RM 74-01 AUTOMATIC TOURBILLON
FREE-SPRUNG BALANCE WITH VARIABLE INERTIA
This type of balance wheel represents the ultimate in innovation. It guarantees greater reliability when subjected to shocks and during movement assembly or disassembly, hence better chronometric results over time.
The regulator index is eliminated, and a more accurate and repeatable calibration is possible thanks to 4 small, adjustable weights located directly on the balance.
- Movement dimensions: 30.70 x 23.70 mm
- Thickness: 6.20 mm
- Number of jewels: 23
- Balance: CuBe, 4 arms, 4 setting weights, moment of inertia of 7.5 mg.cm2, 50º angle of lift
- Frequency: 28,800 vph (4 Hz)
- Balance spring: AK 3
- Shock protection: INCABLOC 908.22.211.100 (transparent)
After years of development in specialised laboratories, Richard Mille and the Groupe IMI have succeeded in eliminating these unwanted binders, conserving only the desirable materials thanks to an innovative process that combines conventional hot-stamping associated with a series of bursts of high-voltage electrical current that augment the kinetics of the sintering. The technique is known as flash sintering.
Materials of a similar composition are employed in ballistic protections and in aerospace for shuttle re-entry components, exterior fuselage pieces and in the brakes on competition vehicles. Cermet has a mass to volume ratio of 4.1 g/cm3 and a hardness of 2,360 Vickers, comparable to other high-performance ceramics, making it eminently suitable for use in bezels, an area highly vulnerable to scratches, while ensuring that entire assembly is light in weight. These bezels are affixed to a caseband made of grade 5 titanium, which also contributes to lowering total mass.
The tripartite case is water resistant to 50 metres, ensured by 2 Nitrile O-ring seals. The case is assembled with 20 grade 5 titanium spline screws and abrasion-resistant washers in 316 L stainless steel.