The RICHARD LANGE collection pays tribute to the company founders, Mr Adolph Lange, first-born son Richard Lange (1845-1932), a bright mind devoted to the scientific evolution of precision watchmaking.This watch features:
Completely polished finished 18kt rose gold case.
Matte silvered dial.
Polished rose gold hands.
Regulator Time Features:
Offset minute sub-dial (top center) with black printed minute chapter ring & red Arabic Numeral 15 minute markers.
Offset hour sub-dial (bottom right) with black Roman Numeral hour markers. The overlapping 8-10 hour segment retracts & is hidden between 12 & 6 o'clock. When the watch hits 6 o'clock the hidden 8,9 & 10 hour segment flips into position & remains in place until 12 o'clock at which time it retracts & is hidden once again.
Offset seconds sub-dial (bottom left), mounted on the Tourbillon, with black printed minute chapter ring & Arabic Numeral on some of the 10 seconds markers.
60 seconds tourbillon visible through the dial opening at the bottom left side of the dial.
With a polished rose gold hand fixed to the tourbillon doubling as a seconds hand.
The tourbillon consists of 84 parts and weighs 0.25 grams. The surface of the cage is black-polished in a process that requires up to 5 days and tolerates no errors.
Introduced by Lange in 2008, Lange has developed a way to stop the tourbillon when the crown is pulled out, so that the watch can be set to a precise second. This patented feature is accomplished with a V-shaped arresting spring that can stop the balance wheel inside the rotating tourbillon cage when the crown is pulled.
A. Lange & Sohne Caliber L072.1, beats at 21,600 vph, composed out of 352 parts (+636 chain parts = 988 total parts), contains 33 Jewels & has an approximate power reserve of 36 hours.
Movement 3/4 back plate is finely finished with striped/ribbed finish and polished beveled edges. The balance-cock is hand engraved making each watch unique.
Pour le Merite:
"Fusee-and-chain transmission": In the Lange & Sohne fusee-and-chain mechanism, the flow of power between the mainspring barrel and the going train is established indirectly by a chain comprised of 636 parts, which create 212 links, which forms a chain 152mm long. One end of the chain is attached to the barrel drum and the other to the fusee. As the mainspring barrel unwinds, the chain wraps around it and reels off the fusee. When the mainspring is fully wound and thus exerts great force, the chain pulls at the smaller radius of the fusee where the leverage is smaller. As the springs tension diminishes, the chain pulls at the larger radius with the higher leverage. Thus, regardless of the state of wind of the mainspring, the same amount of torque is delivered to the escapement, resulting in improved rate accuracy. In the fusee-and-chain transmission mechanism, there is one situation when the cone rotates backward: as the mainspring is being wound. To prevent the watch from stopping while it is being wound, Lange's master watchmakers integrated a marvel of miniaturization inside the fusee. It is a tiny planetary gear train that assures uninterrupted delivery of power to the movement. Additionally, it is endowed with a pretensioning mechanism that allows the characteristics of the mainspring and of the fusee to be perfectly harmonized. Finally, the elaborate construction includes a device that blocks the winding mechanism just before the mainspring is fully wound and stops the movement just before it is fully unwound.
The "fusee-and-chain transmission" is visible through a drop-shaped cutout in the 3/4 plate.