Clockwork Clutch Rocker With Integrated Friction Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing unidirectional coupling devices in watch movements suffer from reliability issues, robustness concerns, bulkiness, and complex assembly methods, with variable pivoting torque and axial/radial play that affect their functionality.
Innovation Solution
A clutch device with a rocker that integrates a friction element and elastic arms to control the pivoting torque and guidance of the driving wheel, using a single-piece rocker with friction surfaces and elastic elements to ensure stable engagement and disengagement based on rotation direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a sliding pinion is used in a curved oblong cutout for unidirectional coupling, then the number of components is reduced, but the axial and radial play becomes difficult to control and pivoting torque becomes variable
Solution Approach 1:
The patent merges the rocker body and friction spring into a single integrated component. The friction spring is formed as an integral part of the rocker, eliminating the need for separate assembly and ensuring consistent friction characteristics. This integration resolves the contradiction by maintaining simple device structure while achieving reliable and consistent pivoting torque control through the built-in friction element.
2Reliability
If a friction spring is added to the sliding pinion to generate sufficient torque, then the pinion can move by torque effect, but the device becomes bulky and cannot be assembled independently
Solution Approach 1:
The friction spring is integrated directly into the rocker body as a single-piece component. The rocker includes a friction element that contacts the driving wheel, and an elastic arm that applies friction force. This integration allows the complete unidirectional coupling mechanism to be assembled as one independent unit, resolving the contradiction between reliable torque generation and assembly independence.
3Ease of manufacture
If conventional assembly means are used for the clutch lever, then the structure is simple, but friction cannot be adequately controlled and pivoting torques become variable
Solution Approach 1:
The friction spring is formed as an integral part of the rocker body through a single manufacturing process. The rocker includes a friction element and elastic arm that are seamlessly combined, eliminating the need for separate assembly steps while ensuring consistent friction characteristics. This resolves the contradiction by achieving both manufacturing simplicity and reliable friction control.
4Reliability
If a friction shim is placed at the pivot axis to hold the corrector against the rocker, then adequate friction is guaranteed, but the assembly becomes less robust due to manufacturing and assembly tolerances
Solution Approach 1:
The friction spring is integrated into the rocker body as a single component, eliminating the need for separate friction shims and their associated assembly tolerances. The elastic arm of the rocker directly applies friction force to the driving wheel, ensuring consistent friction characteristics without sensitivity to assembly tolerances. This resolves the contradiction by achieving reliable friction guarantee while improving robustness against manufacturing variations.
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
The solution provides a simple, reliable, and robust unidirectional coupling mechanism with controlled pivoting torque, enabling precise operation of correction mechanisms in watches, independent of assembly tolerances and reducing the device's size.
Implementation Method 1
at least one friction element (62) intended to apply a friction force to the first mobile (1)
Implementation Method 2
at least one elastic arm (6a, 6b) intended to elastically return said at least one friction element (62) into engagement with the first mobile (1)
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The lever (6) has a guiding element for guiding rotation of a wheel (1). A friction element is attached with a cylindrical portion of the wheel. A resilient element resiliently fixes the friction element in co-operation state with the portion of the wheel. The friction element applies radial force on the portion of the wheel. Another guiding element guides rotation of the lever around another wheel (2). An opening receives the former wheel. The friction element is arranged on a flank or on a flank portion of a slot.