definition
- A gusset watch (so-called also Gusset watch , Pocket watch or Pocket watch ) is a watch that is made to be worn in a pocket , by Opposition to the wristwatch, which is attached to wrist .
- The gusset means the special pocket that we find in our outfits in order to store the watch.
- They were the most common type of watch since their development in the 16th century until wrist watches became popular after the First World War, during which a transitional model , shows trench , or used by soldiers.
- The gusset watches generally have a Channel , in order to allow them to be attached to a vest , a reverse or a belt loop, in order to prevent them from falling. >
- Women's watches were normally in this form, with an accord that was more decorative than protective.
- The channels are often decorated with a pendant in money or enamel, often carrying the arms of a club or a company.
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- Practical gadgets such as watch key of watch, a jacket case or a cigarette cut can also be added On the watch chain .
- The ties designed to be placed in a buttonhole and worn in a jacket or a vest are also common, this type of attachment are often associated with train drivers and bear their name.
- A first reference to the gusset watch is in a November 1462 letter from the Italian watchmaker Bartholomew Manfredi at the Marquis de Mantua federico gonzaga , where he offers him a " pocket clock " Best than that of Duke of Modena .
- At the end of the 15th century, spring clocks appear in Italy and Germany. Peter Henlein , master locksmith of Nuremberg, regularly manufactured gusset watches in 1524.
- Gusset watches have evolved from the marketing watches, supposedly called Nuremberg eggs, worn on chains around the neck. Example of Peter Henlein, 1510, Germanisches Nationalmuseum Nuremberg.
- Subsequently, the manufacture of with his brother in the late 1830s.
history
The first timepieces to be worn, made in Europe in the 16th century, were of transient size between clocks and watches. These "acknowledges" were attached to the clothes or worn on a chain around the neck.
These were heavy brass cylinders in the shape of a drum-shaped diameter, engraved and decorated had only the Hours needle. The dial was not covered with glass, but equipped with a cover articulated in brass, often pierced with a decorative fence that allowed you to read the time without 'Open.
The Movement was made of iron or steel and maintained together by conical pins and holds, until we start using screw after 1550. Many movements included ringing or alarm mechanisms.
Later in the century, there was a trend for Original form watches , and the watchwhips in the shape of books, D 'animals, fruit, stars, flowers, insects, cross and even skulls (skull watches) were made.
Styles changed in the 17th century and men began wearing watches in pockets instead of wearing pendants (Women's watch remained a pendant until the 20th century).
This would have occurred in 1675 when Charles II of England introduced the vests . To hold in the pockets, their shape has become the typical, round and flat cut -off.
From around 1610, the dial is covered with glass. Until the second half of the 18th century, watches were articles from luxury ; The English newspapers of the 18th century often published, to show how appreciated they were, advertisements offering awards ranging from one to five Guinea only for information likely to lead to the recovery of stolen watches.
However, at the end of the 18th century, the watches (although still largely manually manufactured) were more and more common; We made special watches at an advantageous price for sailors, by painting raw but colorful maritime scenes on the dial of the boats.
Until the years 1720, almost all of the watch movements were based on exhaust angle, which had been developed for large clocks public in the 14th century. This type of exhaust included a high degree of friction and had no type of jewelry to protect contact surfaces against wear.
Consequent a high level of precision. Surviving examples are mostly very fast, often earning an hour a day or more.
The first widespread improvement was the cylinder exhaust , developed by Father de Hautefeuille at the beginning of the 18th century and applied by the English manufacturer George Graham.
Then, towards the end of the 18th century, the lever exhaust (invented by Thomas Mudge in 1755) was put into limited production by a handful of manufacturers including Josiah Emery (Switzerland based in London ) and Abraham-Louis Breguet.
Thus, a domestic watch could keep the hour to one minute per day. Lever watches became common after around 1820, and this type is still used in most mechanical watches Today.
in 1857, the American Watch Company of Waltham, in Massachusetts, launched the Waltham Model 57, the First to use interchangeable parts. This has reduced manufacturing and repair costs. Most of the
gusset watches of model 57 were in money. A 90% pure silver alloy commonly used in the dripping of the money into dollars, slightly less pure than British sterling silver (92.5%), which makes it possible to make parts in circulation and other utility objects last In money longer with intensive use.
The watch manufacturer is rationalized; The Japy de Schaffhouse family, in Switzerland, opens the way and, shortly after, the Horlogère native industry developed a lot of new machines, so in 1865, the American Watch Company (known as Waltham) can produce more than 50,000 reliable watches each year.
This evolution brought out the Swiss of their dominant position on the cheap product market, forcing them to improve the quality of their products and to impose themselves as leaders in terms of Precision watchmaking .
Use in railways in the United States
The rise of the railroad in the second half of the 19th century led to the generalization of the use of gusset watches . On April 19, 1891, a famous train accident occurred on the Lake Shore and Michigan Southern Railway in Kipton in Ohio, because one of the quarter of the mechanics teams had stopped for four minutes.
Railway managers therefore mandated webb C. Ball as chief inspector of time, in order to establish precision standards and a reliable inspection system for chronometers railway.
This led to the adoption, in 1893, of strict standards for gusset watches used in railways. These rail quality pocket watches, as they are colloquially called, had to meet the general standards of the railway watches adopted in 1893 by almost all railways.
These standards were as follows: that Gusset watch either with open front, size 16 or 18, have a minimum of 17 ruby, adjusted to at least five positions, keep the hour precisely at the nearest 30 seconds per week, adjusted to temperatures of 34 ° F (1 ° C) at 100 ° F (38 ° C), have a double roller, a steel wheel , a lever , a regulator , a reassembly rod at 12 noon and Arabic figures black on a white dial, with black needles.
types of Gusset watches
There are two main styles of gusset watch: that with valley and open face.
open face watches
An open face watch, or lepine , is a watch whose box does not have metallic cover to protect the crystal. It is typical for an open face watch to have the pendant located at 12:00 and the second dial located at 6:00 am.
Occasionally, a watch movement intended for a hunting box (with reassembly rod at 3 a.m. and the second dial at 6 a.m.) will have an open front box .
Such a watch is known as "Sidewinder". Such Movement can also be equipped with a conversion dial, which moves the winder stem at 12:00 and the dial seconds at 3:00.
After 1908, the watches approved for the rail service had to be nested in open boxes with the reassembly rod at 12:00.
gusset watches housseur
A Gousset watch "Hunter-Case" (trad: housse or hunting case) is a box with a circular metal cover with spring hinge , which closes on the dial and glass of the watch, protecting them from dust, scratches and other damage or debris.
The name comes from England where "fox hunters found it to be able to open their watch and Read the time with one hand, while holding the reins of their " hunter " (horse) in the other hand "; It is also known as " soap " due to its resemblance to a round soap.
Most old cloves and Hunter-Case have hinges of cover in position 9 hours, and tige , Crown and the arc of the watch in the position 3 hours. The Modern gusset watches Hunter-Case generally have the hinges of the lid in the position 6 hours and the stem , the crown and the arc in the 12 -hour position, such as open dial watches. In the two styles of boxes , the dial of the seconds was always in the 6 hour position. A Hunter-Case pocket watch with a spring chain is illustrated at the top of this page.
An intermediate type, known as halfway, is a box model in which the lid external to a glass panel or a hole in the center giving a view of the hands. The hours are marked, often in blue enamel, on the outside lid; Thus, with this type of box , you can read the time without opening the cover.
types of watchmaking movements
key watches
For the very first gusset watches , from their creation in the 16th century to the third quarter of the 19th century, a watch key was necessary for Raise the watch and Adjust the time . This was generally done by opening the bottom of the case and placing the key on the -Montoir Porte (which was placed on the watch wheel of the watch, to raise the spring engine) or by putting the key to the Montreal carrier, which was connected to the wheel of the minutes and turned the needles .
Some watches of the time were equipped with 'Before the watch of an adjustment device, so it was necessary to remove the ice and the telescope to adjust the time.
Many movements of key watches use a rocket to improve isochronism. The rocket is a specially cut conical pulley, fixed by a thin chain at barrel of the engine spring. When the spring is completely rolled up (and its highest torque), all the length of chain is wound around the rocket and the strength of the motor spring is exercised on The smallest part of cone of the rocket. As the spring takes place and its torque decreases, the chain wraps again on the barrel of engine spring and shoots an increasingly large diameter of the Rocket.
This makes it possible to obtain a more uniform couple on the train of watch, which results in a more constant amplitude of balancing and better isochronism. A rocket is a practical necessity in watches equipped with a exhaust shoulder , and can also offer considerable advantages with a lever exhaust And other high -precision exhaust types (model 21 of the Hamilton chronometer of the Second World War uses a rocket in combination with a Cran exhaust ).
The Key watches are also commonly seen with conventional barrels and other types of engine spring barrels , in particular in watchmaking American. p>
Mechanical winding watches
invented by Adrien Philippe in 1842 and marketed by Patek Philippe & amp; Co. In the 1850s, the winding movement deleted the watch key which was until then a necessity for the operation of any pocket watch . The first winding gusset watches were sold during London's major exhibition in 1851 and the first owners of these new types of watches were Queen Victoria and Prince Albert.
Reverse movements are the type of movement the most common in gusset watches old and Modern .
The transition to the use of winding watches occurred almost at the same time as the end of manufacturing and the use of watch at rocket . The distribution by rocket-chain has been replaced by a engine spring in better quality steel (commonly known as " mobile barrel ") allowing more regular release of power to the exhaust mechanism .
However, the reader of this article should not be mistaken that the reassembly and adjustment functions are directly linked to the pendulum and spiral spring . The pendulum and the spiral spring have a separate function: adjust the delay (or exhaust) of the movement .
lever watches
Compulsory for all railway watches after about 1908, this type of pocket watch is adjusted by opening the crystal and the telescope and by pulling the adjustment lever (most chasers have accessible levers without removing the crystal or the telescope), which was generally at 10 or 2 hours positions of the front watches Open, and at 5 am hunting watches. Once the lever has been pulled, you could turn the crown to set the time . The lever was then pushed back inward and the crystal and the telescope were closed on the dial.
This hour adjustment method on pocket watches was preferred by American and Canadian railways, because lever watches make accidental changes impossible.
rod watches
Like the lever movements , these gusset watches had a small needle or a small button next to the rod Watch that was to be sunk before turning the crown to adjust the time and release the needle when the correct time had been set.
jewelry movements
The watchmaking and jewelry have always been two disciplines between-miles. The mechanical watch is intended to be a small piece of jewelry in the shape of a hard mineral. Ruby and sapphire are the most common. Diamond, garnet and glass are often also used.
However, from the beginning of the 20th century, synthetic jewelry was almost universally used. Before this time, natural quality of natural quality was used which did not suit as precious stones. In both cases, jewelry has practically no monetary value.
The most common jewelry jewelry are holes. Housed jewelry is discs (normally in the shape of a flying saucer) which have a carefully formed and dimensioned hole. The pivot of a arbor is in this hole. The jewel offers an extremely smooth and hard surface which is very resistant to wear and, when it is properly lubricated, with very low friction. Thus, perforated jewelry reduces both the friction and wear of the mobile parts of a watch.
The other types of basic jewelry are hooded jewelry, rolls with rolls and jewelry with Pallet.
Capuchon jewelry is always twinned with hole jewelry, and always with a conical pivot. Capuchon jewelry is so called because they "cap" the hole jewels and control the axial movement of the tree, preventing the shoulder of the pivot from contacting the hole jewel. For a properly designed hole and cap jewelry system, the tree pivot carries the cap jewelry as an anchor point on an oil film. Thus, a hooded jewel offers a lower friction and better positions compared to a simple hole jewel.
Roller jewelry, also called pulse jewelry or simply pulse pin, is a thin rod rod or sapphire, generally in the shape of a "D" letter. The jewel of the roller is responsible for coupling movement of pendulum to that of the pallet fork.
Pallet jewelry is on the palette fork and interact with the spare wheel. These are the surfaces which, 5 times per second in a typical exhaust , lock the gears train train and then transfer power to pendulum .
The high jewelry watches add jewelry to other pivots, starting with the palette fork, then the exhaust wheel , the fourth wheel, the third wheel, and finally the central wheel. Such a jewel on the third wheel adds eight rubies, a total of 15 jewelry . Jewelry to the central wheel adds two others giving a total of 17 jewelry. Thus, a watch containing 17 jewelry is considered to be fully jeweler.
In American manufacturers, however, it was common on low -end movements to make jewelry on the third wheel on the upper (visible) watch.
This gives a total of 11 jewelry, but looks like a watch with 15 jewelry, unless the dial is removed. Like pocket watches 15 jewelry and less are often not marked as for the number of jewelry, it is necessary to be extremely cautious when buying movements Who seem to be 15 jewelry. Additional jewelry beyond 17 jewelry is used either to add cap jewelry, or to adorn the barrel of motor spring of the watch. Watches at 19 jewelry, in particular those of Elgin and Waltham, will often have a motor spring barrel jewelry. Alternatively, a watch with 19 jewelry will have additional caps on the spare wheel. Jewelry watches generally have hood jewelry both on the palette fork and the exhaust wheel . The watches with 23 jewelry will have a jewelry barrel and a completely closed exhaust.
complication movements will often have additional jewelry that is used for useful purposes.
a greater number of jewelry is often associated with better quality of watch movements . If it is true that expensive movements often have a higher number of jewelry, the jewelry themselves are not the cause. The jewelry themselves essentially add no monetary value, and beyond 17 offer negligible improvement in the capacity of timing and in the lifespan of Movement . Most of the costs of a more expensive watch are associated with better finishing quality and, above all, with a larger number of adjustments.
adjusted movements
The gusset watches are sometimes engraved with the word "adjusted", or "adjusted to n positions". This means that the watch has been set to maintain the time in different positions and conditions.
The position adjustment is obtained by a careful balancing (regular distribution of weight) of Spiral-Spiral system as well as by meticulous control of the shape and polishing of pivots balanced .
All of this allows the effect of gravity on the watch in different positions . The position adjustments are obtained by a meticulous adjustment of each of these factors, provided by repeated tests on a timing machine .
Thus, the adjustment of a watch to Its position requires many hours of work, which increases the cost of the watch. The Middle Quality Pocket Watches were generally adjusted to 3 positions (dial up, dial down, pendant up) while superior superior watches were generally adjusted to 5 positions ( dial up, dial down, rod up, left upper, right rod) or even 6 positions . After 1908, railway watches were to be adjusted at 5 positions.
The first watches used a pendulum in solid steel. As the temperature increased, the pendulum was enlarged, changing the moment of inertia and the hour of the watch. In addition, the spring was lie down, which reduced its spring constant.
This problem was first resolved by the use of the balance of remuneration. The compensation balance consisted of a sandwich steel ring with a brass ring. These rings were then divided into two parts. The balance would decrease, at least theoretically, with warming, to compensate for the lengthening of spiral spring .
thanks to a careful adjustment of the location of the balance (brass screw Or in gold placed on the edge of the scale), a watch can be set to maintain the time at the same hot temperature level (100 ° F) and cold (32 °). Unfortunately, an adjusted watch would run slowly at temperatures between these two extremes. The problem was completely resolved thanks to the use of special alloys for the pendulum and the spiral spring which were essentially insensitive to thermal expansion. Such an alloy is used in the 992nd and 992b of Hamilton.
The isochronism has sometimes been improved by the use of a stop system, a system designed not to allow engine spring to operate only in its Central beach (the most constant).
The most common method to obtain isochronism is the use of the induction coil breguet , which places part From the most outside the spring in a different plan from the rest of the spring. This allows the spring to "breathe" more uniformly and symmetrically.
There are two types of coils : Progressive winding and z-bend . The progressive winding is obtained by imposing a gradual double twist on the spring, forming the climb in the second plan on half of the circumference; And the zone in Z makes it by imposing two elbows of complementary angles of 45 degrees, accomplishing a climb in the second plan in about three heights of the spring section.
The second method is made for aesthetic reasons and is much more difficult to achieve. Due to the difficulty of forming a stinging , modern watches often use a slightly less effective "dogleg", which uses a series of sharp elbows to place part of the coil The most external as deviation from the rest of the spring .
popularity
gusset watches are not common in Modern time, having been replaced by wristwatches. Until the beginning of the 20th century, the gusset watch , however, remained predominant in men , the wrist watch being considered feminine and non-virile.
In the male mode , gusset watches began to be replaced by bracelet watches at the time of the First World War, when the officers on the ground began to understand that 'A watch carried on the wrist was more easily accessible than another in a pocket .
A transitional design watch, combining the characteristics of pocket watches and modern bracelet watches, was called "trench watch" or "bracelet". However, gusset watches have continued to be widely used in railways, even if their popularity has decreased elsewhere.
The use of Gusset watches in a professional environment ended around 1943. The Royal Navy of the British army distributed to its sailors Gousset watches Waltham , which were 9 movements of jewelry, with dials black and figures coated with radium for radium for Visibility in darkness, in anticipation of the possible invasion of D -Day.
In recent years, in the late 1970s and in the 1980s, three -room costumes For men have returned to fashion, which led to a resurgence of pocket watches , some men who even used pocket of vest for its original use. As the vests have long passed from fashion (in the United States) as part of the city outfit, the only place available to wear a watch is a pants pocket.
The more recent advent of mobile phones and other gadgets brought to the waist has decreased the attraction of transporting an additional object in the same place, especially since these pocket gadgets generally have a function of < Strong> timing themselves.
In some countries, the gift of a gold pocket watch is traditionally offered to an employee at the time of retirement. The pocket watch has regained its popularity thanks to steampunk , a subcultural movement that embraces the arts and modes of the Victorian era , where the gusset watches were almost omnipresent.
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These were heavy brass cylinders in the shape of a drum-shaped diameter, engraved and decorated had only the Hours needle. The dial was not covered with glass, but equipped with a cover articulated in brass, often pierced with a decorative fence that allowed you to read the time without 'Open.
Later in the century, there was a trend for Original form watches , and the watchwhips in the shape of books, D 'animals, fruit, stars, flowers, insects, cross and even skulls (skull watches) were made.
This would have occurred in 1675 when Charles II of England introduced the vests . To hold in the pockets, their shape has become the typical, round and flat cut -off.
From around 1610, the dial is covered with glass. Until the second half of the 18th century, watches were articles from luxury ; The English newspapers of the 18th century often published, to show how appreciated they were, advertisements offering awards ranging from one to five Guinea only for information likely to lead to the recovery of stolen watches.
However, at the end of the 18th century, the watches (although still largely manually manufactured) were more and more common; We made special watches at an advantageous price for sailors, by painting raw but colorful maritime scenes on the dial of the boats.
Until the years 1720, almost all of the watch movements were based on exhaust angle, which had been developed for large clocks public in the 14th century. This type of exhaust included a high degree of friction and had no type of jewelry to protect contact surfaces against wear.
Consequent a high level of precision. Surviving examples are mostly very fast, often earning an hour a day or more.
The first widespread improvement was the cylinder exhaust , developed by Father de Hautefeuille at the beginning of the 18th century and applied by the English manufacturer George Graham.
Then, towards the end of the 18th century, the lever exhaust (invented by Thomas Mudge in 1755) was put into limited production by a handful of manufacturers including Josiah Emery (Switzerland based in London ) and Abraham-Louis Breguet.
Thus, a domestic watch could keep the hour to one minute per day. Lever watches became common after around 1820, and this type is still used in most mechanical watches Today.
in 1857, the American Watch Company of Waltham, in Massachusetts, launched the Waltham Model 57, the First to use interchangeable parts. This has reduced manufacturing and repair costs. Most of the
This evolution brought out the Swiss of their dominant position on the cheap product market, forcing them to improve the quality of their products and to impose themselves as leaders in terms of Precision watchmaking .
Railway managers therefore mandated webb C. Ball as chief inspector of time, in order to establish precision standards and a reliable inspection system for chronometers railway.
This led to the adoption, in 1893, of strict standards for gusset watches used in railways. These rail quality pocket watches, as they are colloquially called, had to meet the general standards of the railway watches adopted in 1893 by almost all railways.
These standards were as follows: that Gusset watch either with open front, size 16 or 18, have a minimum of 17 ruby, adjusted to at least five positions, keep the hour precisely at the nearest 30 seconds per week, adjusted to temperatures of 34 ° F (1 ° C) at 100 ° F (38 ° C), have a double roller, a steel wheel , a lever , a regulator , a reassembly rod at 12 noon and Arabic figures black on a white dial, with black needles.
Occasionally, a watch movement intended for a hunting box (with reassembly rod at 3 a.m. and the second dial at 6 a.m.) will have an open front box .
Such a watch is known as "Sidewinder". Such Movement can also be equipped with a conversion dial, which moves the winder stem at 12:00 and the dial seconds at 3:00.
After 1908, the watches approved for the rail service had to be nested in open boxes with the reassembly rod at 12:00.
The name comes from England where "fox hunters found it to be able to open their watch and Read the time with one hand, while holding the reins of their " hunter " (horse) in the other hand "; It is also known as " soap " due to its resemblance to a round soap.
Some watches of the time were equipped with 'Before the watch of an adjustment device, so it was necessary to remove the ice and the telescope to adjust the time.
Many movements of key watches use a rocket to improve isochronism. The rocket is a specially cut conical pulley, fixed by a thin chain at barrel of the engine spring. When the spring is completely rolled up (and its highest torque), all the length of chain is wound around the rocket and the strength of the motor spring is exercised on The smallest part of cone of the rocket. As the spring takes place and its torque decreases, the chain wraps again on the barrel of engine spring and shoots an increasingly large diameter of the Rocket.
This makes it possible to obtain a more uniform couple on the train of watch, which results in a more constant amplitude of balancing and better isochronism. A rocket is a practical necessity in watches equipped with a exhaust shoulder , and can also offer considerable advantages with a lever exhaust And other high -precision exhaust types (model 21 of the Hamilton chronometer of the Second World War uses a rocket in combination with a Cran exhaust ).
The Key watches are also commonly seen with conventional barrels and other types of engine spring barrels , in particular in watchmaking American. p>
Reverse movements are the type of movement the most common in gusset watches old and Modern .
The transition to the use of winding watches occurred almost at the same time as the end of manufacturing and the use of watch at rocket . The distribution by rocket-chain has been replaced by a engine spring in better quality steel (commonly known as " mobile barrel ") allowing more regular release of power to the exhaust mechanism .
However, the reader of this article should not be mistaken that the reassembly and adjustment functions are directly linked to the pendulum and spiral spring . The pendulum and the spiral spring have a separate function: adjust the delay (or exhaust) of the movement .
This hour adjustment method on pocket watches was preferred by American and Canadian railways, because lever watches make accidental changes impossible.
However, from the beginning of the 20th century, synthetic jewelry was almost universally used. Before this time, natural quality of natural quality was used which did not suit as precious stones. In both cases, jewelry has practically no monetary value.
The other types of basic jewelry are hooded jewelry, rolls with rolls and jewelry with Pallet.
Capuchon jewelry is always twinned with hole jewelry, and always with a conical pivot. Capuchon jewelry is so called because they "cap" the hole jewels and control the axial movement of the tree, preventing the shoulder of the pivot from contacting the hole jewel. For a properly designed hole and cap jewelry system, the tree pivot carries the cap jewelry as an anchor point on an oil film. Thus, a hooded jewel offers a lower friction and better positions compared to a simple hole jewel.
This gives a total of 11 jewelry, but looks like a watch with 15 jewelry, unless the dial is removed. Like pocket watches 15 jewelry and less are often not marked as for the number of jewelry, it is necessary to be extremely cautious when buying movements Who seem to be 15 jewelry. Additional jewelry beyond 17 jewelry is used either to add cap jewelry, or to adorn the barrel of motor spring of the watch. Watches at 19 jewelry, in particular those of Elgin and Waltham, will often have a motor spring barrel jewelry. Alternatively, a watch with 19 jewelry will have additional caps on the spare wheel. Jewelry watches generally have hood jewelry both on the palette fork and the exhaust wheel . The watches with 23 jewelry will have a jewelry barrel and a completely closed exhaust.
a greater number of jewelry is often associated with better quality of watch movements . If it is true that expensive movements often have a higher number of jewelry, the jewelry themselves are not the cause. The jewelry themselves essentially add no monetary value, and beyond 17 offer negligible improvement in the capacity of timing and in the lifespan of Movement . Most of the costs of a more expensive watch are associated with better finishing quality and, above all, with a larger number of adjustments.
All of this allows the effect of gravity on the watch in different positions . The position adjustments are obtained by a meticulous adjustment of each of these factors, provided by repeated tests on a timing machine .
Thus, the adjustment of a watch to Its position requires many hours of work, which increases the cost of the watch. The Middle Quality Pocket Watches were generally adjusted to 3 positions (dial up, dial down, pendant up) while superior superior watches were generally adjusted to 5 positions ( dial up, dial down, rod up, left upper, right rod) or even 6 positions . After 1908, railway watches were to be adjusted at 5 positions.
The first watches used a pendulum in solid steel. As the temperature increased, the pendulum was enlarged, changing the moment of inertia and the hour of the watch. In addition, the spring was lie down, which reduced its spring constant.
This problem was first resolved by the use of the balance of remuneration. The compensation balance consisted of a sandwich steel ring with a brass ring. These rings were then divided into two parts. The balance would decrease, at least theoretically, with warming, to compensate for the lengthening of spiral spring .
thanks to a careful adjustment of the location of the balance (brass screw Or in gold placed on the edge of the scale), a watch can be set to maintain the time at the same hot temperature level (100 ° F) and cold (32 °). Unfortunately, an adjusted watch would run slowly at temperatures between these two extremes. The problem was completely resolved thanks to the use of special alloys for the pendulum and the spiral spring which were essentially insensitive to thermal expansion. Such an alloy is used in the 992nd and 992b of Hamilton.
The most common method to obtain isochronism is the use of the induction coil breguet , which places part From the most outside the spring in a different plan from the rest of the spring. This allows the spring to "breathe" more uniformly and symmetrically.
There are two types of coils : Progressive winding and z-bend . The progressive winding is obtained by imposing a gradual double twist on the spring, forming the climb in the second plan on half of the circumference; And the zone in Z makes it by imposing two elbows of complementary angles of 45 degrees, accomplishing a climb in the second plan in about three heights of the spring section.
The second method is made for aesthetic reasons and is much more difficult to achieve. Due to the difficulty of forming a stinging , modern watches often use a slightly less effective "dogleg", which uses a series of sharp elbows to place part of the coil The most external as deviation from the rest of the spring .
In the male mode , gusset watches began to be replaced by bracelet watches at the time of the First World War, when the officers on the ground began to understand that 'A watch carried on the wrist was more easily accessible than another in a pocket .
A transitional design watch, combining the characteristics of pocket watches and modern bracelet watches, was called "trench watch" or "bracelet". However, gusset watches have continued to be widely used in railways, even if their popularity has decreased elsewhere.
In recent years, in the late 1970s and in the 1980s, three -room costumes For men have returned to fashion, which led to a resurgence of pocket watches , some men who even used pocket of vest for its original use. As the vests have long passed from fashion (in the United States) as part of the city outfit, the only place available to wear a watch is a pants pocket.
The more recent advent of mobile phones and other gadgets brought to the waist has decreased the attraction of transporting an additional object in the same place, especially since these pocket gadgets generally have a function of < Strong> timing themselves.
In some countries, the gift of a gold pocket watch is traditionally offered to an employee at the time of retirement. The pocket watch has regained its popularity thanks to steampunk , a subcultural movement that embraces the arts and modes of the Victorian era , where the gusset watches were almost omnipresent.