g.h.Baillie's assessment of the sesame chain in his book "Watchmakers and Clockmakers of the World" aptly sums up the milestone significance of this ancient mechanism in centuries-old horological history. 
Sesame chain structureCrafts for precisionFrom the concept of clockwork to the concept of clockwork, how to make its power smoothly output to the drive train has become a problem. In the fifteenth and sixteenth centuries, when materials science was barren, the material used for the clockwork was nothing more than ordinary steel that was flattened and quenched and then treated with blue anti-rustThe coiling method is not the current mainstream S-shape, but a simple spiral like a mosquito coil. The power output is polarized, strong at full strings and weak when falling strings. For watches that pursue timekeeping accuracy, it is a hard flaw. Watchmakers tried many methods in the fifteenth and sixteenth centuries. Among them, two have stepped onto the stage of history and will be remembered by future generations. The first is the stackfreed structure invented by the Germans. 
According to the data, the stackfree structure first appeared around 1510, and from the principle point of view, it can indeed average the output torque to a certain extent, but the accuracy is limited and it is very easy to cause wear and tear of parts. The second one is the pagoda wheel. The implementation mechanism is essentially the application of the "moment, force, distance" formula. 
The higher the pagoda wheel, the smaller the diameter, the shorter the distance of force transmission between it and the connected barrel;The lower end is reversed, and the distance of the force becomes longer. In this way, as the mainspring gradually relaxes and the force becomes weaker and weaker, the longer distance can compensate for it. It is not difficult to see that the core component of the pagoda wheel mechanism is not only the fixed hyperboloid conical wheel, but also the power transmission line that connects it to the barrel. This "thread" was originally made of gut or wire, but around 1650, a metal chain composed of individual links began to appear, called fusee chain, which is modernly translated as "sesame chain". 
It was also at that time that the sesame chain wound around the pagoda wheel became the abbreviation of the entire pagoda wheel constant power unit (average clockwork output torque), and was widely used in high-quality watches. 
The constant power structure composed of a barrel, a pagoda wheel, and a sesame chain is habitually called a sesame chainProgress and change Sesame chain temporarily leaves the stageWith the development of materials science, alloys began to be used in watchmaking, and the S-shaped coiling method appeared, and the problem of large output torque drop was alleviated. The need for sesame chains at a practical level has been greatly reduced. Coupled with the popularity of watches, sesame chains will increase the thickness of the case;In the case of miniaturization, the process and cost requirements are extremely high. Over time, the sesame chain, which had led the concept of precision in several eras, left the scene at the beginning of the 20th century, the beginning of the watch era. 
It is not easy to concentrate a sesame chain on a single watch, and it is not an ordinary watchmaker who can make itThe classic has not been forgotten and the sesame chain is resurrected againBy the end of the 20th century, perhaps the positioning of clocks had shifted from the concept of tools to works of art and expression, or perhaps it was ...... of the retro trendThe sesame chain, which had been dormant for decades, has been revived again. However, its positioning has changed from a functional requirement to a decorative element and a tribute to historical feelings and haute horlogerie. (It's the same as a tourbillon).
It should be mentioned here that unlike tourbillons, which are difficult to make because of the precision of the parts, sesame chains are very complex in terms of structure. 
There are dozens of parts for a normal tourbillon, but a sesame chain, such as the Zenith Academy Georges F**Re-Jacot Limited Edition, is as high as 575. Not to mention, there are also requirements for artistic aesthetics. It is precisely because of this that even after hundreds of years of technological precipitation, even if the tourbillon has long been layered, the sesame chain still stands in the minority as always. Article**: Feige talks about fashion Note: The article only represents the author's personal views and is recommended by good articles, if there is any infringement, please contact to delete.