel. The calendar displays advance semi-instantaneously in discrete steps to avoid energy consumption peaks. Corrections of the day-of-week and week-number displays are performed with two push-pieces recessed in the case flank at 8 and 10 o’clock.
The date can be corrected with the crown pulled halfway out. Thanks to a fail-safe concept, the user can perform such corrections at any time of day or night without risking damage to the movement. The manufacture places great emphasis on convenience and user-friendliness. Pursuant to the international ISO 8601 standard, Patek Philippe chose Monday as the first day of the week rather than Sunday, which is commonplace in some countries. The first week of the year is the week that includes the 4th of January.
The 53-graduation scale considers years with an extra week (this happens every five to six years), and the next occurrence is in 2020.
The weekly calendar mechanism is not the only special feature of the Ref. 5212. The watch has a totally new movement based on the self-winding calibre 324. It is the outcome of several years of development work. The calibre designation 26-330 reflects its diameter of 26.6 mm and height of 3.3 mm. The new movement sports several innovations and optimisations that improve its performance and dependability. The first innovation concerns the centre second.
To prevent the second’s hand from vibrating, and to eliminate friction, the manufacture’s engineers decided against the habitual centre second pinion with friction spring. They replaced it with an innovative system based on an anti-backlash third wheel. This patented component is made of a nickel-phosphorous alloy with the LIGA process (lithography, electroplating and moulding) and is then completed with a gold-copper-iridium coating.
It features an avant-garde geometry with long split slotted teeth, each with a tiny integrated 22-micron leaf spring that engages with the second pinion teeth to suppress vibrations of the second’s hand without any prior adjustment work.
The sapphire-crystal case back of the new Calatrava Weekly Calendar timepiece reveals the refined architecture and painstaking finesse of the movement as prescribed by the Patek Philippe Seal.
Patek Philippe Calatrava Weekly Calendar – specification at a glance:
- Movement: 26-330 S C J SE, self-winding mechanical movement, sweep seconds, date, day of the week and week number
- Total diameter: 27 mm
- Casing diameter: 26.6 mm
- Height: 4.82 mm (base movement 3.30 mm, partially integrated weekly calendar mechanism 1.52 mm)
- Number of parts: 304, of which 212 are for the base movement and 92 for the weekly calendar mechanism
- Number of jewels: 50
- Power reserve: Min. 35 hours, max. 45 hours
- Case: Stainless steel, sapphire-crystal case back
- Water resistance: To 30 metres
- Case dimensions: Diameter: 40 mm
- Height (crystal to display back): 10.79 mm
- Height (crystal to lugs): 11.18 mm
- Strap: Calfskin, hand-stitched, bright brown, with stainless steel prong buckle
Patek Philippe Calatrava Weekly Calendar watch – Where and How?
For more information on the Patek Philippe Calatrava Weekly Calendar (Ref. 5212A-001), visit www.patek.com. The watch is priced at 29,500 CHF (around £23,000).