Chair Armrest Assembly Using Tool-Free Lock-and-Rotate Mechanism
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Solution Overview
Problem
Conventional chair armrests are bulky, difficult to assemble, and lack structural strength and tightness, leading to increased manufacturing costs and potential safety risks during use.
Innovation Solution
An easily assembled chair armrest design featuring a connecting portion with a lock head and locking hole/slot mechanism that allows for secure assembly without additional tools, enhancing structural integrity and ease of assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the armrest and armrest support are assembled into one part in advance on the manufacturing end, then the volume is reduced for package and transportation, but the manufacturing cost is increased and the assembly complexity is increased
Solution Approach 1:
The armrest assembly is divided into separate components (armrest body and armrest support) that can be manufactured independently and then easily connected through the locking mechanism, reducing manufacturing complexity while maintaining compact form factor
2Volume of moving object
If the armrest and armrest support are assembled into one part in advance on the manufacturing end, then the volume is reduced for package and transportation, but the assembly process becomes more complex requiring extra fastening parts and tools
Solution Approach 1:
The locking mechanism is designed to be self-contained and tool-free, where the lock head automatically engages with the locking slot through simple insertion and rotation actions, eliminating the need for external fastening parts and tools
Solution Approach 2:
The connecting portion integrates multiple functions into a single component - the lock head serves as both the insertion element and the locking element, while the locking slot combines positioning and securing functions, simplifying the overall assembly process
3Ease of manufacture
If the armrest is assembled at the client end using conventional structures, then the manufacturing cost is reduced, but the structural strength and tightness are reduced
Solution Approach 1:
The lock head features a rounded top surface that rotates within the locking slot, creating a curved engagement path that distributes stress more evenly and enhances the structural strength of the connection compared to straight-line fastening methods
4Ease of manufacture
If conventional armrest designs are used, then the manufacturing is simpler, but the assembly is difficult and requires extra fastening parts and tools
Solution Approach 1:
The locking mechanism is designed to be self-contained and tool-free, where the lock head automatically engages with the locking slot through simple insertion and rotation actions, eliminating the need for external fastening parts and tools
Data Source
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AI summary
An easily assembled chair armrest (1) comprising an armrest support (10), a connecting portion (20), and an armrest (30). The connecting portion (20) with a lock head (21) is selectively disposed on the armrest (30) or the armrest support (10) while a locking hole (321) is arranged at the armrest (30) or the armrest support (10) without the connecting portion (20). A locking slot (322) communicates with the inner side of the locking hole (321). The armrest (30) and the armrest support (10) are in a first assembled state when the lock head (21) is mounted into the locking slot (322) through the lock hole (321). Then the lock head (21) is horizontally rotated a staggered angle within the locking slot (321) so that a lengthwise central axis (32b) of the armrest (30) and a lengthwise central axis (11b) of the armrest support (10) are coupled. Now the armrest (30) and the armrest support (10) are fastened into one part to be in a second assembled state. Thereby both structural strength and tightness are improved.