Two-Stage Switch Rubber Dome Thick Portion Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Two-stage switches used in applications like power window operation lack improved longevity and tactile feel, making them less effective for manual and auto modes.

Innovation Solution

The design incorporates a first and second rubber dome with a slider that deforms the domes, featuring a thick portion on the second rubber dome to enhance durability and tactile feedback, allowing for equal displacement and force requirements between the two stages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional two-stage switch with two rubber domes is used, then the switch can perform manual and auto mode operations, but the tactile feel for two-stage operation is poor and longevity is reduced

Engineering Contradiction:
ImprovelongevityVSAvoidtactile feel
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies local quality by creating a thick portion at a specific location on the second rubber dome (where the slider contacts it) while keeping other portions at normal thickness. This localized thickness increase enhances durability at the contact point without affecting the overall flexibility and tactile feedback of the dome structure, thereby resolving the contradiction between longevity and tactile feel.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the slider presses both rubber domes with equal force, then the structure is simple, but the displacement requirements for two-stage operation are unequal leading to poor tactile feel

Engineering Contradiction:
Improvetactile feelVSAvoidstructure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

By introducing a thick portion at the contact point on the second rubber dome, the patent creates a localized structural variation that allows the slider to press both domes with equal force while achieving equal displacement. The thick portion provides additional structural support that balances the mechanical properties, enabling equal force application without requiring complex adjustment mechanisms.

Inventive Principle:
Principle #3Local quality

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 configuration provides improved tactile feel and extended longevity by ensuring equal displacement and force requirements between the two stages, enhancing user experience and switch durability.

Implementation Method 1

when a pressing member is pressed, the rubber dome deforms toward the substrate, and the movable contact provided within the rubber dome contacts the both fixed contacts

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

A thick portion is formed on a first rubber dome side of the second rubber dome in a direction in which the first rubber dome and the second rubber dome are aligned. The thick portion is thicker than other portions of the second rubber dome.

Methodology Applied
Scientific EffectStructural reinforcement through increased thickness:

Data Source

PatentEP3734628B1Switch device
Publication Date: 2022.11.30 ALPS ALPINE CO LTD
  • EP3734628B1 patent drawingFigure 1
  • EP3734628B1 patent drawingFigure 2
  • EP3734628B1 patent drawingFigure 3A~3B

AI summary

A switch device includes a first rubber dome; a second rubber dome; and a slider disposed on an upper surface of the first rubber dome and an upper surface of the second rubber dome. The slider presses the upper surface of the first rubber dome, causing deformation of the first rubber dome in a case where the slider is moved toward the first rubber dome and the second rubber dome, and the slider presses the upper surface of the second rubber dome, causing deformation of the second rubber dome in a case where the slider is further moved toward the first rubber dome and the second rubber dome in a state in which the first rubber dome is subjected to the deformation. A thick portion is formed on a first rubber dome side of the second rubber dome. The thick portion is thicker than other portions of the second rubber dome.