AN INSPIRED UNDERTAKING
RM 70-01 TOURBILLON ALAIN PROST
Manual winding tourbillon movement with hours, minutes, power-reserve indicator and mechanical odometer.
Limited edition of 30 pieces
Circa 70 hours (± 10%).
BASEPLATE AND BRIDGES MADE OF GRADE 5 TITANIUM
The baseplate and bridges are crafted of grade 5 titanium, a biocompatible, highly corrosion-resistant and remarkably rigid alloy, which enables the gear train to function effortlessly. The alloy is 90% titanium, 6% aluminium and 4% vanadium. This combination further increases the material’s mechanical properties, which explains its frequent use in the aerospace, aeronautics and automobile industries. The baseplate is black PVD treated.
The skeletonised baseplate and bridges were subjected to separate and extensive validation tests to ensure they met rigorous strength requirements.
The mechanical odometer can tally distances of up to 99,999 kilometres, but it can also serve as a reminder, since the mechanism makes it possible to set specific dates or times.
Adjusting the odometer is done using two grade 5 titanium pushers. Located at 2 o’clock, the first pusher is a selector that can synchronise any of 5 selected rollers, or set the complication in neutral position. Depressing the second pusher, at 10 o’clock incrementally rotates the selected roller. Inspired by the gear indicators on the handlebar gearshift, markers on the odometer provide visual confirmation of the selection.
As this function occupies the greater part of the movement, the calibre needed to be as compact as possible, which was achieved by positioning the winding barrel and the tourbillon on the same axis.
Located at 5 o’clock in the shape of a gauge, powered by a planetary differential.
This type of barrel provides the following advantages:
• The phenomenon of periodic internal mainspring adhesion is significantly diminished, thereby increasing performance.
• An excellent mainspring delta curve with an ideal power reserve/performance and regularity ratio.
The design of these screws permits better control of the torque applied during assembly. These screws are therefore unaffected by physical manipulation during assembly or disassembly and age well.
Movement dimensions: 37.10 x 29.73 mm
Thickness: 10.70 mm
Tourbillon diameter: 12.40 mm
Balance diameter: 10.00 mm
Number of jewels: 32
Balance: Glucydur®, 2 arms, 4 setting screws, moment of inertia 10.00 mg•cm2, angle of lift 53º
Frequency: 21,600 vph (3 Hz)
Balance spring: elinvar by Nivarox®
Shock absorbers: KIF Elastor KE 160 B28
Barrel shafts: nickel-free Chronifer® (DIN x 46 Cr 13 + S) with the following characteristics: stainless – antimagnetic - suitable for tempering
Simultaneously tonneau-shaped, rectangular and asymmetrical, the taut, curved lines of the RM 70-01 were designed to ensure fabulous comfort on the wrist and optimised legibility of the dial.
The tripartite case employs Carbon TPT®, a remarkable material with a unique finish obtained by layering hundreds of sheets of carbon fibre using an automated process that changes the orientation of the weft between layers. Heated to 120°C in an autoclave similar to those used for aeronautic components, the material is then ready to be machined at Richard Mille. During this phase, the many layers of Carbon TPT® are revealed, creating random damascene patterns that make each piece unique.
Carbon TPT® is virtually indestructible and possesses exceptional physical properties that make possible a lighter case offering ideal shock protection.
The tripartite case, water resistant to 50 metres, is assembled with 20 spline screws in grade 5 titanium and abrasion-resistant washers in 316L stainless steel.
This additional security system prevents accidental overwinding, which could cause damage to the winding stem or put extreme pressure on the mainspring barrel.
• Anglage and polishing by hand
• Satin-finished bridges
• Locking sections hand polished
• Sapphire-blasted milled sections
• Lapped and polished contact points
• Burnished pivots
• PVD treatment
• Sapphire-blasted surfaces
• Satin-finished surfaces
• Anglage and polishing by hand
• Burnished sections
• Concave chamfering with a diamond tool
• Circular finished faces
• Rhodium plating (before cutting the teeth)
• Minimal corrections applied to the wheels in order to preserve geometry and performance.
FREE-SPRUNG BALANCE WITH VARIABLE INERTIA
The free-sprung balance offers better reliability in the event of shocks, movement assembly or disassembly, and also guarantees better chronometric results over time.
BARREL PAWL WITH PROGRESSIVE RECOIL
This device permits an appreciable winding gain (circa 20%), especially during the start of winding. It is also helpful in distributing the mainspring’s internal tension effectively.
WINDING-BARREL TEETH AND THIRD-WHEEL PINION WITH CENTRAL INVOLUTE PROFILE
The central involute profile of the winding barrel teeth provides an optimal pressure angle of 20°, which promotes effective rotary motion and compensates for variations in the operation of the going train. This, in turn, ensures excellent torque transmission and a distinct improvement in performance.