Coil Spring Lateral Force Control via End Coil Angular Displacement

Solution Overview

Problem

Lateral force generated by compressed coiled springs causes premature failures in mechanical devices like brake actuators, as the underlying mechanical feature responsible for this phenomenon was previously unknown, leading to uncontrolled damage.

Innovation Solution

Monitoring and maintaining the angular displacement of end coils within a specific range (between −1.5° and 2.5° from the spring axis) to control lateral force, using a fixture with a shaft and measurement assembly to align and measure the angular displacement of end coils, thereby optimizing the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If conventional coil spring manufacturing is used, then axial force is generated, but lateral force causes premature failures in mechanical devices

Engineering Contradiction:

Improveaxial forceVSAvoiddevice reliability

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the angular displacement of end coils during manufacturing. By adjusting the angular orientation parameter of end coils to within 2 degrees of perpendicular to the spring axis, the invention eliminates lateral force generation while preserving axial force production, thereby resolving the contradiction between force generation and device reliability

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If angular displacement of end coils is not controlled, then manufacturing is simpler, but lateral force causes damage to mechanical devices

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidlateral force damage

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent implements preliminary action by controlling the angular displacement of end coils during the manufacturing process itself. Rather than attempting to correct lateral force issues after spring assembly, the invention pre-establishes the correct angular orientation (within 2 degrees) of end coils during coiling, preventing lateral force generation before the spring is installed in mechanical devices

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If angular displacement is maintained within -1.5° to 2.5°, then lateral force is controlled below threshold, but measurement and control complexity increases

Engineering Contradiction:

Improvelateral forceVSAvoidmeasurement and control system

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements preliminary action by controlling the angular displacement of end coils during the manufacturing process itself. Rather than attempting to correct lateral force issues after spring assembly, the invention pre-establishes the correct angular orientation (within 2 degrees) of end coils during coiling, preventing lateral force generation before the spring is installed in mechanical devices

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by precisely controlling the angular displacement of end coils during manufacturing. By adjusting the angular orientation parameter of end coils to within 2 degrees of perpendicular to the spring axis, the invention eliminates lateral force generation while preserving axial force production, thereby resolving the contradiction between force generation and device reliability

Inventive Principle:

Principle #35Parameter changes

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 approach significantly reduces lateral load, ensuring mechanical devices operate within safe thresholds, minimizing damage and exceeding SAE J2318 standards by achieving a target axial to lateral force ratio of 67:1 to 80:1, substantially eliminating defects caused by unwanted lateral forces.

Implementation Method 1

Hooke's Law is a principle of physics that defines the actual force of a compressed spring based upon the distance a spring is compressed

Methodology Applied

Scientific EffectHooke's Law: Hooke's Law

Implementation Method 2

Lateral force is the force generated by a compressed spring that is lateral to the axial force along a spring axis, which is defined by a body of a coiled compression spring

Methodology Applied

Scientific EffectAngular displacement:

Data Source

PatentUS9909937B2Method of identifying and reducing lateral force of a coil spring

Publication Date: 2018.03.06 INDIAN HEAD INDUSTRIES INC

AI summary

A method of monitoring lateral force of a coil spring having a body and opposing end coils is disclosed. A fixture includes a base defining a planar surface with a shaft that extends from said planar surface at a normal angle to said planar surface. An axis defined by the coil spring is aligned with the shaft. Angular displacement from the shaft of an end coil is measured, and the angular displacement is correlated with a lateral force value.