Height-Adjustable Backrest Locking Assembly for Stable Positioning
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Solution Overview
Problem
Existing height-adjustable backrest assemblies are inconvenient to operate and lack stability in fixing the backrest at desired heights, failing to provide comfort for users of varying heights.
Innovation Solution
A height-adjustable backrest assembly featuring a coupling groove, abutment member, positioning button, and positioning board with spring mechanism, allowing for easy height adjustment and secure fixation using a combination of inclined guiding faces, stop faces, and spring-activated pivoting, along with a positioning board and transfer groove for precise alignment and stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If height adjustment mechanism with bolts is used, then backrest height can be adjusted for different users, but the adjusting operation becomes inconvenient and the fixing reliability deteriorates
Solution Approach 1:
The patent replaces the traditional bolt-based mechanical fastening system with a spring-loaded pin mechanism. The spring automatically pushes the pin against the backrest, providing both adjustment capability and secure fixation without requiring tools or complex tightening operations. This substitution resolves the contradiction by maintaining height adaptability while dramatically improving ease of operation.
Solution Approach 2:
The spring mechanism provides self-service functionality where the spring automatically maintains constant pressure on the pin, ensuring continuous engagement with the backrest. The system self-regulates the fixing force without requiring user intervention for tightening or adjustment, thereby improving both operational convenience and fixing reliability simultaneously.
2Adaptability or versatility
If height adjustment mechanism with bolts is used, then backrest height can be adjusted for different users, but the fixing reliability and stability deteriorates
Solution Approach 1:
The spring acts as a counterbalancing force that continuously pushes the pin against the backrest, counteracting any forces that might cause the pin to loosen or disengage. This constant counter-pressure ensures reliable fixation at any selected height position, resolving the contradiction between height adaptability and fixing reliability.
Solution Approach 2:
The spring mechanism provides beforehand cushioning by pre-loading the pin against the backrest with constant force. This pre-applied pressure ensures that the pin remains firmly engaged even under varying load conditions, maintaining fixing reliability across all height positions without requiring additional locking mechanisms.
3Ease of operation
If positioning button with spring mechanism is added, then adjusting convenience and fixation reliability are improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple functions into the positioning button assembly: the button itself serves as the actuator, the spring provides both the actuating force and the locking force, and the pin serves as both the positioning element and the locking element. This functional integration achieves improved ease of operation without proportionally increasing device complexity, as a single button operation controls the entire adjustment and locking process.
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 enhances operational convenience and stability by allowing smooth height adjustments and secure fixation of the backrest, ensuring comfort for users of different heights with improved ease of use and reliability.
Implementation Method 1
A spring includes first and second tangs and a coil portion between the first and second tangs. The coil portion is mounted to the mounting section of the positioning button. The pivot extends through the coil portion of the spring and is connected to the connecting member. The first tang abuts against the connecting member, and the second tang abuts against the positioning button.
Data Source
AI summary
A height-adjustable backrest assembly includes a connecting member an upper end mounted between a positioning board having vertically spaced positioning grooves and a backrest movable relative to the positioning board in a vertical direction. A lower end of the connecting member is coupled to a seat or a base. A positioning button is pivotably mounted to the connecting member and has a positioning section biased by a spring to releasably engage one of the positioning grooves. A transfer groove below the bottommost positioning groove receives the positioning button when the positioning section of the positioning button disengages from the positioning grooves. The positioning button abuts against an abutment member on the connecting member to limit the positioning section in a position not aligned with the positioning grooves. The abutment section disengages from the abutment member when an abutment protrusion of the positioning board presses against the positioning section.