RAISING THE BAR FOR THE TOURBILLON; Cartier's Astrorégulateur

Truly important inventions in the watch industry, do not occur every day
and it's been more than a century ago that f.i. the tourbillon was invented by Abraham-Louis Breguet.
And the invention of the 'Minute Repeater' or the 'Perpetual Calendar' movement are also way behind us.
Last January when Cartier presented it's new collection in Geneva, the Cartier booth was extremely busy with press,
actually all week.
The main reason was the presentation of a new invention in high end watch making, something really new and
probably even better than the famous tourbillon system, a development that took Cartier a full 5 years to realize.

- CARTIER, THE ASTRORÉGULATEUR MOVEMENT -

The Calibre 9800 MC is a highly original movement that compensates for the effects of gravity on the timing mechanism
in vertical positions.
The subject of four patent applications, this movement is the fruit of five years of development within the
Cartier Manufacture, where it was designed, developed, produced and assembled.
This new Grande Complication timepiece testifies to Cartier's deep-felt commitment to fine watchmaking.

- ROTONDE DE CARTIER ASTRORÉGULATEUR WATCH CALIBER 9800 MC -



Case: niobium-titanium on leather, diameter: 50 mm
Crown: circular-grained in titanium or 18-carat white gold, set with a sapphire cabochon
Crystal: sapphire, case back: sapphire crystal
Water-resistance: 30 metres / 100 feet / 3 bar
Dial: galvanic guilloché, slate-grey colour, silvered openwork grill with sunburst effect, black transferred Roman numerals
Hands: sword-shaped in blued steel
Strap: black alligator skin & clasp: double adjustable folding in 18-carat gold

Limited series of 50 individually numbered timepieces !

- CALIBER 9800 MC ASTRORÉGULATEUR -



Movement: Manufacture self-winding mechanical, Calibre 9800 MC, hours, minutes, with escapement fitted on the
oscillating weight to counteract the effects of gravity in vertical positions
Casing-up diameter: 15 ½ lines (35.2 mm). Total diameter: 15 ¾ lines (35.8 mm). Thickness: 10.1 mm
Number of jewels: 43. Number of parts: 281. Balance: 21,600 vibrations/hour. Power reserve: approx. 54 hours
Individually numbered movement


- THE TOURBILLION AND CHRONOMETRY -



The 'Astrorégulateur' movement arose out of the consideration of one of watchmaking's most distinguished
complications: the tourbillon.
The tourbillon, which was originally developed by Breguet and patented in 1801, was intended by its inventor to address
the problems posed in watchmaking by the effects of gravity on the escapement components.
A watch will tend to show different rates in different positions, and, reasoned Breguet, if it were possible to produce
a single rate for all the vertical positions, one need only then adjust the flat positions as closely as possible
to the single rate for the vertical positions, and one should, theoretically, see a significant improvement in chronometry.
In the over two centuries, since its invention, the tourbillon has retained its ability to fascinate, both for its legacy as a
potential aid to chronometry (and the great difficulty of making a tourbillon) as well as, in recent years, the sheer
fascination exerted by the beauty of its action.
For Cartier, with its expertise in tourbillon construction, consideration of the problems which the tourbillon is intended
to address naturally led to an inquiry into what other solutions there might be to the problem of rate variations in the
vertical positions.
Though it is often said that the tourbillon eliminates the effects of gravity on the escapement, that, of course,
is not exactly true.
What a tourbillon actually does is create an average of all the rate variations for the vertical positions.
The question then naturally arose as to whether or not it might be possible to attack the problem more directly.

The accuracy of a watch requires a constant frequency of the oscillator. Since the oscillator is never well-balanced and
due to the Effect of gravity, its frequency is affected in vertical positions.

- FINDING AN ALTERNATIVE SOLUTION TO THE PROBLEM OF GRAVITY -



Thus was the Astrorégulateur movement born. The one part of a conventional, modern, self-winding watch which in fact
always comes to rest in exactly the same position regardless of the vertical position of the rest of the watch is, of course,
the oscillating mass (or rotor) of the automatic winding system. The Astrorégulateur watch takes advantage of this fact
by placing all the most sensitive escapement components – the fourth wheel, escape wheel, balance,
and hairspring – on the oscillating mass itself.
Regardless the vertical position assumed by the Astrorégulateur watch, therefore, the escapement components
will tend to remain in a single position – producing, rather than an average of rate variations in the vertical positions,
no variation at all.

- CREATIVE HERITAGE -

It is a testimony to the ability of Cartier to create a fusion of both technically and aesthetically sophisticated watchmaking
that the creative possibilities of such a complication were realized as well.
'The Rotonde de Cartier Astrorégulateur' watch reverses the normal placement of the winding rotor and mounts it on the
front of the movement, where its oscillations are visible through the dial.
The balance is carried atop the oscillating weight, and as the watch moves on the wrist,
the balance continues its vibrations no matter what position the rest of the watch assumes.
The apparent disconnection between the balance and the rest of the movement is a pleasing and masterful illusion.
The charming trompe-l'œil effect of the balance maintaining its equilibrium independently of the rest of the timepiece is
given an additional, subtle, but extremely striking twist by the action of the seconds hand.

- THE PENDULAR SECOND: AN EXTRAORDINARY TECHNICAL FEAT -


(Pendular second displayed on the micro-rotor.)

When one first examines the watch, the seconds hand may at first glance appear to be moving, as one might expect,
with reference to a fixed seconds track on the dial. But on closer examination – and as one watches the timepiece in
motion – it gradually becomes clear that the seconds hand does not move with reference to the dial.
Rather, it moves with reference to the position of the oscillating mass,
on which the sectors for the double-bladed seconds hand are mounted – the entire assembly of oscillating mass,
escapement, and seconds hand are, in a sense, almost a watch within a watch.

- AN INGENIOUS DIFFERENTIAL SYSTEM TO ENSURE CONSTANT CHRONOMETRY -



It is when one reminds oneself that the seconds hand, seconds (fourth) wheel, and escapement must receive power
from the going train that is part of the fixed plate of the rest of the movement that one really begins to wonder how it is
done.
The answer is that a sophisticated differential system has been constructed.
As its name implies, the differential gearing "subtracts" the to and from movement of the oscillating mass from
the power flow between the going train components on the fixed plate, and those on the oscillating mass.
This ensures that no matter what position the oscillating mass assumes, power delivered to the escapement remains
consistent, the seconds hand moves uninterrupted on its course, and the oscillating mass itself continues to efficiently
wind the mainspring.A double differential corrective system to maintain the necessary speed of the oscillator.

- A NIOBIUM-TITANIUM CASE -



Finally, the Astrorégulateur is the first watch from Cartier to make available, in a series produced timepiece,
one of the innovations first introduced in the Cartier ID One Concept Watch, shown in November of 2009.
The case of the Astrorégulateur model is made from the same niobium-titanium alloy as the case of the
Cartier ID One – lending its remarkable resistance to scratches and abrasions, as well as its unusual ability to dampen
and absorb shock rather than transmit it to the interior of the watch.

A niobium-titanium case to dampen shocks.

The revolutionary movement 9800 MC led to four different patents protecting the following innovations:

Mechanism conceived to avoid chronometric variations due to gravity based on a regulating device with balance and
hairspring and the timekeeping device equipped with such a mechanism.
This mechanism contains a geartrain which includes a driving kinematic chain connecting the escapement wheel to a
barrel system within the timekeeping device as well as a corrective kinematic chain which compensates the movements
and the speed of the platform compared to the plate in order that the movements of the platform do not affect chronometry.
The platform bears two epicycloidal gear trains, one for the driving chain and one for the corrective chain,
which have been coupled to avoid perturbing the oscillator.
The fourth wheel is included on the platform to avoid running discrepancies.

- SOLVING THE PROBLEM OF DIFFERENCE BETWEEN POSITIONS: PUTTING THEORY INTO PRACTICE -



Putting theory into practice
All standard movements are subject to deviations in rate between different vertical positions.
These differences are commonly referred to as errors in the positions. In theory, therefore, a watch ought to always be
worn in the position in which it was set.
The concept of the 'Astrorégulateur' movement is based on the fact that the balance and hairspring built into the
oscillating weight constantly bring it back to a fixed vertical position.
Thus it solves the problem of error in the positions.
Cartier nonetheless sought to demonstrate the veracity of this theory through a full series of chronometric tests designed
to put into practice the ingenious mechanism of the 'Astrorégulateur' movement.
These tests are performed on the first production pieces.
The conditions of the test therefore absolutely replicate the conditions with which the clients will be confronted.

No difference between positions

The effects of disruption to the balance are easy to measure.
To detect these effects, watchmakers use an acoustic measuring device to measure the escapement noises
in the movement. By calculating the number of swings of the balance, this instrument helps to assess the
constancy of the frequency.
A perfectly constant frequency ensures the movement has an optimal chronometry.
The frequency of the Astrorégulateur was therefore tested in all positions (known as 3 o’clock, 6 o’clock,
9 o’clock, and 12 o’clock).
This gave rise to the scientific determination of two findings: we note not only that on average there
is no deviation in rate with regard to the initial setting, but we also observe that no deviation in rate occurs
regardless of the position of the watch in a vertical axis.
In practice then the Astrorégulateur presents 0 seconds of deviation in rate.


- SOLVING THE PROBLEM OF DYNAMIC EFFECT -



When a watch is worn in a real-life situation, it is constantly subject to accelerations and decelerations.
If only static tests are carried out, the watches are as such measured and checked without ever having been exposed
to such phenomena.
Limiting the testing to static tests is therefore not representative of a watch being worn in real-life situations.

To compensate for this shortcoming, Cartier has introduced an innovative new test protocol.
The protocol comprises two stages of tests designed to determine whether the observations made on the acoustic device
can be verified in dynamic situations.

Stage 1:

Cartier watchmaking workshops have wear-simulating devices which are ordinarily used to check that the automatic
mechanisms are functioning correctly.

This type of device rotates around several axes:
The main axis performs 4 rotations per minute and each watch performs 20 rotations per minute.

These random movements enable a simulation of dynamic wear.

The test comprises a number of phases:

- The Astrorégulateur watches have a reading taken of their rate in comparison with a radio-controlled control clock,
- then he Astrorégulateur watches are tested on our devices for 24 hours
- The watches have another rate reading taken.
- The second rate reading is compared with the official reading from the radio-controlled control clock.

This comparison is used to establish the difference with regard to the control clock.
The various results show a deviation from the static setting on the watches of only 0 to +1 seconds per day.

- SOLVING THE PROBLEM OF DYNAMIC EFFECT - Stage 2:



In complement to this first test, Cartier sought to confirm these positive findings in real-life conditions of wear.

Astrorégulateur watches were therefore entrusted to the Manufacture staff, as they went about their ordinary daily activities.

- The Astrorégulateur watches have a reading taken of their rate in comparison with a radio-controlled control clock.
- Then the Astrorégulateur watches are tested on the wrists of the subjects for 24 hours.
- The watches have another rate reading taken.
- The second rate reading is compared with the official reading from the radio-controlled control clock.

As with the first series of tests, this comparison is used to establish the difference with regard to the control clock.
The various results show a deviation from the static setting on the watches of only 0 to +1 seconds per day.
The results are therefore entirely consistent with the tests on our wear-simulating devices.

- CONCLUSION -



This series of tests confirms that the Astrorégulateur movement by Cartier perfectly full fils its function of absorption of
dynamic effects. Indeed, the parts rotate in the direction of the acceleration or deceleration of wear, thus absorbing the
g-force that disrupts the balance and hairspring.
The latter then present a very slight imbalance in the vertical positions.
Moreover, the shocks cause impact between the coils which upsets the oscillating frequency.
On the Astrorégulateur movement, the rotation of the oscillating weight absorbs the shocks and thus prevents impact
between the coils.

As such, the two main effects which in theory could have unbalanced the balance and hairspring during the dynamic
tests were offset.

By means of this test protocol, Cartier corroborates the theoretical performance of the Astrorégulateur movement.
Indeed in practice the 'Rotonde de Cartier Astrorégulateur' presents 0 seconds of deviation from rate
in static functioning and less than one second during wear.

The technical side of complicated watches of this level, is of course where it's all about.
But one can wonder if a tourbillon is always bought just for that reason.
From a visual point of view these watches have also a lot to offer.
If the constant moving parts of a tourbillon is what makes these watches very attractive to look at,
the 'Rotonde Astrorégulateur' will fascinate you even more.
The dial, that looks like a 'watch within a watch', is aesthetically very pleasing, due to the winding mass
and escapement components that are visible through the large aperture in the dial.
On close examination the wearer will note that the second hand, which at first appears to rotate in reference
to the main dial, actually rotates in reference to the oscillating mass, on which it's mounted.
The escapement components thus form a 'watch within a watch'.



Cartier presented the 'Rotonde Astrorégulateur' in Geneva, this January and produced just 50 pieces of this
very complex time piece.

When we take the importance of this invention in Fine Watchmaking, in consideration,
it goes without saying that this 'Rotonde Astorégulator', is only the beginning of a new milestone in the world of watches.
And if you ask me; Cartier has raised the bar again and this time for the tourbillon.

GEO

CARTIER forum moderator
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