Back support for a chair
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Office chairs with rigid peripheral frames and woven mesh backrests often lack torsional flexibility, leading to discomfort and limited adjustability, as the rigidity restricts the flexibility of the back support, failing to accommodate various user postures effectively.
Innovation Solution
A back support system featuring a flexible frame with spaced support arms and a suspension mesh that can be tensioned without a rigid peripheral frame, allowing for independent flexing and providing ergonomic support characteristics through adjustable tensioning, with an optional lumbar mechanism for enhanced comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid peripheral frame is used to support the mesh fabric in tension, then the structural strength and stability are improved, but the torsional flexibility and comfort are worsened
Solution Approach 1:
The back support frame is segmented into multiple independent support arms (typically 3-5 arms) that extend from a central spine to the peripheral frame. Each support arm can independently flex and twist, allowing the rigid peripheral frame to maintain structural strength while the segmented internal structure provides torsional flexibility and adaptability to user posture.
Solution Approach 2:
The support arms are designed with dynamic flexibility, allowing them to move and adjust their position in response to user weight and posture. This dynamic capability enables the back support to adapt to various sitting positions while the peripheral frame maintains its rigid structural integrity for supporting the mesh fabric tension.
2Duration of action of stationary object
If a rigid peripheral frame is used, then the mesh fabric can be maintained in tension for long-term comfort, but the flexibility and range of movement are limited
Solution Approach 1:
By segmenting the back support into multiple independent support arms within the rigid peripheral frame, the system maintains the mesh fabric in tension for long-term comfort while allowing individual arms to flex and adapt to user movements, thereby preserving flexibility and range of motion.
Solution Approach 2:
The rigid peripheral frame provides localized tension support at the boundaries where the mesh fabric is attached, ensuring long-term comfort and shape retention. Meanwhile, the internal support arms provide localized flexibility where user contact occurs, allowing ease of movement without compromising overall structural integrity.
3Strength
If the frame is made rigid to support the mesh fabric, then the cushioning and support characteristics are improved, but the comfort for various postures is worsened
Solution Approach 1:
The back support frame is divided into multiple independent support arms that can individually adjust to user weight distribution and posture variations. This segmentation allows the rigid peripheral frame to maintain mesh fabric tension for proper cushioning support, while the flexible internal arms adapt to various sitting positions and user preferences.
Solution Approach 2:
Different regions of the back support have different properties: the peripheral frame provides rigid support for mesh tension and cushioning, while the internal support arms provide flexible, adaptable support that responds to local user posture and weight distribution, enhancing overall comfort and posture adaptability.
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 solution provides increased torsional flexibility and comfort by accommodating various user postures, distributing load effectively, and allowing for customizable support profiles across different regions of the back, enhancing user experience and long-term comfort.
Implementation Method 1
The support arms may be flexed from a first 'pre-tensioned' position into a second tensioned position when the suspension mesh is mounted to the support arms. In this tensioned position, the support arms may allow the back support to promote a desired ergonomic contour
Implementation Method 2
The support arms are spaced apart from one another such that each of the support arms can be independently flexed at the periphery
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
An office-type chair including a back support having a suspension mesh back support and a back support frame. The suspension mesh back support has an integral retaining channel disposed at a peripheral edge thereof, and the back support frame includes a central pair of upright support posts and wedge base for mounting to a chair frame. The back support frame includes a plurality of flexible and spaced support arms extending laterally outward from the upright support posts. The support arms each have a peripheral edge configured for fastenerless attachment in a tensioned state within the suspension mesh retaining channel. An upholstery cover encapsulates the suspension mesh and back support frame. The office chair also includes a lumbar mechanism including a resilient cushion that may be positioned in the space between the suspension mesh and the support frame and adjusted along the vertical extent of the back support by rolling the resilient cushion on the rear of the suspension mesh.