====== Jaeger-LeCoultre Autotractor ======
**Autotractor** is a term for a family of modern, rugged watch movements from [[Jaeger-LeCoultre]]. Due to the numbering of the calibres in this family, it is also often referred to as the "970" family or by the calibre number of the most widely-used variant, [[JLC 975|Calibre 975]].

As Jaeger-LeCoultre was recovering from the quartz crisis and a series of ownership changes, the company decided to begin investing in movement technology. The high-profile [[Jaeger-LeCoultre Hybris Mechanica|Hybris Mechanica]] series brought renewed respect and interest in the company, but it was mainstream watch movement technology that would keep the company in business. Beginning in [[1996]], the company tasked a team, led by R&D Director Jean-Claude Meylan, to produce a new basic automatic movement with the following characteristics Reliable, durable, accurate, easy to maintain, service and regulate and relatively maintenance free. Eight years later, in [[2004]], the Autotractor was launched.

===== Autotractor Features =====
{{wst>image_cr|Jaeger-LeCoultre|Master Compressor GMT}}

Introduced in [[2004]], the "Autotractor" family was designed to bring modern developments to market in a new family of high-end watch movements. Among the main advancements found throughout this family of movements are the following 

  * Ceramic bearings, zirconium-oxide coated in steel, reduce maintenance requirements
  * Unidirectional (counter-clockwise) winding produces more power in real-world use than bi-directional systems
  * A "[[SPYR]]" design for the gear teeth is more rounded to reduce friction and maintain more even torque (as used in the [[JLC Mechaquartz]])
  * A large, [[free-sprung]] [[balance wheel]]
  * Laser-welded [[hairspring]] with adjustment by means of screws on the periphery of the [[balance]]
  * A screwed cross-over bridge rather than a [[balance cock]] for durability and shock resistance
  * "Maltese cross" date changing gear allows instantaneous and bi-directional movement of the date wheel
  * An in-house mainspring manufactured by [[A. Lange & Söhne]]
  * A [[small seconds]] design with the [[center wheel]] in the middle, as in traditional watches

Note that two Autotractor movements, [[JLC 976|Calibre 976]] and [[JLC 986|Calibre 986]], are hand-winding rather than [[automatic]] but retain most other features of the family and are generally considered Autotractor movements.

===== Autotractor Family Calibres =====
The first Autotractor movement was [[JLC 975|Calibre 975]], and it has spawned a family of movements that share a similar design 

  * [[JLC 751|Calibre 751]] - Chronograph
  * [[JLC 752|Calibre 752]] - Chronograph [[world timer]]
  * [[JLC 970|Calibre 970]] - [[Jaeger-LeCoultre Grande Reverso Automatic|Grande Reverso Automatic]] GMT/big Date
  * [[JLC 971|Calibre 971]] - Ladies GMT
  * [[JLC 972|Calibre 972]] - Minute counter
  * [[JLC 975|Calibre 975]] - [[Dual timezone]]
  * [[JLC 976|Calibre 976]] - [[Jaeger-LeCoultre Grande Reverso 976|Grande Reverso 976]] manual winding
  * [[JLC 977|Calibre 977]] - [[Jaeger-LeCoultre Reverso Squadra Hometime|Reverso Squadra Hometime]] GMT/small date
  * [[JLC 979|Calibre 979]] - Depth gauge
  * [[JLC 986|Calibre 986]] - [[Jaeger-LeCoultre Grande Reverso 986 Duodate|Grande Reverso 986 Duodate]] manual winding GMT/date

===== "Autotractorized" Calibres =====
Many of the innovations found in the Autotractor family itself have spread to other contemporary movements from Jaeger-LeCoultre. These are often referred to as being "Autotractorized" and this has led to some confusion regarding their relationship to Cal. 975 and the rest.

The following Calibres feature some elements of the Autotractor design, although they are not part of this family of movements 

  * [[JLC 899|Calibre 899]] (and similar [[JLC 896|896]] and [[JLC 898|898]]) are descendants of [[JLC 889|Calibre 889]] but feature ceramic bearings and SPYR gears
  * [[JLC 925|Calibre 925]] has unidirectional winding
  * [[JLC 938|Calibre 938]] has ceramic bearings and a free-sprung balance along with Jaeger-LeCoultre's signature [[Jaeger-LeCoultre Réserve de Marche|Réserve de Marche]] complication
  * [[JLC 956|Calibre 956]] (and related [[JLC 912|912]]) has ceramic bearings and SPYR gears
  * [[JLC 978|Calibre 978]] has ceramic bearings, SPYR gears, and a similar balance to the Autotractor

===== External Links =====
  * [[http://www.network54.com/Forum/234648/message/1078680164/In+search+of+the+perfect+movement%2C+Autotractor+first+used+in+Home+Time+and+Dualmatic%21|In search of the perfect movement, Autotractor first used in Home Time and Dualmatic!]]
  * [[http://www.thepurists.net/Patrons/Members/wsw/jlc_at/jlc975finweb.htm|Jaeger - Le Coultre caliber 975]]


{{tag>Jaeger-LeCoultre Jaeger-LeCoultre_calibres Jaeger-LeCoultre_Autotractor_calibres}}