Millenary perpetual calendar with deadbeat seconds and power-reserve indication
We have all heard about the seven wonders of the ancient world. With its Tradition of Excellence collection, first launched in 1999, Audemars Piguet is in the process of creating the eight wonders of the horological art. The Manufacture in Le Brassus proudly unveils its Cabinet N°5, issued in a limited edition of 20 watches in platinum. For this exceptional timepiece, Audemars Piguet once again innovates by offering, within an oval Millenary case, a linear read-off perpetual calendar equipped with a brand-new high-performance escapement system requiring no lubrication. A world first heralding a minor revolution in the watchmaking world – and which will doubtless turns collectors' heads around the globe.
A tradition of invention
Representing an essential component of the watch – since its function is to maintain and “count” the oscillations of the regulator organ (balance and spring assembly) – the escapement system has always stimulated watchmakers' inventiveness. One of the main goals is to reduce energy losses to a minimum and to guarantee optimal operation even when subjected to impacts and changes of position. Before the Swiss lever escapement achieved its current dominant position, the greatest horological geniuses had explored various solutions: the crown-wheel escapement, the Graham dead-beat escapement (1718) the Leroy detent escapement (1748), the Mudge lever escapement (1759), etc. In 1791, Robert Robin (1742-1799), former official royal watchmaker, invented a new type of escapement combining the advantages of a detent escapement (high efficiency) with those of the lever escapement (more secure operation). Despite an extremely ingenious principle, the Robin escapement did not enjoy the future it deserved. Certain details of its geometry made it overly sensitive to shocks; complex to manufacture, it also called for a level of accuracy in making it that was not technically feasible in that era.
A tradition of daring
For the Audemars Piguet watchmakers, innovating sometimes means challenging even the most firmly established principles. Faithful to the inventive traditions of the Vallée de Joux, the Manufacture therefore decided to explore paths different from the Swiss lever escapement which has been widely used since the early 20th century. Drawing inspiration from the mechanism proposed by Robin, it has developed an all-new direct-impulse escapement system featuring numerous advantages and is being showcased for the very first time in Cabinet N°5 of the Tradition of Excellence collection. Through its innovative concept and its exceptional performances, this new Audemars Piguet escapement represents a mini-revolution in the field of mechanical horology. It heralds the new generation of Audemars Piguet movements and will enable the Manufacture to enhance the performances still further.
A tradition of performance
The new Audemars Piguet escapement is derived from the 1791 Robin escapement. However, contrary to the latter, it is completely shock-resistant. To solve this issue, the watchmakers of the Manufacture have developed a new “guard-pin” designed to prevent any accidental movements of the “fork”.
Compared with a classic (Swiss lever) escapement, the world-first new system presented by Audemars Piguet displays superior technical characteristics:
• Lubricant-free: the distinctive geometry of the Audemars Piguet escapement means it requires no lubrication – the dream of any watchmaking – thereby facilitating maintenance and avoiding the mechanism being clogged up with grease once the oil has evaporated.
• Detached single-beat escapement : a single impulse corresponds to two vibrations, hence a drop in rating disturbances and extremely high efficiency.
• Direct impulsion : energy is transmitted directly from the escapement to the balance, without the need for a lever, thereby reducing energy losses.
• High efficiency : in a movement with a Swiss lever escapement, the escapement absorbs 65% of the energy. The system developed by Audemars Piguet absorbs just 48%, representing a considerable efficiency gain compared with a classic movement.
• Excellent shock-resistance : the carefully designed shape of the various parts and their ultra-precise blanking guarantee optimal security against “tripping” and “overbanking”.
• Optimal long-term stability : tests conducted over the past five years have shown that this escapement demonstrates excellent operating stability.
• Improved chronometry : the isochronism of the balance and spring assembly may be adjusted by moving the locking point/angle in relation to the impulse transmitted to the balance: reducing mechanical disturbances on the level of the escapement further enhance the precision of the movement.
A tradition of exclusivity
The new calibre 2899 driving the Cabinet N°5 is a mechanical hand-wound oval-shaped movement, made up of 323 parts. It combines the new Audemars Piguet escapement system with a linear read-off perpetual calendar featuring a truly original lay-out. The date is displayed by a pointer sweeping over the rim of the off-centred hour/minute dial, providing optimal readability reinforced by the use of red numerals and a red hand. The name of the month appears in a window above 12 o'clock, while the abbreviation for the day occupies another window along the same vertical axis at 6 o'clock. The leap-year cycle is displayed between the two large blue Arabic 12 and 1 o'clock hour numerals. In addition to its clarity and originality, this perpetual calendar is distinguished by its extreme user friendliness. The calendar indications are adjusted using a pushpiece and correctors recessed into the case middle. A retractable finger system enables “backwards” time-setting even when the perpetual calendar is in operation, thus avoiding any handling errors that might damage the movement. The small off-centred subdial at 7 o'clock represents another exclusive technical feature: deadbeat or jumping seconds. This independent display which jumps once per second and may be stopped without affecting the rate of the watch (hence its name) represents a major horological accomplishment when miniaturised to wristwatch size.
A tradition of endurance and precision.
The Cabinet N°5 has an 7-day power reserve (168 hours) displayed on a pointer-type subdial at 11 o'clock. To guarantee such a level of autonomy, Audemars Piguet has equipped it with a large diameter twin-barrel system. The power-reserve indicator is equipped with a double-cone device which enhances read-off precision. calibre 2899 is also distinguished by the original construction of its regulating organ. It features two balance-springs placed one atop the other but at a 180° angle. This head-to-tail double flat balance-spring system avoids the delicate operation of crafting the overcoil. This arrangement automatically compensates for any possible poising errors in the balance-springs, constituting yet another step towards optimal mechanical precision.
A tradition of modernity
Like all creations in the Tradition of Excellence collection, Cabinet N° 5 is distinguished by its exceptional aesthetic appeal. However, following on from models featuring rather classic lines, Audemars Piguet has opted for a daringly modern creation. Millenary, which is particularly in the spotlight during 2006 with the launch of the Oval Time theme by Audemars Piguet. The daring partially openworked dial enables one to admire the beating heart of the watch, with its variable intertia balance, its double balance-spring and the brand-new Audemars Piguet escapement. The aesthetics are equally daring, based on a resolutely three-dimensional approach and characterised by constant movement. The modern design of the subdials makes a delightful contrast with the horizontal “côtes de Genève” decorative motif inherited from horological traditions. In this attractive interplay of circles featuring red and blue accents, the Audemars Piguet and Tradition d'Excellence signatures are alternately hidden and revealed in time with the rotations of the two visible barrels. On the back of the watch, a sapphire crystal reveals the ratchet-wheels. Cabinet N° 5 is complemented by a crocodile leather strap fitted with an AP folding clasp. Presented in a refined box specific to Tradition of Excellence models, it will be issued – like the four previous watches – in a limited series of 20 in 950 platinum. 2 much-coveted timepieces for this fifth wonder of the watchmaking art interpreted by Audemars Piguet.
• Lubricant-free AP escapement for enhanced efficiency (7-day power reserve)
• High inertia gyromax balance ensuring improved chronometric precision
• 2 balance-springs placed head to tail (at a 180° angle), thus doing away with the overcoil
• Three-dimensional aesthetic appeal on the dial side with a retro-contemporary style
• Deadbeat seconds mechanism
• Perpetual calendar equipped with pushpiece correctors
• “Double cone” and “double rack-pinions” ensuring more accurate read-off
• Stopwork mechanisms eliminating undesirable mainspring torque zones
TECHNICAL SPECIFICATIONS
Tradition d'Excellence, Cabinet N°5
Millenary perpetual calendar with deadbeat seconds and power-reserve indication
Reference
26066PT.OO.D028CR.01
Oval case in 950 platinum
Limited edition of 20
Movement
Calibre: 2899, hand-wound with Audemars Piguet escapement
Total diameter: 32.90 x 37.90 mm
Caging diameter: 32 x 37 mm
Thickness: 9.15 mm
42 jewels
323 parts
Power reserve: 168 hours
Cadence of the balance: 21,600 vibrations per hour
Finishing: all parts finished by hand
Case
950 platinum
Diameter: 47 mm
Transparent sapphire crystal caseback
Water resistance: 20 m
Dial
Gold plate placed on the movement, with applied blued Arabic numerals
Blued openworked hands
Strap
Large square-scale hand-sewn crocodile leather with AP folding clasp in 950 platinum
Functions
Hours, minutes
Deadbeat seconds
Day, date, month and leap-year indications
Power-reserve display
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