Rotary Switch Barrel Spring Conical Guide Asymmetry

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Solution Overview

Problem

Existing rotary switch devices face difficulties in efficiently inserting and positioning cylindrical coil springs due to alignment requirements, leading to poor manufacturing efficiency and inconsistent contact pressure, which affects reliability and longevity.

Innovation Solution

A rotary switch device utilizing a barrel-type compression coil spring with a reduced diameter tip for easy insertion and a cone-shaped spring accommodation hole to ensure precise positioning, maintaining consistent contact pressure and preventing coil spring protrusion, thereby stabilizing the contact pressure and preventing corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cylindrical hole is used to accommodate the cylindrical coil spring, then the spring can be held upright, but the insertion operation becomes troublesome and production efficiency deteriorates

Engineering Contradiction:
Improvespring holding stabilityVSAvoidproduction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the spring accommodation hole from a cylindrical shape to a conical shape with the small diameter at the opening and large diameter at the bottom. This asymmetric design allows the coil spring to be easily inserted from the opening while being securely held at the bottom, eliminating the alignment requirements of cylindrical holes and improving both insertion ease and holding stability.

Inventive Principle:
Principle #4Asymmetry

2Ease of operation

If the coil spring is inserted in an inclined shape, then insertion may be easier, but the spring cannot be positioned at a predetermined position accurately

Engineering Contradiction:
Improveinsertion easeVSAvoidspring positioning precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The conical shape of the spring accommodation hole provides a curved guiding surface that naturally guides the coil spring into the correct position. As the spring is inserted, the conical surface guides it from an inclined entry position to the centered predetermined position at the bottom, simultaneously achieving insertion ease and positioning precision.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution enhances manufacturing efficiency and ensures stable contact pressure, preventing corrosion and contact failure, while reducing the risk of buckling and maintaining favorable workability.

Implementation Method 1

a compression coil spring 10 of a barrel type in which one end is supported by a bottom surface 9 of a spring accommodation hole 8 formed in the rotation operation member 4 and another end is pressed in contact with a back surface against a plate thickness surface forming the contact protrusion part 5 and the contact surface 6 of the movable contact member 7 so as to urge the contact protrusion part 5 and the contact surface 6 to a side of the terminal base 3

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3460820B1Rotary switch device
Publication Date: 2021.01.27 ALPHA
  • EP3460820B1 patent drawingFigure 1
  • EP3460820B1 patent drawingFigure 2
  • EP3460820B1 patent drawingFigure 3~4

AI summary

A rotary switch device includes a terminal base to which a center portion contact and a fixed contact are fixed, a rotation operation member which is operable to rotate around the center portion contact, a plate-like movable contact member which includes a contact protrusion part which is pressed in contact with the center portion contact at one end and a contact surface which is in contact with the fixed contact at the other end of one surface of plate thickness surfaces, and is held in the rotation operation member to cause a short circuit between the center portion contact and the fixed contact, and a compression coil spring of a barrel type of which one end is supported by a bottom surface of a spring accommodation hole formed in the rotation operation member and the other end is pressed in contact with the contact protrusion part and a back surface against a plate thickness surface forming the contact surface to urge the contact protrusion part and the contact surface to a side of the terminal base.