The exquisite case, the novel time display, the singularly complicated functions, all the dizziness makes it easy for people to ignore the simple fact that the watch is a watch at a certain rate The mainspring was released from the machine. The watch is a machine that releases the mainspring at a certain rate. To prevent the mainspring from being loosened too quickly, the end of the mainspring that contacts the inner wall of the mainspring box is bent into an S shape.
Power at the beginning
The existence of the watch, in a real sense, lets his master know what speed the mainspring is releasing at. This is how the power tracer and power pointer come about! If the mainspring is to continue to power the watch, it must be wound on a regular basis. Although the movement only needs to have the ability to run for 24 hours after winding, the power reserve required is actually longer. However, one fact is little known-the power transmitted by the mainspring is not the same. Imagine: when a spring is released, the power it transmits is a variable; the tighter the spring, the greater the torque it transmits to the escapement through the powertrain. When the mainspring was released, the power transmission began to weaken. At the limit of the watch’s power reserve, that is, when the mainspring is almost completely released, the degree of the swing-balance wheel during the tick-tick swing process began to weaken, and the stability of the watch’s speed began to be tested . The long power reserve can ensure that in daily use, a part of the most constant power output of the mainspring is consumed every day, so as to better ensure the accurate movement of the watch.
This is the state where the mainspring is fully loosened in the barrel, and the movement has stopped.
Evolution of early clocks and mainsprings
The modern watch industry originated in Europe in the 13th century, mainly because of the need for religious prayers at that time. The earliest ‘big clocks’ appeared on the tall buildings of some churches and municipalities. The principle of their operation is very simple-relying on a heavy rope to pull a thick roller or roller, so that the latter can use a hand to indicate the time.
After entering the 14th century, more and more such clocks have been built, and similar clock towers have matured in Europe, adding complex functions such as timekeeping and moving figures. The addition of functions means increased power demand. How to ensure that these complex clocks move accurately and use power more efficiently? In particular, the problem of output torque needs to be solved urgently (the same as the current situation where the torque of modern clocks is too high when the clockwork is full and the torque is too low when the clockwork is about to run out). With the more and more complicated clock structure in the middle and late 14th century (already able to reflect the operation of the sun, moon and stars), the intervention of the scientific community has become the driving force for the development of clock technology, so a series of gears that make the power more uniform, The escapement mechanical system came into being.
In the most gloomy early days of watchmaking, keeping the clock running for a day was a challenge. The clock driven by the early mainspring only had 3 gears (4 gears in modern clocks) and the running time was less than 14 hours. What makes these clocks unusual is not that they are accurate, but that they can work. For the clock, the excellent timing function was not realized until the development of the pendulum escapement. And until the appearance of the spiral balance spring, the pocket watch keeps its travel time error within a few minutes every day. In this case, pocket watch travel time of less than 24 hours is no longer a big practical problem.
From the early craftsmen who built the spiral steel wire by the stove to modern Inox (chrome-nickel steel) and Nivaflex (cobalt, nickel, chrome steel) with high-tech colors, not only the material and appearance of the clockwork have changed, There have also been numerous developments in the mechanical structure. The mainspring is a coiled metal bar, which can generally reach 400-500 mm in length, coiled 8-10 times (usually 1 clockwork can provide 6 hours of power). The mainspring is continuously contracted and relaxed 10,000 to 20,000 times without abrasion, and the power is generated between this looseness and tightness. In working condition, the mainspring gradually releases its power from the outside to the inside. Generally, the spring is most motivated when fully wound, while the spring is often underpowered. The mainspring of the early period reflected all the shortcomings of the early watchmaking industry: ‘Steel, the elasticity tends to disappear quickly, and the torque transmitted to the escapement varies.’ Today, the mainspring is no longer easy to break and break, And the power output is uniform, and it is not easily affected by natural factors such as magnetic fields. The most common Nivaflex clockwork is made of iron, nickel, and chromium alloys, and also includes rare elements such as cobalt, molybdenum, and beryllium. It can not only be antimagnetic, corrosion-resistant, not easy to break, not affected by temperature changes, tensile and impact resistance Function, but also full of toughness, which is conducive to the gentle release of power. However, an old problem that plagued clocks before the clockwork was born-balanced power output is always a problem. How to control the power output more accurately under more complicated functions is a problem that all mechanical power meters must solve.
Parmigiani has made great achievements in long-powered models
Considering the size and shape of modern mechanical watches, the mainspring is embedded in the mainspring box. The clockwork is tightened and power is released. The reason is simple, and the method of implementation is not simple. First, the smaller the friction between the spring and the barrel, the better. The power transmitted by the spring is only 55% -60% of its own energy, so improving the material is still one of the ideas to make full use of power. The machinery that relies on clockwork must be improved in structure and materials to reduce the unnecessary loss of power. In this regard, the use of lighter materials can obviously play a role, while some improvements around structures such as transmission gears can also make power output more efficient.
Lange 31 has another power recovery system at the fourth gear
Reducing the frequency of balance wheel swing (hereafter referred to as swing frequency) is a very simple method to increase power, but this often affects the accuracy of the watch and has been used relatively rarely. Around the balance wheel, there is a problem that is very difficult to handle when designing and manufacturing a watch: when the power is sufficient, the balance swings steadily and can be controlled more accurately when traveling; and when the power is not strong, the swing The amplitude of the swing (called the spoke width) will be significantly reduced, and the swing frequency will be accelerated accordingly, which will cause the watch to run faster. When the power is about to be exhausted, the watch will stop completely. This stop is very passive. In order to allow those relatively powerful watches to release power evenly, most modern mechanical movements are equipped with external clockwork hooks and other ‘reduction devices’, such as brake springs, brake cones, brake gears, etc. , So that the mainspring can release its energy more evenly, and it will stop the core before the energy is low enough to affect the running accuracy (the mainspring of the same length can go longer without those mechanisms, but the accuracy is very high difference). Many products have a brake designed to stop the simple movement when the power is insufficient to maintain operation. Similar problems are often manifested in some small table clocks. Although the 8-day power clock can get out of the ‘performance’ of 10 days, the accuracy of the next two days is very poor. Large clocks can greatly increase the utilization rate of clockwork through more complex mechanical structures, and clocks that have built power for more than a year are not a problem, and the latest record of watches has 31 days of power.
The window digital power reserve display of the Jaeger-LeCoultre 8-day power watch is very convenient
In 1913, a watch called Hebdomas was the first to obtain power of up to 8 days. By the 1930s, many watch factories mainly produced ultra-long springs and produced long-power watches that could run for more than a week. Today, some watchmakers still insist that the power output from a single barrel is the most reliable, and it is not prone to problems such as wear caused by complex parts. Considering that the output power of a barrel is difficult to reach for a week or even longer, some people started to develop multiple barrels in clocks to provide greater driving force. As early as the 18th century, two great watch inventors in Switzerland, Henni Louis Jaquet-Droz and Abraham-Louis Breguet, used to connect two barrels in parallel to exert greater impetus. Tiffany’s watchmaker Alfred Helwig managed to power the watch with two barrels connected in series. Relatively speaking, most brands use tandem barrels, and one of their goals is to allow the movement to be made thinner while maintaining automatic winding and longer power. Whether it is in parallel or in series, solving the problem of coordinating two different power sources is the key to the problem. In addition, the increase of mechanical parts brought by multiple barrels has also become an important problem for engineers. The structure of the multi-spring barrel makes the output of the spring power more uniform, while reducing the pressure of the transmission mechanism. In recent years, the increasing popularity of long-powered watches and the increase in watch size have led to the continuous emergence of innovative structures such as three barrels and four barrels. The use of so many barrels is sometimes only for the layout of watch machinery. More reasonable, not necessarily just for longer-term motivation.