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Bernhard Lederer Central Impulse Chronometer with 18K white gold case with blue or rhodium-plated dial

In 2020, Bernhard Lederer introduced Central Impulse Chronometer as a concept watch during the prestigious Grand Prix d’Horlogerie de Genève event.

Result of several years of R&D, this highly technical chronometer wristwatch features a state-of-the-art mechanical movement that merges a new type of escapement, constant force and a double gear train.

Its dial boasts a pair of synchronized seconds hands moving in opposite directions – within two openings in the watch face bordered by interlaced circles forming the figure eight. The movement’s architecture and performance are matched by a refined execution and meticulous finishing down to the smallest detail.

The Lederer Central Impulse Chronometer watch features a well-designed case measuring 44 mm in diameter with a thickness of 12.2 mm. The domed crystals on front and back emphasize its slim silhouette. The dial has two circular opening reveal two synchronized hands moving in opposite directions. These two circles are interlocked in a figure eight.

In 2020, Bernhard Lederer released two concept models: An 18K rose gold version with a solid silvered opaline dial and an 18K white gold variant featuring a skeletonised slate grey sunburst dial.

Now the Central Impulse Chronometer timepiece is commercially available in two white gold versions, featuring a blue or rhodium-plated dial.

Powering the Central Impulse Chronometer watch is the Calibre 9012 with an entirely new high-performance double impulse escapement.

For developing this movement, Bernhard Lederer took inspiration from the Independent Double Wheel Escapement conceived in the late 20th century by George Daniels. Lederer’s aim was to solve the weak points of this kind of escapement. For this reason, the escapement of Lederer’s Central Impulse Chronometer is of a different design.

The Calibre 9012 comprises two independent escapement wheels operating in alternation and connected to an anchor that is absolutely one of a kind. Its profile, rubies, lift angles, even the way it comes into contact with all the components it guides, make this an exceptional creation.

To further optimize precision of the Caliber 9012, Bernhard Lederer installed the two escapement wheels at the end of two separate gear trains, each with its own barrel and its own 10-second constant force remontoire.

In smoothening the driving force to the extreme, optimizing the geometry of the escapement parts, paring down the weight of these energy-intensive components and reducing the internal friction of the escapement to a minimum, Bernhard Lederer has achieved a degree of watchmaking perfection rarely seen. By making the two escapement wheels independent of each other, he essentially freed them.

The two second hands, each linked to its own escapement wheel, are permanently synchronized and show no drift in relation to each other. The precision of each watch is attested by a chronometer certificate.

The 9012 movement has a frequency of 3 Hertz. Instead of traditional steel, the Central Impulse Chronometer movement has titanium components. Much lighter, the moving parts now have less inertia, which enables them to restart more quickly and consume less energy. As a result, the impulses generated by the escapement wheel to the balance wheel are optimized and disturbances are reduced, which ensures isochronism and therefore movement precision.

The energy to power the movement is transmitted from two barrels via two independent gear trains, each linked to a dedicated escapement wheel. Furthermore, Bernhard Lederer has integrated a remontoir d’égalité, i.e. a constant-force mechanism, to accumulate a buffer stock of energy in a spring similar to that of the barrel, but slightly less substantial. It is recharged at 10-second intervals, thus equalizing the driving force with a homogeneous degree of torque to ensure the energy delivered to the balance wheel varies extremely little if at all.

One element that sets the Central Impulse Chronometer escapement apart is the anchor. Here, Lederer reimagined the geometry of the central pallet to increase performance. Now concave, it reduces the contact surface, avoiding any recoil of the escapement wheels.

The impulse, given directly along a straight line connecting the escapement wheel to the balance wheel, is thus theoretically perfect. The axis for the impulse is constant in time, even when the balance wheel has a low amplitude, as caused by shock for instance. This reduces friction, further ensuring that energy distribution to the balance wheel is optimally timed to obtain improved isochronism, hence improved stability.

Made of white gold, the 44 mm round case of the Central Impulse Chronometer watch has soft, elegant lines. Its thin polished bezel enhances the view on the dial. Two circular openings for the seconds hands offer a view of the Calibre 9012 and its most distinctive components, the rewinding mechanism and escapement.

On the case back, a second sapphire crystal is fitted. Identical to crystal on the front, it is domed and engraved and beveled. It offers the view of the three-dimensional, symmetrical, oblique and open-worked architecture of the Caliber 9012. The barrel, wheel, winding mechanism, escapement and balance bridges are all skeletonized with slender geometric shapes.

The two large golden barrels contrast with the movement’s rhodium-plated finishes. The wheel spokes are tangential curves with a unique profile, a Bernhard Lederer hallmark.

The Central Impulse Chronometer boasts various high-quality finishing techniques such as polishing, inward and outward beveling, graining, engraving and satin-finishing to juxtaposing matte and glossy surfaces. All these magnify the spectacular three-dimensional architecture of movement.

In 2021, the Central Impulse Chronometer is available in two limited series in white gold, 25 pieces with a blue dial and the other 25 pieces with a rhodium-plated dial.

Technical details

Reference: 9012

Hours, minutes, small seconds at 8 and 11 o’clock

18K white gold case
Diameter: 44 mm
Thickness: 12.2 mm
Case back: Open, sapphire glass with anti-reflective coating
Water resistance: 3 ATM

Guilloché (exclusive Lederer motif) with two circles interlocked in a figure eight.
Available in two colors, rhodium and dark blue

Mechanical, hand-wound
Number of components: 210
Number of jewels: 45 rubies
Frequency: 21,600 vibrations per hour (3 Hz)
Diameter: 39.3 mm
Thickness: 5.98 mm
Power reserve: 42 hours

Special features
Two barrels
Two independent gear trains
Two constant-force remontoirs
Two escapement wheels with central impulses

Winding & setting
Two-position winding stem:
Position 1: manual winding
Position 2: setting the time

Frosted with hand-beveled bridges, wheels with circular graining and hand beveled spokes, steel parts black polished.

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