Self-compensating spring for a mechanical oscillator of balance-spring type

摘要

A self-balancing spring for a mechanical balance spring oscillator of a watch movement or other precision instrument, in a paramagnetic Nb-Hf alloy has a thermal coefficient of Youngs modulus (CTE) such that it essentially allows the annulment of the following expression: 1/E asterisk dE/dT+3 alpha s-2 alpha b where: E : Youngs modulus for the spring of the oscillator 1/E asterisk dE/dT = CTE = thermal coefficient of Youngs modulus of the oscillator spring alpha s : coefficient of thermal dilation of the oscillator spring alpha b : coefficient of dilation of the balance wheel of the oscillator. The alloy contains between 2% and 30% atomic of Hf.