Chair Backrest Height Locking With Spring-Loaded V-Groove Adjustment
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Solution Overview
Problem
Conventional chairs lack the ability to adjust the height of their backrests to accommodate varying user postures and heights, failing to provide effective support for the user's back.
Innovation Solution
An adjusting device comprising a movable base with V-shaped grooves, a connecting block, and a positioning unit with upholding feet and a spring mechanism, allowing the backrest to be smoothly adjusted in height and securely positioned, utilizing a sliding rail system and locking projections to maintain stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the backrest is made immovable or fixed at a certain level, then the structure is simple and stable, but it cannot be adjusted to accommodate varying user postures and heights
Solution Approach 1:
The backrest is transformed from a fixed structure to a dynamically adjustable one through the integrating mechanism. The movable base can slide along the connecting rod, and the positioning unit with upholding feet can lock at different positions, enabling the backrest to adapt to various user needs while maintaining structural stability when locked.
Solution Approach 2:
The adjusting device is divided into functional segments: the movable base for height adjustment, the connecting rod for structural support, and the positioning unit for locking. This segmentation allows each component to perform its specific function efficiently while contributing to the overall adjustability without excessive complexity.
2Adaptability or versatility
If an adjusting mechanism is added to the backrest, then height adjustability is improved, but the device complexity and structural complexity increase
Solution Approach 1:
The positioning unit is integrated into the connecting block, and the movable base is combined with the connecting rod structure. This merging reduces the number of separate components and simplifies the overall device complexity while maintaining the height adjustment functionality through the coordinated action of the integrated components.
Solution Approach 2:
The positioning unit with upholding feet is nested within the connecting block structure. The upholding feet pivot within the connecting block and engage with the movable base, creating a compact nested arrangement that reduces spatial complexity while providing the necessary locking mechanism for height adjustment.
3Adaptability or versatility
If the backrest height is made adjustable, then user comfort and support are improved, but the stability and security of the backrest position may be compromised
Solution Approach 1:
The upholding feet are designed to pivot and engage with the movable base before the adjusting mechanism is fully actuated. This preliminary engagement ensures that the backrest position is secured in advance, preventing unintended movement and maintaining stability once the desired height is reached.
Solution Approach 2:
The spring mechanism automatically pushes the upholding feet outward to engage with the movable base when the adjusting mechanism is released. This self-service locking action ensures that the backrest position is securely maintained without requiring additional user intervention, thereby improving reliability while preserving adjustability.
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
Enables the backrest to be adjusted to various heights, providing improved support and comfort by allowing the user to customize the height according to their preference, while maintaining stability through the spring mechanism and locking system.
Implementation Method 1
A spring is put between the upholding feet to elastically expand them wide open
Data Source
AI summary
An adjusting device of a chair backrest includes a movable base, a connecting block and a positioning unit. The movable base encompasses an adjusting opening having plural continuous V-shaped grooves in two vertical sidewalls, a stopping groove and a projecting-downward portion, and two sliding rails. The connecting block is fitted in the movable base, possessing a rectangular recess. The positioning unit is installed in the rectangular recess, having two upholding feet fixed with the connecting block and respectively having a locking projection and a locking groove corresponding to each other. A spring is put between the upholding feet to elastically expand them. With the movable base fixed with the backrest and the connecting block fixed with a connecting rod, the movable base can be moved up and down together with the backrest, with the height of the backrest adjusted.