Book-Like Air Filter Design for Easy Lint Removal in Laundry Dryers

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Solution Overview

Problem

Conventional laundry dryers have cumbersome air filters that are difficult to open, which can hinder the removal of lint and fluff, potentially affecting the performance of the dryer components.

Innovation Solution

The air filter is designed with an outer and inner filtering element that can be opened in a book-like manner, featuring an unlocking portion accessible through a first access opening, allowing for easier manual opening by applying a single force in the direction of the airflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a snap-on locking mechanism is used to secure the air filter half-shells, then the air filter remains closed during operation, but the air filter becomes cumbersome to open for cleaning

Engineering Contradiction:
Improveair filter closure during operationVSAvoidair filter opening for cleaning
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The air filter is divided into two separable half-shells that can be easily detached from each other. The locking mechanism is designed so that each half-shell can be independently removed by simply pulling it away from the other half-shell, without requiring complex unlocking actions. This segmentation allows the filter to remain securely closed during operation while being easily openable for cleaning.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If manual pressure is applied to disengage the hook from its seat, then the air filter can be opened, but multiple forces must be applied simultaneously making it difficult to open

Engineering Contradiction:
Improveair filter opening capabilityVSAvoidopening mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The locking function is extracted from a complex multi-force mechanism and simplified to a single-force pull-apart action. The hook-and-seat engagement is designed so that applying force in the direction of airflow automatically disengages the hook from its seat, eliminating the need for simultaneous application of multiple forces. This extraction simplifies the opening operation while maintaining reliable closure during operation.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the air filter is securely locked during operation, then lint trapping is effective, but the filter mesh is at risk of damage during opening

Engineering Contradiction:
Improvelint trapping effectivenessVSAvoidfilter mesh integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The design ensures that the filter mesh is already in place and secured before the half-shells are joined together during assembly. The locking mechanism engages the half-shells in a way that distributes forces away from the filter mesh, preventing damage during the opening and closing operations. The preliminary positioning of the mesh ensures it is protected from the mechanical stresses of the locking mechanism.

Inventive Principle:
Principle #10Preliminary action

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

Facilitates manual unlocking and opening of the air filter, reducing the risk of damaging the filter mesh and improving accessibility for cleaning, thereby maintaining the dryer's performance.

Implementation Method 1

an air filter, arranged or arrangeable in the outlet duct, in an operative position, in which the air filter is passed through by the airflow exiting the drum, so as to trap lint, or other foreign bodies, dragged out of the laundry by the airflow

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP4438799B1Laundry dryer with air filter
Publication Date: 2025.07.16 ELECTROLUX APPLIANCES
  • EP4438799B1 patent drawingFigure 1A
  • EP4438799B1 patent drawingFigure 1B
  • EP4438799B1 patent drawingFigure 2A

AI summary

A laundry dryer (1), comprising: - a casing (2) containing a rotatable drum (3) for holding laundry (4) to be dried; - an air moving system (5) adapted to pass an airflow (6) through said drum (3), while said laundry dryer (1) is in an operative condition; - an outlet duct (7), fluidly connected to said drum (3) for receiving said airflow (6) exiting said drum (3), while said laundry dryer (1) is in said operative condition; - an air filter (8), arranged or arrangeable in said outlet duct (7), in an operative position, in which said air filter (8) is passed through by said airflow (6) exiting said drum (3), so as to trap lint, or other foreign bodies, dragged out of the laundry (4) by said airflow (6), while said laundry dryer (1) is in said operative condition; wherein said air filter (8) comprises: - an outer filtering element (9) comprising a first outer half-shell (10) and a second outer half-shell (11) being rotatably connected to each other in a book-like manner at a first connecting end (12) of said first outer half-shell (10) and at a second connecting end (13) of said second outer half-shell (11), respectively, so as to define a first cavity (14) between said first outer half-shell (10) and said second outer half-shell (11) when said air filter (8) is in a closed condition, in which closed condition a first inlet end (15) of said first outer half-shell (10), distinct from said first connecting end (12), is removably attached to a second inlet end (16) of said second outer half-shell (11), distinct from said second connecting end (13), said first cavity (14) being accessible to a user's finger by a first access opening (17) defined between said first inlet end (15) and said second inlet end (16); - an inner filtering element (18) arranged at least partially within said first cavity (14), said inner filtering element (18) comprising a first inner half-shell (19) and a second inner half-shell (20) being rotatably connected to each other in a book-like manner at a first connection end (21) of said first inner half-shell (19) and at a second connection end (22) of said second inner half-shell (20), respectively, so as to define a second cavity (23) between said first inner half-shell (19) and said second inner half-shell (20) when said air filter (8) is in a closed condition, in which closed condition a first entry end (24) of said first inner half-shell (19), distinct from said first connection end (22), is removably attached to a second entry end (25) of said second inner half-shell (20), distinct from said second connection end (22), said second cavity (23) being accessible to a user's finger by a second access opening (26) defined between said first entry end (24) and said second entry end (25); wherein said air filter (8) comprises an unlocking portion (27), arranged at the inner side (28) of said first outer half-shell (10) facing said first cavity (14), or arranged at the inner side (29) of said first inner half-shell (19) facing said second cavity (23), wherein, when said air filter (8) is in said closed condition, said unlocking portion (27) is accessible to a user's finger through said first access opening (17) and/or through said second access opening (26), and is arranged in such a way that a user can place a finger on said unlocking portion (27) for exerting on said first outer half-shell (10), while holding said second outer half-shell (11) or said second inner half-shell (20), a first opening force to move said first inlet end (15) of said first outer half-shell (10) away from said second inlet end (16) of said second outer half-shell (11), so as to unlock said first outer half-shell (10) from said second outer half-shell (11), and thereby to open said outer filtering element (9).