Offset Dual Spray Arms for Rectangular Dishwasher Coverage

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Solution Overview

Problem

Dishwashers with rectangular washing compartments of different edge lengths face challenges in achieving effective cleaning and drainage, as centrally mounted spray arms often fail to reach all areas, leading to reduced wetting and inefficient cleaning agent distribution, especially in narrower models.

Innovation Solution

A dishwasher design featuring two offset spray devices, one positioned towards the front and the other towards the rear, both supplied by a common inlet pipe with a lowest point above the inlet, allowing for efficient water distribution and drainage, reducing dead volume and water consumption, and enabling effective cleaning across the entire washing compartment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a centrally mounted spray arm is used in a rectangular washing compartment with different edge lengths, then the device structure is simple, but the spray arm cannot reach all areas effectively, leaving unaffected areas and reducing cleaning quality

Engineering Contradiction:
Improvespray device structureVSAvoidcleaning quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The washing compartment is divided into different zones (front, rear, side) that are sprayed by differently positioned spray arms. The first spray device is offset toward the front to spray the front area, while the second spray device is offset toward the rear to spray the rear area, ensuring comprehensive coverage of the rectangular compartment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spray devices are asymmetrically positioned relative to the center of the washing compartment. Instead of symmetric central mounting, the first spray device is offset toward the front edge and the second toward the rear edge, creating an asymmetric arrangement that matches the rectangular geometry and ensures uniform spray distribution across all areas.

Inventive Principle:
Principle #4Asymmetry

2Manufacturing precision

If multiple spray arms are used to cover the rectangular area, then cleaning coverage is improved, but the device complexity and pipeline requirements increase significantly

Engineering Contradiction:
Improvecleaning coverageVSAvoidpipeline complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple spray devices are supplied from a common water supply line that is distributed to both the first and second spray devices. This merging of the water supply system reduces the number of separate pipelines needed while maintaining effective spray coverage in both front and rear areas.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spray devices serve multiple functions: they not only spray the washing compartment areas but also act as drain points for the water supply line. The water supply line is designed to drain into the spray devices, eliminating the need for separate drainage pipelines and reducing overall system complexity.

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

3Device complexity

If a common inlet pipe supplies both spray devices, then pipeline complexity is reduced, but drainage efficiency may be compromised

Engineering Contradiction:
Improvepipeline configurationVSAvoiddrainage efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

Instead of having the water supply line drain to a separate collection point, the system is inverted so that the water supply line itself serves as the drainage path. The line is designed with a downward slope that directs water directly into the spray devices, which then distribute it into the washing compartment. This inversion eliminates dead volume and improves drainage efficiency.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The water supply line performs dual functionality: it supplies water to the spray devices and simultaneously drains water from the system. The line's downward slope and connection to the spray devices enable self-drainage without requiring additional drainage components, making the system self-sufficient.

Inventive Principle:
Principle #25Self-service

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 ensures thorough cleaning up to the front edge of the washing basket, effective drainage, and reduced water contamination in subsequent cycles, while minimizing space requirements and production complexity, with the ability to adjust the inlet pipe for different basket positions.

Implementation Method 1

a common inlet pipe below the washing basket with a component extending in the direction of the front, which has a lowest point above an inlet into the front or rear Has spray device. As a result, only a single line is required to both spray devices... Due to the location of the deepest point, the line can at least almost completely drain, whereby the water can run directly into the spray device underneath.

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2441370B1Dishwasher with at least one spray device
Publication Date: 2020.04.08 BSH HAUSGERATE GMBH
  • EP2441370B1 patent drawingFigure 1
  • EP2441370B1 patent drawingFigure 2
  • EP2441370B1 patent drawingFigure 3

AI summary

The dishwasher has a rinsing container provided with a rinsing basket (4) that contains material to be cleaned. A front spray arm (5) is arranged toward a front side (V) of the rinsing basket in a displaced position. A rear spray arm (6) is designed as an auxiliary spraying system with outlets for water and/or washing liquor (S). The spray arms are supplied by a common intake pipe extending below the rinsing basket with a component toward the front side. The intake pipe includes a deep location (11) above inlets (12, 13) toward the front spray arm or the rear spray arm.