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Sketch du Calibre RVI2023

A micromechanical ballet for the opening act!

Calibre RVI2023

Movement Specifications

Reference

RVI2023

Diameter

36.8mm

Height

6.69mm

Jewels

31

Frequency

2.5 Hz (18,000 A/h)

Power Reserve

(minimum) 80 Hours

Balance

Palladium annular with 4 regulation screws

Balance Bridge and Plate

Titanium

Barrel Ratchet Wheel

with an additional silver plate, engraved, chiseled, and grand feu enameled

Central Turbine of the Micro-Rotor

Platinum

In this initial innovation, Dominique Renaud revisited a cornerstone of mechanical watchmaking: energy. It originates from the rotor of the automatic watch, a mechanism that has seen little evolution since its industrial development between the 1930s and 1940s.

The micro-rotor is an elegant option because it doesn't obstruct the view on the watch mechanism. There is a trade-off, however: this winding system is sensitive to very low efficiency, requiring a large range of motion. The process of generating energy is continually halted by opposing forces that interrupt its acceleration - such as when the wearer is typing on a keyboard, for instance.

Photo de Dominique Renaud dans son atelier
Photo de Dominique Renaud & Julien Tixier dans leur atelier

The challenge is to find a way to harness all the energy that a traditional micro-rotor, by its very nature, fails to convert. The solution resides in the realm of micromechanics, without relying on any external technology.

Dominique Renaud discovered a way to install the auxiliary mechanism at the center of the rotor. However, too strong a shock could potentially break everything. Thus, he envisioned an intermediate spring serving a dual role as both a propeller and a shock absorber. Similar to the strings of a tennis racket, it stores energy and releases it like a catapult.

This spring, which literally dances at the heart of the rotor, could only be called 'the dancer'

Photo closeup du Calibre RVI2023

Into the details

A large spiral connects the axis to the flywheel, acting as the catapult. A spring arm extends from the axis in the opposite direction, serving as the shock absorber - a kind of foot with a heel that strikes a stop in the event of a severe shock. On the axis, the spring functions like a notched clamp, with the upper jaw forming a “hanger”. This hanger acts as an active safety mechanism: it is rigid under normal conditions and secures the flywheel to the axis.

In the event of a shock, the foot strikes the stop and presses on the hanger, which disengages and detaches from the axis, and then repositions itself once the shock has passed and the stored energy is released.

As is the custom with Dominique Renaud, any invention is first tested on a large-scale model, with calculations following afterward. Venturing into territory not mapped out by existing theories is all in a day's work for the practical minds surrounding the watchmaker. This is where the real challenge begins - because the usual calculation methods for the micro-rotor do not apply here. The instrument capable of quantifying the improvement in efficiency doesn't exist - yet.

With Julien Tixier in charge of execution, transforming the concept into its components and moving parts, the 'Monday' extends far beyond mere invention. Indeed, an entire caliber had to be designed around the dancing micro-rotor. Energy generation and efficiency being the focus, mechanics and engineering are at the heart of the design.

From the micro-rotor to the barrel, and from there to the balance wheel, the finishes set the standard. The display is contemporary and refined: hand-beveled and mirror-polished titanium and a balance wheel made from palladium set the tone.