Yesterday A. Lange & Söhne revealed the new Richard Lange Pour le Mérite in a white gold case and black dial limited to only 218 watches. It may look innocent on the outside, but inside there is a mean machine.
Since the revival of A. Lange & Söhne in the autumn of 1994, the exclusive timepieces with the attribute Pour le Mérite have represented the technological avant-garde at A. Lange & Söhne. Each of the four models launched so far is endowed with a fusée-and-chain mechanism. The Richard Lange Pour le Mérite, first introduced in 2009, exemplifies an ambitious tribute to precision in its purest form. The sole objective of its complication is to improve rate accuracy.
The fusée-and-chain mechanism guarantees constant torque and thus stability of the amplitude of the balance across the entire power-reserve range. Wrapped around the mainspring barrel, the chain delivers the power of the mainspring to the wheel train via the cone-shaped fusée. This keeps the torque constant. In principle, the mechanism works like the gearing of a bicycle except that the gear ratios are infinitely variable rather than fixed.
The 636-part chain can support a weight of over two kilograms. But to fully exploit the positive effect of the fusée-and-chain device, the product developers added a technical refinement: two separate mechanisms block the winding system before fully wound and fully unwound states. Both prevent the chain – which is only 0.25 millimetres thick and 156 millimetres long – from being overstressed.
The fusée-and-chain transmission causes the fusée to rotate in one direction during the winding process and in the opposite direction when the watch is running. For this reason, it is necessary to ensure that the watch continues to run even when it is being wound. An elaborate planetary gearing inside the fusée maintains the flow of power from the fusée to the movement during the winding phase. It is composed of 38 tiny parts which the watchmaker must fit into the tight 8.6-millimetre inside diameter of the fusée.
All this remains concealed beneath the black dial of the Richard Lange Pour le Mérite. But the most important parts of the fusée-and-chain device are clearly visible through the sapphire-crystal caseback.
L044.1 Lange Manufactured
Mechanical, manual-winding, fusée-and-chain transmission
31.6 mm in diameter, 6.0 mm thick
Approximately 36 hours of power reserve
279 parts (without chain), 636 in chain alone, 33 jewels
Hours, minutes Small seconds at 4h30
40,5 mm, 10,5 mm thick
Sapphire crystal caseback
Solid Silver- Black
White Roman numerals
Rhodiumed gold hands
Hand-stitched black alligator leather
White gold prong buckle
Read more at A. Lange & Söhne