The luxury watch brand 4N is presenting a timepiece which is completely original and innovative hours and minutes display. It highlights the unique assets that define the brand 4N, marked by a return to a clear and effective numerical display by reinventing the jumping minute hand. The 4N-MVT01/D01 Model, the first of the brand, is manufactured by the famous company Audemars Piguet Renaud & Papi. The watch is limited to only 16 pieces.
While the display and movement are of a mechanical style, the design of the case and details counterbalance the masculine structure of the watch, with flowing lines and marks creating a generous silhouette.
MVT01 is characterised by a manufacturer movement, with a manual winding mechanism and a 12-hour digital display. It is based on a clever configuration of discs rotating in discontinuous mode. Three discs sub-assemblies, made of aluminium or titanium alloys and held in carbon cage structures, are activated to reveal the time on a display which changes as each minute passes (4 discs for the hour, 5 for the minutes and 1 for the tens of minutes).
The mechanism uses a constant-force jump system which guarantees minimum energy consumption, regardless of the winding tension. The patented model solves a number of technical challenges. The original size of the digits (5.5mm) reveals a demanding mechanical design based on a fully manual production process.
The movement is the fruit of a complex setting of the disc mechanism, designed to solve problems of equilibrium, inertia and friction in order to obtain optimal movement and consume as little energy as possible. These operational specifications justify the specific materials chosen for their lightness and perfect mechanical performance – carbon, aluminium and titanium. This model will be available in 18-carat white gold and platinum versions.
The dial, covered by a sapphire glass front, frames the bright orange figures. Sapphire glass at the bottom of the case reveals the subtleties of the mechanical movement. The strap, which is available in a range of noble materials, is mounted on the case by an automatic fastening system and its length can be adjusted as necessary. In addition, the model has an easy time setting system which enables the hours to be set independently of the minutes. All of these specific qualities make this an exclusive contemporary timepiece which will add a beautiful finishing touch to the wearer’s attire.
Jumping minutes and hours
Digital display by discs
Double barrels with simultaneous transmission stop-work
Screwed balance D : 9.12 mm
Breguet overcoil balance-spring
Cadence: 21 00 Alt/hour
Power reserve 237 hours
Finish: all parts finely decorated
White gold or platinum
Limited edition 16 pieces
Retail price: white gold version – 150 000 € (Excluding Taxes)
The secrets of the 4N-MVT01/D01
The greatest numerical display
The task was to conceive and develop the best display using jumping hours and minutes, with the aim of mitigating the flaws inherent to the traditional construction of mechanical watches with numerical jumping hour and minute displays.
There are two such flaws:
– The size of the numbers. Indeed the hours, tens of minutes and minutes are classically shown on 3 discs. The geometry of a watch (size of the housing) necessitates a reduction in the relative diameter of the discs, therefore to have very small numbers on the perimeter of these discs.
– The positioning of these numbers is problematic in itself, taking into account the centre distances and other constraints; the hour display is dispersed on the dial.
The basic idea behind the 4N is to multiply the discs in order to compress the display.
Thus the MVT01/D01 uses 10 discs instead of 3:
4 discs assembled on a cage for the hours, one disc for tens of minutes, 5 discs for the minutes (also in a cage).
These discs overlap each other and are superimposed to display the time in the exact centre of the dial. The size of the numbers is incredibly large (5.5 mm), facilitating unequalled comfort and ease of reading the time.
If jumping time is a very common complication, the opposite can be said for jumping hours and minutes, which is a much rarer complication. The watchmaking pieces available on the market are extremely few for an obvious reason: there is very little torque available for the jump from one minute to the next (to be precise, sixty times less than for that of an hour). In fact the jump release and disc indexing mechanisms are liable to disturb the isochronism of the movement. Several high-end watchmaking parts mitigate this problem by using two driving forces, one for the time cog and one for the display. However, this mechanical principle has its own flaws: in particular it requires a lot of energy and diminishes the watch’s supply proportionately. It also poses obstruction and synchronisation problems.
The 4N-MVT01 only uses one source of energy, in this case a double barrel.
The task was thus to conceive a very energy-efficient mechanical solution for the jump release and indexing of the discs, to work not just for 3 discs, but for 10.
The mechanical solution for the 4N-MVT01/D01 for the indexing of the discs is simple and innovative at the same time: each disc is linked with a wheel, which is itself geared in a fixed crown wheel. At the time of the jump the cage turns, which leads to all the discs turning with each other, thanks to their wheel which is geared on the fixed crown wheel. This indexing is extremely energy-efficient, compared with traditional star-like, jumping or Maltese cross mechanisms.
The development of the jump release solution required a lot of time and iteration. The team of Renaud and Papi worked for many months to develop a system that Giulo Papi calls a mechanical transistor, i.e. a mechanism which, with very little energy, is able to actuate another mechanism which has much more energy. This jump release system makes a success of the feat of using neither a cam (Limaçon in french) nor a spring. Moreover the jump, i.e. the rotation of the cage on a time sector (1/5 of a turn for the minutes cage) is operated by arming a spiral spring over the course of a minute, at the end of which the jump release mechanism releases the rotation of the cage which is pulled by the spiral spring through a fifth of a turn.
This cinematic collection of the cage, discs and disc indexing is independent of the degree of winding of the cylinder; the same amount of energy is always used (the compression of the spring by the cage), thus allowing an optimum adjustment of the jump however wound it is (like a constant force).
Thanks to these innovations the MVT01/D01 boasts an exceptional 237-hour fully-wound life span, which is almost 10 days, putting it way out in front of all other high-end watches with complicated displays, and all this with a spectacular animation every single minute.
The unit comprises 514 components and 78 jewels, which makes the 4N MVT01/D01 one of the most complex timepieces on the market.