Top-Loading Washer Drum Door Safety Mechanism with Position Sensing

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Solution Overview

Problem

Top-loading washing machines lack a reliable mechanism to ensure correct engagement of the safety mechanism and proper closure of the drum doors, especially in automated systems, which can lead to accidental openings during the wash cycle.

Innovation Solution

A sensing system is implemented to detect the relative position of the drum doors with respect to the safety mechanism, using a sensing circuit comprising elements on the drum, safety mechanism, and cabinet, which provides a signal indicating a correct closed configuration, ensuring the safety mechanism is properly engaged.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a safety mechanism is provided to prevent accidental openings of the drum, then safety is improved, but the device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a sensing system that continuously monitors the engagement state of the safety mechanism and door closure status. The sensing device detects whether the door is properly closed and the safety mechanism is engaged, providing feedback signals to the control unit. This feedback mechanism ensures safety without requiring complex mechanical interlocks, as the control unit can respond to the sensed state to prevent operation when safety conditions are not met.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex mechanical safety verification mechanisms with a sensing-based detection system. Instead of using purely mechanical interlocks and levers to ensure safety, the invention uses sensing devices (such as magnetic sensors, optical sensors, or micro switches) to detect the engagement state and communicate this information electronically to the control unit, thereby reducing mechanical complexity while maintaining safety.

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

2Reliability

If a sensing system is implemented to detect correct engagement, then reliability is improved, but the device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sensing system provides continuous feedback to the control unit about the door closure and safety mechanism engagement status. This feedback enables the control unit to verify proper engagement and prevent drum operation when safety conditions are not satisfied, thereby improving reliability through information-based verification rather than complex mechanical verification.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The sensing device acts as an intermediary between the mechanical safety mechanism and the control unit. It translates the physical engagement state into an electrical signal that the control unit can process, thereby bridging the mechanical and electronic domains without requiring direct complex mechanical-linkage verification in the control system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If the safety mechanism prevents accidental openings, then harmful factors are reduced, but the ease of operation decreases

Engineering Contradiction:
Improveaccidental openingsVSAvoidease of operation
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The sensing system continuously monitors the door closure and safety mechanism engagement, providing real-time feedback to the control unit. This feedback mechanism automatically prevents drum operation when the door is not properly closed or the safety mechanism is not engaged, thereby preventing accidental openings without requiring additional manual verification steps from the user.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The safety system performs self-verification through the sensing device that automatically detects whether the door is closed and the safety mechanism is engaged. The control unit uses this information to automatically enable or disable drum operation, thereby providing self-service safety verification that prevents accidental openings while maintaining ease of operation for legitimate use.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3309287B1Top-loading washing and/or drying machine with safety mechanism
Publication Date: 2019.10.02 WHIRLPOOL CORP
  • EP3309287B1 patent drawingFigure 1~2
  • EP3309287B1 patent drawingFigure 2a~2d
  • EP3309287B1 patent drawingFigure 3~4

AI summary

The present invention is related to a top-loading washing and/or drying machine comprising: a cabinet (C); a drum (10) rotatably mounted within the cabinet (C) about a horizontal axis and having an aperture (12) on its cylindrical side; at least a drum door (14a, 14b) supported by the drum (10) for opening and closing the aperture (12); a safety mechanism (22) supported by the drum (10) and/or by the door (14a, 14b) and configured to selectively lock and unlock the door (14a, 14b). A sensing device is configured to sense a relative position of the door (14a, 14b) with respect to the safety mechanism (22). The sensing device is operatively connected to a control unit to provide a signal indicating a correct closed configuration of the door (14a, 14b).