Style Watches

The parts of its sum: anatomy of a chronograph

Although quartz technology has radically simplified the inner mechanics of the modern chronograph, its mechanical counterparts remain among the most complex and compelling timepieces ever crafted.
Aurelio Icasiano III | Aug 29 2018

Tag Heuer’s fifth in-house movement, the Calibre 1887 is named after the year Edouard Heuer received a patent for the oscillating pinion, a mechanism that would change the landscape of the watchmaking world. Replacing the complex clutch systems that were used in the era, the oscillating pinion simplified the construction of chronographs and remains in use today.

Photo courtesy of Tag Heuer

1. Oscillating pinion
The oscillating pinion functions much like a vehicle’s transmission system, coordinating the functions of the chronograph. 

2. Barrel
The barrel is where the mainspring is housed—the thin, coiled, metal ribbon that powers a watch. From the barrel, the torsion is slowly released and is distributed to the other parts of the watch.

3. Pillar wheel
Acting as the link to the different levers of the chronograph, the pillar wheel allows the user to start, stop, and reset the complication. With the amount of time it takes to manufacture one, only the higher quality chronographs are built with this particular mechanism.

4. Balance wheel
The balance wheel is the timekeeping element in a watch’s architecture. Rotating back and forth, the wheel regulates the beat of the watch, allowing the timepiece to tick out the seconds accurately.

5. Escapement wheel
From the barrel, the energy of the main spring gets transferred throughout the watch, and the escapement wheel is the piece that transfers this energy to the balance wheel, keeping it in constant motion.

6. Main plate
The main plate is where the other parts of the movement are mounted, a multi-layered component that facilitates motion.


This article first appeared in Vault issue #15, 2014. Banner photo by annca for Pixabay.