Dishwasher Lower Rack Lifting and Pull-Out Guide to Prevent Collision

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Solution Overview

Problem

Existing domestic dishwashers require users to kneel or bend to load or unload the lower rack, which can be inconvenient and may lead to collisions between the lower and upper washware holders, potentially causing damage.

Innovation Solution

A domestic dishwasher with a lifting device and guide device that allows the lower washware receptacle to be raised and lowered, and a guide device with multiple rails that enables the lower receptacle to be pulled out far enough to prevent collisions with the upper receptacle, providing a gap between the rear wall of the lower receptacle and the front edge of the washing compartment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the lower washware receptacle is positioned near the bottom of the washing tub, then the dishwasher structure is compact and space-efficient, but users must kneel or bend to load or unload items causing inconvenience and potential collision with the upper rack

Engineering Contradiction:
Improveease of loading and unloading lower rackVSAvoidstructural simplicity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The lower washware receptacle is made dynamically movable between a lower storage position and an elevated loading position through a lifting device. This allows the rack to be raised to an ergonomically convenient height for users during loading and unloading operations, then lowered to its compact storage position when not in use, eliminating the need for users to kneel or bend while maintaining structural compactness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The lifting device is activated before the user begins loading or unloading the lower rack, preliminarily raising it to the optimal working height. This preliminary positioning action prevents the need for users to adopt awkward postures during the actual loading/unloading process and prevents potential collisions with the upper rack by establishing proper spatial separation in advance.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the lower rack is raised to an upper position for easy access, then user convenience is improved, but the risk of collision with the upper washware holder increases potentially causing damage

Engineering Contradiction:
Improveaccessibility of lower rackVSAvoidcollision prevention between racks
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The lower rack's vertical position is dynamically adjusted based on operational needs. When raised to the upper position for loading/unloading, the lifting device incorporates guide mechanisms and positioning systems that ensure the rack is elevated precisely to a predetermined safe height that maintains clearance from the upper washware holder, thereby preventing collisions while maximizing accessibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The lifting device acts as an intermediary mechanism between the lower and upper racks. It controls the vertical movement of the lower rack, ensuring that when raised, it achieves the optimal position for user access without encroaching on the space occupied by the upper rack. The lifting device's controlled motion and positioning capabilities serve as a mediator that resolves the spatial conflict between the two racks.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If a lifting device is added to raise the lower basket, then ease of operation is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveease of accessing lower rackVSAvoidnumber of components
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The lifting device is designed to be manually operated by the user through a simple actuating mechanism, eliminating the need for complex motorized systems, sensors, or control electronics. The user themselves provides the lifting force through a lever, pump, or cable system, making the device self-servicing and mechanically simple while still achieving the goal of raising the lower rack to an accessible height.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The lifting device serves as a mechanical intermediary that translates a simple user input force into the vertical lifting motion of the lower rack. By using basic mechanical elements such as levers, pulleys, or scissor mechanisms, the device multiplies the user's input force to lift the rack with minimal complexity, avoiding the need for electric motors or complex control systems while still providing the desired functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 improves accessibility and prevents damage by allowing the lower washware holder to be completely shifted out of the washing compartment, ensuring safe loading and unloading while maintaining the upper holder's position, thus enhancing user convenience and safety.

Implementation Method 1

The guide device comprises a first guide rail (24) connected to the washing compartment (2), a second guide rail (28) that can be displaced linearly along the first guide rail (24)

Methodology Applied
Scientific EffectLinear displacement through guide rails:

Implementation Method 2

a lifting device (15) which is set up to raise the lower washware receptacle (12) from a starting position (AP) to an end position (EP) or to lower it from the end position (EP) to the starting position (AP)

Methodology Applied
Scientific EffectMechanical lifting:

Data Source

PatentEP3338613B1Domestic dishwasher
Publication Date: 2020.03.11 BSH HAUSGERATE GMBH
  • EP3338613B1 patent drawingFigure 1
  • EP3338613B1 patent drawingFigure 2~3
  • EP3338613B1 patent drawingFigure 4

AI summary

The invention relates to a household dishwasher (1) with a washing container (2), a lower wash item holder (12), an upper wash item holder (13), a lifting device (15) which is set up to lift the lower wash item holder (12) from a starting position ( AP) to an end position (EP) or to lower it from the end position (EP) to the starting position (AP), and a guide device (20) with the help of which the lifting device (15) is in the starting position (AP) together with the lower washware receptacle ( 12) can be moved out of the washing compartment (2) in a pull-out direction (A) far enough for a distance (a) to be provided between a rear wall (21) of the lower wash-ware receptacle (12) and a front edge (22) of the washing compartment (2).