Appliance door latch system with pre-latching catch alignment system and appliance with said door latch system
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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 performance problems and noise during operation.
Innovation Solution
A door latch system with a floating catch carrier and pre-latching catch alignment system that automatically adjusts the catch to align with the striker, ensuring consistent engagement and reducing noise by using a compact configuration with smaller components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If large latch cams with large slots are used to accommodate component misalignment, then the latch can receive strikers regardless of assembled position, but the mounting location options are limited and the components become larger
Solution Approach 1:
The latch system is divided into separate functional components: a latch cam mounted on the door and a striker mounted on the housing. The latch cam includes a slot that receives the striker, allowing relative movement and misalignment accommodation without requiring oversized components. This segmentation enables each component to be optimized independently for size and function.
Solution Approach 2:
The latch cam is designed to rotate dynamically during the latching operation. The slot in the latch cam is oriented to allow the striker to move through it as the cam rotates, accommodating misalignment while maintaining compact dimensions. The dynamic rotation enables the latch to self-align and absorb position variations without requiring large clearances.
2Adaptability or versatility
If loose-fitting latch cams with large clearances are used to accommodate misalignment, then the latch can operate despite component position variations, but loud slapping or clunking noises are generated during door closing
Solution Approach 1:
The latch cam slot and striker interface are designed with curved surfaces that guide the engagement process. The cam slot has a curved path that smoothly guides the striker into position, eliminating sudden impacts and reducing noise. The curved geometry ensures continuous contact and controlled movement, preventing the slapping sounds associated with loose-fitting rectangular slots.
Solution Approach 2:
The latch cam is designed to pre-align with the striker before final engagement. The slot geometry and cam rotation sequence ensure that the striker is gradually guided into the latched position, preventing sudden impacts. This preliminary alignment action occurs before the door fully closes, reducing the impact velocity and eliminating loud clunking noises.
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 system provides quiet and consistent operation by accommodating variations in latch component positions, allowing for tighter fits and reduced noise during latching events, while enabling installation in challenging locations.
Implementation Method 1
Over-center spring mechanisms are typically used to actuate latch cams, with springs that are energized as the doors are opened. However, when the springs release their energy as the doors close, loose-fitting latch cams can produce loud noises.
Implementation Method 2
The floating catch carrier may lift upwardly to accommodate the striker passing under the catch during an appliance door latching event
Data Source
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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.