Greubel Forsey Invention Piece 2 : Homage to Quadruple Tourbillon
Swiss luxury watch brand Greubel Forsey pays tribute to its Quadruple Tourbillon by presenting the Invention Piece 2.
The Invention Pieces are special horology creations made to honour the Swiss Maison’s own master piece complications. In 2007, Greubel Forsey introduced the Invention Piece 1 to pay homage to the Double Tourbillon 30° and in 2009, Invention Piece 3 honoured the Tourbillon 24 Secondes.
This year, the Swiss haute horologerie brand introduces Invention Piece 2 to pay 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 complete the dial.
Unveiled first time at SIHH 2011, the Greubel Forsey Invention Piece 2 is available in limited edition of 11 pieces in platinum and 11 in red gold.
Fitted on a hand-sewn black alligator strap, the 43.50 mm diameter case in Platinum 950 or 18k 5N red gold features asymmetrical convex sapphire crystal glasses on the front and rear sides.
Technical details
Model: Greubel Forsey Invention Piece 2
Movement
Mechanical hand-wound movement, Calibre GF03n. Movement with patented tourbillon. Quadruple Tourbillon, hour and minute display, small second indicator, power-reserve indicator.
Diameter: 37.0 mm
Cage diameter: 36.40 mm
Thickness : 11.87 mm
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 finish, hand bevelled, straight-grained flanks, polished counter-sinks
Number of parts
Complete movement: 594 components
1 double tourbillon cage: 129 components
Weight of one double cage: 1.17 g
Number of jewels: 64, Olived-domed jewels in gold chatons
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
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 fi xed 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
