Bistable Bending Spring Unit for Shoe Step-In Aid

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Solution Overview

Problem

Existing shoes with entry aids lack compatibility with various insole types and durability, particularly in transitioning between open and closed states, and do not provide adequate comfort during the switching process.

Innovation Solution

A shoe design featuring a bistable bending jump unit with a bistable leaf spring and housing, allowing for independent opening and closing mechanisms compatible with both solid and soft insoles, utilizing triggering means to switch between stable states, and a method for producing such shoes that includes attaching the bending jump unit between the insole and shoe sole, ensuring compatibility with different manufacturing processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a bistable element is integrated into the shoe to enable automatic opening and closing, then the ease of operation is improved, but the device complexity increases

Engineering Contradiction:
Improveease of opening and closing shoeVSAvoidcomplexity of opening and closing mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent integrates the bistable element directly into the shoe structure, merging the opening/closing mechanism with the shoe's insole and upper components. This consolidation allows the shoe to automatically transition between open and closed states through the bistable element's inherent mechanical properties, improving ease of operation while avoiding the need for separate, complex actuating mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bistable element is designed to automatically transition between stable states based on applied forces during normal shoe wear and removal. The element serves itself by utilizing the natural biomechanics of putting on and taking off shoes, eliminating the need for external actuators, motors, or complex control systems, thereby maintaining simplicity despite the automated function.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If the shoe is designed to accommodate various insole types, then the adaptability is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecompatibility with different insole typesVSAvoidprecision of attaching bending jump unit
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent designs the bending jump unit with universal attachment features that can interface with multiple insole types including rigid, semi-rigid, and flexible insoles. The unit incorporates standardized mounting points and flexible connection methods that adapt to different insole materials and construction methods (glued, nailed, or sewn), enabling one mechanism to serve multiple insole configurations without requiring precision customization for each type.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The bending jump unit is designed with adjustable parameters such as flex point location, spring stiffness, and attachment geometry that can be modified during manufacturing to accommodate different insole types. These parameter variations allow the same basic mechanism to be adapted to rigid insoles requiring precise positioning or flexible insoles allowing greater tolerance, thereby managing manufacturing precision requirements across diverse applications.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If triggering means are added to the housing to enable state switching, then the ease of operation is improved, but the device complexity increases

Engineering Contradiction:
Improveease of transitioning between statesVSAvoidcomplexity of triggering mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the triggering function from complex mechanical actuating systems and implements it through simple, intuitive interface elements integrated into the shoe's existing structure. The triggering means utilize natural user interactions such as pressure application or simple lever movements that are already part of the shoe-wearing process, eliminating the need for separate, complex triggering mechanisms while maintaining ease of operation.

Inventive Principle:
Principle #2Taking out (Extraction)

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 the shoe's functionality and durability by allowing easy transition between open and closed states with various insoles, providing increased comfort and compatibility with different manufacturing methods, while maintaining the shoe's structural integrity and ease of use.

Implementation Method 1

a bistable leaf spring designed to jump between two stable states... in the event of a bending moment acting on the bending jump unit, it exerts pressure on a first side of the leaf spring in order to trigger a change of the leaf spring

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3829380B1Shoe with step-in aid and method for producing a shoe with step-in aid
Publication Date: 2023.11.22 BENDYS GMBH
  • EP3829380B1 patent drawingFigure 1
  • EP3829380B1 patent drawingFigure 2
  • EP3829380B1 patent drawingFigure 3

AI summary

The invention relates to a shoe with a step-in aid and a method for producing a shoe with a step-in aid, wherein the shoe comprises a shoe upper, an insole and a shoe sole and a bistable bending spring unit which is situated in the region of a bending point of the insole and a bending point of the shoe sole and has two stable states which correspond to a closed state and an open state of the shoe.