Elastomer Overload Spring for Compact Automatic Door Seals

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Solution Overview

Problem

The use of coil springs in automatic door seals limits design flexibility due to space requirements, particularly in narrow seals, as they need to accommodate the spring's diameter, restricting the construction of very narrow seals.

Innovation Solution

Replacing coil springs with elastomer-based springs, such as O-rings, which can be made narrow and used as both return and overload springs, allowing for a more compact design without relying on standardized coil springs, and incorporating a scissor mechanism with a bearing element and push rods to manage the sealing strip's movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If coil springs are used as overload springs in automatic door seals, then the seal can provide reliable overload protection, but the seal width is increased due to the diameter requirement of coil springs

Engineering Contradiction:
Improveoverload protectionVSAvoidseal width
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent changes the geometric parameters of the spring from a circular coil configuration to a wave profile configuration. This parameter change allows the spring to achieve the same elastic function with a significantly reduced width, transforming the spring from a standardized cylindrical component to a custom-shaped elastic element that fits within narrow seal profiles while maintaining overload protection capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a wave profile spring that functions as a flexible thin-walled elastic structure. This wave-shaped element can deform elastically under load while occupying minimal width space, effectively replacing the bulky coil spring with a thin, flexible elastic component that provides the same protective function without increasing seal width

Inventive Principle:
Principle #30Flexible shells and thin films

2Ease of manufacture

If standardized coil springs are used, then the manufacturing is simplified and reliable, but the design flexibility for narrow seals is reduced

Engineering Contradiction:
Improvespring manufacturingVSAvoiddesign flexibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by designing the spring with a specific wave profile geometry tailored to the narrow seal application. Instead of using a universal coil spring design, the spring is locally optimized with a wave shape that provides the required elasticity while fitting within the constrained width, allowing customization for specific seal narrowness requirements while maintaining manufacturability through standardized wave profile production methods

Inventive Principle:
Principle #3Local quality

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 solution enables the creation of more compact and flexible automatic door seals that can be used in narrower applications without risking damage from overloads, as the elastomer springs and scissor mechanism ensure smooth operation and protection against excessive force.

Implementation Method 1

the overload spring is a spring made of an elastomer

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4001577B1Automatic seal with an elastomer overload spring
Publication Date: 2024.11.06 ATHMER
  • EP4001577B1 patent drawingFigure 1
  • EP4001577B1 patent drawingFigure 2
  • EP4001577B1 patent drawingFigure 3

AI summary

The invention relates to an automatic seal - with a retaining means (8), - with a sealing strip (2, 3) having a sealing profile (3), - with a trigger (6) for introducing a force to move the sealing strip (2, 3) into the seal, - with a push rod (5) and with at least one mechanism (4) for transmitting a movement of the trigger (6) to the sealing strip (2, 3), which can be moved from a sealing position to a release position and vice versa by means of the movement mechanism (4), - with a return spring (7) and/or at least one overload spring (9), - wherein the push rod (5) is coupled to the trigger (6) to transmit the movement of the trigger (6) to the push rod (5), - wherein the push rod (5) is coupled to the movement mechanism (4), optionally via the overload spring (9), - wherein optionallythe push rod (5) is at least indirectly connected to the holding means (8) via a return spring (8) and - wherein the return spring (8) and/or the overload spring (9) is a spring made of an elastomer.