Greubel Forsey Invention Piece 1
Honoring the first invention
The Invention Piece 1 embodies Robert Greubel and Stephen Forsey’s wish to honor the Double Tourbillon 30° and to raise the bar yet another notch by opening up whole new vistas for their first major invention. Both the architecture of the movement and the display of information symbolize the four years of meticulous research that the Inventor Watchmakers have devoted to developing the new mechanism.
In this Invention Piece 1, the creative Greubel Forsey twosome has rearranged the volumes and surfaces of the timepiece according to a new technical and aesthetic structure. The latter places the Double Tourbillon 30° at the centre of a semi-circular hour and minute display, thereby visually reinforcing the link between the mechanism responsible for measuring the time and its “symbolic” indication.
Compared with the Double Tourbillon 30°, the movement driving the Invention Piece 1 has been profoundly modified to off-center the double cage by shifting it slightly to the left and distinctly higher. This position freed up space to place the object of the invention at the very center of the highly original hour and minute display. Two triangular indicators – a red one for the hours and a blue one for the minutes – enable the observer to follow the passing of time on the mechanism’s two concentric semi-circles.
To facilitate read-off, the 12-hour and 0-minute markers are aligned at the traditional 12 o’clock position.
Magnificently evoking the mechanical genius of the Invention Piece 1, the various speeds of rotation of these different elements give an idea of the complexity of the mechanism: whereas the outer cage takes four minutes to perform a complete rotation and the inner cage just 60 seconds, the double hands turn in 24 hours for the hours display and two hours for minutes.
Around the tourbillon with its indicators, the absence of a dial reveals the frosted nickel silver bridges that are clearly visible on three distinct levels.
This opening provides a view of the concentric gearing serving to drive the hour and minute indicators. The off-centred small seconds and power-reserve displays are reminiscent of a miniature solar system.
While the case with its signature Greubel Forsey lugs is immediately recognizable, this Invention Piece 1 expresses its unique nature, reinforced by an unexpected detail: directly engraved on a plate appearing on the case-back, a unique message from the Inventor Watchmakers will forever accompany the owner of this exceptional timepiece.
388 parts contribute to the smooth running of the movement driving the Invention Piece 1, including 128 for the double cage that weighs just 1.17 grams.
The Invention Piece 1 is produced in a single edition comprising three versions of 11 watches each, a number chosen for its symbolic value representing the Robert Greubel and Stephen Forsey partnership.
Mechanical hand-wound movement, GF Calibre 02n
Off-centered Double Tourbillon 30°, Outer Tourbillon 4-minute rotation indicator, Inner Tourbillon 60-second rotation indicator, hours and minutes display,
seconds display, power-reserve indicator. Patented DT30° mechanism
Unique edition of 33 pieces
Diameter: 36.4 mm
Thickness: 12.72 mm
Number of parts
Complete movement: 388 parts
Tourbillon cage: 128 parts
Weight of the cage: 1.17 g
Number of jewels
Olive-domed jewels in gold chatons
Series-coupled fast-rotating double barrel (1 turn in 3.2 hours), equipped with a slip-spring to avoid excessive tension
Free sprung balance with white gold mean-time screws (10.7 mm diameter)
Phillips terminal curve
Spotted and frosted nickel silver
Frosted and gold-finished nickel silver
“Message from the Inventor Watchmakers” text in relief on a gold plate
Involute circle profile
Conical gearing with corrected profile
Inclined at a 30° angle, 1 rotation per minute
1 rotation in 4 minutes
Hand-bevelled and open-worked cage pillars
Solid gold counterweight plate
Hours and minutes
72-hour power reserve on a sector
In gold or platinum with convex sapphire crystal, 3 versions in series of 11 each
Transparent back with convex sapphire crystal
Raised engraving of the name of the Invention on a hand-punched background
Gold security screws
Hand-engraved individual number
Diameter: 43.5 mm
Thickness: 16.64 mm
Water resistance of the case
3 ATM – 30 m – 100 ft
Gold with engraved and black lacquered GF logo
Hours (red triangle) and minutes (blue triangle)
Power-reserve pointers in flame-blued steel
Hand-sewn black or brown alligator leather with gold folding clasp, hand-embossed with the Greubel Forsey initials