Vertical Uncoupling Device for Watch Movement Friction Reduction
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Solution Overview
Problem
Current automatic winding mechanisms in watch movements face issues with energy wastage due to friction in uncoupling devices, space constraints, and complex design, particularly in vertical uncoupling devices where friction torque is high and lubrication is required, and the control lever occupies valuable space.
Innovation Solution
A compact uncoupling device design where the coupling wheel is secured to a sliding arbour that rotates and slides in fixed bearings, allowing the return spring to apply force directly at the axis of rotation, reducing friction and height, and enabling easy manual uncoupling by overcoming the spring's axial thrust.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vertical uncoupling device with a control lever is used, then the uncoupling function is achieved, but the friction torque increases and lubrication is required
Solution Approach 1:
The patent removes the control lever and its associated groove from the coupling wheel, extracting the source of high friction torque. The uncoupling function is achieved through a simpler mechanism where the mobile coupling device is directly actuated without requiring a lever to overcome groove friction, thereby eliminating the harmful friction effect while maintaining reliability
Solution Approach 2:
Instead of using a lever that pushes against the groove of the coupling wheel (which creates high friction), the patent inverts the approach by having the mobile coupling device directly engage and disengage from the fixed coupling device through axial movement. This reverses the mechanism from lever-based force application to direct mechanical engagement, eliminating the friction problem
2Reliability
If a vertical uncoupling device with control lever is used, then the uncoupling function is achieved, but the space requirements increase
Solution Approach 1:
The patent extracts the control lever and its attachment mechanism from the design, removing the components that occupied valuable space next to the uncoupling device. The simplified direct-actuation mechanism requires significantly less space while maintaining the uncoupling function
Solution Approach 2:
The patent merges the control function directly into the mobile coupling device itself, eliminating the need for a separate control lever and its attachment structure. This consolidation reduces the overall space requirement while maintaining full functionality
3Device complexity
If a lateral uncoupling device is used, then the design complexity is reduced, but the lateral space requirement increases
Solution Approach 1:
The patent transitions from lateral uncoupling (horizontal movement) to vertical uncoupling (axial movement perpendicular to the movement plane). This dimensional change allows the uncoupling device to be compact in the lateral direction while providing sufficient space for the mobile coupling device to move axially, thus reducing lateral space requirements while maintaining manageable design complexity
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 reduces energy wastage, minimizes space requirements, and simplifies the watch movement by lowering the friction torque and eliminating the need for complex lubrication, while allowing for reliable manual uncoupling of the barrel.
Implementation Method 1
one of the coaxial wheels, called the coupling wheel, is mobile in the axial direction and is biased by a return spring, which tends to mesh the coupling elements
Implementation Method 2
the coupling wheel is secured to a sliding arbour, which is mounted so that it slides and rotates in fixed bearings
Data Source
AI summary
A vertical type uncoupling device, in particular in an automatic watch winding mechanism that includes an oscillating mass and a gear train connecting the oscillating mass to a barrel (9), wherein a gear train includes a direction reverser device (11, 12), a reduction gear (13, 14, 15, 16) and the uncoupling device (20). The uncoupling device includes two coaxial wheels (17, 7) that can be coupled in rotation in one direction owing to respective Breguet toothings (21, 22) arranged on the opposite flanks of the wheels. The coaxial wheel (17), which is mobile in the axial direction, is secured to a sliding arbour (18), which is mounted so as to rotate and slide in fixed bearings (24, 25). A return spring (26) includes an elastic strip that abuts against one end of the sliding arbour (18) to tend to engage and keep meshed the Breguet toothings. This design reduces friction and saves space. Other applications of this type of uncoupling device in a watch movement are described.