BREGUET MAGNETIC PIVOT
Oil and water don’t mix and the same can be said for a watch escapement and
magnetism. It’s a well-known fact. The majority of watch houses these days are
striving to make their watches more anti-magnetic than ever before so as to
improve timekeeping and accuracy.
However, Breguet decided to take a different route. By adding two magnets
into an escapement and making it an integral part of the structure, Breguet’s
watchmakers have managed to achieve the exact opposite of magnetic interfer-
ence, resulting in greater accuracy and improved timekeeping.
To ensure the watch stays antimagnetic, the entire escapement is constructed
from silicon - escape wheel, balance springs (the watch has two) and pallet fork.
This ensures magnetic interference does not affect the escapement functions.
The escapement features two magnets, both hovering above the pivots of the
balance staff located on top of the end-stone jewels. In essence, these magnets
take the place of a traditional brass spring that in traditional escapements
would absorb impact.
The magnet, which sits above the dial side pivot, is stronger than the magnet
located on the movement side pivot, which forces the balance towards the dial,
in turn allowing the bottom pivot to appear suspended. This means that the tip
of that movement side pivot is not in contact with the end stone.
The purposes of the magnets are twofold: to allow the balance to return quicker
to regular oscillations after a shock, and to reduce friction in various positions.
If the watch receives a small blow, the magnets are powerful enough to keep
the balance in its position, which allows the escapement to continue functioning
without interruption. If a larger blow is received, the balance will return to its
original position faster due to the magnetic pull.
This is an interesting concept put forth by Breguet, but whether this has
actual increased performance in a real-world scenario is something to be
looked into further.
98 | INTERNATIONAL WATCH | FALL 2018
Where this escapement shines in my opinion is the vertical positions. Many
watches spend their life in these positions simply due to the fact that is how your
arm naturally hangs. The friction placed on the balance pivots at this point is
greatest, as the length of the pivot, no longer just the tip, is in contact with a jewel.
Simply put, more surface contact = more friction = decreased performance.
With the magnets in play, the stones no longer rest on their length but stay
suspended by the magnetic field, which will decrease friction and increase
accuracy and performance.
The Breguet magnetic pivot is certainly an interesting design and I think
Breguet sums it up nicely: “It is likely that the impact of this important invention
will not be fully assessed for some years yet.”