Door-locking device with improved safety module
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current door-locking devices in washing machines face safety risks due to stress on the door lug and slider, leading to potential 'stall positions' where the sensor switch opens too close to the locking point, preventing the coil from being energized and hindering the locking pin's movement, especially when the drum is heavily loaded.
Innovation Solution
A door-locking device with a safety module featuring a main conductive plate fixed to the locking pin, a sensor switch, and a safety pin with rotational reliefs, allowing the safety pin to rotate and interact with the slider, ensuring the sensor switch remains closed until the door is fully locked, thus preventing premature opening and ensuring the locking pin can move from the retracted to the extracted position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sensor switch opens too close to the locking point under heavy loads, then the coil cannot be energized and the locking pin cannot move, but this creates a safety risk and stall position
Solution Approach 1:
The safety pin is designed to rotate dynamically around its axis rather than moving linearly. The rotation is enabled by rotational reliefs (cam surfaces) that interact with the slider, allowing the safety pin to adapt its position automatically based on the slider's movement and the main plate's position, ensuring reliable sensor switch operation under varying load conditions
Solution Approach 2:
The safety pin acts as an intermediary element between the slider and the sensor switch. It translates the slider's movement into a controlled opening/closing action of the sensor switch through its rotation, ensuring that the switch opens at the correct moment and preventing premature opening that would cause stall positions
2Reliability
If the safety pin opens the sensor switch too early, then the coil cannot be energized to move the locking pin, but this prevents proper locking
Solution Approach 1:
The safety pin's rotation provides feedback about the slider's position and the main plate's movement. The rotational reliefs are designed so that the safety pin only opens the sensor switch after detecting that the main plate has moved sufficiently, ensuring the locking pin is ready to engage before the door is considered closed
Solution Approach 2:
The safety pin's rotation mechanism performs a preliminary action by preparing the sensor switch state in advance. As the main plate moves during door closing, the safety pin rotates progressively, ensuring the sensor switch is in the correct state before the locking pin needs to engage, preventing any stall conditions
3Reliability
If the main plate is fixed to the locking pin, then the main plate position changes with locking pin movement, but this requires the safety pin to adapt to varying positions
Solution Approach 1:
The rotational reliefs on the safety pin are designed with asymmetric cam surfaces that create different rotation characteristics depending on the direction and speed of the main plate's movement. This asymmetry allows the safety pin to automatically adjust its rotation and timing to match the varying position of the main plate, ensuring reliable sensor switch operation despite the dynamic coupling
Solution Approach 2:
The safety pin mechanism changes its operational parameters (rotation angle, speed, and timing) dynamically based on the main plate's position. The rotational reliefs are designed to transform the linear movement of the main plate into proportional rotational movement of the safety pin, automatically adapting to the varying parameters caused by the fixed coupling between the main plate and locking pin
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
This design enhances safety by preventing the safety switch from opening too close to the locking point, ensuring the locking pin can move correctly, even under heavy loads, thereby maintaining the door's locked state and preventing accidental unlocking.
Implementation Method 1
a coil that can be activated energized by the control logic of the washing machine, a locking pin, driven by said coil by means of suitable mechanical means
Data Source
AI summary
A door-locking device for a household appliance, such as a washing machine, a dishwasher and the like, of the type having a door, with a lug, wherein the door-locking device comprises a slider arranged so as to assume a disengagement and an engagement position with the lug of the household appliance door, a detection and safety module.