AN IMMACULATELY FINISHED MOVEMENT.
The perfect movement of the LANGE 1 TOURBILLON PERPETUAL CALENDAR is just as refined as the dial. Beneath the unidirectionally winding central rotor in gold and platinum, the delicate tourbillon cage rotates about its own axis once a minute, thus compensating the influence of gravity on the balance wheel with its eccentric poising weights.
The Lange balance spring and the balance wheel with eccentric poising weights, developed and manufactured in-house, are responsible for the optimised rate accuracy of the self-winding calibre. Both components are perfectly matched to assure that the movement, which beats at a frequency of 21,600 semi-oscillations per hour, runs with extreme precision.
A CALENDAR MECHANISM UNLIKE ANY OTHER.
The patent-pending sampling mechanism for the month durations is just as precise. Contrary to conventional perpetual calendars, the number of days in a month is not defined by program wheels but by the month ring itself as it rotates about its axis once a year. The inside features a circumferential contour with undulated recesses. A sampler lever glides along this contour and is deflected by a magnitude that corresponds to the depth of the respective recess. The more it is deflected, the shorter the month. In February, an extender of the sampler lever contacts a cam beneath the leap-year display. This defines the exact duration of the month in leap years as well.
PROGRESS IN PRECISION WATCHMAKING – STANDSTILL.
The patented stop-seconds mechanism of the tourbillon with its V-shaped arresting spring is a fascinating device which allows the watch to be set with one-second accuracy. When the crown is pulled, its two dissimilar arms advance into the kinetic range of the classic screw balance and thus stop the tourbillon. The device is optimised in such a way that the balance can be stopped regardless of its amplitudinal position and no matter where the tourbillon carriage happens to be. Additionally, the energy of the balance spring is stored so that the balance can automatically resume oscillating as soon as the crown is pushed home again. The construction of the tourbillon in the LANGE 1 TOURBILLON PERPETUAL CALENDAR is a filigreed work of art. It consists of 69 parts yet weighs a scant 0.5 grams.
