Breguet overcoil
巻上げヒゲゼンマイ／マキアゲヒゲゼンマイ
宝玑双层游丝
Breguet overcoil
Spiral plat coudé ou Bréguet
Glossary
Thematic
Regulation, Technic
Sometimes referred to as a \Breguet spiral\" it controls the rate at which the mainspring unwinds.
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