Mechanical watch

A mechanical watch is a watch that uses a clockwork mechanism to measure the passage of time, as opposed to quartz watches which function electronically via a small battery. A mechanical watch is driven by a mainspring which must be hand-wound periodically. Its force is transmitted through a series of gears to power the balance wheel, a weighted wheel which oscillates back and forth at a constant rate.   A device called an escapement 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 clocks, which appeared in the 15th century.

Mechanical watches are typically not as accurate as modern electronic quartz watches,[1][2][3] and they require periodic cleaning by a skilled watchmaker.[3] Since the 1970s, quartz watches have taken over most of the watch market, and mechanical watches are now mostly a high-end product, purchased for aesthetic reasons, for appreciation of their fine craftsmanship,[2] or as a status symbol.[2]

Russian finished watch movement
The movement of a Russian watch

Components

Prim mechanical wrist watch disassembled whole
Mechanical wrist watch disassembled
Montre mysterieuse-IMG 4639
A so-called "mystery watch" c. 1890, it is fitted with a cylinder escapement.

The internal mechanism of a watch, excluding the face and hands, is called the movement. All mechanical watches have these five parts:

  • A mainspring,[4] which stores mechanical energy to power the watch.
  • A gear train, called the wheel train,[5] 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 seconds, minutes, and hours. A separate part of the gear train, called the keyless work, allows the user to wind the mainspring and enables the hands to be moved to set the time.
  • A balance wheel, which oscillates back and forth. Each swing of the balance wheel takes precisely the same amount of time. This is the timekeeping element in the watch.
  • An escapement 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.[6] 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 off at a given time.
  • Chronograph—a watch with additional stopwatch 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—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—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

The mechanical watch is a mature technology, and most ordinary watch movements have the same parts and work the same way.[7]

Pocketwatch cutaway drawing
Cutaway drawing of pocketwatch, with parts labeled

Mainspring and motion work

The mainspring that powers the watch, a spiral ribbon of spring steel, is inside a cylindrical barrel, 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.

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.

Animated watch movement. For clarity in this diagram the watch gears are arranged in a line, with the balance wheel on the left and the hands on separate wheels, rather than located concentrically as in an actual watch.
Naturejournal36londuoft 0523
The movement of a chronograph pocketwatch from the 1880s.

Escapement

The fourth wheel also drives the escape wheel of the lever escapement. 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 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 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. The mass of the balance wheel combines with the stiffness of the spring to precisely control the period 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-meter2 and is the stiffness (spring constant) of its balance spring 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, and can be slid 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 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 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.[8]

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 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.[9]

Watch jewels

Watch jewel bearing and capstone
Jewel bearing and capstone used in balance wheel pivot
Watch jewel bearing
Ordinary 'hole jewel' bearing

Jewel bearings were invented and introduced in watches by Nicolas Fatio (or Facio) de Duillier and Pierre and Jacob Debaufre around 1702[10][11] 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, quartz, or even glass jewels; only top quality watches used sapphire, ruby, or diamond.[10] 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 (Al2O3), 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.[12] The advantage of using jewels is that their ultrahard slick surface has a lower coefficient of friction 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.[13]

Purposes

Jewels serve two purposes in a watch.[14] First, reduced friction can increase accuracy. Friction in the wheel train bearings and the escapement causes slight variations in the impulses applied to the balance wheel, 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, jewels are used for the parts that work by sliding friction:[14]

  • Pallets - These are the angled rectangular surfaces on the lever 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

Where jewels are used in watches[15][16][17]
7 jewel lever watch - has these jewels:
  • 1 impulse pin
  • 2 pallets
  • 2 balance staff bearings
  • 2 balance staff capstones
11 jewel watch - adds:
  • 2 lever bearings
  • 2 escape wheel bearings
15 jewel watch - adds:
  • 2 fourth wheel bearings
  • 2 third wheel bearings
17 jewel watch - adds:
  • 2 center wheel bearings
21 jewel watch - adds:
  • 2 lever capstones
  • 2 escape wheel capstones
23 jewel watch - adds:
  • 2 mainspring barrel bearings
Self winding watches add 4 or more

in the winding mechanism, for a total of 25-27

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 that transmits force from the mainspring barrel to the balance wheel - since only they are constantly under force from the mainspring.[18] 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) 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. 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.[15] 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.[19] 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 chronometers, 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.[18][19] 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.[20]

In 1974, the International Organization for Standardization (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 put a stop to 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.[19] 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:

History

Peter Henlein has often been described as the inventor of the first pocket watch, the "Nuremberg egg", in 1510, but this claim appears to be a 19th-century invention and does not appear in older sources.[21]

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 created his marine chronometers. Precision was attained as from 1854 first by the Waltham Watch Company, through the industrialisation of the manufacturing process of the movement part, in order to attain the necessary precision: they won a Gold Medal at the 1876 Philadelphia Centennial Exposition with a lot of watches taken at random out of the production line, showing the way to their peers in U.S.A. (e.g. Elgin Watch Company) and the worldwide watch industry.

Mechanical watches are powered by a mainspring. Modern mechanical watches require of the order of 1 microwatt of power on average. Because the mainspring 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 were created which served to better isolate the watch from its time source, the balance spring, watches could be built without a fusee and still be accurate.

In the 18th century the original verge escapement, which required a fusee, was gradually replaced in better French watches with the cylinder escapement, and in British watches with the duplex escapement. Then in the 19th century both were superseded by the lever escapement which has been used almost exclusively ever since. A cheaper version of the lever, the pin lever escapement, patented in 1867 by Georges Frederic Roskopf 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. Whereas a mechanically-wound watch must be wound with the pendant 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.[22]

See also

References

  1. ^ Hahn, Ed; et al. (The TimeZone Community) (2003-10-04). "Question 1.5: Why should I get a mechanical watch when a quartz watch is so much cheaper and more accurate?". Mechanical Watch FAQ V1.0. TimeZone.com. Retrieved 2017-02-20.
  2. ^ a b c Lynch, Annette; Strauss, Mitchell (2007). Changing Fashion: A Critical Introduction to Trend Analysis and Cultural Meaning. Berg. pp. 148–149. ISBN 1845203909.
  3. ^ a b Haines, Reyne (2010). Vintage Wristwatches. Krause Publications. p. 9. ISBN 1440214794.
  4. ^ Hand-winding Mechanical Watch Movement Mainspring
  5. ^ Mechanical Clock / Watch Movement Gear Train Photos
  6. ^ Nicolet, J. C. (2008). "What is a perpetual calendar watch?". Questions in Time. Retrieved 2008-06-07.
  7. ^ The parts are shown in detail in Odets, Walt. "Illustrated Glossary of Watch Parts". TimeZone Watch School. TimeZone.com. Retrieved 2008-07-05.
  8. ^ THE PURSUIT OF CENTER SECONDS BY WALT ODETS "Archived copy". Archived from the original on 2012-09-14. Retrieved 2012-01-04.CS1 maint: Archived copy as title (link)
  9. ^ THE PURSUIT OF CENTER SECONDS Part 2 BY WALT ODETS "Archived copy". Archived from the original on 2012-01-12. Retrieved 2012-01-04.CS1 maint: Archived copy as title (link)
  10. ^ a b Milham, Willis I. (1945). Time and Timekeepers. New York, USA: MacMillan. pp. 114–116.
  11. ^ "Jewel". Encyclopedia of Antiques. Old and Sold Antique Marketplace. Retrieved 2008-05-31.
  12. ^ Hahn, Ed; et al. (The TimeZone Community) (2003-10-04). "Question 1.1.4: Why do they use synthetic ruby?". Mechanical Watch FAQ V1.0. TimeZone.com. Retrieved 2008-07-02.
  13. ^ Hahn, Ed (2000-01-31). "Coefficients of friction for various horological materials". TZ Classic Forum. TimeZone.com. Retrieved 2008-07-02.
  14. ^ a b Schlitt, Wayne (2004). "Why watches have jewels". Help. The Elgin Watch Collector's Site. Retrieved 2008-07-02.
  15. ^ a b Hahn, Ed; et al. (The TimeZone Community) (2003-10-04). "Question 1.1.3: What does 17 jewels mean?". Mechanical Watch FAQ V1.0. TimeZone.com. Retrieved 2008-07-02.
  16. ^ Milham, Willis I. (1945). Time and Timekeepers. New York, USA: MacMillan. pp. 114–116. ISBN 0-7808-0008-7.
  17. ^ What is a Watch? Advertising pamphlet. Illinois, USA: The Elgin Watch Co. 1950. on Wayne Schlitt's The Elgin Watch Collector's Site, retrieved on 2008-07-02
  18. ^ a b Hahn, Ed; et al. (The TimeZone Community) (2003-10-04). "Question 1.1.5: Are more jewels better?". Mechanical Watch FAQ V1.0. TimeZone.com. Retrieved 2008-07-02.
  19. ^ a b c Berkavicius, Bob (September 25, 2002). "83 jewels too many?". From the workbench. TimeZone.com. Archived from the original on July 2, 2008. Retrieved 2008-07-02.
  20. ^ Photos of it can be seen in Berkavicius article
  21. ^ pp. 121 ff., History of the hour: clocks and modern temporal orders, Gerhard Dohrn-van Rossum, University of Chicago Press, 1996, ISBN 0-226-15510-2.
  22. ^ "What is Automatic Watch Movement Disassembly - Automatic Winding mechanism Date Mechanism". horologyzone.com. Retrieved 11 January 2018.

External links

Automatic watch

An automatic watch, also known as self-winding watch, is a mechanical watch in which the natural motion of the wearer provides energy to run the watch, making manual winding unnecessary. A mechanical watch which is neither self-winding nor electrically driven is called a manual watch.

Besançon Astronomical Observatory

The Besançon Astronomical Observatory (French: Observatoire de Besançon; Observatoire des sciences de l'Univers de Besançon) is an astronomical observatory owned and operated by the Centre national de la recherche scientifique (CNRS, National Center for Scientific Research). It is located in Besançon, France.

In the past, the Besançon Observatory participated in assessing and rating Swiss timepiece movements for accuracy. As marine navigation adopted the usage of mechanical timepieces for navigational aid, the accuracy of such timepieces became more critical. From this need developed an accuracy testing regime involving various astronomical observatories. In Europe, the Neuchatel Observatory, Geneva Observatory, Besançon Observatory and Kew Observatory were examples of prominent observatories that tested timepiece movements for accuracy. The testing process lasted for many days, typically 45 days. Each movement was tested in 5 positions and 2 temperatures, in 10 series of 4 or 5 days each. The tolerances for error were much finer than any other standard, including the ISO 3159 chronometer standard that other testing bodies such as COSC use. Movements that passed the stringent tests were issued a certification from the observatory called a Bulletin de Marche, signed by the Director of the Observatory. The General Bulletin Order stated the testing criteria, and the actual performance of the movement. A movement with a bulletin from an observatory became known as an Observatory Chronometer, and such were issued a chronometer reference number by the Observatory.

The role of the observatories in assessing the accuracy of mechanical timepieces was instrumental in driving the mechanical watchmaking industry toward higher and higher levels of accuracy. As a result, today high quality mechanical watch movements have an extremely high degree of accuracy. However, no mechanical movement could ultimately compare to the accuracy of the quartz movements being developed. Accordingly, such chronometer certification ceased in the late 1960s and early 1970s with the advent of the quartz watch movement.

Complication (horology)

In horology, a complication refers to any feature in a mechanical timepiece beyond the simple display of hours and minutes. A timepiece indicating only hours and minutes is otherwise known as a simple movement. Common complications in commercial watches are day/date displays, alarms, chronographs (stopwatches), and automatic winding mechanisms.

The more complications in a mechanical watch, the more difficult it is to design, create, assemble, and repair. These stipulations do not apply or refer to quartz watches. A typical date-display chronograph may have up to 250 parts, while a particularly complex watch may have a thousand or more parts. Watches with several complications are referred to as grandes complications.

The initial ultra-complicated watches appeared due to watchmakers' ambitious attempts to unite a great number of functions in a case of a single timepiece. The mechanical clocks with a wide range of functions, including astronomical indications, suggested ideas to the developers of the first pocket watches. As a result, as early as in the 16th century, the horology world witnessed the appearance of numerous complicated and even ultra-complicated watches.

Ultra-complicated watches are produced in strictly limited numbers, with some built as unique instruments. Some watchmaking companies known for making ultra-complicated watches are Breguet, Patek Philippe, and Vacheron Constantin.

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 jewel material is usually synthetic sapphire or ruby (corundum). Jewel bearings are used in precision instruments where low friction, long life, and dimensional accuracy are important. Their largest use is in mechanical watches.

Mystery watch

A mystery watch is a generic term used in horology to describe watches whose working is not easily deducible, because it seems to have no movement at all, or the hands don't seem to be connected to any movement, etc.

One example is a type of mechanical watch where the movement is transmitted to the hands through a transparent crystal toothed wheel.

This first see-through watch, called in French montre mystérieuse (mysterious watch), was invented by Hugues Rime and marketed by the French firm Armand Schwob et frère. As an item of historical/horological value, it is preserved in various museum collections, such as British Museum, German Clock Museum, International Museum of Horology, Musée d'art et d'histoire of Neuchâtel and the National Watch and Clock Museum.

Nivarox

Nivarox (full business name Nivarox - FAR SA) is a Swiss company formed by a merger in 1984 between Nivarox SA and Fabriques d'Assortiments Réunis (FAR). It is currently owned by the Swatch Group. Nivarox is also the trade name of the metallic alloy from which its products are fabricated. Its notable property is that its coefficient of elasticity is remarkably constant with temperature. Nivarox is most famous for producing hairsprings which are attached to the balance wheel inside a mechanical watch movement, as well as mainsprings which provide the motive power for the watch.

The Nivarox story began in 1933 when Dr. Straumann perfected the process of hairspring manufacturing in his Waldenbourg laboratory. FAR was the corporate name chosen in 1932 for the entity comprising several companies and subsidiaries located in Le Locle, Switzerland, manufacturing various watch components.

Pallet (disambiguation)

Pallet may refer to:

Pallets in transport:

Pallet, a portable platform used in the transportation of goods

Pallet inverter, a machine that is used to turn over pallets

Pallet jack, a tool used to lift and move pallets

Pallet racking, material handling storage aid system

Pallet Rack Mover, a device that makes it possible to move pallet racks

Palletizer, a machine for placing materials onto pallets

Pallet crafts, art projects using discarded wooden pallets

Pallet (furniture), a bed that is made of straw or is of a makeshift natureIn horology:

Pallet fork, an integral component of the lever escapement of a typical mechanical watch

Pin-pallet escapement, an inexpensive, less accurate version of the lever escapementOthers:

Pallet, a diminutive of Pale (heraldry)

Pallet, a GUI for the software MacPorts

Pallet, a case of bottled water (colloquial)

Pallet fork

The pallet fork is a component of the lever escapement of a mechanical watch. The pallet fork and the lever form one component that sits between the escape wheel and the balance wheel. Its purpose is to lock the escape wheel, and release it one tooth at a time at each swing of the balance wheel, and also give the balance wheel small pushes to keep it going.

In early watches the pallet fork and the lever were made as separate components and joined together. In later watches they were made as a single component as shown in the picture. The combined component is often referred to simply as the "lever". In a straight line Swiss lever type escapement, the lever is shaped like a 'T' or an anchor, which gives this escapement its alternative name of anchor escapement. The lever is pivoted in the center; in operation it rocks back and forth. On the arms of the 'T' are angled surfaces called pallets which alternately engage the teeth of the escapement's escape wheel. The central shaft of the lever ends in a fork, which gives pushes to the balance wheel's impulse pin, which is set off center in a disk on the balance wheel's shaft. To reduce friction, the pallets are made of precisely shaped pieces of ruby jewel. The pallet which the teeth first contact is called the entry pallet, while the other one is called the exit pallet.

Under the fork there is a projecting guard pin which passes through a notch in a separate safety roller disk on the balance shaft. In normal operation it doesn't have a function. Its purpose is to make sure the fork is in the right position to receive the impulse pin if a jar to the watch prematurely 'unlocks' the lever from the escape wheel.

Mechanical alarm clocks and kitchen timers use a less accurate form of the lever in which vertical metal pins are substituted for the pallet jewels. This is called a Roskopf or pin-pallet escapement, and was previously used in cheap pin-lever watches.

Patek Philippe SA

Patek Philippe SA is a Swiss luxury watch and clock manufacturer founded in 1839, located in Canton of Geneva and the Vallée de Joux. Since 1932, it has been owned by the Stern family in Switzerland. Patek Philippe is one of the oldest watch manufacturers in the world with an uninterrupted watchmaking history since its founding. It designs and manufactures timepieces as well as movements, including some of the most complicated mechanical watches. The company maintains over 400 retail locations globally and over a dozen distribution centers across Asia, Europe, North America and Oceania, and in 2001 it opened the Patek Philippe Museum in Geneva.Patek Philippe is widely considered to be one of the most prestigious watch manufacturers in the world. Over the years, notable Patek Philippe patrons and timepieces owners include Queen Victoria, Queen Elizabeth II, Pope Pius IX, Marie Curie, Albert Einstein, John F. Kennedy, Nelson Mandela, Pablo Picasso, Pyotr Tchaikovsky and Leo Tolstoy. As of 2018, among the world's top ten most expensive watches ever sold at auctions, seven are Patek Philippe watches. In particular, Patek Philippe Henry Graves Supercomplication, the world's most complicated mechanical watch until 1989, currently holds the title of the most expensive watch ever sold at auction, fetching 24 million US dollars (23,237,000 CHF) in Geneva on November 11, 2014.

Power reserve indicator

Power Reserve Indicator (originally called Réserve de Marche) is a complication of the watch, which is designed to show the amount of remaining stored energy. The power reserve indicator indicates the tension on the mainspring at any particular moment.

Repeater (horology)

A repeater is a complication in a mechanical watch or clock that chimes the hours and often minutes at the press of a button. There are many types of repeater, from the simple repeater which merely strikes the number of hours, to the minute repeater which chimes the time down to the minute, using separate tones for hours, quarter hours, and minutes. They originated before widespread artificial illumination, to allow the time to be determined in the dark, and were also used by the visually impaired. Now they are mostly valued as expensive novelties by watch and clock enthusiasts. Repeaters should not be confused with striking clocks or watches, which do not strike on demand, but merely at regular intervals.

Ronda (watchmaker)

Ronda AG is a Swiss manufacturer of quartz and mechanical watch movements. The company was founded in 1946 by William Mosset and the current headquarters are located in Lausen, Basel-Landschaft.Their movements are used in variety of watches around the world, including RSC pilot's watches, Shinola and Mondaine watches.

Shock-resistant watch

Shock resistant is a common mark stamped on the back of wrist watches to indicate how well a watch copes with mechanical shocks. In a mechanical watch, it indicates that the delicate pivots that hold the balance wheel are mounted in a spring suspension system intended to protect them from damage if the watch is dropped. One of the earliest and most widely used was the Incabloc system, invented in 1934. Before the widespread adoption of shock-resistant balance pivots in the 1950s, broken balance wheel staffs were a common cause of watch repairs.

Tianjin Seagull

Tianjin Seagull Watch Group (Chinese: 天津海鸥) is a watchmaking company located in Tianjin, China. Founded in 1955, it is the world's largest manufacturer of mechanical watch movements, producing one quarter of total global production by volume.

Vacheron Constantin

Vacheron Constantin SA (French pronunciation: ​[va.ʃə.rɔ̃ kɔ̃s.tɑ̃.tɛ̃]) is a Swiss luxury watch and clock manufacturer founded in 1755. Since 1996, it has been a subsidiary of the Swiss Richemont Group. Vacheron Constantin is one of the oldest watch manufacturers in the world with an uninterrupted watchmaking history since its founding. It employs around 1,200 people worldwide as of 2018, most of whom are based in the company's manufacturing plants in Canton of Geneva and Vallée de Joux in Switzerland.Vacheron Constantin is a highly regarded watch manufacturer. Over the years, notable Vacheron Constantin patrons and timepieces owners include Queen Elizabeth II, Pope Pius XI, Napoléon Bonaparte, Marlon Brando, William James, John D. Rockefeller, Diana Princess of Wales, Harry S. Truman, Wright brothers, and so on. The Vacheron Constantin pocket watch No. 402833 (1929), which was owned by King Fuad I of Egypt, ranks as one of the most expensive watches ever sold at auction, fetching US$2.77 million (3,306,250 CHF) in Geneva on April 3, 2005. In 2015, Vacheron Constantain introduced the pocket watch Reference 57260, which currently holds the title of the most complicated mechanical watch ever made in the world, with 57 horological complications.

Valjoux

Valjoux (for Vallée de Joux, "Joux Valley") is a Swiss manufacturer of mechanical watch movements. It is known primarily for chronograph ébauche movements that are used in a number of mid- to high-range mechanical watches: The company has been a part of ETA for a number of years and is a member of the Swatch Group.

Watch

A watch is a timepiece intended to be carried or worn by a person. It is designed to keep working despite the motions caused by the person's activities. A wristwatch is designed to be worn around the wrist, attached by a watch strap or other type of bracelet. A pocket watch is designed for a person to carry in a pocket. The study of timekeeping is known as horology.

Watches progressed in the 17th century from spring-powered clocks, which appeared as early as the 14th century. During most of its history the watch was a mechanical device, driven by clockwork, powered by winding a mainspring, and keeping time with an oscillating balance wheel. These are called mechanical watches. In the 1960s the electronic quartz watch was invented, which was powered by a battery and kept time with a vibrating quartz crystal. By the 1980s the quartz watch had taken over most of the market from the mechanical watch. Historically, this is called the quartz revolution. Developments in the 2010s include smartwatches, which are elaborate computer-like electronic devices designed to be worn on a wrist. They generally incorporate timekeeping functions, but these are only a small subset of the smartwatch's facilities.

In general, modern watches often display the day, date, month and year. For mechanical watches, various extra features called "complications", such as moon-phase displays and the different types of tourbillon, are sometimes included. Most electronic quartz watches, on the other hand, include time-related features such as timers, chronographs and alarm functions. Furthermore, some modern smartwatches even incorporate calculators, GPS and Bluetooth technology or have heart-rate monitoring capabilities, and some of them use radio clock technology to regularly correct the time.

Today, most watches in the market that are inexpensive and medium-priced, used mainly for timekeeping, have quartz movements. However, expensive collectible watches, valued more for their elaborate craftsmanship, aesthetic appeal and glamorous design than for simple timekeeping, often have traditional mechanical movements, even though they are less accurate and more expensive than electronic ones. As of 2018, the most expensive watch ever sold at auction is the Patek Philippe Henry Graves Supercomplication, which is the world's most complicated mechanical watch until 1989, fetching 24 million US dollars (23,237,000 CHF) in Geneva on November 11, 2014.

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 trains which is not used in other applications of gears.

Watch movements are very standardized, and the wheel trains of most watches have the same parts. The wheel trains of clocks are a little more varied, with different numbers of wheels depending on the type of clock and how many hours the clock runs between windings (the "going"). However, the wheel trains of clocks and watches share the same terminology, and are similar enough that they can be described together. The large gears in timepieces are generally called wheels, the smaller gears they mesh with (large to small, large to small) are called pinions, and the shafts that the wheels and pinions are mounted on are called arbors. The wheels are mounted between the plates of the movement, with the pivots rotating in holes in the plates. The pivot holes have semicircular depressions around them, called oil cups, to hold the oil in contact with the shaft by capillary action. There are several wheel trains in a typical clock or watch.

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