Removable Chronograph Wheel Clamp for Wear-Free Assembly
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Solution Overview
Problem
The assembly and dismantling of removable wheels in horological movements are difficult due to premature wear, buckling, and flexion of parts, requiring specific tools and skills, and the resizing of components, which complicates maintenance and repair.
Innovation Solution
A chronograph module with a removable wheel that uses elastic arms forming a clamp to grip the primary shaft, allowing easy assembly and dismantling without specialized tools, facilitated by an overlapping design that avoids hafting and enables precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a hub is used to press the removable wheel onto the shaft, then the wheel can be securely fastened, but the shaft and wheel undergo buckling or flexion causing premature wear and operational failure
Solution Approach 1:
The invention divides the fastening function into multiple independent elements: the hub is segmented into a hub body and a separate pressing element, allowing the pressing force to be applied through a dedicated mechanism rather than direct pressing, thus avoiding buckling and flexion of the shaft and wheel while still achieving secure fastening
Solution Approach 2:
The invention introduces an intermediary pressing element that transfers the fastening force from the hub to the wheel without direct contact between the hub and wheel. This intermediary mechanism distributes the force evenly and prevents concentration of stress that would cause buckling or flexion, thereby maintaining reliability while achieving secure fastening
2Strength
If a thick hub is used to withstand pressing and support the wheel, then the wheel can be securely mounted, but the wheel requires resizing during fitting and dismantling is difficult requiring driving out the hub
Solution Approach 1:
The hub is segmented into a hub body and a separate pressing element that can be independently removed. This allows the wheel to be mounted securely during operation while enabling easy dismantling by simply removing the pressing element without needing to drive out the entire hub or perform resizing operations
Solution Approach 2:
The pressing element is designed to be dynamically removable and repositionable, transforming the static, permanent hub structure into a dynamic system where the pressing component can be easily added or removed. This allows the wheel to be securely mounted during operation while facilitating easy dismantling and refitting without specialized tools or operations
3Strength
If the shaft is kept in bearing-blocks at each end, then the shaft is securely supported, but the shaft cannot be fitted with the removable wheel already fastened and the bearing-blocks cannot be added subsequently
Solution Approach 1:
The fastening system is segmented into the shaft, the wheel, and a separate pressing element. This segmentation allows the shaft to be first securely supported in the bearing-blocks, then the wheel to be positioned on the shaft, and finally the pressing element to be added to complete the fastening. This eliminates the constraint that would otherwise require the wheel to be pre-fastened before shaft installation
Solution Approach 2:
The shaft is first installed and securely supported in the bearing-blocks before the wheel is added. The pressing element is then applied as a preliminary action to fasten the wheel to the shaft in its final position. This sequence of preliminary actions allows proper support establishment while enabling subsequent wheel installation without requiring complex disassembly or reconfiguration
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
Facilitates the assembly and dismantling of the removable wheel, preventing defects and reducing maintenance time, while ensuring secure fitting and easy access for repairs.
Implementation Method 1
a first and a second elastic arm forming a clamp configured to grip the primary shaft
Data Source
AI summary
A chronograph module (1) including a plate, a primary shaft (3), and a primary disk (4) extending on an orthogonal plane to a longitudinal axis of the shaft. The primary shaft is fitted on the plate, such that the primary disk is engaged with a geartrain of the chronograph module. A removable wheel (2) is fitted on the primary shaft (3), and includes a peripheral gear structure and first (22) and second elastic arms (23) forming a clamp (30) to grip the primary shaft. A radial support surface (25) supports the elastic arms to assemble the removable wheel on the primary shaft. The arrangement and dimensions of the removable wheel produces an overlap of the removable wheel and an overlapping part of the module, such that the assembly of the overlapping part required the absence of the removable wheel whereas the primary shaft is fitted on the chronograph module.