Calibre Mb M66.26 Chronographe Monopoussoir 1/1000Th - Montblanc MB M13.21 Manual Del Usuario

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Calibre MB M66.26 Calibre MB M66.26
Chronographe Monopoussoir 1/1000th
Available in the TimeWalker Collection
For more than one hundred years, the Minerva Montblanc Manufacture in Villeret has belonged to a tight
circle of renowned manufacturers whose chronographs are designed to measure short intervals of time with
unparalleled precision. In 1916, Minerva pioneered a mechanical chronograph that guaranteed accuracy
to the hundredth of a second via a hand needing just three seconds to make its way around the dial. This
instrument, reworked in 1936 with the large chronograph seconds hand achieving one revolution per
second, represented an essential source of inspiration for the design of calibre MB M66.26 Chronographe
Monopoussoir 1/1000th.
This calibre is equipped with two balance-wheels: the first is a large screwed balance-wheel that beats at a
frequency of 18,000 vibrations per hour (2.5 Hz) for time indications; the second is a small balance-wheel
that oscillates at a frequency of 360,000 vibrations per hour (50 Hz) for chronograph indications.
As such, it accomplishes 100 back-and-forth movements every second (50 in one direction and 50 in the
other). However, on calibre MB M66.26 this tempo not only determines the movement of the direct-drive
seconds hand but delivers an impulse as well, with which a new type of wheel – known as a 1/1000th mobile
– is sent into rotation within the gear-train. Driven by this device, it turns around its axis at a uniform speed
of ten revolutions per second, thus providing the relation with which the hundredth of a second can be
further divided into ten equal parts.
The chronograph function is controlled by means of a column wheel consisting of two levels, the first of
which controls the starting, stopping and resetting of the hundredths of the balance-wheel while the second
is devoted to the control of the 1/1000th mobile.
Calibre MB M66.26 features a power reserve of 100 hours for time indication and 45 minutes for the
chronograph indication.