Portable Chair Hub Structure for Foldability and Ground Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing portable chairs face challenges in stability, comfort, and ease of carrying due to weak structural intersections, large volume when folded, and poor performance on uneven or wet surfaces.
Innovation Solution
A portable chair design featuring hubs with radially extending frames and a central support frame, connected by elastic strings, providing stability and comfort through a compact folding mechanism and rotatable hubs for even surface adaptation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If frames are connected through central hinges with fabric sheet, then the chair is easily folded and unfolded with small volume, but the structural strength at frame intersection is weak
Solution Approach 1:
The chair structure is divided into separate modular components: hub assembly, leg frames, pole frames, and fabric sheet. Each component can be independently manufactured and assembled, allowing the frames to connect to the hub without weak intersection points while maintaining foldability through separable couplings.
Solution Approach 2:
The leg frames and pole frames are designed to nest within each other when folded, with the fabric sheet wrapping around the assembled frame structure. This nesting arrangement minimizes volume while maintaining structural integrity through the hub-centered radial configuration.
2Volume of moving object
If fabric sheet is made small and flat for portability, then the chair volume is reduced, but comfortability for long-term sitting deteriorates
Solution Approach 1:
The fabric sheet is designed with dynamic tensioning through elastic strings that allow it to conform to the user's body shape during use, providing comfort. When folded, the fabric wraps compactly around the frame structure, minimizing volume while maintaining the ability to expand and adapt during operation.
Solution Approach 2:
The fabric sheet transitions between two states: a compact wrapped state for portability and an expanded tensioned state for use. Elastic strings and coupling mechanisms enable the fabric to change from a small folded package to a fully extended comfortable seating surface, adjusting parameters of area and tension based on operational needs.
3Ease of operation
If hinge structure is employed at multiple points for foldability, then the chair can be folded easily, but the structure becomes complicated and foreign matters may intrude into hinge portions
Solution Approach 1:
The traditional hinge structure is extracted and replaced with a hub-centered radial coupling system. Leg frames and pole frames connect directly to the hub through separable couplings rather than intersecting hinges, eliminating the complex network of hinge joints while preserving foldability through the radial arrangement around the central hub.
Solution Approach 2:
The hub serves as an intermediary component that mediates the connection between all frame elements. Instead of multiple hinge points where foreign matters could intrude, all connections converge at the hub through separable couplings, simplifying the structure and eliminating hinge joints while maintaining the ability to fold and unfold easily.
4Device complexity
If traditional frame intersection structure is used, then the chair structure is simple, but stability on uneven or wet ground surfaces deteriorates
Solution Approach 1:
The hub assembly incorporates asymmetric adjustment capabilities that allow the radial frame configuration to adapt to uneven ground surfaces. The separable couplings enable individual leg frames to be adjusted independently, providing stability on uneven or wet ground while maintaining overall structural simplicity through the centralized hub design.
Solution Approach 2:
The radial frame structure with separable couplings provides dynamic adaptability to ground conditions. The hub-centered design allows the chair to adjust its stance and distribution of weight across different surfaces, improving stability on uneven or wet ground while keeping the structure simple through the convergence of all frames at the central hub.
Data Source
AI summary
The portable chair of the disclosure includes: hubs respectively installed at both left and right sides of the chair; a central support frame connecting both left and right hubs; front and rear leg frames respectively having base ends separably coupled to the lower front and rear outer peripheral surfaces of the respective hubs and respectively having free ends disposed in a manner of radially extending toward the ground surface; front and rear pole frames respectively having base ends separably coupled to the upper front and rear outer peripheral surfaces of the respective hubs and respectively having free ends disposed in a manner of radially extending toward the sky; and a fabric sheet coupled to the free ends of the front and rear pole frames. The structural rigidity is excellent, and the chair may land on the ground surface in a stable posture.