Bi-material Shockproof Bearing for Timepiece Arbour
Solution Overview
Problem
Existing shock-absorbing bearings for timepieces are not shock-resistant due to increased Young's modulus of plastic materials during impacts, leading to local plastic deformation and malfunction.
Innovation Solution
A shock-absorbing bearing system using a metallic pivoting means with a recess for a synthetic insert, where the pivoting means and insert are designed to maintain constant damping and friction characteristics, with the pivoting means comprising a metallic material and the insert made of a polymer such as polyoxymethylene or polyamide, allowing the pivot to spin freely and reducing friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If plastic material is used for the pivot system to enable shock absorption through deformation, then shock absorption capability is improved, but shock resistance deteriorates due to increased Young's modulus during impact causing local plastic deformation
Solution Approach 1:
The invention uses a bi-material system combining a metallic pivot module (providing shock resistance and structural integrity) with a plastic insert (providing shock absorption through controlled deformation). This composite structure allows the metal to resist shock forces while the plastic absorbs energy, resolving the contradiction between shock absorption capability and shock resistance.
Solution Approach 2:
The invention applies different material properties to different parts of the pivot system: the metallic pivot module provides rigid shock-resistant structure, while the plastic insert provides compliant shock-absorbing contact surfaces. This local differentiation of material quality allows simultaneous achievement of shock absorption and shock resistance.
2Ease of manufacture
If plastic material is used for the pivot system, then manufacturing ease is improved through injection molding, but friction increases leading to malfunction
Solution Approach 1:
The metallic pivot module maintains structural integrity and lower friction characteristics, while the plastic insert provides ease of manufacture through injection molding. The metal-plastic composite structure combines the manufacturing advantages of plastic with the low-friction properties of metal.
Solution Approach 2:
The plastic insert acts as an intermediary between the metal pivot and the housing, providing a self-lubricating interface that reduces friction while maintaining the structural benefits of metal. The insert mediates the interaction between metal components and plastic housing.
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 system provides reliable and consistent shock absorption by maintaining stable resistance and reducing friction, preventing deformation and malfunction, and eliminating the need for additional lubrication.
Implementation Method 1
elastic means arranged to allow said pivot module to be mounted suspended and to exert on said pivot module at least one axial force
Implementation Method 2
the pivoting means and insert are designed to maintain constant damping and friction characteristics
Implementation Method 3
maintain constant damping and friction characteristics
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A shock absorber bearing for an arbor of a timepiece wheel. The arbor includes a pivot-shank, the bearing includes a support including a housing arranged to receive a suspended pivot mechanism, and the pivot mechanism is arranged to absorb, at least in part, any shocks experienced by the timepiece wheel.