Glossary
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97
The French-Swiss physicist worked among other things on the definition of
the international prototype meter and discovered the Invar
*
alloy in 1896
with its extremely slight heat expansion. He received the Nobel Prize for it in
1920.
Harrison was a carpenter by trade, but soon worked as a watchmaker.
After beginning with the revolutionary manufacture of clock towers and
grandfather clocks made of wood, from 1730 he concentrated for the rest
of his life on making and optimizing Marine chronometers
*
for the British
admiralty. In 1761 his son William proved the incredible precision of the
ingenious H4 during a test run to Jamaica.
Part of the Dial train
*
. The Hour wheel is driven by the Minute wheel
*
pinion
*
and makes one full revolution in twelve hours. The hour hand is attached to
the pipe of the Hour wheel.
Dutch physicist, astronomer, and mathematician. He used Galileo Galilei’s
*
knowledge for his investigation of pendulum
*
motion and discovered that the
oscillation of the pendulum
*
is independent of its displacement. He ended up
developing a pendulum clock and registered it for a patent in 1664. In 1675
he developed the balance oscillating system using an Archimedian balance
spring
*
and utilized it in his own pocket watches.
Called in French the ellipse because it used to be elliptical in shape, this is
another name for the Discharging pallet
*
.
Also called the great roller. It is perched upon the balance staff and bears the
Impulse pallet
*
.
A surface on pallets
*
. The escape wheel tooth glides along its inclined surface
during the lifting phase, thus sending impulse energy to the balance.
Part of the escapement affecting the length of the balance spring, making it
possible to alter the oscillation frequency.
Part of the index
*
apparatus in which the outer end of the balance spring is
conducted to adjust its effective length.
Part of the Dial train
*
. Together with the pinion it is located on the stud for
the Intermediate wheel
*
and is driven by the Quarter wheel
*
(located on
the Minute wheel
*
arbor). It drives the Hour wheel
*
.
Guillaume,
Charles-Edouard
(1861-1938)
Harrison, John
(1693-1776)
Hour wheel
Huygens Christiaan
(1629-1695)
Impulse pallet
Impulse roller
Impulse surface
Index
Index key
Intermediate wheel
Friction
Friction al-rest
escapement
Friction bearing
Galilei, Galileo
(1564-1642)
Gear train
Glucydur
Graham escapement
Graham, George
(approx. 1673-1751)
During the designing of the movement of your precision clock, great value
was placed on decreasing friction. For this reason, most of the Gear train
*
pivots and arbors are equipped with Ball bearings
*
. Sometimes friction is
necessary, for example in the Dial train’s
*
slipping clutch, which makes setting
hands possible.
Improvement upon the Recoil escapement
*
and predecessor of the detached
escapement. In the Friction al-rest escapement, the oscillator
*
was not in
permanent contact with the escape wheel
*
for the first time, but rather rested
during the complementary arc. Thus, it only moved forward in steps.
A bearing that sees the pivot borne in a hole. Since the material surfaces
glide across each other, it is necessary to use lubrication alongside choosing
different materials for each of the components.
Italian mathematician, physicist and astronomer. Around 1590 he examined
the pendulum
*
and discovered that the Period of oscillation
*
was not
determined by its weight, but by its length. After that, and to his final days,
he occupied himself with concepts for a pendulum
*
clock, but never made it.
The collection of toothed wheels
*
in a timepiece. The Gear train transmits
energy to the escapement. It is calculated to rotate individual arbors at certain
speeds. Normally there are four wheels in a Gear train: the main wheel, the
Center wheel
*
, the Fourth wheel
*
, and the Third wheel
*
. The escape wheel
is not generally seen as part of the Gear train.
Derived from glucinum (French word for beryllium) and dur (French for
»hard«). A very hard alloy of copper and 2-3 percent beryllium. It is non-
magnetic, doesn’t oxidize, and only expands slightly with heat. Also called
beryllium copper.
Because of the special shape of the pallets
*
, the escape wheel
*
comes to
a standstill during its resting phase. Graham’s escapement allowed for
enormous progress in precision timekeeping and has served fine timepieces
well for centuries
After his apprenticeship, Graham worked with the influential English
watchmaker Thomas Tompion
*
in London, with whom he was friends to his
death. Graham became a partner of Tompion and married his niece, Elizabeth.
Graham developed the quicksilver compensation pendulum
*
and, most
importantly, the revolutionary Lever escapement
*
named for him.
H
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