Espagnolette Fitting Transmission Gearing Compact Design
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Solution Overview
Problem
Existing window and door locking mechanisms, such as espagnolette fittings, require a large installation space due to the complex arrangement of components, which limits their compactness and efficiency in translating rotary motion into linear motion.
Innovation Solution
A step-up gear design with a drive pinion and a gear system where the slide is guided on the connecting rod, allowing for two distinct gear ratios and a variable translation mechanism, enabling smooth locking and efficient movement by adjusting the guide of the crank pin across different sections of the connecting link, thereby optimizing space usage and reducing frictional resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a complex arrangement of components is used in the locking mechanism, then the transmission ratio and movement efficiency are improved, but the installation space increases
Solution Approach 1:
The patent combines the drive pinion and the gear into a single integrated component, eliminating the need for separate mounting brackets and reducing the overall installation space while maintaining the transmission ratio and movement efficiency
Solution Approach 2:
The slide is positioned within the recess of the housing, nesting components within each other to minimize the external dimensions and installation footprint of the locking mechanism
2Adaptability or versatility
If a crank mechanism with levers is used, then the transmission ratio varies with lever position, but the device complexity and space requirements increase
Solution Approach 1:
The patent extracts the essential function of variable transmission ratio from the complex crank mechanism and implements it through a simpler arrangement where the slide's position in the recess provides the necessary movement variation without requiring multiple levers and articulation points
Solution Approach 2:
Instead of using a crank mechanism that converts rotary motion to linear motion through complex lever articulation, the patent inverts the approach by using a guided slide that directly translates rotary motion along a predetermined path within the recess, achieving variable transmission through geometry rather than mechanism 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 achieves a compact and stable transmission gear with adjustable path settings, allowing for high transmission ratios when needed and low frictional resistance, enhancing the overall efficiency and smoothness of the locking mechanism.
Implementation Method 1
a gear (12) coupled to the nut (11) for driving a connecting rod (7), wherein the gear (12) is arranged between a slide (14) and the connecting rod (7) and has a transmission ratio not equal to 1:1
Implementation Method 2
the slide (14) is guided on the connecting rod (7)... reducing frictional resistance
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
A transmission mechanism (9) for a window connecting rod fitting (3) has two devices arranged one behind the other for driving a connecting rod (7), each with a transmission ratio other than 1:1. One device has a toggle lever (17) guided in a cam (21). The other device has a slide (14) driven by a drive pinion (13). This allows a large transmission ratio to be achieved with small dimensions of the transmission mechanism (9).