Timepiece assembly comprising a balance wheel and a balance shaft

The watch assembly addresses the challenge of assembling fragile balance wheels by using a dual annular rim and Belleville washer locking member to ensure precise and stable retention, overcoming issues of centering and friction in silicon balance wheels.

EP4575661B1Active Publication Date: 2026-07-01RICHEMONT INTERNATIONAL SA
View PDF 2 Cites 0 Cited by

Patent Information

Authority / Receiving Office
EP · EP
Patent Type
Patents
Current Assignee / Owner
RICHEMONT INTERNATIONAL SA
Filing Date
2023-12-21
Publication Date
2026-07-01

AI Technical Summary

Technical Problem

Existing methods for assembling balance wheels, particularly those made of fragile materials like silicon, face challenges in maintaining centering during deformation and ensuring sufficient clamping force due to low friction, especially when subjected to shocks.

Method used

A watch assembly design featuring a balance shaft with dual annular rims and a locking member with a concavity, allowing for elastic deformation to securely lock the balance wheel without continuous contact, using a Belleville washer-type locking member to ensure clamping force independent of the driving force.

Benefits of technology

The solution provides precise assembly and stable retention of balance wheels made of brittle materials like silicon, maintaining precision and stability during rotation by controlling clamping force through elastic deformation and non-continuous contact.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure IMGF0001
    Figure IMGF0001
Patent Text Reader

Abstract

The invention relates to a watch assembly comprising: - a balance shaft (10) provided with a first annular rim (11) defining a first axial stop, a first bearing surface (13) of diameter D adjoining the first annular rim (11), - a balance (20), comprising a hub (22) provided with a central opening, through which the balance (20) is adjusted on the first bearing surface (13), bearing on the first axial stop, - a locking member (30), rigidly mounted on the balance shaft (10) and arranged so as to lock the balance (20) against the annular rim. According to the invention, the locking member (30) has a concavity in its part situated around the shaft (10), which limits the contact between the locking member (30) and the balance (20) to an area situated around an annular portion, surrounding the shaft (10).
Need to check novelty before this filing date? Find Prior Art