Appliance Door Latch with Floating Catch Carrier for Quiet Alignment

Solution Overview

Problem

Appliance door latch systems in dishwashers and front-loading washing machines face misalignment issues due to manufacturing and assembly variations, leading to noisy operation and limited mounting options, as large, loose-fitting latch cams are required to accommodate height variations.

Innovation Solution

A compact appliance door latch system with a pre-latching catch alignment mechanism, featuring a floating catch carrier that automatically aligns with the striker assembly, ensuring consistent engagement points and reducing noise through passive height adjustment, allowing for tighter fits and smaller component sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If large, loose-fitting latch cams are used to accommodate door height variation, then the latch can receive strikers regardless of assembled position, but the latch components limit mounting location options and produce loud noises during operation

Engineering Contradiction:

Improvelatch component position accommodationVSAvoidnoise during latching operation

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The pre-latching alignment system performs alignment of the catch and striker before the main latching engagement. The alignment block contacts the striker first and guides it into proper position, ensuring that when the catch engages the striker, they are already aligned. This preliminary alignment action eliminates the need for large clearances and prevents misalignment-related noise during the actual latching event.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If large, loose-fitting latch cams are used to accommodate door height variation, then the latch can receive strikers regardless of assembled position, but the latch components limit mounting location options

Engineering Contradiction:

Improvelatch component position accommodationVSAvoidlatch component size

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The pre-latching alignment system performs alignment of the catch and striker before the main latching engagement. The alignment block contacts the striker first and guides it into proper position, ensuring that when the catch engages the striker, they are already aligned. This preliminary alignment action eliminates the need for large clearances and prevents misalignment-related noise during the actual latching event.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The alignment block serves as an intermediary element between the striker and the catch. It contacts the striker first and transfers it into the correct position, acting as a mediator that facilitates proper alignment without requiring the catch itself to be large or have loose tolerances. This intermediary component enables precise engagement while maintaining compact dimensions.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If tight-fitting latch cams are used to reduce noise, then the latching operation is quiet, but the latch cannot accommodate manufacturing and assembly variations in door height

Engineering Contradiction:

Improvenoise during latching operationVSAvoidtolerance accommodation

Core Design Contradiction:

Object-generated harmful factorsVSAdaptability or versatility

Solution Approach 1:

The pre-latching alignment system performs alignment of the catch and striker before the main latching engagement. The alignment block contacts the striker first and guides it into proper position, ensuring that when the catch engages the striker, they are already aligned. This preliminary alignment action eliminates the need for large clearances and prevents misalignment-related noise during the actual latching event.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The alignment block serves as an intermediary element between the striker and the catch. It contacts the striker first and transfers it into the correct position, acting as a mediator that facilitates proper alignment without requiring the catch itself to be large or have loose tolerances. This intermediary component enables precise engagement while maintaining compact dimensions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11272826B2Appliance door latch system with pre-latching catch alignment system

Publication Date: 2022.03.15 ILLINOIS TOOL WORKS INC

AI summary

An appliance door latch system is provided that automatically aligns latching components each time an appliance door is closed with a pre-latching catch alignment system. The pre-latching catch alignment system may include a floating catch carrier that is deflected by a door-mounted latch feature to passively reposition a catch to properly align with the striker assembly.