Limited Edition of 50 Pieces Each
The Calibre FB-T.FC is equipped with an exclusive constant-force regulation system with suspended fusée and chain transmission, equipped with a differential winding system. It also has a highly distinctive power reserve mechanism.
The barrel and fusée of Calibre FB-T.FC are linked by a chain comprising no less than 474 steel links, including more than 300 pins measuring barely 0.30 mm in diameter and all hand assembled. The chain measures a total 28 cm long and the maximum tension exercised upon it once in place amounts to three kilos. When the mainspring is associated with a fusée, the barrel drum turns in one direction when the spring winds down and in the opposite direction when it is wound up, thus causing the chain to wrap around the drum. A distinctive feature of Calibre FB-T.FC lies in the fact that its fusée mechanism has been equipped with an unusually designed differential gear.
Directly linked to the barrel via a driving wheel, the mechanism uses the winding and letting down motion of the mainspring to make a truncated cone move up and down along a threaded arbor secured to the mainplate.
When the barrel sets the driving wheel into motion, the latter drives the cone by means of two long pegs that push it clockwise when moving upwards and counter-clockwise when travelling downwards, respectively corresponding to the winding and letting down of the mainspring.
A mobile arm tipped with a roller jewel serves as a feeler-spindle in measuring the up-anddown motion of the cone, bringing the arm closer or further away from the centre of rotation. A rake-shaped element along the axis of the arm transmits the movement's power-reserve level to a hand.
Equipped with an aerodynamically shaped oversized variable-inertia balance oscillating at a low frequency (3 Hz), the tourbillon carriage of the watch performs one rotation per minute.
The balance is made of copper beryllium (CuBE) and equipped with a self-compensating balance-spring made from an unbreakable, rust-free and anti-magnetic ferromagnetic alloy.
The terminal curve of the balance-spring is delicately shaped by hand in harmony with the noblest watchmaking traditions. To ensure fine adjustment of its amplitude, the rim (felly) of the balance is fitted with two sets of maillechort inertia-blocks, one complete and the other truncated so as to ensure independent adjustment.
The 67-part titanium tourbillon carriage is held in place by a bridge with a single arch and poised by means of two 18kt gold studs.
The direct-drive seconds display is enabled by the fact that the direct-drive seconds wheel is identical and co-axial with the wheel driving the tourbillon carriage.
Technical Specifications:
The case, in 18kt white gold and titanium or in 18kt rose gold and black ceramic, measures 44mm x 13mm. It has double AR-coated sapphire crystals and it is water resistant to 30 meters. The 18kt white or rose gold crown has an 18kt rose or black ceramic gold medallion, and the octagonal case is also fitted with four portholes with glareproofed sapphire crystals.
Movement is the Swiss manual wind Ferdinand Berthoud in-house caliber FB-T.FC with 46 jewels, 21,600 vph and a power reserve of 53 hours. Suspended fusée - chain constant-force transmission regulation. Suspended mobile power-reserve cone low-frequency tourbillon with central seconds. Balance-spring with hand-shaped Philips terminal curve. Nickel silver half-bridges supported by stylised titanium pillars. It is COSC-certified as a chronometer.
Dial and hands: Vertical satin-finish ruthenium or black dial with cut-out center, 18kt blued gold hours, minutes and power-reserve hands. Blued bronze seconds hand. Functions and displays: display of the hours, minutes at 12 o'clock on a white lacquered dial, power-reserve display in an openworked subdial at 9 o'clock and tourbillon at 6 o'clock.
It comes on a hand-sewn rolled-edge alligator leather strap with an 18kt white or rose gold and titanium or black ceramic folding clasp.
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