Four-Way Selector Switch with Force Sensing and Mechanical Detents

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Solution Overview

Problem

Four-way stick-type selector switches in automotive applications face challenges in achieving long-term reliability for detecting switch position while providing haptic feedback due to small angular displacement and cantilevered structures.

Innovation Solution

A four-way selector switch design incorporating a pivotable lever with orthogonally mounted force sensors and a mechanical detent system, along with a processor to detect user input and generate control signals, providing independent mechanical haptic feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a cantilevered structure is used for the selector switch, then the switch can be compact and easy to integrate, but the reliability of detecting switch position deteriorates due to small angular displacement

Engineering Contradiction:

Improveswitch sizeVSAvoidswitch position detection reliability

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent replaces mechanical position detection mechanisms with a non-mechanical sensor system. Force sensors (such as strain gauges, inductive sensors, or piezoresistive sensors) are integrated into the base to detect lever position and orientation without relying on mechanical switches or contacts. This substitution eliminates the reliability issues associated with small angular displacement in cantilevered structures while maintaining compact dimensions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The force sensors serve multiple functions: they detect lever position, determine orientation (up/down/left/right), and can potentially measure force magnitude. This multi-functionality allows the compact cantilevered structure to maintain reliable detection across all four directions without requiring separate mechanical detection mechanisms for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Volume of moving object

If a cantilevered structure is used for the selector switch, then the switch can be compact, but the provision of haptic feedback becomes challenging

Engineering Contradiction:

Improveswitch sizeVSAvoidhaptic feedback provision

Core Design Contradiction:

Volume of moving objectVSEase of operation

Solution Approach 1:

The patent introduces a mechanical detent system as an intermediary between the lever and the base. This detent system includes a spring-loaded plunger that engages with detent plates positioned at each of the four positions. The detent mechanism provides mechanical haptic feedback (click sensation) to the user when the lever reaches a selected position, while the force sensors independently detect the position electronically. This intermediary mechanism resolves the conflict between compact size and haptic feedback provision.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If non-mechanical detection means are used, then the switch position detection reliability is improved, but the device complexity increases

Engineering Contradiction:

Improveswitch position detection reliabilityVSAvoidsensor and processor integration complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the detection and processing functions into a single integrated system. The force sensors are directly mounted on the base and connected to a processor that evaluates the sensor signals to determine lever position and orientation. This integration eliminates the need for separate mechanical linkages, switches, or contact systems, reducing overall device complexity despite the introduction of electronic components. The processor simply reads sensor outputs and generates appropriate control signals.

Inventive Principle:

Principle #5Merging (Combining)

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

Ensures reliable detection of switch position and effective haptic feedback, enhancing the switch's operational reliability and user experience.

Implementation Method 1

The force sensors can be digital strain gauges

Methodology Applied

Scientific EffectStrain gauge effect: Piezoresistive Effect

Implementation Method 2

The force sensors can, in certain embodiments, be inductive sensors

Methodology Applied

Scientific EffectInductive sensing: Electromagnetic Induction

Implementation Method 3

The force sensors can, in certain embodiments, be piezoresistive sensors

Methodology Applied

Scientific EffectPiezoresistive sensing: Piezoresistive Effect

Implementation Method 4

the mechanical detent system includes a spring-loaded plunger interacting with a detent plate

Methodology Applied

Scientific EffectSpring elasticity: Elasticity

Data Source

PatentUS20250315075A1Force sensing four-way selector switch with mechanical haptic feedback

Publication Date: 2025.10.09 KOSTAL OF AMERICA

AI summary

A four-way selector switch, suitable for various automotive applications, including mirror position switches, turn signal switches, wiper/washer switches, storing column tilt/position switches, and electronic gear selectors, have a lever pivotably mounted on a base, two force sensors oriented orthogonally to each other, a mechanical detent system, and a processor for evaluating user input to generate an appropriate control signal.