Sliding Drum Door Latch for Secure Top-Loading Washer Closure

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing washing machine drum door latching systems are unreliable when fabrics are trapped between the doors, leading to unintentional opening during rotation, and require high forces for operation, which can cause interference with other drum parts and user discomfort.

Innovation Solution

A security latch with a sliding member and support body, made of plastic, that allows for easy unlatching with reduced force, featuring a beak-shaped stop portion and elastic means to maintain the latch position, guiding the sliding member to move tangentially and radially, ensuring secure closure and automatic latching without user intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a robust security latch is used to prevent door opening during rotation, then reliability is improved, but the force required to operate the latch increases

Engineering Contradiction:
Improvedoor securityVSAvoidlatch operation force
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The latching system is divided into two independent parts: a closing system (hooks and slots) that handles normal door closure, and a security latch that provides additional prevention against unintentional opening. This segmentation allows each subsystem to be optimized independently, with the security latch requiring minimal operation force while the closing system provides the primary latching function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The security latch is positioned and configured to act as a preliminary protective measure. The stop portion of the sliding member is arranged to engage with the door rim before any significant opening force can act on the closing system, preventing fabric entrapment and subsequent door opening during drum rotation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a robust security latch is used to prevent door opening during rotation, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvedoor securityVSAvoidlatch structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sliding member serves multiple functions: it acts as a stop to prevent door opening, guides the latching motion, and works with the spring to provide automatic engagement. The support body integrates the sliding member, spring, and guiding features into a single compact assembly that attaches to the door section, reducing overall system complexity despite enhanced security functionality.

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

Solution Approach 2:

The security latch is designed to engage and disengage automatically based on door position and applied forces. The spring returns the sliding member to its engaged position with the door rim after closure, and the guiding means ensure proper alignment during engagement, eliminating the need for complex manual operation mechanisms.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the sliding member moves perpendicular to drum surface, then unlatching is easier, but interference with other drum parts occurs

Engineering Contradiction:
Improveunlatching forceVSAvoidinterference with drum parts
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The sliding member is designed to move at an angle relative to the drum surface, combining radial and tangential components of motion. This angular movement trajectory allows the sliding member to clear other drum parts during operation while still effectively disengaging the latching mechanism, resolving the interference issue while maintaining ease of operation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 provides a reliable and user-friendly latching system that prevents unintentional door opening during spin cycles with lower force requirements, maintaining mechanical play and engagement while being less robust and cost-effective.

Implementation Method 1

a spring returned pusher that is movable in the direction opposite to the hooks

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The pusher is provided with a flat base collar which limits the movement of the pusher

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP2348148B1Top-loading clothes washing machine drum comprising a locking device with a sliding latch
Publication Date: 2013.03.27 WHIRLPOOL CORP
  • EP2348148B1 patent drawingFigure 1~2a
  • EP2348148B1 patent drawingFigure 3~4
  • EP2348148B1 patent drawingFigure 5~6

AI summary

A security latch (4) for preventing the unintentional release of drum access doors (100,200) of a top loading clothes washing machine drum provided with two door sections, one of the door sections carrying the catches, the other carrying the slots. The security latch is associated with a stop (T) against the rim (R) of the door containing the slots, when the doors are closed. The stop is positioned on the door carrying the catches and comprises a push button which is returnable towards the outside of a hollow socket by a spring (K). The stop (T) is the end of a member (S) which is slidable towards the drum interior according to a sliding direction (D) which forms a predetermined acute angle (α) with a tangential direction of the drum circumference at the intersection point (P) with the same circumference.