Key Structure Rocker Mechanism for Wear Reduction

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Solution Overview

Problem

The key cap in electronic apparatuses, such as smartphones, experiences excessive wear and potential sticking due to tilting and shaking when pressed with uneven force, leading to a widened gap between the key cap and housing, causing functional failure.

Innovation Solution

A key structure incorporating a rocker with a length greater than a predetermined value, where the rocker's first end is fixed to the key cap and the second end is hinged to the housing, allowing the key cap and rocker to rotate as a whole, minimizing tilting and friction, and optionally featuring a rotation shaft and mounting hole configuration for assembly stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the key cap is pressed with uneven force, then the key cap can be activated, but the key cap tilts and shakes causing excessive wear

Engineering Contradiction:
Improvekey cap activationVSAvoidkey cap wear resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces a rocker mechanism that transforms the static key cap structure into a dynamic system. The rocker allows the key cap to rotate and pivot during pressing, accommodating uneven force application while maintaining stable contact with the housing through controlled movement rather than uncontrolled tilting and shaking.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rocker serves as an intermediary element between the key cap and the housing. It mediates the interaction by providing a hinge connection that allows controlled rotation, thereby preventing direct harmful contact between the key cap and housing side walls while still enabling effective force transmission to activate the switch.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the key cap tilts and shakes frequently, then activation is possible, but the gap between key cap and housing enlarges causing sticking

Engineering Contradiction:
Improvekey cap activationVSAvoidgap maintenance
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The rocker mechanism provides controlled dynamic movement that replaces uncontrolled tilting and shaking. By hinging the key cap to the housing through the rocker, the system allows necessary activation movement while maintaining stable gap dimensions through the constrained rotation path, preventing the key cap from sinking or getting stuck.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the rocker length is increased, then tilting and friction are reduced, but device complexity increases

Engineering Contradiction:
Improvekey cap stabilityVSAvoidrocker assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the key structure into distinct functional components: the key cap, the rocker, and the housing with separate mounting elements. This segmentation allows the rocker to be optimized independently for its stabilizing function with appropriate length and hinge positioning, while the overall assembly remains modular and manageable in complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rocker serves multiple functions simultaneously: it acts as a hinge connection, provides structural support, controls the movement trajectory of the key cap, and maintains stable gaps with the housing. By consolidating these functions into a single component, the design achieves high reliability without proportionally increasing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 prevents key cap tilting and wear, maintaining the gap between the key cap and housing, ensuring normal operation by controlling the key cap's movement track and reducing assembly complexity.

Implementation Method 1

the rocker has a first end fixed to the key cap and a second end hinged to the housing, the key cap and the rocker being able to pivot and activate the electronic switch

Methodology Applied
Scientific EffectRotation:

Data Source

PatentEP3477674B1Key structure and electronic apparatus
Publication Date: 2023.06.28 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3477674B1 patent drawingFigure 1
  • EP3477674B1 patent drawingFigure 2
  • EP3477674B1 patent drawingFigure 3

AI summary

The present disclosure relates to a key structure and an electronic apparatus. The key structure includes a housing (1), an electronic switch (2), a key cap (3) and a rocker (4). The housing (1) is provided with an opening (11) configured to mount the key cap (3), the electronic switch (2) is located inside the housing (1) and corresponds to a position of the opening (11), and the key cap (3) is mounted in the opening (11). The rocker (4) has a first end fixed to the key cap (3) and a second end hinged to the housing (1). The rocker (4) has a length larger than or equal to a first predetermined value.