Greubel Forsey Double Tourbillon 30° Vision

When Robert Greubel and Stephen Forsey first decided to develop a high performance tourbillon regulator, they set out to both pay homage to its famous inventor, Abraham Louis Breguet, and to make a decisive technical advancement.
In order to respond to the specific requirements of the tourbillon in a wristwatch, Greubel Forsey developed an innovative double tourbillon. One carriage, rotating in 60 seconds and inclined at 30°,  rotates inside another, which is itself rotating every four minutes. Rotating a tourbillon inside another tourbillon in this manner averages out errors induced by the force of gravity on the balance. The construction allows for superior chronometric performance; a minimum volume/maximum balance diameter ratio; and enables the superbly finished mechanism to be appreciated visually.
The Double Tourbillon 30° is now available in two renditions: 'Vision' and 'Secret'. Vision features an open dial displaying the complication for all to view, while 'Secret' conceals its artistry behind the dial while allowing viewing discreetly through the display back.

Technical Data:

Case:	Other	Category:	Complication/Fine watchmaking
Bracelet strap:	Leather	Size:	Ø 44.0 mm
Buckle:	Folding Buckle	Thickness:	16.0 mm
Setting:	No	Waterproofness:	30 m

Movement:	Not available Manufacture movement
Functions:	Tourbillon, Power-reserve indication

Reference:	n/a	Collection:	Inventions
Year:	2008

Sources info: World Tempus

Greubel Forsey- Double Tourbillon Technique

A Journey into the heart of the mechanism

The Double Tourbillon Technique is an entirely original and innovative interpretation of Greubel Forsey’s first fundamental invention, the Double Tourbillon 30°. It is a timepiece with a boldly assertive character and a totally unique architecture.

The Double Tourbillon Technique is a case study in precision mechanical watchmaking with the sapphire crystal acting as a portal through which to observe the mesmerising workings of the intricately interlocking parts. The eye is naturally drawn from one gear to the next, enabling careful observation of each separate element.

A true work of technical art

With the Double Tourbillon Technique, Robert Greubel and Stephen Forsey have created a truly stunning timepiece that is faithful to their philosophy of technical visibility. Each and every element of the mechanism is enhanced and displayed without overshadowing others.

At the heart of the timepiece is the Double Tourbillon 30° mechanism?; however, to perpetuate the art of horology and contribute to its 21st century development, several additional technical elements have been added, including four fast-rotating co-axial barrels guaranteeing 120 hours of autonomy.

Admirers can even enjoy the sight of the barrels rotating while winding and unwinding. Coupled to these barrels is the visible spherical differential that drives the power reserve indicator. The hours are displayed on a transparent sapphire crystal ring fitted inside the inner circumference of the bezel to ensure full visual access to the astonishingly three-dimensional depth of the mechanism. Transparency is also reflected in the luminous open-worked signature Greubel Forsey hands and both the power reserve indicator at 3 o’clock and sub-seconds dial at 9 o’clock are strikingly enhanced by their red triangular pointers.

Case:	Red Gold	Category:	Complication/Fine watchmaking
Bracelet strap:	Leather	Size:	Ø 47.5 mm
Buckle:	Pin Buckle	Thickness:	16.8 mm
Setting:	No	Waterproofness:	30 m

Movement:	Manual-winding mechanical Power reserve : 120 h , 21600 variations / hours
Functions:	Hours, Minutes, Seconds, Tourbillon, Power-reserve indication

Reference:	GF 02s	Collection:	Double Tourbillon 30°
Year:	2010

Sources from World Tempus

GREUBEL FORSEY - Invention Piece 3

To pay homage to their third invention, the Tourbillon 24 Secondes Incliné, Robert Greubel and Stephen Forsey have taken on the challenge of housing a watch mechanism, combining complex and innovative techniques within an unprecedented architectural setting.

The third invention consists of a single tourbillon cage inclined at a 25° angle and performing a rapid rotation in 24 seconds. This utterly original mechanism guarantees the watch maximum efficiency and optimal performance on the wrist. Invention Piece 3 features a totally unconventional display with the plates themselves serving as the base for the timekeeping indicators. The four gold plates are engraved with a portion of a personal message from Robert Greubel and Stephen Forsey providing an insight into the complex process involved in creating the extraordinary mechanism of this third invention.

TECHNICAL DATAS

Mechanical hand-wound movement, Calibre GF 01n
Tourbillon 24 Secondes Incliné, hours and minutes display,
Seconds display and power-reserve indicator.
Unique series of 33 pieces
Movement dimensions  
• Diameter : 36.40 mm
• Thickness : 11.51 mm

Number of parts  
• Complete movement : 370 parts
• Tourbillon cage: 87 parts
• Weight of the cage : 0.39 g

Number of jewels  
• 42
• Olive-domed jewels in gold chatons

Power reserve  
72 hours

Barrels  
Rapid rotating twin barrels (1 turn in 3.2 hours) equipped with a slipping spring to avoid excessive tension

Balance wheel  
Variable-inertia with gold mean-time screws (10 mm diameter)

Frequency  
21,600 vibrations/hour

Balance spring  
• Phillips terminal curve
• Geneva-style stud

Main Plates    Nickel silver

Sources from World Tempus