Asymmetric Force Feedback Mechanism for Clear Actuation Onset

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Solution Overview

Problem

Existing devices lack a clear mechanism to inform users of actuation initiation, leading to potential inadvertent operation, as the force feedback is often consistent with the degree of operation without distinct indication.

Innovation Solution

A device with sector-shaped driving and follower members and a biased roller system that compresses a spring when the user starts to rotate the input device, providing a 'spike' in force feedback to indicate actuation, featuring a projection and recess mechanism with sector-shaped profiles and a frictional brake to prevent initial follower member rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If force feedback is made consistent with the degree of operation, then the device provides smooth operation, but the user cannot clearly detect when actuation begins

Engineering Contradiction:
Improvesmooth operationVSAvoiddetection of actuation initiation
Core Design Contradiction:
Ease of operationVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies periodic action by creating a distinct, temporary force feedback spike at the specific moment when actuation begins. The cam mechanism generates a periodic force variation pattern where the follower experiences a sudden increase in force followed by a return to normal operation forces, allowing the user to detect actuation initiation while maintaining smooth continuous operation throughout the cycle

Inventive Principle:
Principle #19Periodic action

2Difficulty of detecting and measuring

If a spike in force feedback is provided to indicate actuation, then the user can detect actuation initiation, but the operation becomes less smooth

Engineering Contradiction:
Improvedetection of actuation initiationVSAvoidsmooth operation
Core Design Contradiction:
Difficulty of detecting and measuringVSEase of operation

Solution Approach 1:

The patent applies local quality by concentrating the force feedback modification to a very specific localized moment in the operation cycle. The cam profile is designed so that only a small portion of the cam rotation creates the force spike, while the remainder of the cycle maintains smooth, consistent force feedback. This allows detection of actuation initiation without disrupting the overall smoothness of operation

Inventive Principle:
Principle #3Local quality

3Speed

If the follower member rotates immediately with the driving member, then the device responds quickly to user input, but the user cannot feel a distinct indication of actuation

Engineering Contradiction:
Improveresponse speedVSAvoiddetection of actuation initiation
Core Design Contradiction:
SpeedVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces a cam mechanism as an intermediary between the driving member and the follower member. This cam intermediary transforms the direct rotational motion into a modified motion pattern where the follower experiences a force spike through cam profile geometry, allowing both quick response and clear tactile indication of actuation initiation

Inventive Principle:
Principle #24Intermediary (Mediator)

4Difficulty of detecting and measuring

If a cam mechanism with asymmetric profile is used, then distinct force feedback is provided, but the device complexity increases

Engineering Contradiction:
Improvedetection of actuation initiationVSAvoidmechanism complexity
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent merges the cam mechanism with the existing driving and follower members, integrating the force feedback generation function into the existing motion transmission path. The cam is incorporated as part of the driving member assembly, and the follower is integrated into the same housing structure, reducing overall device complexity while still providing distinct force feedback

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

The device provides a clear and distinct force feedback 'spike' to users when actuation begins, helping to prevent accidental operation while allowing deliberate operation to proceed smoothly, with no spike during return to the original position.

Implementation Method 1

The edge of the plate forming the driving member has a profile with a step in it, such that when the step is moved past the roller, the biasing spring is compressed, and this compression is felt by the user as an increase in the force transmitted back to the user.

Methodology Applied
Scientific EffectSpring compression: Spring

Implementation Method 2

Braking means may be provided to prevent motion of the follower member in either direction until motion of the driving member is transmitted to the follower member.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3229098B1Device with asymmetric feedback
Publication Date: 2024.07.17 RATIER FIGEAC SAS
  • EP3229098B1 patent drawingFigure 1~2
  • EP3229098B1 patent drawingFigure 3~4
  • EP3229098B1 patent drawingFigure 5A~5D

AI summary

A device for connection to an input device actuated by a user comprises: a driving member for connection to the input device; a follower member; wherein motion of the driving member is only transmitted to the follower member after the driving member has been moved by a certain amount; and wherein means are provided to transmit a force back to the user as the driving member is moved in one direction.