Curved Laundry Drum Embossing for Better Liquid Exchange

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Solution Overview

Problem

Existing laundry drum designs that aim for more intensive mechanical treatment of laundry often compromise on gentleness and reduce the washing and rinsing effectiveness due to reduced flood hole areas and inefficient liquid exchange.

Innovation Solution

The drum shell is designed with curved embossings that have a single axis of symmetry in the circumferential direction, eliminating corner flood holes and featuring arc-like contours that facilitate gentler treatment and improved liquid exchange through strategically placed flood holes on steep parts of the embossings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If regular polygonal embossings with corner flood holes are used, then mechanical treatment intensity is improved, but liquid exchange capacity deteriorates due to reduced total flood hole area

Engineering Contradiction:
Improvemechanical treatment intensityVSAvoidliquid exchange capacity
Core Design Contradiction:
PowerVSQuantity of substance

Solution Approach 1:

The patent transitions from regular polygonal embossings with multiple small corner flood holes to asymmetric curved embossings with a single large central flood hole. This asymmetric design eliminates the corner flood holes that limited total area and replaces them with one strategically positioned flood hole of greater cross-section, thereby improving liquid exchange capacity while maintaining mechanical treatment effectiveness through the curved embossing profile

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent changes the parameters of the flood holes by increasing the cross-sectional area of individual flood holes and reducing their total number. The transition from multiple small corner flood holes to fewer larger central flood holes represents a parameter change that increases the total flood hole area available for liquid exchange, directly addressing the deterioration in liquid exchange capacity

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If flood hole area is reduced for mechanical treatment, then laundry protection is improved, but washing and rinsing effectiveness deteriorates due to decreased suds permeation

Engineering Contradiction:
Improvelaundry protectionVSAvoidwashing and rinsing effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent applies local quality by positioning flood holes in specific locations on the curved embossing surfaces where they can optimally serve both functions. The flood holes are placed on the steepest parts of the curved embossings, allowing them to provide mechanical protection through the embossing structure while simultaneously enabling effective suds permeation and liquid exchange through their strategic positioning and increased cross-sectional area

Inventive Principle:
Principle #3Local quality

3Power

If corner flood holes are present on embossing contours, then mechanical treatment is intensified, but liquid exchange efficiency deteriorates due to disturbing flood hole locations

Engineering Contradiction:
Improvemechanical treatment intensityVSAvoidliquid exchange efficiency
Core Design Contradiction:
PowerVSProductivity

Solution Approach 1:

The patent extracts the flood holes from their traditional corner positions on embossing contours and relocates them to central positions on curved embossing surfaces. This extraction and relocation eliminates the 'disturbing' corner flood hole locations and replaces them with optimally positioned central flood holes that improve liquid exchange efficiency while the curved embossing profile maintains the necessary mechanical treatment intensity

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

This design enhances the mechanical treatment of laundry while maintaining gentleness, improves washing and rinsing effectiveness by optimizing suds permeation and liquid exchange, and reduces membrane-like vibrations for better stability and acoustic performance.

Implementation Method 1

liquid exchange between the interior and the exterior of such a laundry drum is clearly reduced considerably

Methodology Applied
Scientific EffectGravity-driven flow: Gravitation

Implementation Method 2

the throughput capacity of the drum shell can be increased without having to accept a reduction in the gentleness of the laundry

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

the suds permeation decreases

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP1974083B1Laundry drum
Publication Date: 2009.06.10 BSH HAUSGERATE GMBH
  • EP1974083B1 patent drawingFigure 1~3
  • EP1974083B1 patent drawingFigure 4~5
  • EP1974083B1 patent drawingFigure 6~7

AI summary

A laundry drum 1 for a laundry treatment machine, which is mounted inside a housing G such that it can rotate about an axis A which is not oriented in the direction of gravity and has a drum casing 2 which is bent in this way and is provided with stamped recesses 4, if the intention is to increase the throughflow performance of the drum casing 2 in the case of intensive mechanical treatment in comparison with known laundry drums, without having to accept a reduction in laundry protection. This is effected by way of a drum casing 2, the stamped recesses 4 of which are curved and the contour of which which lies in alignment with the drum casing 2 forms a surface area having a plurality of arcuate edges 41 to 43 which merge continuously into one another, and has only one single axis of symmetry 44 which extends at least approximately in the circumferential direction of the drum casing 2.