![Russian finished watch movement](https://upload.wikimedia.org/wikipedia/commons/f/f2/Russian_finished_watch_movement.jpg)
A mechanical watch is a
watch
A watch is a portable timepiece intended to be carried or worn by a person. It is designed to keep a consistent movement despite the motions caused by the person's activities. A wristwatch is designed to be worn around the wrist, attached by ...
that uses a
clockwork mechanism to measure the passage of time, as opposed to
quartz watch
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
es which function using the
vibration
Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic function, periodic, such as the motion of a pendulum ...
modes of a
piezoelectric
Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied Stress (mechanics), mechanical s ...
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
tuning fork
A tuning fork is an acoustic resonator in the form of a two-pronged fork with the prongs (tines) formed from a U-shaped bar of elastic metal (usually steel). It resonates at a specific constant pitch when set vibrating by striking it against ...
, or
radio watches, which are quartz watches synchronized to an
atomic clock
An atomic clock is a clock that measures time by monitoring the resonant frequency of atoms. It is based on atoms having different energy levels. Electron states in an atom are associated with different energy levels, and in transitions betwee ...
via
radio waves. A mechanical watch is driven by a
mainspring
A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. ''Winding'' the timepiece, by turning a knob or key, stores energy in ...
which must be wound either periodically by hand or via a
self-winding mechanism. Its force is transmitted through a series of gears to power the
balance wheel
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a ...
, a weighted wheel which oscillates back and forth at a constant rate. A device called an
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
releases the watch's wheels to move forward a small amount with each swing of the balance wheel, moving the watch's hands forward at a constant rate. The escapement is what makes the 'ticking' sound which is heard in an operating mechanical watch. Mechanical watches evolved in Europe in the 17th century from spring powered
clock
A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and the ...
s, which appeared in the 15th century.
Mechanical watches are typically not as accurate as quartz watches,
and they require periodic cleaning and calibration by a skilled watchmaker.
Since the 1970s, quartz watches have taken over most of the watch market, and mechanical watches are now mostly marketed as a luxury product, purchased for their
aesthetic
Aesthetics, or esthetics, is a branch of philosophy that deals with the nature of beauty and taste, as well as the philosophy of art (its own area of philosophy that comes out of aesthetics). It examines aesthetic values, often expressed th ...
and
luxury
Luxury may refer to:
* Luxury goods, an economic good or service for which demand increases more than proportionally as income rises
*Luxury tax, tax on products not considered essential, such as expensive cars
**Luxury tax (sports), surcharge pu ...
values, for appreciation of their fine craftsmanship,
or as a
status symbol
A status symbol is a visible, external symbol of one's social position, an indicator of economic or social status. Many luxury goods are often considered status symbols. ''Status symbol'' is also a sociological term – as part of social and soci ...
.
Components
![Omega Speedmaster Schumacher Edition10 36 22 158000](https://upload.wikimedia.org/wikipedia/commons/a/ab/Omega_Speedmaster_Schumacher_Edition10_36_22_158000.jpeg)
The internal mechanism of a watch, excluding the face and hands, is called the
movement. All mechanical watches have these five parts:
* A
mainspring
A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. ''Winding'' the timepiece, by turning a knob or key, stores energy in ...
, which stores mechanical energy to power the watch.
* A
gear train
A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage.
Gear teeth are designed to ensure the pitch circles of engaging gears roll on each other without slipping, providing a smooth transmission ...
, called the
wheel train In horology, a wheel train (or just train) is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear tr ...
, which has the dual function of transmitting the force of the mainspring to the balance wheel and adding up the swings of the balance wheel to get units of
second
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds ...
s,
minute
The minute is a unit of time usually equal to (the first sexagesimal fraction) of an hour, or 60 seconds. In the UTC time standard, a minute on rare occasions has 61 seconds, a consequence of leap seconds (there is a provision to insert a nega ...
s, and
hour
An hour (symbol: h; also abbreviated hr) is a unit of time conventionally reckoned as of a day and scientifically reckoned between 3,599 and 3,601 seconds, depending on the speed of Earth's rotation. There are 60 minutes in an hour, and 24 ho ...
s. A separate part of the gear train, called the
keyless work In horology, a wheel train (or just train) is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear tr ...
, allows the user to wind the mainspring and enables the hands to be moved to set the time.
* A
balance wheel
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a ...
, which
oscillates
Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...
back and forth. This is the timekeeping element in the watch. Its timekeeping accuracy is due to the fact that it is a
harmonic oscillator
In classical mechanics, a harmonic oscillator is a system that, when displaced from its Mechanical equilibrium, equilibrium position, experiences a restoring force ''F'' Proportionality (mathematics), proportional to the displacement ''x'':
\v ...
, with a
period of oscillation which is very constant, dependent on the inertia of the wheel and the elasticity of the
balance spring
A balance spring, or hairspring, is a spring attached to the balance wheel in mechanical timepieces. It causes the balance wheel to oscillate with a resonant frequency when the timepiece is running, which controls the speed at which the wheels of ...
.
* An
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
mechanism, which has the dual function of keeping the balance wheel vibrating by giving it a push with each swing, and allowing the watch's gears to advance or 'escape' by a set amount with each swing. The periodic stopping of the gear train by the escapement makes the 'ticking' sound of the mechanical watch.
* An indicating dial, usually a traditional
clock face with rotating hands, to display the time in human-readable form.
Additional functions on a watch besides the basic timekeeping ones are traditionally called ''
complications''. Mechanical watches may have these complications:
*
''Automatic winding'' or ''self-winding''—in order to eliminate the need to wind the watch, this device winds the watch's mainspring automatically using the natural motions of the wrist, with a rotating-weight mechanism.
* ''Calendar''—displays the date, and often the weekday, month, and year. ''Simple calendar'' watches do not account for the different lengths of the months, requiring the user to reset the date 5 times a year, but ''perpetual calendar'' watches account for this, and even leap years. An ''annual calendar'' does not make the leap year adjustment, and treats February as a 30-day month, so the date must be reset on March 1 every year when it incorrectly says February 29 or 30.
* ''Alarm''—a bell or buzzer that can be set to go on at a given time.
* ''
Chronograph
A chronograph is a specific type of watch that is used as a stopwatch combined with a display watch. A basic chronograph has an independent sweep second hand and a minute sub-dial; it can be started, stopped, and returned to zero by successive ...
''—a watch with additional
stopwatch
A stopwatch is a timepiece designed to measure the amount of time that elapses between its activation and deactivation.
A large digital version of a stopwatch designed for viewing at a distance, as in a sports stadium, is called a stop clock. ...
functions. Buttons on the case start and stop the second hand and reset it to zero, and usually several subdials display the elapsed time in larger units.
* ''Hacking'' feature—found on military watches, a mechanism that stops the second hand while the watch is being set. This enables watches to be synchronized to the precise second. This is now a very common feature on many watches.
* ''Moon phase dial''—shows the phase of the moon with a moon face on a rotating disk.
* ''Wind indicator'' or ''power reserve indicator''—mostly found on automatic watches, a subdial that shows how much power is left in the mainspring, usually in terms of hours left to run.
* ''
Repeater
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some ...
''—a watch that chimes the hours audibly at the press of a button. This rare complication was originally used before artificial lighting to check what time it was in the dark. These complex mechanisms are now only found as novelties in extremely expensive luxury watches.
* ''
Tourbillon
In horology, a tourbillon (; "whirlwind") is an addition to the mechanics of a watch escapement to increase accuracy. It was developed around 1795 and patented by the Swiss-French watchmaker Abraham-Louis Breguet on June 26, 1801. In a tourbill ...
''—this expensive feature was originally designed to make the watch more accurate, but is now simply a demonstration of watchmaking virtuosity. In an ordinary watch the balance wheel oscillates at different rates, because of gravitational bias, when the watch is in different positions, causing inaccuracy. In a tourbillon, the balance wheel is mounted in a rotating cage so that it will experience all positions equally. The mechanism is usually exposed on the face to show it off.
Mechanism
![Pocketwatch cutaway drawing](https://upload.wikimedia.org/wikipedia/commons/6/67/Pocketwatch_cutaway_drawing.jpg)
The mechanical watch is a
mature technology
A mature technology is a technology that has been in use for long enough that most of its initial faults and inherent problems have been removed or reduced by further development. In some contexts, it may also refer to technology that has not se ...
, and most ordinary watch
movements have the same parts and work the same way.
Mainspring and motion work
The ''
mainspring
A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. ''Winding'' the timepiece, by turning a knob or key, stores energy in ...
'' that powers the watch, a spiral ribbon of spring steel, is inside a cylindrical
barrel
A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, ...
, with the outer end of the mainspring attached to the barrel. The force of the mainspring turns the barrel. The barrel has gear teeth around the outside that turn the ''center wheel'' once per hour — this wheel has a shaft that goes through the dial. On the
dial side the ''cannon pinion'' is attached with a friction fit (allowing it to slide when setting the hands) and the minute hand is attached to the cannon pinion. The cannon pinion drives a small 12-to-1 reduction gearing called the
motion work that turns the hour wheel and hand once for every 12 revolutions of the minute hand.
For the same rate of oscillation, the duration of run, runtime or power reserve of a mechanical watch is mainly a question of what size of mainspring is used, which is, in turn, a question of how much power is needed and how much room is available. If the movement is dirty or worn, the power may not transfer from the mainspring efficiently to the escapement. Service can help restore a degraded runtime.
Most mechanical watch movements have a duration of run between 36 and 72 hours. Some mechanical watch movements are able to run for a week. The exact duration of run for a mechanical movement is calculated with the formula
where
is the number of barrel teeth,
is the number of center pinion leaves,
is the number of revolutions of the barrel, and
is the number of revolutions of the center pinion — the run duration.
Wheel train
The center wheel drives the pinion of the third wheel, and the third wheel drives the pinion of the fourth wheel. In watches with the seconds hand in a subsidiary seconds dial, usually located above the 6 o'clock position, the fourth wheel is geared to rotate once per minute, and the second hand is attached directly to the arbour of this wheel.
Escapement
The fourth wheel also drives the ''escape wheel'' of the
lever escapement
The lever escapement, invented by the English clockmaker Thomas Mudge in 1754 (albeit first used in 1769), is a type of escapement that is used in almost all mechanical watches, as well as small mechanical non-pendulum clocks, alarm clocks, an ...
. The escape wheel teeth alternately catch on two fingers called ''pallets'' on the arms of the ''
pallet lever'', which rocks back and forth. The other end of the lever has a fork which engages with an upright ''impulse pin'' on the ''
balance wheel
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a ...
'' shaft. Each time the balance wheel swings through its center position, it unlocks the lever, which releases one tooth of the escape wheel, allowing the watch's wheels to advance by a fixed amount, moving the hands forward. As the escape wheel turns, its tooth pushes against the lever, which gives the balance wheel a brief push, keeping it swinging back and forth.
Balance wheel
The
balance wheel
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a ...
keeps time for the watch. It consists of a weighted wheel which rotates back and forth, which is returned toward its center position by a fine spiral spring, the
balance spring or "hair spring". The wheel and spring together constitute a ''
harmonic oscillator
In classical mechanics, a harmonic oscillator is a system that, when displaced from its Mechanical equilibrium, equilibrium position, experiences a restoring force ''F'' Proportionality (mathematics), proportional to the displacement ''x'':
\v ...
''. The mass of the balance wheel combines with the stiffness of the spring to precisely control the
period
Period may refer to:
Common uses
* Era, a length or span of time
* Full stop (or period), a punctuation mark
Arts, entertainment, and media
* Period (music), a concept in musical composition
* Periodic sentence (or rhetorical period), a concept ...
of each swing or 'beat' of the wheel. A balance wheel's
period of oscillation ''T'' in seconds, the time required for one complete cycle (two beats), is
:
where
is the wheel's
moment of inertia in kilogram-meter
2 and
is the stiffness (
spring constant
In physics, Hooke's law is an empirical law which states that the force () needed to extend or compress a spring by some distance () scales linearly with respect to that distance—that is, where is a constant factor characteristic of th ...
) of its
balance spring
A balance spring, or hairspring, is a spring attached to the balance wheel in mechanical timepieces. It causes the balance wheel to oscillate with a resonant frequency when the timepiece is running, which controls the speed at which the wheels of ...
in newton-meters per radian. Most watch balance wheels oscillate at 5, 6, 8, or 10 beats per second. This translates into 2.5, 3, 4, and 5 Hz respectively, or 18000, 21,600, 28,800, and 36,000 beats per hour (BPH). In most watches there is a ''regulator'' lever on the balance spring which is used to adjust the rate of the watch. It has two ''curb pins'' which embrace the last turn of the spring, holding the part behind the pins motionless, so the position of the curb pins determines the length of the spring. Moving the regulator lever slides the curb pins up or down the spring to control its effective length. Sliding the pins up the spring, shortening the spring's length, makes it stiffer, increasing
in the equation above, decreasing the wheel's period
so it swings back and forth faster, causing the watch to run faster.
Keyless work
A separate set of gears called the ''
keyless work In horology, a wheel train (or just train) is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear tr ...
'' winds the mainspring when the ''crown'' is rotated, and when the crown is pulled out a short distance allow the hands to be turned to set the watch. The stem attached to the crown has a gear called the ''clutch'' or ''castle wheel'', with two rings of teeth that project axially from the ends. When the stem is pushed in, the outer teeth turn the ''
ratchet
Ratchet may refer to:
Devices
* Ratchet (device), a mechanical device that allows movement in only one direction
* Ratchet, metonomic name for a socket wrench incorporating a ratcheting device
* Ratchet (instrument), a music instrument and a ...
wheel'' on top of the mainspring barrel, which turns the shaft that the inner end of the mainspring is attached to, winding the mainspring tighter around the shaft. A spring-loaded
pawl or ''click'' presses against the ratchet teeth, preventing the mainspring from unwinding. When the stem is pulled out, the inner teeth of the castle wheel engage with a gear which turns the minute wheel. When the crown is turned, the friction coupling of the cannon pinion allows the hands to be rotated.
Center seconds
If the seconds hand is co-axial with the minute and hour hand, that is it is pivoted at the center of the dial, this arrangement is called "center seconds" or "sweep seconds", because the seconds hand sweeps around the minute track on the dial.
Initially center seconds hands were driven off the third wheel, sometimes via an intermediate wheel, with the gearing on the outside of the top plate. This method of driving the seconds hand is called indirect center seconds. Because the gearing was outside the plates, it added to the thickness of the movement, and because the rotation of the third wheel had to be geared up to turn the seconds hand once a minute, the seconds hand had a fluttering motion.
In 1948 Zenith introduced a watch with a redesigned gear train where the fourth wheel was at the center of the movement, and so could drive a center seconds hand directly. The minute wheel, which had previously been at the center of the movement, was moved off center and drove the minute hand indirectly. Any fluttering due to the indirect gearing is concealed by the relatively slow movement of the minute hand. This redesign brought all the train gearing between the plates and allowed a thinner movement.
Watch jewels
Jewel bearing
A jewel bearing is a plain bearing in which a metal spindle turns in a jewel-lined pivot hole. The hole is typically shaped like a torus and is slightly larger than the shaft diameter. The jewels are typically made from the mineral corundum ...
s were invented and introduced in watches by
Nicolas Fatio (or Facio) de Duillier and Pierre and Jacob Debaufre around 1702
to reduce friction. They did not become widely used until the mid-19th century. Until the 20th century they were ground from tiny pieces of natural gems. Watches often had
garnet
Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives.
All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different s ...
,
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
, or even glass jewels; only top quality watches used
sapphire
Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide () with trace amounts of elements such as iron, titanium, chromium, vanadium, or magnesium. The name sapphire is derived via the Latin "sapphir ...
or
ruby
A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sa ...
.
In 1902, a process to grow artificial sapphire crystals was invented, making jewels much cheaper. Jewels in modern watches are all synthetic sapphire or (usually) ruby, made of
corundum
Corundum is a crystalline form of aluminium oxide () typically containing traces of iron, titanium, vanadium and chromium. It is a rock-forming mineral. It is a naturally transparent material, but can have different colors depending on the pres ...
(Al
2O
3), one of the hardest substances known. The only difference between sapphire and ruby is that different impurities have been added to change the color; there is no difference in their properties as a bearing.
The advantage of using jewels is that their ultrahard slick surface has a lower
coefficient of friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative lateral motion of ...
with metal. The
static coefficient of friction of steel-on-steel is 0.58, while that of sapphire-on-steel is 0.10-0.15.
Purposes
Jewels serve two purposes in a watch.
First, reduced
friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative lateral motion of t ...
can increase accuracy. Friction in the
wheel train In horology, a wheel train (or just train) is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear tr ...
bearings and the
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
causes slight variations in the impulses applied to the
balance wheel
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a ...
, causing variations in the rate of timekeeping. The low, predictable friction of jewel surfaces reduces these variations. Second, they can increase the life of the bearings. In unjeweled bearings, the pivots of the watch's wheels rotate in holes in the plates supporting the movement. The sideways force applied by the driving gear causes more pressure and friction on one side of the hole. In some of the wheels, the rotating shaft can wear away the hole until it is oval shaped, eventually causing the gear to jam, stopping the watch.
Types
In the
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
, jewels are used for the parts that work by sliding friction:
*Pallets - These are the angled rectangular surfaces on the
lever
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or ''fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is div ...
that are pushed against by the teeth of the escape wheel. They are the main source of friction in a watch movement, and were one of the first sites to which jewels were applied.
*Impulse pin - The off center pin on a disk on the balance staff which is pushed by the lever fork, to keep the balance wheel moving.
In bearings two different types are used:
*Hole jewels - These are donut shaped sleeve bearings used to support the arbor (shaft) of most wheels.
*Capstones or cap jewels - When the arbor of a wheel is in the vertical position, the shoulder of the arbor bears against the side of the hole jewel, increasing friction. This causes the rate of the watch to change when it is in different positions. So in bearings where friction is critical, such as the balance wheel pivots, flat capstones are added at each end of the arbor. When the arbor is in a vertical position, its rounded end bears against the surface of the capstone, lowering friction.
Where they are used
The number of jewels used in watch movements increased over the last 150 years as jeweling grew less expensive and watches grew more accurate. The only bearings that really need to be jeweled in a watch are the ones in the ''
going train'' - the
gear train
A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage.
Gear teeth are designed to ensure the pitch circles of engaging gears roll on each other without slipping, providing a smooth transmission ...
that transmits force from the
mainspring
A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. ''Winding'' the timepiece, by turning a knob or key, stores energy in ...
barrel
A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, ...
to the
balance wheel
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a ...
- since only they are constantly under force from the mainspring.
The wheels that turn the hands (the
motion work) and the calendar wheels are not under load, while the ones that wind the mainspring (the
keyless work In horology, a wheel train (or just train) is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear tr ...
) are used very seldom, so they do not wear significantly. Friction has the greatest effect in the wheels that move the fastest, so they benefit most from jewelling. So the first mechanism to be jeweled in watches was the balance wheel pivots, followed by the
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
. As more jeweled bearings were added, they were applied to slower moving wheels, and jewelling progressed up the going train toward the barrel. A 17 jewel watch has every bearing from the balance wheel to the center wheel pivot bearings jeweled, so it was considered a 'fully jeweled' watch.
In quality watches, to minimize positional error, capstones were added to the lever and escape wheel bearings, making 21 jewels. Even the mainspring barrel arbor was sometimes jeweled, making the total 23. When self-winding watches were introduced in the 1950s, several wheels in the automatic winding mechanism were jeweled, increasing the count to 25–27.
'Jewel inflation'
It is doubtful whether adding jewels in addition to the ones listed above is really useful in a watch.
It does not increase accuracy, since the only wheels which have an effect on the balance wheel, those in the
going train, are already jeweled.
Marine chronometer
A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation. It is used to determine longitude by comparing Greenwich Mean Time (GMT), or in the modern ...
s, the most accurate portable timepieces, often have only 7 jewels. Nor does jeweling additional wheel bearings increase the useful life of the movement; as mentioned above most of the other wheels do not get enough wear to need them.
However, by the early 20th century watch movements had been standardized to the point that there was little difference between their mechanisms, besides quality of workmanship. So watch manufacturers made the number of jewels, one of the few metrics differentiating quality watches, a major advertising point, listing it prominently on the watch's face. Consumers, with little else to go on, learned to equate more jewels with more quality in a watch. Although initially this was a good measure of quality, it gave manufacturers an incentive to increase the jewel count.
Around the 1960s this 'jewel craze' reached new heights, and manufacturers made watches with 41, 53, 75, or even 100 jewels.
Most of these additional jewels were totally nonfunctional; they never contacted moving parts, and were included just to increase the jewel count. For example, the Waltham 100 jewel watch consisted of an ordinary 17 jewel movement, with 83 tiny pieces of ruby mounted around the automatic winding rotor.
In 1974, the
International Organization for Standardization
The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Ar ...
(ISO) in collaboration with the Swiss watch industry standards organization
Normes de l'Industrie Horlogère Suisse (NIHS) published a standard, ISO 1112, which prohibited manufacturers from including such nonfunctional jewels in the jewel counts in advertising and sales literature. This stopped the use of totally nonfunctional jewels. However, some experts say manufacturers have continued to inflate the jewel count of their watches by 'upjeweling'; adding functional jeweled bearings to wheels that do not really need them, exploiting loopholes in ISO 1112.
Examples given include adding capstones to third and fourth wheel bearings, jeweling minute wheel bearings, and automatic winding
ratchet pawls. Arguably none of these additions adds to the accuracy or longevity of the watch.
World time
Some fine mechanical watches will have a ''world time'' feature, which is a ''city bezel'' as well as an ''hour bezel'' which will rotate according to the cities relative time zone.
There are usually 27 cities (corresponding to 24 major time zones) on the city bezel, starting with
GMT/UTC:
*
UTC±00:00 -
London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...
*
UTC+01:00 -
Amsterdam
Amsterdam ( , , , lit. ''The Dam on the River Amstel'') is the Capital of the Netherlands, capital and Municipalities of the Netherlands, most populous city of the Netherlands, with The Hague being the seat of government. It has a population ...
*
UTC+01:00 -
Berlin
Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...
*
UTC+01:00 -
Brussels
Brussels (french: Bruxelles or ; nl, Brussel ), officially the Brussels-Capital Region (All text and all but one graphic show the English name as Brussels-Capital Region.) (french: link=no, Région de Bruxelles-Capitale; nl, link=no, Bruss ...
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Paris
Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...
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Cairo
Cairo ( ; ar, القاهرة, al-Qāhirah, ) is the capital of Egypt and its largest city, home to 10 million people. It is also part of the largest urban agglomeration in Africa, the Arab world and the Middle East: The Greater Cairo metro ...
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Moscow
Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million ...
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Abu Dhabi
Abu Dhabi (, ; ar, أَبُو ظَبْيٍ ' ) is the capital and second-most populous city (after Dubai) of the United Arab Emirates. It is also the capital of the Emirate of Abu Dhabi and the centre of the Abu Dhabi Metropolitan Area.
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Dubai
Dubai (, ; ar, دبي, translit=Dubayy, , ) is the most populous city in the United Arab Emirates (UAE) and the capital of the Emirate of Dubai, the most populated of the 7 emirates of the United Arab Emirates.The Government and Politics of ...
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Karachi
Karachi (; ur, ; ; ) is the most populous city in Pakistan and 12th most populous city in the world, with a population of over 20 million. It is situated at the southern tip of the country along the Arabian Sea coast. It is the former cap ...
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Dhaka
Dhaka ( or ; bn, ঢাকা, Ḍhākā, ), formerly known as Dacca, is the capital and largest city of Bangladesh, as well as the world's largest Bengali-speaking city. It is the eighth largest and sixth most densely populated city ...
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Bangkok
Bangkok, officially known in Thai language, Thai as Krung Thep Maha Nakhon and colloquially as Krung Thep, is the capital and most populous city of Thailand. The city occupies in the Chao Phraya River delta in central Thailand and has an estima ...
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Taipei
Taipei (), officially Taipei City, is the capital and a special municipality of the Republic of China (Taiwan). Located in Northern Taiwan, Taipei City is an enclave of the municipality of New Taipei City that sits about southwest of the n ...
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Beijing
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Beijing ( ; ; ), alternatively romanized as Peking ( ), is the capital of the People's Republic of China. It is the center of power and development of the country. Beijing is the world's most populous national capital city, with over 21 ...
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Hong Kong
Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...
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Seoul
Seoul (; ; ), officially known as the Seoul Special City, is the capital and largest metropolis of South Korea.Before 1972, Seoul was the ''de jure'' capital of the Democratic People's Republic of Korea (North Korea) as stated iArticle 103 ...
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Tokyo
Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...
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Sydney
Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...
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Melbourne
Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...
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Nouméa
Nouméa () is the capital and largest city of the French special collectivity of New Caledonia and is also the largest francophone city in Oceania. It is situated on a peninsula in the south of New Caledonia's main island, Grande Terre, a ...
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Auckland
Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The List of New Zealand urban areas by population, most populous urban area in the country and the List of cities in Oceania by po ...
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Samoa
Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands (Savai'i and Upolu); two smaller, inhabited islands (Manono Island, Manono an ...
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Honolulu
Honolulu (; ) is the capital and largest city of the U.S. state of Hawaii, which is in the Pacific Ocean. It is an unincorporated county seat of the consolidated City and County of Honolulu, situated along the southeast coast of the island ...
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Anchorage
Anchorage () is the largest city in the U.S. state of Alaska by population. With a population of 291,247 in 2020, it contains nearly 40% of the state's population. The Anchorage metropolitan area, which includes Anchorage and the neighboring Ma ...
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Los Angeles
Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world' ...
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Vancouver
Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the ...
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Denver
Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...
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Chicago
(''City in a Garden''); I Will
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New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...
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Toronto
Toronto ( ; or ) is the capital city of the Canadian province of Ontario. With a recorded population of 2,794,356 in 2021, it is the most populous city in Canada and the fourth most populous city in North America. The city is the ancho ...
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Caracas
Caracas (, ), officially Santiago de León de Caracas, abbreviated as CCS, is the capital and largest city of Venezuela, and the center of the Metropolitan Region of Caracas (or Greater Caracas). Caracas is located along the Guaire River in the ...
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Puerto Rico
Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...
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Buenos Aires
Buenos Aires ( or ; ), officially the Autonomous City of Buenos Aires ( es, link=no, Ciudad Autónoma de Buenos Aires), is the capital and primate city of Argentina. The city is located on the western shore of the Río de la Plata, on South ...
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South Georgia and the South Sandwich Islands
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, song =
, image_map = South Georgia and the South Sandwich Islands in United Kingdom.svg
, map_caption = Location of South Georgia and the South Sandwich Islands in the southern Atlantic Oce ...
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Azores
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, motto =( en, "Rather die free than subjected in peace")
, anthem= ( en, "Anthem of the Azores")
, image_map=Locator_map_of_Azores_in_EU.svg
, map_alt=Location of the Azores within the European Union
, map_caption=Location of the Azores wi ...
History
Peter Henlein
Peter Henlein (also spelled Henle or Hele) (1485 - August 1542), a locksmith and clockmaker of Nuremberg, Germany, is often considered the inventor of the watch., p.31 He was one of the first craftsmen to make small ornamental portable clocks wh ...
has often been described as the inventor of the first
pocket watch
A pocket watch (or pocketwatch) is a watch that is made to be carried in a pocket, as opposed to a wristwatch, which is strapped to the wrist.
They were the most common type of watch from their development in the 16th century until wristw ...
, the "Nuremberg egg", in 1510, but this claim appears to be a 19th-century invention and does not appear in older sources.
Until the
quartz revolution of the 1970s, all watches were mechanical. Early watches were terribly imprecise; a good one could vary as much as 15 minutes in a day. Modern precision (a few seconds per day) was not attained by any watch until 1760, when
John Harrison
John Harrison ( – 24 March 1776) was a self-educated English carpenter and clockmaker who invented the marine chronometer, a long-sought-after device for solving the problem of calculating longitude while at sea.
Harrison's solution revol ...
created his
marine chronometer
A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation. It is used to determine longitude by comparing Greenwich Mean Time (GMT), or in the modern ...
s. Industrialization of the movement manufacturing process by the
Waltham Watch Company
The Waltham Watch Company, also known as the American Waltham Watch Co. and the American Watch Co., was a company that produced about 40 million watches, clocks, speedometers, compasses, time delay fuses, and other precision instruments in the Un ...
in 1854 made additional precision possible; the company won a gold medal at the 1876 Philadelphia Centennial Exposition for their manufacturing quality.
Mechanical watches are powered by a
mainspring
A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. ''Winding'' the timepiece, by turning a knob or key, stores energy in ...
. Modern mechanical watches require of the order of 1
microwatt of power on average. Because the
mainspring
A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. ''Winding'' the timepiece, by turning a knob or key, stores energy in ...
provides an uneven source of power (its torque steadily decreases as the spring unwinds), watches from the early 16th century to the early 19th century featured a chain-driven
fusee which served to regulate the torque output of the mainspring throughout its winding. Unfortunately, the
fusees were very brittle, were very easy to break, and were the source of many problems, especially inaccuracy of timekeeping when the fusee chain became loose or lost its velocity after the lack of maintenance.
As new kinds of
escapements
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
were created which served to better isolate the watch from its time source, the
balance spring
A balance spring, or hairspring, is a spring attached to the balance wheel in mechanical timepieces. It causes the balance wheel to oscillate with a resonant frequency when the timepiece is running, which controls the speed at which the wheels of ...
, watches could be built without a
fusee and still be accurate.
In the 18th century the original
verge escapement
The verge (or crown wheel) escapement is the earliest known type of mechanical escapement, the mechanism in a mechanical clock that controls its rate by allowing the gear train to advance at regular intervals or 'ticks'. Its origin is unknown. V ...
, which required a fusee, was gradually replaced in better French watches with the
cylinder escapement, and in British watches with the
duplex escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
. Then in the 19th century both were superseded by the
lever escapement
The lever escapement, invented by the English clockmaker Thomas Mudge in 1754 (albeit first used in 1769), is a type of escapement that is used in almost all mechanical watches, as well as small mechanical non-pendulum clocks, alarm clocks, an ...
which has been used almost exclusively ever since. A cheaper version of the lever, the
pin lever escapement
A Roskopf, pin-lever, or pin-pallet escapement is an inexpensive, less accurate version of the lever escapement, used in mechanical alarm clocks, kitchen timers, mantel clocks and, until the 1970s, cheap watches now known as pin lever watches. ...
, patented in 1867 by
Georges Frederic Roskopf
Georges Frederic Roskopf (15 March 1813 – 14 April 1889), the inventor of the pin-pallet escapement, was born in Germany and became a naturalized Swiss citizen.
Early life and introduction
In 1829, when Roskopf was 16, he went to La Chaux-de ...
was used in inexpensive watches until the 1970s.
As manual-wound mechanical watches became less popular and less favored in the 1970s, watch design and industrialists came out with the
automatic watch
An automatic watch, also known as a self-winding watch or simply an automatic, is a mechanical watch where the natural motion of the wearer provides energy to wind the mainspring, making manual winding unnecessary if worn enough. It is distingu ...
. Whereas a mechanically-wound watch must be wound with the
pendant
A pendant is a loose-hanging piece of jewellery, generally attached by a small loop to a necklace, which may be known as a "pendant necklace". A pendant earring is an earring with a piece hanging down. Its name stems from the Latin word ...
or a levered setting, an automatic watch does not need to be wound by the pendant; simply rotating the watch winds the watch automatically. The interior of an automatic watch houses a swiveling metal or brass "plate" that swivels on its axis when the watch is shaken horizontally.
See also
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Chronograph
A chronograph is a specific type of watch that is used as a stopwatch combined with a display watch. A basic chronograph has an independent sweep second hand and a minute sub-dial; it can be started, stopped, and returned to zero by successive ...
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Jewel bearing
A jewel bearing is a plain bearing in which a metal spindle turns in a jewel-lined pivot hole. The hole is typically shaped like a torus and is slightly larger than the shaft diameter. The jewels are typically made from the mineral corundum ...
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Quartz watch
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
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Railroad chronometers A railroad chronometer or railroad standard watch is a specialized timepiece that once was crucial for safe and correct operation of trains in many countries. A system of timetable and train order, which relied on highly accurate timekeeping, was ...
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Skeleton watch
A skeleton watch is a mechanical watch in which all of the moving parts are visible through either the front of the watch, the back of the watch or a small cut outlining the dial.
True 'skeletonization' also includes the trimming away of any ...
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Tourbillon
In horology, a tourbillon (; "whirlwind") is an addition to the mechanics of a watch escapement to increase accuracy. It was developed around 1795 and patented by the Swiss-French watchmaker Abraham-Louis Breguet on June 26, 1801. In a tourbill ...
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Marine chronometer
A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation. It is used to determine longitude by comparing Greenwich Mean Time (GMT), or in the modern ...
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ETA SA
ETA SA Manufacture Horlogère Suisse (ETA SA Swiss Watch Manufacturer) designs and manufactures quartz watches and both hand-wound and automatic-winding mechanical and movements. Commonly referred to as ETA, the company is headquartered in Gren ...
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Lemania
Lemania was a Swiss watch manufacturer and manufacturer of watch movements.
It was founded in 1884 by Alfred Lugrin (1858-1920), who had trained at Jaeger-LeCoultre. Lugrin received awards and gold medals at exhibitions in Milan in 1906 and in B ...
References
External links
AnimagraffsVideo Assembly of a Rolex 3135 Mechanical Watch Movement, Alliance HorlogereExplanations Of The Mechanical Movements In A Watch, TimeZone.comVideo: ''The Inner Workings of a Mechanical Watch''Caliber Guide
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Watches
Articles containing video clips
ja:機械式腕時計