Seat connecting device with adjustable backrest
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Solution Overview
Problem
Conventional swivel chairs lack an adjustable backrest, requiring excessive force to adjust the tilt angle due to complex mechanisms and limited force transmission, which affects user comfort and mechanism durability.
Innovation Solution
A seat connecting device with an adjustable backrest featuring a tray connected to a gas spring, a seat back connector with a triangular adjuster, a universal joint, and a bevel gear system for efficient force transmission, along with a tilt control assembly using a tilt rope and handle, and a lifting adjust assembly utilizing a gas spring paddle, allowing for precise and controlled adjustments with reduced user force requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a complex tightness adjusting mechanism with two-direction ropes and lifter is used, then the back frame tightness can be adjusted, but the force required for adjustment increases excessively
Solution Approach 1:
The patent extracts the tightness adjustment function from the complex two-direction rope mechanism and implements it through a simpler threaded rod mechanism. The threaded rod directly adjusts the distance between the back frame connection tail plate and seat pan connection tail plate, eliminating the need for complex rope winding and unwinding mechanisms while reducing the adjustment force required.
Solution Approach 2:
Instead of using ropes to pull and push the back frame for tightness adjustment, the patent inverts the approach by using a threaded rod that directly pushes or pulls the back frame connection tail plate. This inversion simplifies the mechanism and reduces the force required by converting the two-direction rope system into a single-threaded adjustment system.
2Strength
If elastic drawing is used for tightness adjustment, then the mechanism can provide pre-tightening force, but the tensile strength of the elastic drawstring limits the adjustment capability
Solution Approach 1:
The patent changes the adjustment parameter from elastic drawstring tension to threaded rod linear displacement. By using the threaded rod mechanism, the system can achieve a wider range of tightness adjustments by changing the linear position rather than relying on the limited tensile strength of an elastic drawstring. This allows continuous adjustment over a broader range while maintaining adequate pre-tightening force.
3Ease of operation
If conventional swivel chair mechanisms are used, then rotation and movement are flexible, but the backrest tilt angle cannot be adjusted
Solution Approach 1:
The patent segments the seat structure into distinct components: the seat pan, the back frame, and the backrest. By separating the back frame from the seat pan through the connection tail plates and allowing independent adjustment of the back frame's position and angle, the system enables backrest tilt adjustment while preserving the flexible rotation and movement of the overall swivel chair structure.
4Device complexity
If excessive force is required for backrest adjustment, then the adjustment mechanism can be simple, but the durability and service life of the mechanism decreases
Solution Approach 1:
The patent incorporates a shock absorption mechanism that dynamically responds to excessive adjustment forces. When excessive force is applied during backrest adjustment, the shock absorption mechanism activates to protect the threaded rod and connection components from damage. This allows the mechanism to remain relatively simple while significantly improving durability and service life through dynamic force management.
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 enables timely and accurate adjustment of seat back tightness and tilt, reducing the risk of damage and extending the product's service life by improving force transmission and control, while allowing for comfortable and easy adjustments of seat height and extension.
Implementation Method 1
a tray for connecting a gas spring
Implementation Method 2
a tray for connecting a gas spring; a lifting adjust assembly utilizing a gas spring paddle
Implementation Method 3
a bevel gear system for efficient force transmission
Implementation Method 4
a bevel gear system for efficient force transmission
Implementation Method 5
a universal joint
Implementation Method 6
the first hinge part is hinged to the first hinge point of the tray, the second hinge part is hinged to the second hinge point
Data Source
AI summary
Embodiments provide a seat connecting device with an adjustable backrest, belonging to the technical field of swivel chairs. In the embodiments, the seat connecting device includes a seat back tightness control assembly including a control handle, a universal joint, a transmission rod, a first bevel gear, a second bevel gear, a lifting part, a mounting seat of the lifting part, and a tightness adjust rod.