Trigger Sprayer Spring Fatigue via Curved Lever Surface

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Solution Overview

Problem

Conventional trigger-type liquid sprayers fatigue easily due to excessive deformation of the spring member when the operation lever is swung widely for spraying a large amount of liquid, leading to reduced durability.

Innovation Solution

The trigger-type liquid sprayer incorporates a spring member with a fixed part located in front of the operation lever's swing center and an inclined surface on the operation lever, which reduces the movement range and deformation of the spring member by allowing the projection to move backward while moving relatively forward with the inclined surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the operation lever is swung widely to spray a large amount of liquid, then the spraying quantity is increased, but the spring member undergoes excessive deformation and becomes fatigued easily

Engineering Contradiction:
Improvespraying quantityVSAvoidspring member durability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The inclined surface is designed as a curved surface rather than a flat plane. When the projection contacts the curved inclined surface, it allows the spring-side projection to move backward while the lever-side projection moves forward, reducing the relative displacement between the two projections and thereby reducing spring deformation while maintaining wide lever swing capability for large spraying quantities

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the geometric parameters of the spring member by repositioning the spring-side projection backward and modifying the inclined surface curvature. This parameter change allows the spring to accommodate large lever swings with reduced deformation amplitude, maintaining reliability while enabling high spraying quantity operation

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the spring member is designed to accommodate large lever swing range, then the spraying capacity is improved, but the spring member deformation increases and fatigue occurs

Engineering Contradiction:
Improvelever swing rangeVSAvoidspring member strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The curved inclined surface enables the spring member to adapt to large lever swing ranges by converting linear displacement into a combination of backward movement of the spring-side projection and forward movement of the lever-side projection. This curvature-based mechanism maintains spring strength by reducing deformation amplitude while preserving full lever swing adaptability

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention introduces dimensional complexity by allowing the spring-side projection to move not only with the lever swing but also independently backward along the curved inclined surface. This multi-dimensional movement pattern enables the spring to accommodate large swing ranges without excessive deformation, preserving strength while enhancing adaptability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 reduces the fatigue of the spring member and the force required to swing the operation lever, enhancing the durability and efficiency of the sprayer.

Implementation Method 1

When the operation lever 103 is swung backward, a back end part of the lever-side projection 106 presses a front wall of the spring-side projection 105 to elastically deform the spring member 104, so that the operation lever 103 is urged forward by elastic force generated by the elastic deformation

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3705189B1Trigger type liquid ejector
Publication Date: 2023.04.26 YOSHINO KOGYOSHO CO LTD
  • EP3705189B1 patent drawingFigure 1
  • EP3705189B1 patent drawingFigure 2(a)~2(c)
  • EP3705189B1 patent drawingFigure 3

AI summary

There is provided a trigger-type liquid sprayer in which a spring member urging an operation lever is less likely to be fatigued. A trigger-type liquid sprayer according to the present invention includes a sprayer main body (2) attached to a container (A), an operation lever (4) held to be swingable in a front-back direction with respect to the sprayer main body (2), and a spring member (5) urging the operation lever (4) forward. The spring member (5) includes a fixed part (5d) that is located in front of a swing center (C) of the operation lever (4) and is fixed and held to the sprayer main body (2), and a projection (5e) that is located below the fixed part (5d). The operation lever (4) includes an inclined surface (4e) that is inclined upward from downward and frontward from backward and is urged by the projection (5e) abutting against the inclined surface (4e).