Spectacle Hinge Anti-Seizing Sleeve and Friction Ring
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Solution Overview
Problem
Existing hinge devices for spectacle frames face issues such as screw slackening due to cyclic rotation, seizing between hinge elements, and loss of frictional effect over time, leading to jamming and increased play in the coupling.
Innovation Solution
A hinge device featuring fork-shaped hinge elements with anti-seizing sleeves made of a softer material and an elastically flexible friction ring that compensates for wear, maintaining frictional resistance by deforming to apply pressure between the elements, preventing unscrewing and jamming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If screws or threaded pins are used to form hinge pins for pivotable connection, then the sides can be pivotally connected to the frames, but the screws may spontaneously unscrew due to cyclic rotation, requiring periodic tightening
Solution Approach 1:
A nylon insert is introduced as an intermediary component between the screw and the hinge elements. The nylon insert has a self-locking mechanism with ribs that engage with the screw threads, preventing the screw from unscrewing during cyclic rotation. This mediator absorbs the harmful unscrewing motion while maintaining the pivotal connection stability.
Solution Approach 2:
The hinge device combines different materials with complementary properties: metal screw for strength, nylon insert for self-locking and friction resistance, and metal hinge elements for structural integrity. This composite material approach allows each component to address specific problems - the nylon prevents screw backout while the metal parts provide mechanical strength.
2Ease of manufacture
If the hinge elements are made of the same material for simplicity, then manufacturing is easier, but the continual sliding contact causes seizing after a certain number of rotation cycles
Solution Approach 1:
Different materials are used for the male and female hinge elements. Specifically, the male element and female element are made from different metal alloys or heat treatments, creating local quality differences. This material differentiation reduces galling and seizing during sliding contact while maintaining manufacturing feasibility through standard metallurgical processes.
3Reliability
If the hinge elements are designed for initial frictional resistance, then rotation is controlled initially, but the frictional effect is lost over time due to increased play in the coupling
Solution Approach 1:
The nylon insert is pre-configured with a friction surface that compensates for future wear. As the hinge elements wear and play increases over time, the nylon insert maintains constant frictional resistance through its self-locking rib mechanism, which continuously engages with the screw threads. This beforehand cushioning ensures that rotation control is maintained throughout the product lifecycle.
Solution Approach 2:
The friction characteristics of the nylon insert change adaptively over time. The self-locking ribs are designed to maintain optimal engagement pressure despite wear in the hinge elements. As play increases, the nylon insert's friction surface adjusts its effective contact area and pressure distribution to maintain consistent rotational resistance, effectively changing friction parameters to compensate for 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 solution effectively prevents screw slackening and jamming while maintaining initial frictional resistance over time, ensuring smooth and durable pivoting of spectacle sides.
Implementation Method 1
an elastically flexible friction ring that compensates for wear, maintaining frictional resistance by deforming to apply pressure between the elements
Implementation Method 2
anti-seizing sleeves made of a softer material
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
What is described is a hinge device for connecting the sides (2) to the fronts of spectacle frames (4), comprising a first and a second hinge element (6, 7) pivoting about a hinge axis (X), the first element (6) comprising a substantially fork-shaped body (8) with a first and a second arm (9, 10) opposed to one another, between which the second hinge element (7) is interposed, and a screw means (16) forming a hinge pin, passing through respective holes formed coaxially in the first and the second hinge element (6, 7), so as to be, respectively, locked by a screw engagement in the first hinge element (6) and housed rotatably in the second hinge element (7). The device further comprises at least a first anti-seizing sleeve (18) provided in the hole (13) of the second hinge element (7) and capable of being engaged by the hinge screw (16) in a rotatable coupling, the sleeve (18) comprising at least a first surface (20) extending in a contact area and capable of relative sliding between the hinge elements (6, 7), at least one ring (22) of elastically flexible material, fitted on the hinge screw (16) and capable of being deformed elastically as a result of the tightening of the screw so as to exert a relative pressure between the first and the second hinge element (6, 7), thereby increasing the friction provided between the hinge elements, and at least one bush (23) mounted in a seat of the first hinge element (6), coaxially with the hinge screw (16), and capable of accommodating the ring (22), the bush (23) including at one of its axial ends a bearing shoulder (24) for the ring (22), and being capable of making contact with the first surface of the anti-seizing sleeve (18), so that the bush (23) is biased axially against the sleeve (18) by the elastic action generated by the friction ring (22) as a result of the tightening of the hinge screw (16).