Chair Backrest Operation Member Layout for Single-Posture Control
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Solution Overview
Problem
Existing office chairs with rotating backrests have poor operability as the operating lever and adjustment knob are separated in the forward/rearward direction, requiring users to change posture for continuous operation, and they are difficult to assemble due to separate components.
Innovation Solution
A chair design where the first operation member for regulating the backrest rotation and the second operation member for returning the backrest to its initial state are positioned on opposite sides of a base member extending in the widthwise direction, allowing for easy operation without changing posture and facilitating unitized assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the operating lever and adjustment knob are disposed at positions separated in the forward/rearward direction, then the structure is simple, but the operability is poor as users need to change posture to operate both components
Solution Approach 1:
The patent transitions from arranging operation members in the forward/rearward direction (one dimension) to arranging them in the widthwise direction (another dimension). This dimensional change allows both the operating lever and adjustment knob to be positioned laterally on opposite sides of the base member, enabling users to operate both components with hands positioned naturally on either side without changing posture, thereby resolving the operability issue while maintaining structural simplicity
2Ease of manufacture
If the operating lever and adjustment knob are disposed at positions separated in the forward/rearward direction, then the components can be independently designed, but the assembly workability is poor as they cannot be unitized
Solution Approach 1:
The patent merges the operating lever and adjustment knob into a single integrated assembly by positioning them on opposite sides of a common base member. This merging allows both operation members to be unitized as one assembly unit, significantly improving assembly workability. The base member serves as a unifying structure that holds both components, enabling them to be installed together as a single unit rather than separately, thus resolving the assembly difficulty while maintaining independent design capability
3Device complexity
If the operating members are positioned close together, then the assembly is simplified, but the interference between operation members increases
Solution Approach 1:
The patent employs asymmetric positioning of the operating members by placing them on opposite sides of the base member in the widthwise direction. This asymmetric arrangement creates sufficient lateral spacing between the operating lever and adjustment knob, preventing interference during operation. The asymmetric layout allows each component to occupy its own spatial zone while maintaining a compact overall structure, thus resolving the interference issue without complicating the component arrangement
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 chair provides improved operability as users can operate the backrest regulation and return functions with one hand each without changing posture, and the integrated components enhance assembly workability.
Implementation Method 1
the return part may have a spring configured to bias the backrest in the inclined state in a direction of returning to the initial state
Data Source
AI summary
A chair has a support structure, a backrest supported rotatably with respect to the support structure around a first axis extending in a widthwise direction of the support structure and displaceable to an inclined state inclined rearward from an initial state, a regulating part that regulates rotation around the first axis of the backrest, a return-part that returns the backrest in the inclined state to the initial state, a first-operation-member that allows a seated person to operate the regulating part, a second-operation-member that allows the seated person to operate the return-part, and a base-member that supports the first-operation-member and the second-operation-member, the base-member extends in the widthwise direction, the first-operation is supported by a first-support-part provided on one end side in the widthwise direction of the base-member, and the second-operation-member is supported by a second-support-part provided on other end side in the widthwise direction of the base-member.