Switch Plunger Torsion Spring Biasing Direction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional switches with high spring constants for maintaining contact pressure suffer from reduced operability due to increased force required for plunger movement, especially when the number of contacts increases.

Innovation Solution

A switch design utilizing torsion springs that bias the plunger differently depending on its position, with upper torsion springs abutting perpendicular to the returning direction at the reference position and changing to a side surface bias between the reference and operation positions, reducing the force required for plunger movement and enhancing operability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a spring with a large spring constant is used to maintain contact pressure, then the contact pressure between contacts is improved, but the force required for plunger movement increases and operability deteriorates

Engineering Contradiction:
Improvecontact pressureVSAvoidoperability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The spring's biasing direction is made dynamic rather than fixed. The spring switches between abutting the surface perpendicular to the returning direction (providing contact pressure) and abutting the side surface (reducing operation resistance), allowing the system to adapt its mechanical characteristics based on the plunger position and operational phase

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring constant's effective value changes based on the plunger position. When the plunger is at the reference position, the spring abuts the perpendicular surface providing high biasing force for contact pressure. When the plunger moves toward the operation position, the spring transitions to abutting the side surface, effectively reducing the spring constant and thus reducing the force required for operation

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the number of contacts is increased, then the switching capability is improved, but the biasing force required increases and operability deteriorates

Engineering Contradiction:
Improvenumber of contactsVSAvoidoperability
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The dynamic positioning of the spring allows the system to handle multiple contacts without proportionally increasing operation force. The spring transitions from providing maximum biasing force (when abutting the perpendicular surface) to providing reduced biasing force (when abutting the side surface), enabling multi-contact switches to maintain good operability

Inventive Principle:
Principle #15Dynamics

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 switch achieves improved operability by minimizing the increase in biasing force as the plunger moves, allowing for smoother operation and reduced load necessary for pressing, even with multiple contacts.

Implementation Method 1

a contact pressure spring which biases the plunger

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the contact pressure spring abuts against a surface perpendicular to the returning direction when the plunger is in the reference position, and abuts against a side surface of the plunger when the plunger is located at a position between the operation position and the predetermined position

Methodology Applied
Scientific EffectTorsion spring mechanism: Torsion Spring

Data Source

PatentEP3166119B1switch
Publication Date: 2018.09.12 OMRON CORP
  • EP3166119B1 patent drawingFigure 1
  • EP3166119B1 patent drawingFigure 2A~2B
  • EP3166119B1 patent drawingFigure 3

AI summary

Provided is a switch 1 with excellent operability. The switch 1 is provided with a plunger 30, a lower torsion spring 50 in which a biasing direction changes according to the movement of the plunger 30. The lower torsion spring 50 biases the plunger 30 in a returning direction when the plunger 30 is in a reference position, and biases the plunger 30 in a direction different from the returning direction when the plunger 30 is in an operation position.