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2. A
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Eng
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Twin-barrel system - Power reserve
The red power-reserve indicator is located at the top
of the dial. The rapid-rotation twin-barrel system –
with a maximum number of revolutions restricted to
19.75 – guarantees constant force during the full ten
days of autonomy, thus ensuring enhanced efficiency
and improved timekeeping. This is because the power
reserve actually provided by the twin parallel-moun-
ted bridges is equivalent to twelve days. However, an
ingenious locking system – in the zones indicating
full (C–D) and low (A–B) charge levels – concentrates
the watch operation on the ten days of mediumlevel
running, which are the most regular (B–C), thereby
ensuring optimal efficiency.
The 19.75 winding revolutions of each barrel – a well-
above-average figure – are facilitated by the use of a
particularly thin spring. This specific feature ensures
far more flexible and regular transmission of energy
to the gearwheels, resulting in higher rating precision
and reliability.
The power-reser ve indicator of The
Tourbillon,
Chronograph Royal Oak Concept Carbon
benefits from
two other developments that guarantee reliable and
accurate display thanks to perfect adjustment and
permanent winding of the indicator hand.
The power-reserve indicator with double inverted
cone transmission was developed by Audemars
Piguet. The Manufacture has now adapted this system
to a wristwatch format, enabling extremely accurate
adjustment of the amplitude of the indicator hand. A
beryllium copper cone coated in amorphous carbon
moves up and down the barrel-arbor according to the
degree of winding of the watch; when the position
is low, the barrel is fully wound, and vice versa. In
contact with this mobile cone, a second cone, also
coated in amorphous carbon, picks up this information
to transmit it to the power-reserve indicator hand at
12 o’clock. The planetary differential type gear limits
the choice of positioning for the power-reserve hand,
while the cone transmission system provides more
scope thanks to the lever.
1 jour ¾
10 jours
¼ jour
1 day ¾
10 days
¼ day
1 Tag ¾
10 Tage
¼ Tag
1 giorno ¾
10 giorni
¼ giorno
1 día ¾
10 días
¼ día
1
день
¾
10
дней
¼
день
1
日
¾
10
日
¼
日
1
天
¾
10
天
¼
天
Twin barrel movement with power-reserve cone and locking system
