Clockwork Module Positioning via Archimedean Spiral Cam
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Solution Overview
Problem
The existing methods for positioning a module in a watch movement, such as the escapement holder, face challenges due to manufacturing tolerances, leading to variable center distances between mobile components, which affects the precision and efficiency of the gear train and escapement operation.
Innovation Solution
The use of an eccentric with an Archimedean spiral profile allows for adjustable center distance positioning between the module and the base, enabling precise alignment by rotating the eccentric around its geometric center, thereby optimizing the meshing of the mobile components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the module is positioned by simple vertical translation using feet and holes in the base, then the manufacturing process is simple, but the center distance between the first and second mobiles varies significantly due to manufacturing tolerances
Solution Approach 1:
The patent applies preliminary action by pre-positioning the first mobile (escapement pinion) relative to the second mobile (wheel 14) using a temporary support structure during assembly. This allows the center distance to be predetermined and maintained before final fixation, compensating for manufacturing tolerances in the feet and holes. The support structure holds the module in the correct position relative to the base, ensuring precise meshing between the mobiles.
2Strength
If the module is fixed by screws after positioning, then the module is securely attached to the base, but the center distance variation due to tolerances cannot be corrected
Solution Approach 1:
The patent performs preliminary positioning and adjustment of the module before final screw fixation. A temporary support structure is used to hold the module in the correct position, allowing the center distance to be optimized for proper meshing between the escapement pinion and wheel 14. Only after this preliminary positioning is complete are the fixation screws applied, thereby preserving the precisely adjusted center distance.
3Measurement precision
If the escapement holder is rotated to make parts bear against each other, then positioning is improved, but the center distance between escape pinion and wheel remains uncontrolled due to assembly tolerances
Solution Approach 1:
The patent introduces a temporary support structure as an intermediary element between the module and the base during assembly. This support structure mediates the positioning process by maintaining a predetermined center distance between the first and second mobiles, allowing precise meshing to be achieved despite tolerances in the escapement holder rotation and bearing surfaces.
Data Source
AI summary
The clockwork (30) has a module (36) fitted with a wheel set (18) meshed with another wheel set, which is pivoted on a base. A positioning unit positions the module on the base, and is formed by a cam (40) whose periphery (42) forms an Archimedes spiral or an optimized Archimedes spiral. The cam adjusts distance (L) of centers between the wheel sets to be adjusted when the cam is rotated about center of the Archimedes spiral. The module is designed as a platform escapement. The wheel sets are designed as an escape pinion and a gear train wheel, respectively. An independent claim is also included for a method for adjusting distance of centers between two clockwork wheel sets.