U-Shaped Chair Frame With Inward-Bent Sections
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Solution Overview
Problem
Conventional waiting room chairs with metallic frames and plastic seating portions face issues of restricted leg movement, increased weight, and lengthy assembly times due to the presence of a transverse element and the need for screw fixation, which affects stability and usability.
Innovation Solution
A chair design featuring a frame with U-shaped parts connected by a transverse element with inward-bent sections for enhanced stability, allowing snap coupling with the seating portion without screws, and incorporating anti-skid coverings and engagement elements for easy stacking and alignment, reducing weight and assembly time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a transverse element is added to connect the two front legs, then the stability of the chair is improved, but the freedom of movement of the user's legs is reduced and the overall weight increases
Solution Approach 1:
The patent removes the transverse element that connected the two front legs in conventional chairs. Instead, it uses a different structural approach where the U-shaped parts and bent sections of the transverse portions provide stability without the obstructive horizontal connector, thereby eliminating the restriction on leg movement while maintaining chair stability.
Solution Approach 2:
The patent introduces inward bending of the transverse portions at the front and/or rear legs, creating a three-dimensional structural solution. This bending in the vertical and lateral dimensions provides stability without requiring a horizontal transverse element that would obstruct leg movement in the horizontal plane.
2Stability of the object's composition
If a transverse element is added to connect the two front legs, then the stability of the chair is improved, but the overall weight of the chair increases
Solution Approach 1:
The patent eliminates the additional transverse element that would increase weight. The stability is achieved through the optimized configuration of existing frame components, specifically the U-shaped parts and the inward bending of transverse portions, removing unnecessary material and reducing overall weight.
3Reliability
If the body is joined to the frame by fixing with screws, then the stability and reliability of the chair is improved, but the assembly time increases
Solution Approach 1:
The patent designs the frame with U-shaped parts that can be separately manufactured and then assembled. The modular structure allows for pre-fabricated components that connect through simplified joints, reducing the need for extensive screw fixation and enabling faster assembly while maintaining structural integrity.
Solution Approach 2:
The frame components are pre-formed into U-shaped parts with specific geometries that facilitate easy assembly. The inward bending of transverse portions is done during manufacturing, creating ready-to-assemble components that require minimal field assembly operations, thus reducing assembly time while ensuring reliable connections.
4Ease of manufacture
If the transverse portions are straight, then the manufacturing is simpler, but the stability of the chair is reduced
Solution Approach 1:
The patent applies localized bending only to specific sections of the transverse portions (at the front and/or rear legs) rather than making the entire transverse portions curved. This maintains simplicity in manufacturing for the majority of the component while introducing stability-enhancing geometry only where structurally necessary.
Data Source
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AI summary
A chair, which comprises a frame (20) with at least two U-shaped parts (11), each one defining a pair of supporting legs (11a, 11b), of which one is a front leg (11a) and the other is a rear leg (11b), and a transverse portion (12) for resting on the ground. The two front legs (11a) and the two rear legs (11b) are connected in an upper region by a respective transverse element (13a, 13b) and each transverse portion (12) of the respective U-shaped part (11) has a section (14) bent inward at the part resting on the ground of the respective front leg (11a) and/or of the rear leg (11b).