Vehicle Power Leg Rest Linkage for Stable Low-Weight Folding
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Solution Overview
Problem
Conventional power leg rests for vehicles have complex structures with many components, leading to high manufacturing costs, increased weight, and reduced durability, which can result in frequent failures during folding and unfolding operations.
Innovation Solution
A power leg rest design utilizing a tilt motor and a movable lead nut bracket on a lead screw as the output shaft, reducing the number of components and weight, and enabling stable folding and unfolding operations through a linkage system of fixed plates, main links, support pipes, and driving links.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a motor and recliner with multiple mounted parts are used for folding and unfolding operations, then the leg rest can perform the required function, but the number of components increases and the structure becomes complex
Solution Approach 1:
The patent extracts and eliminates the complex recliner mechanism from the conventional leg rest design. Instead of using a motor-driven recliner with multiple mounted parts, the invention uses a simplified linkage mechanism consisting of main links, support pipes, and driving links that directly connect to the seat cushion frame, thereby reducing structural complexity while maintaining the folding and unfolding function
Solution Approach 2:
The patent merges the motor mounting structure with the existing seat cushion frame by fixing the motor to the frame directly. The linkage mechanism components (main links, support pipes, driving links) are integrated into a unified structure where multiple components work together as a single mechanical system, reducing the number of separate mounted parts compared to conventional recliner designs
2Reliability
If a motor and recliner with multiple mounted parts are used for folding and unfolding operations, then the leg rest can perform the required function, but the weight increases
Solution Approach 1:
The patent removes the heavy recliner mechanism from the leg rest design. By replacing it with a lighter linkage mechanism composed of thin-walled main links, support pipes, and driving links, the overall weight of the leg rest is reduced while preserving the essential folding and unfolding capability
Solution Approach 2:
The patent employs a dynamic linkage mechanism where the main links, support pipes, and driving links move relative to each other during folding and unfolding operations. This dynamic structure allows the leg rest to achieve the required motion with lighter components compared to a static, heavily-braced recliner design
3Reliability
If a motor and recliner with multiple mounted parts are used for folding and unfolding operations, then the leg rest can perform the required function, but the manufacturing cost increases
Solution Approach 1:
The patent extracts the complex recliner assembly from the design, eliminating the need for multiple precision-mounted parts. The simplified linkage mechanism with fewer components reduces manufacturing complexity, assembly difficulty, and overall production cost while maintaining functional reliability
Solution Approach 2:
The driving links in the patent serve multiple functions: they connect the main links to the seat cushion frame, provide structural support, and enable the folding motion. This multi-functionality reduces the total number of components needed compared to conventional designs where each function requires a separate component, thereby lowering manufacturing cost
4Device complexity
If the number of mounted parts is reduced, then the manufacturing cost and weight decrease, but the durability may deteriorate
Solution Approach 1:
The patent designs the linkage mechanism with dynamic connections between main links, support pipes, and driving links that allow controlled movement during operation. The hinge connections and pivot points are designed to accommodate operational stresses, maintaining durability despite the reduced number of components compared to rigid, over-braced conventional designs
Solution Approach 2:
The patent merges multiple structural functions into integrated components. The main links serve both as structural supports and as motion-transmitting elements. The support pipes are integrated with the linkage mechanism rather than being separate bracing elements, reducing component count while maintaining the structural integrity and durability needed for reliable operation
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 allows for stable folding and unfolding operations while reducing the number of components and weight, thereby enhancing the durability of the power leg rest.
Implementation Method 1
a lead nut bracket (70) coupled to a lead screw (32) and movable forwards and backwards
Implementation Method 2
a pair of main links, each being hingedly fastened to an external surface of an corresponding one of the fixed plates by a first hinge pin
Data Source
AI summary
A power leg rest for a vehicle includes a pair of fixed plates; a main pipe connected to between internal surfaces of the fixed plates; a tilt motor tiltably mounted to the main pipe; a pair of main links fastened to external surfaces of the fixed plates by respective first hinge pins; a support pipe connected to between front end portions of the main links; a lead nut bracket coupled to a lead screw and movable forwards and backwards and hingedly fastened to the support pipe; a pair of leg rest links mounted on both sides of a leg rest frame; and a pair of driving links, each being hingedly fastened to corresponding ones of the leg rest links, the main links, and the fixed plates, operating in linkage with the main link, and folding or unfolding the pair of leg rest links.