====== Gyrotourbillon ======
{{wst>image_cl|Jaeger-LeCoultre|Reverso Gyrotourbillon 2 Nahaufnahme|Jaeger-LeCoultre Reverso **Gyrotourbillon** 2}}

**Gyrotourbillon** (and the related **Spherotourbillon**) is an elaborate watch movement from [[Jaeger-LeCoultre]] in which a [[tourbillon]] rotates on two different axes.

===== Overview =====
{{wst>image_cr|Jaeger-LeCoultre|Gyrotourbillon 1}}

A [[tourbillon]] movement is designed to rotate the [[balance]] to compensate for the effects of gravity. However, a single-axis tourbillon only performs this function then held parallel to the axis. This was effective in a [[pocket watch]], which usually rested vertically in a pocket, but serves no purpose in a wristwatch resting flat, perpendicular to the axis of rotation.

In [[2004]], Jaeger-LeCoultre introduced a spherical dual-axis tourbillon which solved this problem by rotating the tourbillon cage itself. Known as the **Gyrotourbillon**, this was a complex and beautiful mechanism showcased in a number of [[Jaeger-LeCoultre Hybris Mechanica|high-end watches]]. [[Jaeger-LeCoultre Gyrotourbillon 1|The original Gyrotourbillon]] spherical outer cage rotated once per minute, with the inner cage mounted perpendicular and rotating once every 24 seconds.

The [[Jaeger-LeCoultre Reverso Gyrotourbillon 2|Gyrotourbillon 2]] increased the speed of the movement to 28,800 A/h and the speed of the inner cage to one rotation per 18.75 seconds. Another advance in the Gyrotourbillon 2 is the use of a cylindrical [[balance spring]], a technology previously used in [[marine chronometer]]s but not wrist watches.

{{wst>image_cr|Jaeger-LeCoultre|Duometre a Spherotourbillon|Jaeger-LeCoultre Duomètre à Sphérotourbillon}}

Jaeger-LeCoultre brought the 2-axis tourbillon to a wider audience starting in [[2012]] with the **Spherotourbillon**. Like the Gyrotourbillon, this is an inclined tourbillon movement with two axes of rotation. But the movement was simplified and refined to be smaller, use fewer components, and be easier to construct and service. The tourbillon is mounted to a gear set at a 20 degree angle to the movement plate. The tourbillon rotates every 30 seconds, while the inclined axis rotates every 15 seconds. It also uses a cylindrical balance spring like the Gyrotourbillon 2. The initial [[Jaeger-LeCoultre Duomètre à Sphérotourbillon|Duomètre à Sphérotourbillon]] model also included [[flyback]] [[hacking]] seconds operated by a reset pusher.

In [[2016]], another Reverso appeared The [[Jaeger-LeCoultre Reverso Tribute Gyrotourbillon|Reverso Tribute Gyrotourbillon]] is entirely different from its predecessor with a smaller Gyrotourbillon lacking the spherical cage entirely. A hemispherical balance spring appears again, and the inner cage now rotates at a quick 12.6 seconds. The balance is designed to resemble the "JL" anchor rather than a wheel.

The [[Jaeger-LeCoultre Master Grande Tradition Gyrotourbillon 3 Jubilee|Gyrotourbillon 3]] returns to a 24 second rate for the inner cage but is a [[flying tourbillon|flying]] design with no upper bridge. It also uses a spherical balance spring, the first ever devised.

===== Jaeger-LeCoultre Models =====
==== Gyrotourbillon ====
  * [[2004]] - [[Jaeger-LeCoultre Gyrotourbillon 1|Master Gyrotourbillon 1]]
  * [[2008]] - [[Jaeger-LeCoultre Reverso Gyrotourbillon 2|Reverso Gyrotourbillon 2]]
  * [[2013]] - [[Jaeger-LeCoultre Master Grande Tradition Gyrotourbillon 3 Jubilee|Master Grande Tradition Gyrotourbillon 3 Jubilee]]
  * [[2016]] - [[Jaeger-LeCoultre Reverso Tribute Gyrotourbillon|Reverso Tribute Gyrotourbillon]]
  * [[2019]] - [[Jaeger-LeCoultre Master Grande Tradition Gyrotourbillon Westminster Perpétuel|Master Grande Tradition Gyrotourbillon Westminster Perpétuel]]

==== Spherotourbillon ====
  * [[2012]] - [[Jaeger-LeCoultre Duomètre à Sphérotourbillon|Duomètre à Sphérotourbillon]]
  * [[2015]] - [[Jaeger-LeCoultre Duomètre Sphérotourbillon Moon|Duomètre Sphérotourbillon Moon]]

===== Videos =====
  * [[https://www.youtube.com/watch?v=AWdlPMQlig4|Jaeger-LeCoultre Gyrotourbillon, Cage Movement]], 0:44 (YouTube)
  * [[https://www.youtube.com/watch?v=MTj__XKPl5M|Jaeger-LeCoultre Gyrotourbillon 1]], 2:01 (YouTube)


{{tag>Watch_videos Terms}}