Bernhard Lederer unveils the Central Impulse Chronometer 'InVerto'

Bernhard Lederer unveiled the Central Impulse Chronometer 'InVerto', an even more virtuoso iteration of the model released in 2021. Price: CHF150,000

Master watchmaker Bernhard Lederer has introduced the Central Impulse Chronometer 'InVerto', an even more virtuoso iteration of the Central Impulse Chronometer model released in 2021 which incorporates his break-through double impulse escapement, coupled with double gear train and two constant force mechanisms.

Differently from that model, winner of the Innovation Prize at the Grand Prix d’Horlogerie de Genève (GPHG) 2021, in the new Central Impulse Chronometer 'InVerto' the entire movement – along with its ingenious invention – is fully revealed on the dial side.

The mechanism has been turned over, allowing a full view of the movement’s architecture while the watch is worn. No parts are concealed. 

Housed in a 44 mm x 12.2 mm case crafted from black DLC (Diamond-Like-Carbon) treated stainless steel, the hand-wound 9018 InVerto Calibre is comprised of 212 components and operates at a frequency of 3 Hz (21,600 vibrations per hour) with 42 hours of power reserve.

Showcased through a panoramic sapphire crystal with double anti-reflective coating, this exceptional chronometer - the result of 10 years of research and development - features a truly unique escapement, the most important assembly inside a movement that regulates the timekeeping. 

In fact, Lederer's natural escapement is composed of two escapement wheels operating in alternation. They are installed at the end of two separate gear trains, each with its own barrel and its own 10-second remontoir d'égalité (a constant-force mechanism), and connected to an anchor whose geometry has been designed to reduce contact timing. 

The solution designed by Lederer makes the transmission of energy to the balance wheel as uniform as possible. Moreover, the impulses are lighter in impact and friction is minimized. The benefits are improved chronometer performance, rate stability throughout the entire power reserve, and longevity of the watch mechanism.

The remontoir d'égalité consists in accumulating an energy buffer in a spring similar to the one in the barrel, but one that is much shorter and lighter. Recharged in 10-second intervals, it capitalizes on the fact that the force of an unwinding spring is stronger when it is tightly wound up, and weaker when it is almost completely unwound. This variation in torque has a direct impact on isochronism. The remontoir evens out the force, maintaining a consistent torque profile and delivering precise energy to the balance wheel with minimal variations.

The combination of two remontoires with the escapement was a first in watchmaking history. It yields remarkable chronometric precision and exceptional frequency stability, validated by the Besançon Observatory and the COSC (Contrôle Officiel Suisse des Chronomètres).

While the dual seconds hands, a hallmark of the Central Impulse Chronometer presented in 2021, are absent from the visible part, they are not forgotten in this new concept. In fact, Bernhard Lederer included a seconds hand on the back side in order to enable COSC certification of the chronometer.

The Central Impulse Chronometer model released in 2021 and, below the case back of the new 'InVerto'

The technical excellent of the movement is combined to an avant-garde look.

The entire movement, including the bridges and mainplate, is finished in black. All components are finished by hands with satin, sandblasted, and brushed surfaces as well as polished chamfers. 

The bridges are frosted and hand-beveled, the wheels feature circular graining and hand-beveled spokes, the stone settings are hand-polished, and the steel components are mirror-polished.

All components, including the watch hands, something very rare in the watch industry, are produced in-house in the brand's workshop in Saint-Blaise by a team of more than 25 employees. 

The new Bernhard Lederer Central Impulse Chronometer InVerto, ref. CIC 9018 InVerto, will be produced in limited series of only 18 pieces with a price of CHF 150,000 (excluding sales taxes). ledererwatches.com