Household Appliance Door Latch With Child-Safe Lock Inhibition

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Solution Overview

Problem

Existing door closing mechanisms for household appliances, such as washing machines, lack adequate safety features to prevent accidental closure by children, which can lead to trapping and safety risks.

Innovation Solution

An improved door closing apparatus with a manually controllable safety element that prevents the stop mechanism from locking when a baby enters the chamber, ensuring the door remains open and preventing suffocation risks, combined with a return mechanism to facilitate safe door operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the stop mechanism is designed to automatically lock the striker in the retracted position, then the door closing reliability is improved, but the safety risk increases due to potential accidental closure by children

Engineering Contradiction:
Improvedoor closing reliabilityVSAvoidsafety risk from accidental closure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The safety element is positioned to preemptively block the locking path of the stop mechanism. Before the striker can be accidentally locked by a child, the safety element physically prevents the stop mechanism from reaching its locking position, thereby counteracting the potential harmful action in advance

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The safety element acts as an intermediary component between the striker and the stop mechanism. It mediates the interaction by selectively allowing or blocking the locking action based on whether the safety element is in its blocking position, thus controlling the transmission of the locking function

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a safety element is added to prevent accidental locking, then the safety is improved, but the device complexity increases

Engineering Contradiction:
Improvesafety from accidental closureVSAvoidmechanism complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The safety element is merged with the existing door closing mechanism components. It is integrated into the interaction between the striker and stop mechanism, sharing space and functional pathways with existing parts rather than adding completely separate components

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The safety element serves multiple functions: it blocks the locking path to prevent accidental closure, and simultaneously works in conjunction with the return means to ensure proper door operation. This multi-functionality reduces the need for additional separate safety devices

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

3Ease of operation

If the striker is allowed to move freely between retracted and extracted positions, then the ease of operation is improved, but the risk of unintended locking increases

Engineering Contradiction:
Improvedoor operation flexibilityVSAvoidrisk of unintended locking
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the locking availability based on the position of the safety element. When the safety element is in the blocking position, the striker can move freely without risk of locking. When the safety element is retracted, the locking function becomes available for intentional operation by the user

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2837759B1Apparatus for controlling the closing of a door of a household appliance
Publication Date: 2018.07.04 ELBI INT
  • EP2837759B1 patent drawingFigure 1~2
  • EP2837759B1 patent drawingFigure 3
  • EP2837759B1 patent drawingFigure 4

AI summary

An apparatus (10) for controlling the closing of a door (D) of a household appliance (W), comprising an engagement element (11), which is fitted on the casing (C) of the household appliance (W) and is arranged for being held in a releasable manner by a retaining element (16) fitted on the door (D). The engagement element (11) comprises: a support body (12); and a striker (14), which is adapted to be coupled in a releasable manner to the retaining element (16) and is movable between a retracted position and an extracted position. When the striker (14) is coupled to the retaining element (16) and assumes the retracted position and the extracted position, respectively, the door (D) is suited to be in a complete closing condition and in a pre-opening condition, respectively. The apparatus (10) comprises, furthermore: a stop mechanism (18) tending to move from a release condition, in which it (18) is adapted to liberate said striker (14), to a locking condition, in which it (18) is adapted to hold said striker (14), when it is in said retracted position; a driving means (20), which is arranged for controlling the movement of the stop mechanism (18) from the locking condition to the release condition. The stop mechanism (18) comprises a safety element (18a), which can be manually controlled by a user and can be moved to an inhibition arrangement, in which it forcedly constrains the stop mechanism (18) in the release condition.