AlTiN - standing for a group of metastable hard coatings consisting of aluminum, titanium and nitride – is an application which was originally developed for industry. An AlTiN coating has the effect of multiplying the resistance of the underlying metal to scratches, shocks, oxidation and even acids.
The dial of the UR-210 AlTiN features a traditional power reserve indication at one o’clock. In a near mirror image at 11 o’clock we find a similar indication. No, it isn’t a duplicate fail-safe, but something much more important which deserves our full attention, because it is actually a world-first complication that indicates winding efficiency over the last two hours. The UR-210’s satellite complication with retrograde minute is both highly original and totally explosive. The principal feature is a high-tech, oversized, three-dimensional retrograde minute hand.
Its function is to enclose the hour satellite and indicate the time as it transverses the 0-to-60-minute scale. This one-hour journey through time, tracing an arc of 120°, is smooth and fluid. But the true nature of the piece is revealed at the end of the 59th minute. Then a sharp distinct “click” signals the return of the minute hand to its starting point. In less than 0.1 of a second the hand flies back to dock with the next hour satellite. This lightning fast retrograde system is based on three key elements:
- A central axis set in ruby bearings provides excellent stability for the satellite/retrograde complication. A cylindrical marine chronometer type spring runs vertically around the axis and generates the optimal tension required for the retrograde minutes flyback.
- A minute hand, which also forms a frame for the hour satellites, displays the time in an extraordinary way. Milled from aluminum to exacting tolerances of approximately 3 microns, the whole structure has a total weight of just 0.302g and is counter balanced by a brass weight. This three-dimensional cage offers rigidity as it transfers energy from the cylindrical flyback spring in the top center of the carrousel to the double-star gear underneath.
- A double coaxial star-shaped cam regulates the retrograde mechanism through its gearing and its rotation defines the trajectory of the minute hand. When the minute hand reaches 60, the double star trips a (one of three) hockey-stick shaped spring under the mechanism, which liberates the minute to fly back to the next hour satellite at 0-minutes.