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Glossary of watchmaking

Index (Regulator)

Raquette | 緩急針/カンキュウシン | 微调器(调速器)

Index (Regulator)

A device for adjusting a watch's rate by increasing or reducing the effective length of the balance spring. The index is a steel lever, the shorter end of which carries the curb pins which embrace the spring, and the longer end of which passes over a scale marked in French A and R (avance and retard) or in English F and S (fast and slow). The index is friction-fitted on the balance's endpiece. The watch is regulated by moving the index forwards; the result of this can be gauged from the graduations on the balance cock.