Balance Wheel Plastic Fixing to Protect the Staff Pivot
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Solution Overview
Problem
Existing horology devices face issues with excessive driving forces on balance staffs, particularly when the balance staff pivot dimensions are smaller than the balance staff body, leading to potential damage and inefficiency.
Innovation Solution
A horology device design where a first component with a plastically deformable portion is fixed to a second component using plastic deformation, allowing the balance wheel to be mounted with greater torque resistance and avoiding excessive axial forces on the balance staff pivot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the balance wheel plate is driven onto the balance staff using conventional pressing methods, then the balance wheel can be mounted on the balance staff, but excessive axial forces are applied to the balance staff pivot which is smaller in dimension than the balance staff body, potentially causing damage
Solution Approach 1:
The fixing mechanism is segmented into two distinct phases: first, the balance wheel plate is slipped onto the balance staff without applying excessive force; second, the protrusions on the plate are deformed plastically to create permanent fixation. This segmentation allows the mounting process to avoid excessive axial forces on the pivot while still achieving secure attachment.
Solution Approach 2:
The balance wheel plate is preliminarily positioned on the balance staff by slipping it on without excessive force, and only after proper positioning is achieved, the plastic deformation of the protrusions is performed to secure the connection. This preliminary positioning action prevents excessive forces from being applied to the pivot during the final fixation step.
2Ease of manufacture
If the balance wheel plate is driven onto the balance staff using conventional pressing methods, then the balance wheel can be mounted on the balance staff, but the geometric integrity of the balance staff and its pivot may be compromised
Solution Approach 1:
The fixation process is divided into two independent steps: first, the balance wheel plate is slipped onto the balance staff without applying excessive force that could compromise the pivot; second, the protrusions are deformed plastically to secure the connection. This segmentation protects the geometric integrity of the pivot while achieving secure mounting.
Solution Approach 2:
The protrusions on the balance wheel plate serve as an intermediary mechanism that transfers the fixation function away from the pivot area. By deforming these protrusions against the cylindrical surface of the balance staff, the secure connection is achieved without applying excessive forces to the vulnerable pivot, thus preserving geometric integrity.
3Device complexity
If the balance wheel plate jackets the balance staff over practically the entirety of the height, then the geometry of the balance staff is simplified, but the forces induced by driving on the plate could prove excessive for the balance staff pivot
Solution Approach 1:
The fixation mechanism is segmented so that the balance wheel plate can indeed jacket the balance staff for simplified geometry, but the actual fixation is achieved through localized plastic deformation of protrusions rather than through axial pressing forces. This allows the simplified geometric design to be maintained while avoiding excessive forces on the pivot.
Solution Approach 2:
The conventional mechanical pressing system that applies axial forces along the length of the balance staff is replaced with a localized plastic deformation system. The protrusions are deformed against the cylindrical surface of the staff, substituting the axial force mechanism with a radial deformation mechanism that does not compromise the pivot.
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
This design enhances torque resistance and prevents shifting of the balance wheel, ensuring stable operation and reducing the risk of damage to the balance staff, while maintaining the geometric integrity of the components.
Implementation Method 1
The first component is fixed permanently to the second component by plastic deformation of the at least one portion against the second component
Data Source
AI summary
A horology device that includes a first component having at least one plastically deformable portion, and a second component provided with a surface, notably a surface of revolution and/or of guidance and/or of attachment of the first component relative to the second component, the first component being fixed permanently to the second component by plastic deformation of the at least one portion against the second component, in a plane perpendicular or substantially perpendicular to an axis of said surface of the second component.