Elastically Deformable Filter Layer for Adjustable Pore Size

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing water-bearing household appliance filters, such as those used in washing machines and dishwashers, face challenges including high manufacturing costs, contamination issues, limited application due to heat-dependent switching, and inefficient filtration due to complex designs and shape memory alloy components that can be impaired by contamination.

Innovation Solution

An elastically deformable filter layer with adjustable pore size, made from materials with a Poisson's ratio of 0.2 to 0.5, such as rubber-based materials, which can be stretched or compressed to vary the filter effect independently of inflow pressure, allowing for stepless adjustment of permeability and easy cleaning, thereby enhancing filtration efficiency and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If shape memory alloy is used to control filter openings, then the filter can switch between open and closed states, but the design becomes complex and manufacturing costs increase

Engineering Contradiction:
Improvefilter switching capabilityVSAvoidsieve design complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent removes the shape memory alloy elements and tongue-like tabs from the filter design, extracting the problematic switching mechanism while retaining the essential filtration function through a simpler membrane structure with adjustable openings

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive shape memory alloy components with a more economical filter membrane design that achieves the same switching functionality through mechanical actuation, reducing manufacturing costs while maintaining adaptability

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Extent of automation

If shape memory alloy is used to control filter openings, then automatic switching is achieved, but contamination impairs functioning and the filter effect deteriorates

Engineering Contradiction:
Improveautomatic switchingVSAvoidfilter effect
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The filter membrane is designed to be easily removable and replaceable by the user, allowing self-service cleaning and maintenance that restores filtration effectiveness without requiring complex automated cleaning mechanisms

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The filter openings are designed to be dynamically adjustable through mechanical actuation, allowing the filter to adapt to different operational conditions while maintaining reliability through simple, contamination-resistant construction

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If heat influence is used to switch filter openings, then switching is achieved, but only indirect switching is possible and delay occurs during heating and cooling

Engineering Contradiction:
Improvefilter switchingVSAvoidswitching delay
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent replaces thermal actuation with direct mechanical actuation of the filter membrane, eliminating the time delays associated with heating and cooling cycles while enabling precise, on-demand control of filter openings

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The filter switching is designed to occur on demand through mechanical actuation rather than relying on periodic thermal cycles, allowing immediate response to operational requirements without waiting for temperature changes

Inventive Principle:
Principle #19Periodic action

4Reliability

If multiple filters with different mesh sizes are used, then comprehensive filtration is achieved, but manufacturing costs increase

Engineering Contradiction:
Improvefiltration effectivenessVSAvoidnumber of filters
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The filter membrane is designed with adjustable openings that can adapt to different filtration requirements, allowing a single filter to perform multiple filtration functions that would otherwise require several different filters, thereby reducing device complexity while maintaining comprehensive filtration effectiveness

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

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 adaptive filter layer effectively filters out dirt particles and detergent residues, maintains water quality by reusing washing and rinsing water, and prevents clogging by allowing for mechanical adjustment of pore size, ensuring optimal filtration during different washing and rinsing steps without the need for multiple filters, thus maximizing water savings and maintaining washing results.

Implementation Method 1

An elastically deformable filter layer (20) with open recesses (22) extending perpendicularly to a filter side (23, 24) through the filter layer (20) is provided. The elastically deformable filter layer (20) can be stretched and/or compressed along one or along the respective extension direction of the open recesses (22)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The elastically deformable filter layer can be stretched and/or compressed along one or along the respective extension direction of the open recesses (22). The material of the filter layer has a Poisson's ratio of 0.2 to 0.5

Methodology Applied
Scientific EffectPoisson's effect: Poisson's Effect

Data Source

PatentEP2638940B1Water-conducting domestic appliance with an adjustable filter
Publication Date: 2018.05.30 BOSCH SIEMENS HAUSGERATE GMBH
  • EP2638940B1 patent drawingFigure 1~2
  • EP2638940B1 patent drawingFigure 3~4
  • EP2638940B1 patent drawingFigure 5~6

AI summary

The filter (2) has an elastically deformable filter layer (20), which is provided with several open recesses (22). The elastically deformable filter layer is stretched and/or is compressible. The open recesses are extended vertically to filter sides (23,24) of the filter layer. The elastically deformable filter layer is stretched and/or is compressible along the respective extending direction (26) of the open recesses.