Spectacle Hinge With Elastic Pad And Notch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional spectacle temple hinges experience decreasing friction and screw loosening over time due to wear, leading to unstable branch movement and increased risk of disassembly, affecting the quality and usability of eyeglasses.
Innovation Solution
A hinge design featuring a knuckle with a convex edge and a notch, combined with an elastic pad and spring mechanism that maintains friction and radial tension on the screw, ensuring consistent branch movement and preventing unscrewing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hinges use a simple knuckle-mortise-screw structure, then the device complexity is low, but the friction decreases gradually due to wear, causing screw loosening and branch disassembly
Solution Approach 1:
The hinge is divided into distinct functional components: a knuckle with convex edge, a pad with bearing wall, elastic means (spring), and a notch mechanism. Each component serves a specific function - the convex edge provides a bearing surface, the pad creates friction through the bearing wall, the elastic means maintains constant pressure, and the notch prevents disengagement. This segmentation allows each part to be optimized for its specific function while working together to solve the friction stability problem.
Solution Approach 2:
The elastic means (spring) is pre-loaded to exert a constant urging force on the pad, ensuring that the bearing wall maintains continuous contact with the convex edge throughout the hinge's operation. This preliminary action compensates for wear over time, as the spring's elastic deformation adjusts to maintain the required friction force, preventing screw loosening and branch disassembly.
2Reliability
If the bearing wall extends over a large arc, then the friction control is improved, but the angular size of the pad increases, affecting the folding position
Solution Approach 1:
The bearing wall is designed with specific local geometric properties - it extends over an arc that is at least a quarter of the arc along which the convex edge extends, but not the entire arc. This local quality ensures sufficient friction control through the bearing surface while limiting the pad's angular size to allow proper folding of the branch along the frame. The convex edge's curvature matches the bearing wall, optimizing contact in the critical friction zone.
Solution Approach 2:
The bearing wall extends over a partial arc (at least one quarter of the total convex edge arc) rather than the full arc. This partial action provides sufficient friction control through the bearing surface while avoiding excessive pad angular size that would interfere with the folding position. The notch further refines this by providing a housing for the pad in the folding position, allowing the branch to fold despite the pad's angular dimensions.
3Reliability
If the screw is tightly secured to maintain friction, then the friction stability is improved, but the risk of screw loosening due to wear increases
Solution Approach 1:
The elastic means (spring) creates a self-adjusting friction mechanism. As the knuckle and mortise wear over time, the spring's elastic deformation increases slightly, automatically compensating for the wear and maintaining constant friction force. This self-service mechanism eliminates the need for periodic manual tightening of the screw, as the system automatically maintains the required friction to prevent branch disassembly.
Solution Approach 2:
The friction force is maintained through changes in the elastic deformation of the spring rather than through constant screw tightness. As wear occurs, the spring's compression or tension adjusts to maintain the required contact force between the bearing wall and convex edge. This parameter change approach transforms the friction maintenance from a static (screw tightness) to a dynamic (elastic deformation) system that adapts to wear.
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 design maintains controlled branch movement and prevents screw loosening throughout the eyeglasses' lifespan, enhancing user experience and reducing the risk of disassembly.
Implementation Method 1
This friction has the disadvantage of decreasing gradually as the pair of glasses is used, due to wear of the surfaces in contact
Implementation Method 2
the hinge comprises elastic means urging the slider towards said edge
Implementation Method 3
The shoe, pressed against the knuckle, also makes it possible to create a radial tension on the screw, which turns out to favorably oppose the unscrewing of this screw
Data Source
Figure 1~3
Figure 4~7
Figure 8
AI summary
According to the invention, - the knuckle (3) that this hinge comprises has a convex edge (3b) in the form of an arc of a circle which forms a notch (8) on the internal side of the knuckle (3); - the hinge (1) comprises a shoe (5) intended to bear against said edge (3b), forming a wall (5b) for bearing against this edge (3b), extending over an arc representing at least one quarter of the arc along which the edge (3b) extends; - the hinge (1) comprises an elastic means (6) that urges the shoe (5) towards said edge (3b), such that said bearing wall (5b) is pressed against this edge, - said notch (8) is dimensioned so as to partially accommodate the shoe (5) in the folded position of the temple (2) along the frame.