Invention Piece 1 White gold case

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.

Invention Piece 1 Red gold case

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.

Invention Piece 1

Technical Specifications

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

Movement
Movement dimensions
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
38
Olive-domed jewels in gold chatons

Power reserve
72 hours

Barrels
Series-coupled fast-rotating double barrel (1 turn in 3.2 hours), equipped with a slip-spring to avoid excessive tension

Balance wheel
Free sprung balance with white gold mean-time screws (10.7 mm diameter)

Frequency
21’600 vibrations/hour

Balance spring
Phillips terminal curve
Geneva-style stud

Main Plates
Spotted and frosted nickel silver

Bridges
Frosted and gold-finished nickel silver
“Message from the Inventor Watchmakers” text in relief on a gold plate

Gearing
Involute circle profile
Conical gearing with corrected profile

Inner Tourbillon
Inclined at a 30° angle, 1 rotation per minute

Outer Tourbillon
1 rotation in 4 minutes
Hand-bevelled and open-worked cage pillars
Solid gold counterweight plate

Displays
Hours and minutes
Small seconds
72-hour power reserve on a sector

Habillage
Case
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

Case dimensions
Diameter: 43.5 mm
Thickness: 16.64 mm

Water resistance of the case
3 ATM – 30 m – 100 ft

Crown
Gold with engraved and black lacquered GF logo

Hands
Hours (red triangle) and minutes (blue triangle)
Small seconds
Power-reserve pointers in flame-blued steel

Strap
Hand-sewn black or brown alligator leather with gold folding clasp, hand-embossed with the Greubel Forsey initials