Door locking device for household appliances and bistable mechanism
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Solution Overview
Problem
Existing door locking devices for household appliances face issues with compensating for door travel and position tolerances, leading to improper locking or misalignment, and are prone to wear and maintenance challenges due to complex mechanisms and enclosed designs.
Innovation Solution
A door locking device with a bistable mechanism using a cursor and elastic recovery means, allowing the cursor to take two stable positions, and a compensation mechanism like a coil spring to absorb extra door travel, ensuring proper locking without relying on precise machining or complex actuation systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a door locking device uses a lever actuated directly by the door to move a hook into the locking position, then the device can achieve simple mechanical operation, but it cannot compensate for door travel and position tolerances, leading to improper locking or misalignment
Solution Approach 1:
A slide component is introduced as an intermediary between the lever and the hook. The slide includes a slot that guides the hook's movement and a face that contacts the lever. This intermediary mechanism allows the system to accommodate variations in door travel while ensuring reliable hook positioning and locking engagement.
2Reliability
If the door locking device uses inclined planes on the hook and slide to rotate the hook into the locking condition, then the device can achieve functional locking, but it requires very accurate machining to ensure correct hook movement, affecting production costs
Solution Approach 1:
The design transitions from relying on precisely machined inclined planes to using a slide with a slot and face geometry that is less sensitive to manufacturing variations. The slot's orientation and the face's angle are designed to provide robust mechanical advantage for hook rotation without requiring extreme machining precision, thereby reducing production costs while maintaining locking reliability.
3Ease of operation
If the door locking device uses inclined surfaces that contact each other during operation, then the device can achieve hook actuation, but it is prone to wear after a certain number of operating cycles, exposing the device to the risk of seizure
Solution Approach 1:
The slide acts as a mediator that reduces direct contact and friction between the lever and hook. The slot in the slide guides the hook's movement with minimal friction, and the face of the slide contacts the lever rather than the hook directly. This intermediary mechanism significantly reduces wear on critical components, extending the service life of the locking device.
4Reliability
If the door locking device is housed in a closed shell, then the device can be protected, but it cannot be opened for maintenance by a user, causing accumulated dirt on the inclined planes contact interface to operate the device incorrectly
Solution Approach 1:
The housing is divided into at least two separable parts that can be detached from each other. This segmentation allows users or maintenance personnel to open the housing to access and clean the inclined planes and other internal components, removing accumulated dirt that could interfere with device operation, while still providing protection when the housing is assembled.
5Reliability
If the door locking device uses a pin that engages into a hole in the slide to prevent sliding, then the device can lock the hook in position, but it cannot compensate for extra door travels, with the risk of improper locking
Solution Approach 1:
The system transitions from a static pin-hole connection to a dynamic slide mechanism with a slot. The slot allows the hook to move dynamically within a controlled range, accommodating variations in door travel. The slide itself can move along the lever's face, providing adaptability to different door positions while maintaining stable hook locking through the engagement geometry of the slot and hook.
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 reliable and durable door locking with compensation for tolerances and extra travel, reducing the risk of misalignment and wear, while simplifying the design and maintaining proper operation even under anomalous conditions.
Implementation Method 1
said recovery means comprise at least an elastic means or at least one spring so arranged as to allow a relative elastic movement between the head and the body
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
The invention relates to a door actuation and/or locking device (1,11) for household appliances, wherein a hook (5,50) movable into at least one condition of engagement with the door is locked into said condition by a cursor (60) associated with bistable latching means. In particular, the cursor (60) has a body (62) with a central seat (67) that houses rotation and/or engagement guides (68,69): the bistable latching means (65) comprise a rotatable pin (66) that cooperates with said guides (68, 69) to ensure that the cursor takes distinct positions of stable equilibrium (60). The invention also comprises a bistable mechanism, in particular associated with the door locking device and/or to actuation means.