Dual-Spring Joystick Return Mechanism for Compact Haptic Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing joystick devices with haptic feedback mechanisms often result in increased height and design constraints due to the need for multiple springs and housing interactions, limiting their compactness and flexibility.

Innovation Solution

A joystick device utilizing dual coil springs with a unique arrangement where one spring provides initial return force and another spring engages at a triggering position, allowing for a stepwise increase in haptic feedback without increasing height, and enabling flexible housing designs by eliminating the need for housing contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple springs are used to provide haptic feedback with stepwise increase, then the haptic feedback accuracy is improved, but the device height increases

Engineering Contradiction:
Improvehaptic feedback accuracyVSAvoiddevice height
Core Design Contradiction:
Measurement precisionVSLength of moving object

Solution Approach 1:

The patent implements a nested spring arrangement where the first spring and second spring are positioned concentrically around the lever shaft. The first spring is attached between the first spring seat and second spring seat, while the second spring is attached between the second spring seat and third spring seat. This nesting configuration allows multiple springs to occupy the same radial space, providing stepwise haptic feedback without increasing the axial height of the device.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Measurement precision

If multiple springs and spring seats are arranged along the lever, then the haptic feedback mechanism is improved, but the housing and spring seat design constraints increase

Engineering Contradiction:
Improvehaptic feedback mechanismVSAvoidhousing and spring seat design constraints
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the haptic feedback mechanism into segmented functional zones along the lever's rotational path. The first spring engages during initial tilt angles (first angular range), while the second spring engages at larger tilt angles (second angular range). This segmentation allows each spring to be optimized for its specific engagement zone, reducing overall design constraints while maintaining precise haptic control throughout the lever's range of motion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring seats are pre-positioned at specific locations along the lever to enable automatic engagement of the appropriate spring at predetermined tilt angles. The second spring seat is positioned such that the second spring becomes active only after the lever reaches a specific angular position, providing preliminary configuration that simplifies the housing design by eliminating the need for complex activation mechanisms.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If a single spring provides return force, then the device structure is simplified, but the fail-safe capability is reduced

Engineering Contradiction:
Improvedevice structureVSAvoidfail-safe capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a fail-safe mechanism by providing two independent springs that can compensate for each other. If one spring fails or loses effectiveness, the second spring continues to provide the necessary return force to ensure the lever returns to its neutral position. This redundancy is built into the structure beforehand, ensuring continuous operational safety without requiring complex monitoring or backup systems.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 dual spring design provides a compact, fail-safe mechanism with adjustable triggering positions, enhancing haptic feedback accuracy and maintaining device safety with reduced height, while ensuring continued operation even if one spring fails.

Implementation Method 1

a first spring extending along the lever between the first spring seat and the second spring seat and configured to be subjected to compression and urge the lever to the initial position as the second spring seat moves toward the first spring seat

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a second spring separate from the first spring and extending along the lever, wherein the second spring is disposed between the first spring seat and the second spring seat and configured to be subjected to compression and urge the lever to the initial position as the second spring seat moves toward the first spring seat

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4109205A1Joystick device with haptic feedback
Publication Date: 2022.12.28 APEM
  • EP4109205A1 patent drawingFigure 1
  • EP4109205A1 patent drawingFigure 2
  • EP4109205A1 patent drawingFigure 3

AI summary

A joystick device 10 disclosed herein provides a return function for urging a lever 20 to its initial position. The device includes a first spring 30 and a second spring 40, each of which extends along the lever 20 and is disposed between an upper spring seat 32 and a lower spring seat 34. The springs 30 and 40 are subjected to compression to provide an urging force as the lever 20 is tilted from the initial position.