Technology and Function
of the Mechanica M
2
Technical Information
of the Mechanica M
2
84
85
The Dial train
The last subgroup of our Mechanica M2 that needs discussing is the
Dial train
*
.
The Dial train has the task of reducing the precisely defined number
of rotations of the minute hand to that of the hour hand in a ratio of
12:1.
In order to guarantee the same direction of motion of the two hands
as well as the concentric display, we use gearing with two meshes
*
and individual reductions of 2:1 and 6:1.
The minute hand is perched directly upon the Center wheel
*
arbor.
In order to set the hands, it is necessary to decouple the Center wheel
arbor from the rest of the Gear train
*
. This is solved by the so-called
friction of cannon pinion on the center arbor
*
, which is found
between the Center wheel with its riveted pinion
*
and the Center
wheel arbor. This friction
*
is created by a pre-tensioned, five-legged
friction spring between the Center wheel and the Center wheel arbor
and corresponds to a slipping clutch.
Since the minute hand constitutes a one-armed lever, which
lends the Gear train energy over the course of the first half of an
hour with its dead load and takes it away during the second
half of the hour, we have added a counterweight
*
under
the Quarter wheel
*
. This compensates for the disturbing
influence of the unbalance caused by the hand.
Hour wheel
Out of all these points a solid Gear train is created that meets the
standards of a precision table clock in every way.
Quarter wheel
with
counterweight
Minute wheel
Intermediate wheel
with pinion
The Movement
◊
Plates
*
crafted in 4 mm high-strength aluminum with permanent
surface protection from an extra-hard anodized
*
layer
◊
Gear train
*
mounted in 10 Stainless steel
*
precision ball bearings
◊
Pinions crafted in hardened steel
◊
Gear wheels crafted in brass
*
with fine legs, milled, finely polished,
and gold-plated
◊
Minute hand with counterweight
*
The Spring barrel
◊
Core mounted in 2 Stainless steel
*
precision ball bearings
◊
Even spring tension via stopworks
*
◊
Seven-day power reserve
The Escapement
◊
Swiss lever escapement
*
with 11 ruby jewel bearings
◊
18,000 semi-oscillations
*
per hour (corresponds to 2.5 Hertz)
◊
Pallet
*
lever with jewel pallets
◊
Incabloc shock protection
◊
Nivarox
*
flat hairspring with Terminal curve
*
◊
Regulating index
*
on engraved scale
The Dial
◊
Bezel
*
milled from solid bronze
*
◊
Dial made of hardened anodized
*
aluminum
◊
Hands crafted in blued
*
steel
The Clock
◊
Case crafted in solid, untreated precious wood in cherry wood,
maplewood, and walnut or in black painted alder
◊
Case is sealed to protect the movement from dust
◊
Hidden accessories drawer in the cornice
◊
Rate precision: under optimal conditions
pprox. +/- 5 seconds per day
