Folding Chair Armrest Locking Device to Prevent Accidental Folding
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Solution Overview
Problem
Conventional folding chairs lack a securing structure to maintain the unfolded state, leading to accidental folding and potential injuries due to joint bending under inappropriate forces.
Innovation Solution
A folding chair armrest locking device with a casing, rack, and locking module that allows switching between fastened and unfastened states, using a wrench to mesh or disengage dentate portions for securing the chair in either state, enhancing user safety and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional folding chairs are designed without securing structures, then the chairs can be easily folded and stored, but the joints tend to bend under inappropriate force and switch to folded state accidentally, causing safety hazards
Solution Approach 1:
The locking device is pre-configured with a locking element and dentate portions that automatically engage when the chair is in the unfolded state. The resilient component pre-loads the locking element, so that the locking action occurs automatically before any accidental folding can occur, preventing the safety hazard rather than reacting to it
Solution Approach 2:
The locking device applies a preliminary counteracting force through the resilient component that pushes the locking element into engagement with the dentate portions. This preliminary anti-action prevents the joints from bending under inappropriate force by maintaining a constant locking force that counteracts any unintended folding tendency
2Reliability
If a locking device is added to maintain the unfolded state, then safety is improved, but the device complexity increases with additional components like locking elements, wrenches, and resilient components
Solution Approach 1:
The locking device uses a resilient component that provides dynamic adaptation to loading conditions. The resilient nature allows the locking element to maintain constant contact and locking force without requiring complex control systems, sensors, or adjustable mechanisms. The dynamic elasticity of the resilient component automatically compensates for variations in chair usage and loading
Solution Approach 2:
The locking device is designed to be self-operating through the interaction between the resilient component, locking element, and dentate portions. The resilient component automatically pushes the locking element into engagement without requiring external power sources, control systems, or complex actuation mechanisms. The user simply needs to manually operate the wrench to release the lock when desired
3Reliability
If the locking element is designed to automatically mesh with dentate portions, then the chair remains securely locked, but the ease of switching between locked and unlocked states is reduced
Solution Approach 1:
The wrench serves as an intermediary tool that mediates between the user and the locking mechanism. Instead of requiring the user to directly manipulate the locking element or its resilient component, the wrench provides a simple lever arm that applies force to the locking element through its handle, making the unlocking operation intuitive and easy to perform
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 device prevents unintended folding or unfolding, ensuring user safety and allowing smooth transitions between unfolded and folded states while adjusting comfort settings.
Implementation Method 1
a resilient component disposed in the storage and resiliently supporting the locking element, wherein the resilient component pushes the locking element to allow the second dentate portion to mesh with the first dentate portion when the wrench is located at a locked position
Implementation Method 2
when the wrench pivotally rotates to an unlocked position, the locking element is pulled downward to cause complete separation of the second dentate portion and the first dentate portion, and the wrench abuts against the casing to enable the locking element to compress the resilient component
Data Source
AI summary
A folding chair armrest locking device and a folding chair are introduced to enhance user safety of the folding chair. The folding chair armrest locking device includes a casing having therein a storage and an armrest fitting portion in communication with the storage; a rack having an armrest coupling portion and a first dentate portion and being partially disposed in the armrest fitting portion, with the first dentate portion partially facing the storage; and a locking module having a locking element, a wrench and a resilient component, the locking element having a first end with a second dentate portion, the second dentate portion being disposed in the storage and facing the first dentate portion, the wrench having a pivotal connection portion eccentrically positioned and pivotally connected to a second end of the locking element, and the resilient component being disposed in the storage and resiliently supporting the locking element.