The LANGE 1 TOURBILLON PERPETUAL CALENDAR is the tenth masterpiece added to the iconic LANGE 1 family of timepieces. As the name suggests, the model unites two classic complications: Tourbillon & Perpetual calendar.
The off-centre configuration of the LANGE 1 dial offers ideal prerequisites for the integration of a perpetual calendar. This is because the calendar displays can be neatly positioned outside the hour and minute circle without compromising the readability of the time indication in any way.
The harmoniously balanced integration of Perpetual calendar and hidden complexity (only a modest inscription at 12 o’clock refers to the tourbillon) enhances the classic nature of the timepiece.
To create the prerequisites for integrating a calendar in the dial architecture of the LANGE 1, the manufactory’s calibre designers devised the very first rotating peripheral month ring ever implemented in a wristwatch. The underside of the ring has recesses of different depths for the respective durations of each month and features an innovative sampling mechanism. This one-of-a-kind design has been registered for patent.
All displays of the perpetual calendar – the outsize date, the retrograde day, the month ring, the aperture leap year, and the moon-phase indication – switch instantaneously and thus always deliver unambiguous readings. The mechanism is designed such that it must only be advanced by one day on March 1st of the secular year 2100. And the moon-phase display will even run true for 122 years before it needs to be corrected by one day. Corrections are easy to perform with recessed push pieces that allow the calendar indications to be advanced individually or collectively.
One objective in the development of the LANGE 1 TOURBILLON PERPETUAL CALENDAR was that nothing should obstruct the legibility of the indications on the dial.
The dial has no aperture for the tourbillon but it is visible through the sapphire-crystal caseback. Here the filigreed cage rotates about its axis once a minute to eliminate the influence of gravity on the balance wheel and its eccentric poising weights.
Combined with the proprietary Lange balance spring, it assures an extremely high degree of rate accuracy. Both components are exactly matched to one another to achieve optimised precision at the movement’s rated frequency of 21,600 semi-oscillations per hour. The patented stop-seconds mechanism makes it possible to instantly block the balance inside the tourbillon cage at any time by pulling the crown, so the watch can be set to one-second accuracy.
The high winding efficiency of the new automatic calibre L082.1 is attained with a heavy central rotor whose middle segment with the embossed A. Lange & Söhne signature is made of 21-carat gold. The platinum centrifugal mass on the outer periphery of the rotor has an even higher density than gold, so it imparts extra momentum to the winding process. Thus, even the slightest motion of the wrist is converted into winding energy. The result: the maximum power reserve of 50 hours is available after a very short time on the wrist.
The movement is endowed with many iconic Lange-style quality hallmarks such as the movement parts lavishly decorated by hand, the free-hand engravings on the tourbillon and intermediate-wheel cocks, and the four gold chatons secured to the plate with thermally blued screws.
The upper part of the tourbillon cage is black polished. A flawless diamond endstone serves as a bearing for the tourbillon. It is a reminiscence of historic Lange pocket watches that belonged to the high-end “1A” category.
The LANGE 1 TOURBILLON PERPETUAL CALENDAR is available in a pink gold or platinum case with a diameter of 41.9 millimetres. Platinum model is strictly limited to an edition of 100 watches.
Model: A. Lange & Söhne Lange 1 Tourbillon Perpetual Calendar
Reference 720.025: Platinum version with rhodié dial
Reference 720.032: 18K Pink gold version with argenté dial
Material: Platinum or 18K Pink gold
Diameter: 41.9 mm
Glass and caseback made of sapphire
Caliber L082.1 Automatic
Tourbillon with patented stop-seconds mechanism
50 hour power reserve
Perpetual calendar with outsize date, retrograde weekday display, month ring and leap year display
Moon phase display
Solid silver rhodié (platinum version) or argenté (pink gold version)
Hands: rhodium-plated gold or pink gold hands
Hand-stitched crocodile strap
Platinum version is limited to 100 pieces
Image Credit: Lange Uhren GmbH