THE PATENTED RECIPE.
它具有MORITZ GROSSMANN GLASHÜTTE I/SA品牌機芯的所有標誌性特徵與手工藝細節。此外，更增添了全新的格羅斯曼擺輪、經過進一步改進的格拉蘇蒂棘輪、按鈕式手動上鏈裝置，以及動力儲存顯示。
THE STRAP WINDER WITH SETTING CROWN
The power needed to tension the mainspring is built up with a winding stem that enters the case at 6 o‘clock. To assure that the strap comfortably hugs the wrist, both the winding stem and the strap bar on the opposite side are inclined inward by 22°. A special bevel gear pair establishes the connection between the inclined winding stem and the horizontally orientated movement. When the watch is being wound, the strap can deliver much more torque than a crown because it is easy to grasp. The energy is swiftly transmitted via a bevel gear to two wheel sets with a high-efficiency ratio. A backstop ratchet allows bidirectional winding. Only very few back-and-forth motions of the strap are needed to fully wind the watch. Inside the case, the movement was
turned by 30°, so the timesetting crown is positioned at 4 o‘clock. As before, the handsetting mechanism is activated by pulling the setting crown.
Since the winding stem could turn with the strap while the watch is being worn, the backstop tolerates a certain amount of deflection without causing the stop click to instantly block the stem. The backstop and the main stopwork are dimensioned such that the engagement of a pawl requires a rotation of at least 20°.
The ratchet wheel has only eight teeth, so the stopwork cannot be overloaded when very fast winding movements are performed. In the calibre 102.2, a mainspring with a bridle – commonplace in selfwinding watches – prevents damage that could be caused by excessive force. The bridle is pressed against the inside of the mainspring barrel and generates frictional torque that as a rule is 10% higher than the maximum torque of the spring. So when the mainspring is fully wound, turning the crown is met with resistance but it does not lurch.
THE OSCILLATOR WITH STOP SECONDS
The Grossmann balance, modified for the TEFNUT calibres, is clearly smaller than in the larger ATUM and BENU movements. It is designed for a high moment of inertia with minimal mass and beyond the mass and poising screws offers sufficient precision adjustment options.
The stop-seconds mechanism is activated when the setting crown is pulled. A spring firmly attached to the main plate presses against the safety roller and thus prevents inadvertent contact with the polished outer surface of the balance-wheel rim or maladjustment of the delicate poising screws. The spring is controlled by a linkage-type slide that for the strap winder is connected directly with the arresting spring and is thus uncoupled from the winding motion.