Montres DeWitt presents a platinum edition of its 2006 novelty, the Tourbillon Force Constante, which represented a landmark development in watchmaking history, providing the answer to a question as old as the mechanical movement itself: how can one ensure the perfectly regular transmission of energy to the mechanism?
This apparently simple question calls for a technically complex response. Between a fully wound and a depleted power-reserve, the barrel-spring supplies a steadily diminishing amount of energy as it uncoils. This difference naturally affects a watch’s regularity and precision. This specific concern has been the subject of endless research since the 17th century, but no concept has resolved the problem as brilliantly as the DeWitt Tourbillon Force Constante.
DeWitt’s solution involves inserting an additional mechanism into a traditional mechanical movement in order to exchange a motive power, which may be variable or irregular (effort of gear-train or barrel-spring), for another, perfectly constant force – whatever the degree of winding of the barrel. In other words, the device is designed to transmit impulses whose energy remains identical and regular, however taut the barrel-spring, thanks to three additional wheels: one to ensure correct gear operation; and two intermediate wheels between the motive force (barrel) and the regulator (tourbillon).
This solution absorbs the force generated by the barrel once every second, and redistributes it to the tourbillon every 10 seconds. To see how the system operates, watch the elegant inertia weight of the constant force device (in the form of a cross with its four arms ending a hammer) as it completes 6 revolutions per minute. The device also features its own balance-spring. This enables the mainspring to be constantly supplied with a level of energy superior to that required by the tourbillon regulator (patented by DeWitt).
By designing a system that relays energy to the power-reserve indicator, Maison DeWitt has introduced a landmark innovation to the tourbillon force constante. Rotating the crown when winding the barrel-spring drives a miniature chain consisting of 192 hand-crafted elements, which uses an intermediate wheel to activate the power-reserve indicator sliding on a worm screw. If the pointer is in the red zone, the power-reserve is close to zero; when it is in the green zone, it means the barrel-spring is sufficiently wound.
This ingenious mechanism (the patented, mechanical manually-wound Calibre DW 8050) is a marvel in itself – and has aesthetic panache to match. Dial openings reveal the complexity of the mechanism and its various devices. The chain provides amazing balance. The visual harmony extends beyond mere mechanics.
Model: ACADEMIA FORCE CONSTANTE A CHAINE
Mechanical, manually wound, manufactured by DeWitt
Power-Reserve: 72 hours with chain-driven device
Regulating Organ: Tourbillon with Constant Force
Movement Thickness: 7.8mm
Movement Diameter: 30mm
Vibrations 21,600 vph
Balance: Special 4-arm Gyromax
Escapement: 52° lift angle
Power-Reserve Indicator on worm screw
Côtes de Genève
Interhorn Width: 21mm
Water-Resistance 30 meters
Buckle: Folding Clasp in 750 Platinum
Strictly limited edition