Watch Stud Holder Screw Fixing Torsional Breakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing stud holder designs in high-end watch mechanisms are prone to breakage due to torsional forces when the screw head is blocked, leading to regular failures during assembly and adjustment of the hairspring.
Innovation Solution
A modified stud holder assembly where the screw passes through the eyebolt and cooperates with a thread on the stud, allowing elastic deformation between the screw head and threads, reducing torsional stress and enabling traction instead of torsion, with adjustable features for precise alignment and height adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the screw head is blocked on the eyebolt during assembly, then the fixing force is increased, but the screw is subjected to torsional forces that lead to regular breakage
Solution Approach 1:
The patent inverts the traditional screw fixing approach by making the eyebolt (stud) threaded instead of the stud holder. This allows the screw to engage with the eyebolt's threads rather than having the eyebolt engage with the stud holder's threads, fundamentally changing the load path and eliminating the blocking issue that caused torsional breakage
Solution Approach 2:
The patent changes the threading parameter from the stud holder to the eyebolt. The eyebolt now comprises a thread that cooperates with the screw, while the stud holder has a smooth bore without threads. This parameter change redistributes the mechanical stresses and allows the screw to work in traction rather than torsion
2Reliability
If the screw works between its foot and threads in a blocked configuration, then the fixing is secure, but the head cannot rotate freely causing regular breakage
Solution Approach 1:
The patent inverts which component contains the threads - the eyebolt now has the thread instead of the stud holder. This allows the screw to rotate freely within the smooth bore of the stud holder while engaging the threads on the eyebolt, separating the rotation function from the blocking function
Solution Approach 2:
The patent segments the functions of threading and blocking into separate components: the eyebolt provides the threading function for screw engagement, while the stud holder provides the blocking function through its smooth bore geometry. This segmentation allows each component to optimize its specific function without compromising the other
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 significantly reduces the risk of screw breakage, ensures precise adjustment and maintenance, and allows integration into high-end watch movements with improved reliability and interchangeability.
Implementation Method 1
the screw works normally, by elastic deformation, between its head and its threads
Data Source
Figure 1~6
Figure 7~10
AI summary
Assembly (20) for retaining or supporting a clockwork spiral spring (21), comprising a stud (1) and a stud holder (2), which stud holder (2) comprises: - a first housing (3) for receiving said stud (1); - means for fixing said stud (1) comprising at least one screw (5); - and means for fixing said stud holder (2) to an escapement mechanism (30), said stud (1) comprising at least one orientation surface (7) defining a direction for retaining or supporting said spiral spring (21). Said at least one screw (5) passes, at least partially, through said stud (1) for maintaining it in the indexed and locking position.