Mechanical Reverser for Watch Winding with Elastic Clutch
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Solution Overview
Problem
Existing automatic winding devices for mechanical watches and small portable electronic devices are bulky, require many parts, and have high frictional forces in the free direction at high speed, making them inefficient and costly to produce.
Innovation Solution
A simplified inverter mechanism with a reduced number of parts, featuring a drive wheel and a driven wheel with a clutch device made of elastic material, utilizing a curved locking arm and spring mechanism to couple and uncouple the wheels based on the direction of rotation, allowing for efficient one-way or two-way operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional cam or lever-pawl mechanisms are used for automatic winding, then the winding function is achieved, but the device becomes bulky and requires many parts
Solution Approach 1:
The patent combines the driving wheel and driven wheel into a single integrated component with a cup-shaped structure housing the clutch device. The locking arm is integrated with the driving wheel, and the spring is embedded within the cup structure. This merging of multiple functional elements into fewer components directly reduces the number of parts while maintaining the automatic winding function.
Solution Approach 2:
The clutch device is nested within the cup-shaped structure of the driven wheel. The locking arm pivots within the cup, and the spring is housed inside the same cup structure. This nested arrangement allows multiple components to occupy the same spatial envelope, reducing the overall device footprint and part count while preserving the winding mechanism's functionality.
2Reliability
If traditional roller mechanisms or arms/pawls are used, then the winding mechanism functions, but frictional forces are high at high speed
Solution Approach 1:
The locking arm dynamically transitions between engaged and disengaged states based on the direction of rotation. During the free direction, the locking arm pivots to disengage from the cup wall, eliminating frictional contact. During the driving direction, the locking arm engages with the cup wall to transmit torque. This dynamic state change reduces energy loss from friction during the free rotation phase.
Solution Approach 2:
The invention changes the contact parameter between the locking arm and cup wall from continuous contact to intermittent contact. By modifying the engagement state based on rotation direction, the friction parameter varies: high friction during engagement (driving phase) and zero friction during disengagement (free phase). This parameter change reduces overall energy loss, particularly at high speeds where the disengagement phase occurs frequently.
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 reduces bulkiness and production costs while maintaining or exceeding the performance of prior art devices, with improved efficiency and reduced frictional forces, enabling effective automatic winding and energy supply for small devices.
Implementation Method 1
a spring integral with said arm
Data Source
Figure 1~3
Figure 4~5
Figure 6~9
AI summary
The mechanism comprises, mounted for free rotation on an axis 6, a driving wheel (5) driven by an oscillating drive pinion (3) and a driven wheel (7) meshing with the first moving part (1) of a kinematic chain and having a cup (11) to house a clutch device (10) comprising at least one curved locking arm (12), one end (14) of which has a pivot point (14a, 14b) on the driving wheel (5) and the other end (16) of which has a fulcrum (16a) against the inner wall (2) of the cup (11) of the driven wheel (7) under the action of a spring (20) formed from the material of said arm (12). The pivot point (14b) preferably moves along a cam (21). Application to automatic winding by oscillating weight.