Reflectively Symmetrical Fluid Bladder Modules for Footwear Cushioning

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Solution Overview

Problem

Existing footwear cushioning systems face challenges in maintaining consistent air pressure within multi-chamber bladders due to airflow restrictions and complex manufacturing processes, particularly when incorporating multiple chambers.

Innovation Solution

A sole design featuring discrete fluid-filled bladder modules with reflectively symmetrical pairs laterally spaced apart, each having two fluidly connected pods, simplifies manufacturing by reducing the need for multiple mold cavities and ensures effective fluid transfer and localized cushioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple chamber bladders are incorporated into footwear, then cushioning performance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecushioning performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bladder system is divided into multiple fluidly isolated chambers (first chamber, second chamber, third chamber) that are spatially separated and independently formed. Each chamber can be manufactured separately using single-cavity molds, then assembled into the footwear sole, thereby maintaining complex cushioning functionality while simplifying the manufacturing process

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple bladder chambers are integrated into a single footwear sole structure, combining multiple cushioning functions into one unified component. The chambers are arranged in specific configurations (e.g., heel region, midfoot region, forefoot region) to provide comprehensive cushioning coverage while being manufactured as integrated units

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If multiple chamber bladders are used, then cushioning effectiveness is improved, but air pressure consistency deteriorates due to airflow restrictions

Engineering Contradiction:
Improvecushioning effectivenessVSAvoidair pressure consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The bladder system separates air chambers into fluidly isolated compartments (first chamber with first air, second chamber with second air, third chamber with third air). This segmentation prevents airflow restrictions between chambers, allowing each chamber to maintain independent and consistent air pressure without being affected by other chambers, thereby improving pressure consistency while maintaining cushioning effectiveness

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Fluid barriers or septa are introduced as intermediary elements between adjacent bladder chambers to prevent air mixing while allowing structural integration. These intermediaries ensure that air pressure remains consistent within each chamber by blocking restricted airflow paths, yet still allow the chambers to be part of a unified cushioning system

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If reflectively symmetrical bladder modules are used, then manufacturing is simplified, but design flexibility is reduced

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddesign flexibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

While maintaining reflectively symmetrical pairs for mass production efficiency, the patent incorporates laterally asymmetrical bladder configurations in specific regions (e.g., different chamber arrangements in heel vs. forefoot, or different chamber sizes on medial vs. lateral sides). This allows customization for specific performance requirements while still using symmetrical mold cavities for the paired components, balancing manufacturing simplicity with design flexibility

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 design provides tailored cushioning support to the foot by maintaining fluid flow within each module, reducing manufacturing complexity and cost while enhancing comfort and responsiveness to foot impacts.

Implementation Method 1

fluid-filled bladder modules coupled to a bottom surface of the upper sole... providing a desired cushioning effect to a wearer's foot

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

discrete bladder modules to provide a desired cushioning effect... absorbs shocks

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4381983B1Article of footwear having a reflectively symmetrical fluid cushioning system
Publication Date: 2025.08.06 REEBOK INTERNATIONAL LIMITED
  • EP4381983B1 patent drawingFigure 1
  • EP4381983B1 patent drawingFigure 2
  • EP4381983B1 patent drawingFigure 3

AI summary

An article of footwear includes an upper and a sole coupled to the upper. The sole includes an upper sole and a plurality of fluid filled bladder modules coupled to a bottom surface of the upper sole. The plurality of fluid-filled bladder modules include a first bladder module disposed in a first region of the sole and a second bladder module disposed in the first region of the sole, where the second bladder module is spatially separated in a transverse direction from the first bladder module and the first and second bladder modules do not extend into a second region of the sole. The first and second bladder modules are each fluidly isolated from remaining bladder modules. The first and second bladder modules are each asymmetrical. The first bladder module is reflectively symmetrical with respect to the second bladder module.