Dishwasher Door Latch Retraction Using a Bowden Cable Mechanism

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Solution Overview

Problem

Existing dishwashers face issues with automatic retraction of the locking pin after replacing the electric geared motor, leading to increased costs and wear, and pose a risk of injury and damage due to the large opening gap and protruding catch.

Innovation Solution

A dishwasher design utilizing a cable or Bowden cable coupled with a pivoted deflection lever and a spring-based retraction mechanism, allowing the locking pin to automatically retract back to its original position using user-applied force, minimizing wear and eliminating the need for expensive electric motors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an electric geared motor is used to automatically retract the locking pin, then the door can be automatically opened by a large gap for drying, but the device becomes expensive and wear-prone

Engineering Contradiction:
Improveautomatic door opening gapVSAvoiddrive mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The user's manual door opening action automatically performs the retraction function through the cable mechanism, eliminating the need for an electric motor. The system uses the user's input energy to achieve the retraction that would otherwise require a powered mechanism.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the electric geared motor with a purely mechanical cable-based retraction mechanism. This mechanical system uses the door's movement to automatically retract the locking pin, eliminating expensive and wear-prone electrical components while maintaining the automatic retraction function.

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

2Productivity

If the locking pin remains protruding after door opening to maintain a large gap, then drying is supported, but the risk of injury and damage increases

Engineering Contradiction:
Improvedrying efficiencyVSAvoidsafety risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The locking pin dynamically changes its position based on door state - protruding when the door is closed to maintain sealing, and retracted when the door is opened to eliminate safety hazards. This dynamic adaptation allows the system to optimize for drying efficiency during the wash cycle and for safety during unloading.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cable mechanism provides automatic feedback-based retraction - when the user opens the door, the cable detects this movement and automatically triggers the locking pin retraction. This feedback loop ensures the locking pin is retracted whenever the door is opened, eliminating the need for separate sensors or control systems.

Inventive Principle:
Principle #23Feedback

3Device complexity

If a cable mechanism is used for retraction instead of an electric motor, then cost and wear are reduced, but the mechanism must be simple and robust

Engineering Contradiction:
Improvedrive mechanismVSAvoidmechanical robustness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent extracts the retraction function from the powered domain and places it in the mechanical domain. By removing the electric motor and using only a cable and pulley system, the design achieves simplicity and robustness while maintaining reliability through passive mechanical operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cable mechanism uses inexpensive, easily replaceable components compared to an electric motor. If wear occurs, the simple cable can be quickly replaced without dealing with complex electrical systems, maintaining high reliability at low cost.

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

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 solution enables cost-effective and robust door operation with reduced wear and safety risks by using cheaper drives and eliminating the need for additional components, ensuring efficient door closure and improved user safety.

Implementation Method 1

a push rod (6) which can be moved when the door (4) is closed, biased in the inserted state by two tension springs (8)

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

the means include a cable or Bowden cable coupled to the door

Methodology Applied
Scientific EffectMechanical coupling: Chain

Implementation Method 3

the door actuates the cable or Bowden cable via a pivoted deflection lever

Methodology Applied
Scientific EffectLever mechanism: Lever

Data Source

PatentEP2280632B1Dishwasher having a device for opening the door in gaps
Publication Date: 2012.01.25 MIELE & CO KG
  • EP2280632B1 patent drawingFigure 1~2
  • EP2280632B1 patent drawingFigure 3a~3b
  • EP2280632B1 patent drawingFigure 4a~4b

AI summary

The invention relates to a dishwasher (1) having a rinsing container (2) that can be closed by a pivoting door (4), wherein to provide locking a locking device disposed on the door (4) engages into a clamp (5) disposed on the rinsing container (2), and wherein to open the door in gaps the clamp (5) is disposed on an adjustable connecting rod (6) that is adjustable in the opening direction by means of a drive. In order to also ensure the automatic retracting of the clamp when the electric gear motor is replaced with a more cost-effective drive, the invention provides means for returning the clamp (5) at least approximately to the initial position thereof opposite to the opening direction as a result of the further opening movement of the door (4).