Annular Oscillating Mass Assembly for Shock-Resistant Timepieces

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing annular oscillating masses in automatic watches are prone to deformation during assembly and can be dislodged by shocks, affecting their smooth functioning and quality.

Innovation Solution

The oscillating mass is designed with a carrier bow having coaxial toothing and a heavy sector attached via blom studs with an uneven surface, forming a glue reservoir for a secure assembly, and includes shoulders and chamfered ends to facilitate insertion and reduce stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If driven pins or blom studs are used to assemble the oscillating mass elements, then the assembly is secured, but the oscillating mass is easily deformed and the pins can be dislodged by shocks

Engineering Contradiction:

Improveassembly securityVSAvoiddeformation resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The oscillating mass is divided into multiple elements (carrier bow, heavy sector, balance wheel) that are assembled together using blom studs. This segmentation allows each element to be optimized independently while maintaining overall structural integrity and reducing stress concentration points.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs specific geometric features (shoulders, chamfers, rounded edges) and material selection beforehand to cushion and distribute shock loads. The carrier bow includes shoulders that absorb impact forces, preventing direct transmission to the blom studs and preventing dislodgement while maintaining assembly security.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If driven pins or blom studs are used to assemble the oscillating mass elements, then the assembly is secured, but the geometry of the toothed bow is impaired

Engineering Contradiction:

Improveassembly securityVSAvoidtoothed bow geometry

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The toothed bow geometry is separated into distinct elements (carrier bow with toothing, heavy sector) that are assembled using blom studs. This allows the toothed bow to be manufactured with high precision independently, then assembled without deformation, maintaining geometric integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The carrier bow includes pre-designed shoulders and chamfered features that cushion assembly forces before they reach the toothed portions. This beforehand cushioning protects the precision toothed geometry from deformation during the blom stud insertion process.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Ease of manufacture

If traditional assembly methods are used, then assembly is simple, but shock resistance is poor

Engineering Contradiction:

Improveassembly simplicityVSAvoidshock resistance

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent incorporates shoulders, chamfers, and rounded edges in the carrier bow and heavy sector that provide beforehand cushioning against shock loads. These features are integrated into the simple blom stud assembly process, maintaining ease of manufacture while dramatically improving shock resistance.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The oscillating mass elements are made from materials with different properties (carrier bow from softer material, heavy sector from denser material) to create a composite structure. This composite approach maintains simple assembly while improving shock absorption and resistance.

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides improved shock resistance and maintains the geometry of the toothed bow, ensuring a reliable and smooth operation of the oscillating mass.

Implementation Method 1

the heavy sector is fastened to the carrier bow at several points via blom studs with an uneven surface to form a reservoir for holding glue

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

baking the oscillating mass in the oven to polymerise the glue

Methodology Applied

Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentUS20250348041A1Annular oscillating mass and timepiece comprising such an oscillating mass

Publication Date: 2025.11.13 MONTRES BREGUET SA

AI summary

An oscillating mass (1) for a self-winding timepiece including a carrier bow (2) including a first transmission part (20) provided with coaxial toothing (21) to drive the winding of the timepiece and a second supporting part (22), and including a heavy sector (3) or attached to the second supporting part of the carrier bow (2). The heavy sector (3) is attached to the carrier bow at several points via blom studs (4) with an uneven surface to form a reservoir for holding glue.