Leg Support Cam Linkage for Stable Weight Transfer
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Solution Overview
Problem
Existing leg supporting apparatuses fail to provide stable weight support and efficient energy transfer during walking, especially for users with weakened muscular strength, as they often require external energy sources and lack efficient mechanisms for rotational force transfer.
Innovation Solution
A leg supporting apparatus with a coupling structure that includes a rotational force transferring member, such as a cable or links, and a clutch system, allowing the thigh frame to move along a downwardly-concave curve regardless of calf frame pivoting direction, with a cam and latch mechanism to ensure stable support and energy transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a leg supporting apparatus uses a conventional joint structure without a cam mechanism, then the structure is simpler, but the thigh frame cannot maintain stable weight support when the calf frame pivots in different directions
Solution Approach 1:
The patent introduces a cam mechanism as an intermediary component between the calf frame and thigh frame. The cam profile acts as a mediator that converts the pivoting motion of the calf frame into controlled movement of the thigh frame along a downwardly-concave curve, ensuring stable weight support regardless of the direction in which the calf frame pivots.
Solution Approach 2:
The patent employs a downwardly-concave curved path for the thigh frame's end movement. This curvature is specifically designed to maintain the center of weight at the lowest point of the curve, providing stable support. The cam mechanism's profile is shaped to guide the thigh frame along this curved trajectory, utilizing geometric curvature to achieve stability.
2Power
If the thigh frame is rigidly connected to the calf frame, then the structure is simpler, but rotational force cannot be efficiently transferred during walking
Solution Approach 1:
The patent replaces a rigid connection with a dynamic coupling mechanism consisting of the cam, latch, and rotational force transferring member. This dynamic structure allows the thigh frame to pivot relative to the calf frame while still enabling efficient rotational force transfer during the walking cycle. The mechanism adapts its configuration based on the direction and magnitude of applied forces.
Solution Approach 2:
The patent extracts the rotational force transfer function from a rigid connection and implements it through a separate, dedicated mechanism. The rotational force transferring member (such as a cable or linkage) is specifically designed to transfer rotational forces between the calf and thigh frames, separating this function from the overall structural connection.
3Ease of operation
If external energy sources are used to assist walking, then user mobility can be improved, but the device requires power supply and control systems
Solution Approach 1:
The patent designs a self-service mechanism where the user's own walking motion provides the energy for assistance. The cam and latch mechanism automatically engage and disengage based on the natural gait cycle, and the rotational force transferring member passively transfers forces without requiring external power. The system serves itself by utilizing the user's biomechanical energy.
Solution Approach 2:
The patent employs periodic action through the cam mechanism that engages and disengages in rhythm with the user's walking cycle. The latch mechanism periodically locks and unlocks to provide assistance during specific phases of gait, creating a rhythmic, periodic operation that matches the natural cadence of walking without requiring continuous external energy input.
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 apparatus effectively stabilizes user weight by maintaining the center of weight on the lowest point of the downwardly-concave curve, enabling efficient energy transfer and stable support without external energy sources, enhancing user mobility and comfort.
Implementation Method 1
a cam and latch mechanism to ensure stable support and energy transfer
Implementation Method 2
a clutch system, allowing the thigh frame to move along a downwardly-concave curve
Implementation Method 3
a rotational force transferring member, such as a cable or links
Implementation Method 4
The apparatus effectively stabilizes user weight by maintaining the center of weight on the lowest point of the downwardly-concave curve
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Example embodiments relate to a link assembly and a leg supporting apparatus using the same. A top end of a frame mounted on a user's thigh can move along a downwardly-concave trajectory. A center of weight of the leg supporting apparatus placed on the top end of the frame converges on a lowest point of the downwardly-concave trajectory so that the user's weight can be stably supported.