Movement is the engine of the watch. It can be mechanical and have as oscillator a balance wheel and have as energy reservoir a barrel with a spring inside that you tighten either manually with the crown or by your gestures if it is equipped with an automatic winding. It can also be electronic and have as oscillator a quartz and have a battery as energy reservoir that we must change on average every two years. In its most basic version a movement can display hours, minutes and sometimes seconds. However, many other complications can be added to a movement, whether it is mechanical or electronic.


Mainplate is the base plate that supports all the components of the movement. It is the frame of the movement. It will be designed to accommodate the various elements of the movement, for this, the plate is worked, drilled or refined in some places. The plate is also an aesthetic element for a watch with a glass back or a skeleton watch.


Bridges are shaped elements generally machined from the same material as the mainplate. Positioned and fixed on the latter, they allow the various components of the movement to be held in place and to pivot. A mechanical watch generally has several bridges. Their name is determined by the function they perform.


Movement structures can include rarer constructions such as pillars. Replacing the body of the bridges they serve as supports for thin surfaces playing the role of the bridge surfaces.


Barrel of a watch functions as an energy accumulator. It is composed of four elements. A drum with teeth around which is a spring wound around a central axis and a cover closing all this.


Ratchet and the crown wheel are two wheels of which the first is on the barrel axis and the second between the ratchet and the winding pinion.


Minute wheel is positioned between the mainplate and the dial. It ensures that the difference in rotation between the hour hand and the minute hand is 1/12.


Gear-train is a series of different wheels, each equipped with a wheel and a pinion on the same axis. Thus the rotation can be multiplied or divided.


Escape-wheel is easily recognized by the particular shape of its teeth. It is located between the fourth wheel and the pallets.


Pallets is the part between the balance wheel and the escapement wheel, also called the anchor wheel. Its anchor shape gives it its name. It has two functions. It gives impulses to the balance wheel to keep it in motion, and it retains the energy of the barrel which it distributes to the balance wheel at regular intervals.


There are different types of escapements and different ways to classify them. One way to classify them is by three categories, the recoil escapement, the rubbing rest escapement, and the free escapement. The most commonly used escapement is the so-called Swiss Anchor escapement, which falls into the category of free escapement.


Balance wheel is the metronome of the timepiece, it gives it its rhythm. On wall clocks it is a pendulum (also called a balance). On portable watches, pocket watches or wristwatches, it is a wheel without teeth that goes back and forth thanks to a spiral spring and the energy received by the anchor.


Balance-spring is the spring attached to the center of the balance wheel. Its length, which can often be adjusted, is crucial because it defines the speed of the watch.


Winding stem is a stem that connects the crown of a watch to the movement. It has two functions, to wind the movement and to set the time.



Pinion is, in diameter, the smaller of the two components found on the wheels of a gear train. It is made of steel and usually has between 6 and 14 teeth.


Countershaft or countershafts are a series of toothed wheels which are generally made of steel. They have only one tooth per axis. A gearbox reverses the direction of rotation on each axis, unlike a belt transmission.


These parts are located on the mainplate on the dial side. They are used to switch between the winding and time setting functions by means of springs and a sliding arm in a sliding pinion.


Cannon-pinion is a cylindrical pinion with steel friction which is driven on the axis of the center wheel. On its axis comes to fix the hand of the minutes. Its friction allows to disengage the hands from the initial mechanism to allow the setting of the time.


Hour-wheel, also known as the barrel wheel, is the wheel on which the hour hand is fixed. It is located just below the dial and above the movement.


Oscillating weight is a weight attached to the automatic system. It allows, thanks to the gestures of the wearer, to automatically wind the watch he is wearing. When it works without stops, which is nowadays in a large part of the cases, the oscillating weight can also be called rotor.


Automatic system is a complementary mechanism that is fixed on the bridges or on the mainplate on the bridge side. This autonomous system works in concert with the movement’s winding system. It holds the oscillating weight and by a set of cogs and inverters transmits the energy to the barrel.


Reversers are two wheels allowing to transmit the energy of the oscillating weight to the barrel in the right direction and whatever the direction of rotation of the oscillating weight.


Differential is a mechanical system that adaptively distributes rotational force.


Anti-shock devices that appeared in almost all mechanical watches from the middle of the 20th century have reduced the number of after-sales service interventions. There are a few different ones.


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