In ten years, no less than six significant inventions have sprung from Greubel Forsey's EWT think tank, three of which (to date) have been celebrated by Invention Pieces (IP). In 2007, IP1 paid homage to the Double Tourbillon 30°; in 2009, IP3 honoured the Tourbillon 24 Secondes; and today IP2 pays tribute to the Quadruple Tourbillon with a completely new architecture in which the focus is on its exclusive mechanism.
The two double tourbillons systems are presented head to tail and coupled by a spherical differential. A sub-dial at 5 o'clock conceals triple mainspring barrels and features a red triangle indicating hours and a rotating disk indicates minutes. Small seconds dial at 10 o'clock and 56-hour power reserve indicator at 11 o'clock compete the dial.
A unique edition of 11 pieces in platinum and 11 in red gold.
Invention piece 2
Unique edition of 11 pieces in platinum and 11 pieces in 5n red gold. mechanical hand-wound movement, Calibre GF03n
Quadruple Tourbillon • hour and minute display • small second indicator power-reserve indicator.
Movement with patented tourbillon
Movement dimensions
• Diameter: 37.0 mm
• Cage diameter: 36.40 mm
• Thickness : 11.87 mm
Number of parts
• Complete movement: 594 composants
• 1 double tourbillon cage: 129 composants
• Weight of one double cage: 1.17 g
Number of jewels
• 64
• Olived-domed jewels in gold chatons
Power reserve: 56 hours
Barrels
• Rapid rotating triple barrels (1 turn in 3.2 hours)
• equipped with a slipping spring to avoid excess tension
Balance wheel
Free sprung balance with white gold mean-time screws (10.70 mm diameter)
Frequency: 21'600 vibrations/hour
Balance spring
• Phillips terminal curve
• Geneva-style stud
Main Plates
Nickel silver, spotted nickel-palladium fi nish, hand bevelled, straight-grained fl anks, polished counter-sinks
Bridges
• Nickel silver bridge, frosted, spotted with polished bevelling, nickel-palladium finish
• Gold nameplate bearing the individual number of the timepiece
• 4 steel Double Tourbillon bridges hand-bevelled, flat black polished with polished counter-sinks
Gearing
• Involute circle profile
• Conical gearing with corrected profiles
Inner Tourbillon
Inclined at a 30°angle, 1 rotation per minute
Outer Tourbillon
• 1 rotation in 4 minutes
• Hand-bevelled and openworked cage pillars
• 1 gold Greubel Forsey counterweight per cage
Displays
• Hours and minutes
• Small seconds sub dial (mean performance)
• 56-hour power reserve on a sector
• Tourbillon rotation sapphire crystal indicator (outer cage) in 4 minutes at 1 o'clock
Exterior
Case
• Platinum 950 or 18k 5N red gold with asymmetrical convex sapphire crystal
• Transparent back with asymmetrical convex sapphire crystal
• Lateral window with shaped sapphire crystal
• Gold security screws
• Polished bezel and centre band with hand-finished straight graining
• Hand-engraved individual number
• Raised engraving of the name of the Inventors on a hand-punched background
• Unique edition of 11 pieces in platinum and 11 pieces in 5N red gold
Case dimensions
• Diameter: 43.50 mm
• Thickness: 16.28 mm
Water resistance of the case: 3 atm - 30 m - 100 ft
Crown
Platinum or 5N red gold with engraved and black lacquered GF logo
Dial
• 22k gold hour indicators with red triangle
• 22k gold Greubel Forsey initials in centre
Hands
• Minute-indicator: rotating disc with fixed blue triangle
• Small second in flame-blued polished steel
• Power-reserve in flame-blued polished steel
• Sapphire crystal 4-minute indicator
Strap and clasp
• Hand-sewn black alligator
• Platinum 950 or 18k 5N red gold folding clasp, hand-engraved with the Greubel Forsey logo
