Spring Core End Ring Structure to Prevent Roll-Packing Hooking

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Solution Overview

Problem

Conventional spring core units face issues with roll packing due to bent tails of open end springs hooking into lacing wires or end rings, making them unusable, and require excessive wire usage during manufacturing.

Innovation Solution

The design features a spring with a straight free leg having V-shaped or U-shaped stamping/bending, preventing lateral shifting within the helical lacing wire and allowing for secure attachment, while omitting bent tails to save wire, and a method of producing spring core units with coiled springs having one end ring bent before assembly to accommodate smaller heights and higher spring rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bent tails are provided on the free legs of end rings, then the springs can be securely attached to the helical lacing wire, but the bent tails hook into opposite lacing wires or end rings during roll packing, making the spring core unusable

Engineering Contradiction:

Improveattachment securityVSAvoidhooking during roll packing

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful bent tail portion from the spring design while retaining the essential attachment function. By replacing the bent tail with a straight free leg that is retained within the helical lacing wire, the harmful hooking action during roll packing is eliminated while maintaining secure attachment capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of the bent tail by transforming it into a straight configuration. The straight free leg, when retained within the helical lacing wire, provides secure attachment without the harmful hooking effect, effectively converting the design flaw into a functional advantage.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If bent tails are provided on the free legs of end rings, then the springs can be attached to the helical lacing wire, but excessive wire is used during manufacturing

Engineering Contradiction:

Improveattachment capabilityVSAvoidwire consumption

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent removes the unnecessary bent tail portion from the spring design, thereby reducing wire consumption during manufacturing while preserving the essential attachment function through the straight free leg configuration retained within the helical lacing wire.

Inventive Principle:

Principle #2Taking out (Extraction)

3Ease of operation

If the free leg is made relatively long with bent tail, then attachment to lacing wire is possible, but lateral shifting of end rings within the helical lacing wire occurs

Engineering Contradiction:

Improveattachment flexibilityVSAvoidpositional stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent introduces the helical lacing wire as an intermediary that retains the straight free leg of the end ring. This configuration provides both attachment flexibility and positional stability, preventing lateral shifting while maintaining ease of operation during assembly.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP2719307B1Spring, spring core unit and method of producing a spring core unit

Publication Date: 2016.04.06 SPUHL GMBH

Figure 1
Figure 2
Figure 3~4

AI summary

A spring (2) for a spring core unit (1), the spring (2) having a spiral body and an end ring (3) with a substantially straight leg (4). The leg (4) is provided with at least one V-shaped bending (5) or at least one U-shaped bending.