Knock-Down Chair Base Assembly with Tool-Free Locking Legs
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Solution Overview
Problem
Existing chair base assemblies are large and expensive to pack due to their inability to be separated into smaller pieces, leading to significant packaging waste and difficulties in disassembly without tools.
Innovation Solution
A self-locking assembling and disassembling arrangement for the chair base assembly, featuring a central hub with side receptacles that allow legs to be locked and unlocked in a releasable manner, enabling easy assembly and disassembly without tools.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the base is made as a one-piece cast metal structure, then the structural strength and stability are improved, but the packaging cost and waste increase due to inability to separate into smaller pieces
Solution Approach 1:
The base is divided into multiple separable components: a central hub, multiple legs, and a centre column. Each leg can be independently attached to the hub, allowing the base to be disassembled into smaller packaging units, reducing packaging waste while maintaining structural integrity when assembled.
2Strength
If the gas spring column is press fit into the base, then the connection strength is improved, but the ease of disassembly deteriorates as tools or large force are needed to separate them
Solution Approach 1:
The connection between the centre column and hub transitions from a static press-fit to a dynamic, controllable connection. The leg locking components can be engaged or disengaged by rotating the legs, allowing easy assembly and disassembly without tools while maintaining strong connection when locked.
Solution Approach 2:
The locking mechanism is designed to be self-servicing through user action. Rotating the legs automatically engages or disengages the locking components, eliminating the need for external tools or complex disassembly procedures while ensuring secure connection.
3Ease of manufacture
If the base is designed as a large one-piece structure, then the manufacturing simplicity is improved, but the productivity deteriorates due to inefficient shipping and packaging requirements
Solution Approach 1:
The base components (hub, legs, column) can be manufactured separately and assembled later, allowing for more efficient packaging and shipping. This segmentation enables better space utilization during transport while maintaining manufacturing simplicity through standardized components and assembly procedures.
4Ease of operation
If locking components are added to enable easy disassembly, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The locking functionality is merged into the leg structure itself through integrated locking components. The legs incorporate notches and interacting protrusions that provide locking capability without requiring separate, complex locking mechanisms, thus maintaining simplicity while enabling easy assembly and disassembly.
Data Source
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AI summary
The present disclosure relates to a chair base assembly, the assembly comprising a central hub with a centre receptacle for receiving a centre column adapted to support a chair part and at least three side receptacles an opening in a radiant direction from a centre of the central hub, wherein each side receptacles comprises a receiving portions adapted for receiving a leg in a lockable and releasable manner, the side receptacles and the leg comprises corresponding locking components , , wherein the side receptacles comprising respective orifices with at least a lower section, and a hub locking component on an upper section within the orifice, wherein the respective legs comprises a first end adapted to be attached in the side receptacle and a second end adapted to be supported on the ground, to support a wheel or a support, wherein the first end of the leg comprises the leg locking component.