Robert Greubel and Stephen Forsey are first and foremost inventors whose goal is to improve the precision of mechanical watches. Their mechanisms find their way into timepieces only after a prolonged period of fundamental research, development and validation, carried out under their Experimental Watch Technology (EWT) platform. They have produced three major inventions to date – the Double Tourbillon 30°, the Quadruple Tourbillon à Différentiel Sphérique and the Tourbillon 24 Secondes Incliné – which they present in various collections. Others are in the pipeline, notably a balance and spring in Diamantchrone and an equality differential.
For its debut appearance at the SIHH this year, Greubel Forsey launched a new edition of its first invention. The movement of the Double Tourbillon Technique reveals its mechanical intricacy for all to see. Four barrels coupled to a spherical differential supply a 120-hour power reserve. The Greubel Forsey philosophy is inscribed on plates affixed to the side of the case.
The third invention has given rise to two distinct timepieces. One is a relatively classic watch with central hour and minute hands. The other is Invention Piece 3, so-named because it benefits from an exceptional architecture, devised to draw attention to the Tourbillon 24 Secondes Incliné. Timekeeping indications, including a 24-hour display, are set directly on the plates. Extracts from a message from Robert Greubel and Stephen Forsey, giving insight into the history of this invention, are inscribed on four engraved plates. In both the limited edition and the series piece, the tourbillon is positioned off-centre and can be observed through the dial and the side of the case.