Asymmetrical Coil Spring Assembly for Progressive Mattress Support

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Solution Overview

Problem

Traditional spring mattresses provide uneven cushioning support for users of different weights due to linear or non-linear spring compression, leading to discomfort for lighter users and excessive wear due to significant compression, especially in non-linear spring designs which are difficult to manufacture.

Innovation Solution

Innerspring assemblies featuring asymmetrical springs with a combination of upper conical and lower cylindrical portions, providing distinct spring rates to ensure non-linear compression for lighter users and maintaining firmness for heavier users, while minimizing overall coil compression and manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conical springs with non-linear spring rates are used, then lighter users experience better comfort, but heavier users must significantly compress the springs which reduces mattress life

Engineering Contradiction:
Improvecomfort for lighter usersVSAvoidmattress life
Core Design Contradiction:
Ease of operationVSDuration of action of stationary object

Solution Approach 1:

The spring is divided into two distinct segments: an upper conical portion that provides non-linear compression for lighter users, and a lower cylindrical portion that maintains firmness for heavier users. This segmentation allows each portion to serve its specific function, preventing excessive compression while maintaining comfort across different weight ranges.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the spring have different geometric properties: the upper portion is conical with varying diameter to provide progressive resistance, while the lower portion is cylindrical with constant diameter to provide consistent support. This local differentiation of properties enables the spring to adapt its characteristics to different loading conditions.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If conical springs are used to provide non-linear compression, then lighter users experience better comfort, but the irregular shape makes manufacturing and assembly difficult

Engineering Contradiction:
Improvecomfort for lighter usersVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The spring is divided into two distinct segments: an upper conical portion that provides non-linear compression for lighter users, and a lower cylindrical portion that maintains firmness for heavier users. This segmentation allows each portion to serve its specific function, preventing excessive compression while maintaining comfort across different weight ranges.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the spring have different geometric properties: the upper portion is conical with varying diameter to provide progressive resistance, while the lower portion is cylindrical with constant diameter to provide consistent support. This local differentiation of properties enables the spring to adapt its characteristics to different loading conditions.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If linear spring rate springs are used, then manufacturing is simple, but lighter users experience insufficient comfort

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcomfort for lighter users
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

Different portions of the spring have different geometric properties: the upper portion is conical with varying diameter to provide progressive resistance, while the lower portion is cylindrical with constant diameter to provide consistent support. This local differentiation of properties enables the spring to adapt its characteristics to different loading conditions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The spring features an asymmetric geometry with a conical upper portion and a cylindrical lower portion. This asymmetry creates different spring rates at different heights, allowing the spring to provide progressive resistance that adapts to user weight while maintaining manufacturing feasibility.

Inventive Principle:
Principle #4Asymmetry

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 provides consistent comfort for a wide range of users by allowing the upper conical portion to compress before the lower cylindrical portion, reducing wear and simplifying manufacturing through a more regular shape, thus offering a balanced firmness and longevity for mattresses.

Implementation Method 1

The upper spring portion has a first substantially linear spring rate and the lower spring portion has a second substantially linear spring rate

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

When a user sleeps on the surface of the mattress, he/she applies a weight on the underlying springs, which in turn compress to provide adequate cushioning support

Methodology Applied
Scientific EffectSpring compression: Spring

Implementation Method 3

The upper spring portion has a first substantially linear spring rate and the lower spring portion has a second substantially linear spring rate

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

springs having a linear spring rates. Such springs compress a distance that is linearly proportional to the weight of the user

Methodology Applied
Scientific EffectSpring compression: Spring

Data Source

PatentEP2209403B1Combined cylindrical and conical springs
Publication Date: 2016.05.18 DREAMWELL LTD
  • EP2209403B1 patent drawingFigure 1A~1C
  • EP2209403B1 patent drawingFigure 2A~2B
  • EP2209403B1 patent drawingFigure 3A~3C

AI summary

A mattress comprising asymmetrical coil springs with nonlinear spring rates provides comfort to users with different weights. The lower portion of the spring is cylindrical and the upper portion is conical or frustoconical. This arrangement causes the spring to undergo linear compression before undergoing nonlinear compression. The result is a mattress that is sufficiently soft for lighter users and sufficiently firm for heavier users.