Dial Holder Stopper Unit Prevents Wrong Engagement

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Solution Overview

Problem

In air conditioning operating devices, the dial is prone to freely rotating and engaging at the first holding position when the second holding position loosens, preventing the assembly of the rotary unit at the delivery destination.

Innovation Solution

An operating device with a dial holder, elastic engagement pawl, and stopper unit that restricts rotation towards the first holding position, ensuring the dial remains at the second holding position even if the engagement with the second engagement portion loosens, using an elastic engagement pawl that is elastically deformed to prevent engagement with the first engagement portion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the dial is provided with holding positions for assembly and inspection, then the dial can be held at predetermined positions during assembly and inspection processes, but the dial may freely rotate and engage at the wrong holding position when the second holding position loosens

Engineering Contradiction:
Improveholding stabilityVSAvoidengagement position reliability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The stopper unit is pre-installed on the base member to prevent the dial holder from rotating toward the first holding position. This preliminary protective measure ensures that even if the elastic engagement pawl disengages from the second engagement portion, the dial cannot accidentally engage with the first engagement portion, thus preventing assembly errors at the delivery destination

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The stopper unit acts as an intermediary protective element between the dial holder and the first engagement portion. It physically blocks the rotation path of the dial holder, preventing direct contact between the elastic engagement pawl and the first engagement portion, thereby eliminating the risk of wrong engagement

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the elastic engagement pawl is designed to be elastically deformable, then the dial can be held at the second holding position with flexible engagement, but the pawl may be engaged with the first engagement portion when rotation toward the first holding position occurs

Engineering Contradiction:
Improveengagement flexibilityVSAvoidengagement position accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The stopper unit is pre-positioned to block the rotational path before the elastic engagement pawl can accidentally engage with the first engagement portion. This preliminary protective action maintains the flexibility of the elastic pawl while preventing wrong engagement

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The stopper unit serves as an intermediary barrier that prevents the elastic engagement pawl from contacting the first engagement portion during unintended rotation, thus preserving both the elastic flexibility and the positional accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If no click mechanism is provided, then the dial can rotate freely for easy positioning, but the dial is liable to freely rotate and cannot be held at predetermined positions during assembly

Engineering Contradiction:
Improverotation freedomVSAvoidposition holding capability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The holding mechanism is segmented into two independent parts: the elastic engagement pawl for maintaining held positions and the stopper unit for preventing unintended rotation. This segmentation allows the dial to rotate freely when not engaged while providing reliable holding when engaged, without requiring a click mechanism

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stopper unit acts as an intermediary protective element that prevents the dial from rotating into the wrong position, complementing the elastic engagement pawl's holding function without restricting necessary rotation freedom during positioning

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Prevents the dial from being engaged and held at the first holding position when the second holding position loosens, allowing for proper assembly of the rotary unit at the delivery destination.

Implementation Method 1

the elastic engagement pawl is elastically deformed so as to be inclined with respect to a face of the base member

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2397350B1Operating device
Publication Date: 2014.01.15 KK TOKAI RIKA DENKI SEISAKUSHO
  • EP2397350B1 patent drawingFigure 1
  • EP2397350B1 patent drawingFigure 2
  • EP2397350B1 patent drawingFigure 3

AI summary

In a case where the engagement of an elastic engagement pawl (31) with a second engagement portion (13) is released and a dial holder (26) is rotated in the direction toward a first holding position from a state that the dial holder (26) is positioned at a second holding position, the rotation of the dial holder (26) in the direction toward the first holding position is restricted by a stopper unit (17,34) and the elastic engagement pawl (31) is elastically deformed so that the elastic engagement pawl (31) is not able to be engaged with a first engagement portion (11). The first holding position is in a state that the elastic engagement pawl (31) is engaged with the first engagement portion (11) and the second holding position is in a state that the elastic engagement pawl (31) is engaged with the second engagement portion (12).