Pièce de Résistance for the Double Balancier concept
Greubel Forsey (GF)'s latest product, the Double Balancier Convex, took 15 years to launch. The Double Balancier (DB) concept was first patented in 2007 and subsequently exhibited in a single prototype at GF's Experimental cheap replica watches Technology (EWT) division, first discovered by our friends at Hodinkee. The balance wheel and escapement of that prototype are stacked one on top of the other between seven and nine o'clock, inclined at a gentle 20° angle. The running seconds have three subdials - one for each regulating organ, with a larger third subdial placed in the middle, showing the average of its two smaller siblings.
Then came the first Double Balancier in the 2013 series, albeit in small batches of six pieces. The two balance wheels are separated for the first time at 5 and 9 o'clock, connected only by a spherical differential hidden beneath the single running seconds subdial at 7 o'clock. They are positioned at the more extreme 35° inclination in different three-dimensional planes. This is probably the first time anyone has seen a standard balance wheel with a lever escapement look (and function) so extreme. The 72-hour power reserve indicator at two o'clock also makes its debut on this watch. GF is so proud of this achievement that they engraved a brief heartfelt message on the side of the strap: (translated from French) "We, the inventors of watchmaking, have brought this extraordinary timepiece to life, creating A delicate alchemy between force and technicality. Our know-how and craftsmanship is reflected in the sophistication of this achievement developed for you.”
In 2016, following two invention patents, GF will redesign the dial layout of the DB, further pulling back the curtain on the dial to reveal the sublime, multi-layer constant differential at the heart of the concept. This time around, the seconds subdial will take the second spot in the differential, which is unfortunately relegated to a less conspicuous spot on the dial. Aside from subtle design tweaks to the power-reserve indicator and dial colors and fonts, the aforementioned changes are the most prominent and eye-catching. By revealing the inner workings of the movement, the wearer can see even more incredible depth of construction, this time with a double balance wheel angled at 30°. The joy of experiencing the magic of invention is sure to last long after the trick is revealed.Greubel Forsey Double Balancier Convexe SHH Edition
The 2022 Double Balancier Convex distills the past 15 years of Greubel Forsey craftsmanship into a watch that not only incorporates the design cues of the last two DBs, but, crucially, uses the first of its kind in 2019. The titanium oval case (now 43.5mm) GMT Sport emerges – a departure from the traditional round white gold case used in the previous DB. Its shape is neither oval nor tonneau-shaped, but a perfect blend of the two. To accommodate this unique shape, both the front and back of the movement and the sapphire crystal had to follow the same contours. There's no cheating with a flat bottom cover. The lugs complement the case, and the included rubber strap with a titanium folding clasp screws directly onto the lugs. From the front, it appears that there are no lugs at all. That's where the genius of the seemingly earless design lies. The rubber strap can be replaced with a three-link titanium bracelet, which flows seamlessly into the case when connected. boom! Instantly transformed into an "all-in-one" bracelet watch. Disappointingly, the titanium bracelet with the buckle fine-tuning is not included, but can be requested separately.
On the face of it, the proud inscription on the bezel of the Balancier S is gone, and DB Convex has simply put its art and engineering in its place. The bezel itself is a few millimeters higher than the case, accentuating the view of the dial. What dial is this.
More than half of the dial is now open and can only be described as an asymmetrical semi-circle, with the engraved and lacquered 72-hour power reserve indicator at two o'clock the only bracket remaining on it. The twin barrels stacked coaxially (on the same axis) at 10 o’clock are now pushed out from under the dial through an inscribed barrel cover. Interestingly, the barrel moves more than twice as fast as a conventional barrel, taking 3.2 hours to make one revolution compared to 8 hours for a full turn. Although the movement is manually wound, one of the mainsprings has a sliding rein (visible only in automatic movements) to relieve excess tension when winding.discount replica watches
On the periphery, the minute markers are also engraved and coated with Super-LumiNova, with hour markers applied at five-minute intervals. The minute and hour hands are also filled with Super-LumiNova and curved to accommodate the curvature of the dial and crystal. The movement that drives these hands is now supported by a skeletonized mini bridge that rises from the movement plate to meet them on an elevated plane.
To allow the balance wheel and constant differential space to function, the top barrel drives the cannon pinion directly, eliminating the need for a traditional gear train layout. It's unclear if there's a gear train connecting the fourth wheel of each balance to the running seconds indicator, as we don't know what's under it. However, it stands to reason that the running seconds should be the average of the oscillatory outputs of the two balances.
If you're wondering how the Double Balancier concept pursues timekeeping, it differs from the other, more common, double balance watch, which relies on resonance or vibration effects for precision. The sloping balance wheel, which is currently tilted by 30° in the escapement platform, is never in an absolutely vertical orientation when the watch is in a vertical position. Therefore, the balance never experiences a full downward gravitational pull. The use of the Breguet upper loop (also known as the Phillips terminal curve, because the mathematician Edward Phillips improved Breguet's design) also positioned the center of gravity of the swing at the center of the balance. Aesthetically, we like that the balance uses timing screws instead of timing weights,Jacob & Co ASTRONOMIA CASINO
The differential between the balances employs a constant-force mechanism to regulate the speed of each balance, thereby averaging their oscillating speeds, making them synchronised with each other. In the differential there is the equivalent of three third wheels lined up in a row, with the top and bottom wheels driving two separate fourth wheels left and right. There is a coil spring, fixed to two of the three spokes of each wheel, which acts as a tensioner, releasing and receiving energy from the balance in a controlled manner. The wheel in the middle of this stack turns and drives the center wheel with an already balanced force, and then the rest of the motion works. The fourth wheel itself uses a sloping gear to drive the sloping escape wheel.
A polished blued steel hand sits on top of the entire unit and indicates the number of minutes it takes for the differential to make one revolution. Why ask for four minutes? Well, the gear ratio in the differential has to be doubled to receive energy from both balance wheels, and if one balance wheel stops moving, the second hand takes two minutes instead of one to make one revolution.
All the scientific engineering is beautiful because of the finishing of the movement. Here we find bridges with polished bevels, countersunk holes for screws and ruled flanks just for variety. The flat tops of the differential and balance bridge are also finished in black finish. The matte black finish on the dial and main board keeps all the bright work from disappearing from view. Despite the deliberate asymmetry of the dial layout, the overall design is visually harmonious in its high level of finish and color contrast. Pablo Picasso said it best, and it applies here: "Learn the rules like a pro, so you can break them like an artist." Devon Tread 2 Ghost