====== JLC 174 ======
Calibre **JLC 174** is a special limited-edition [[tourbillon]] movement from [[Jaeger-LeCoultre]].

{{wst>image_cr|Jaeger-LeCoultre|Reverso Gyrotourbillon 2 Rückseite}}

Calibre 174 was an important development for Jaeger-LeCoultre and the watch industry. In addition to a 2-axis [[tourbillon]], it was the first wristwatch to feature a cylindrical [[balance spring]]. Patented in [[1782]] by Englishman [[Arnold, John|John Arnold]], the cylindrical balance spring makes a watch more [[isochronous]] thanks to two Phillips terminal curves. But the technology had never before been miniaturized and used in a wristwatch before the [[2008]] introduction of Calibre 174 in the [[Jaeger-LeCoultre Reverso Gyrotourbillon 2|Reverso Gyrotourbillon 2]]. And in this case, it was even smaller than normal, having to fit inside a miniature [[tourbillon]] in a Reverso case.

Introduced in [[2004]] in their [[JLC 177|Calibre 177]], Jaeger-LeCoultre's spherical tourbillon is technically very impressive. It features two tourbillon carriages The outer carriage rotates every sixty seconds and carries an inner carriage with the balance wheel, balance spring, and escapement. This inner carriage rotates 3.2 times per minute, exposing the 14 karat gold balance wheel once per minute. The entire tourbillon mechanism consists of 90 parts yet weighs just 1/3 gram thanks to aluminum and titanium construction.

Unlike JLC 177, calibre 174 operates at 4 Hz (28,800 A/h) and pairs the mainspring with a torque restricting device on the [[barrel]]. This allows Jaeger-LeCoultre to guarantee a full 50 hour power reserve, with the watch stopping at 50 hours when the torque is too low. It also prevents over-winding the manual mechanism. Overall, the 174 is made up of 373 pieces. It has 58 jewels.

Jaeger-LeCoultre only ever used this calibre in the limited-edition [[2008]] [[Jaeger-LeCoultre Reverso Gyrotourbillon 2|Reverso Gyrotourbillon 2]], winner of the "Complicated Watch Prize" at the [[2008]] [[Grand Prix d' Horlogerie de Genève]].

===== See also =====
  * [[JLC 177]]
  * [[Jaeger-LeCoultre Reverso Gyrotourbillon 2]]
  * [[Tourbillon]]


<WRAP ud ud_mov>

**Manufacturer:**
  * [[Jaeger-LeCoultre]]

**Description:**
  * [[Hand-winding]] movement
  * 373 components

**Functions:**
  * Hour, minute
  * Seconds
  * [[24 hour]] indicator
  * [[Power reserve indicator]]

**Data:**
  * H 11.1 mm
  * 58 [[jewels]]
  * 28800 A/h
  * Power reserve 50 Hours

**Production period:**
  * [[2008]]
</WRAP>

{{tag>Movements Manual_winding_movements Tourbillon_movements Grande_complication_movements Jaeger-LeCoultre_calibres}}