Exoskeleton Load-Balancing Mechanism With Compact Spring-Lever Layout
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Solution Overview
Problem
Existing exoskeletons face challenges in providing a compact, robust, and mechanically simple elastic load-balancing mechanism that allows for adequate elastic force return while maintaining freedom of movement, particularly for the whole body.
Innovation Solution
An exoskeleton mechanism incorporating a lever system with a stiff compression spring, using a connection element, housing, and flexible traction elements to balance loads, minimizing the footprint and allowing high-intensity force return.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional elastic load-balancing mechanism is used, then adequate elastic force return is achieved, but the mechanism occupies large transverse dimensions and lacks compactness
Solution Approach 1:
The patent inverts the conventional approach by using a compression spring instead of a tension spring, and by positioning the spring inside the oscillating housing rather than outside. This inversion allows the spring to push against a stop rather than pull on a lever, fundamentally changing the spatial arrangement and enabling compact integration within the housing boundaries.
Solution Approach 2:
The compression spring is nested within the housing, with the spring contained inside the oscillating volume defined by the housing walls. The stop is positioned within the housing to receive the spring force, creating a nested arrangement where the spring, stop, and housing form a compact integrated assembly that minimizes transverse footprint.
2Force
If a stiff compression spring is used to return high-intensity force, then adequate elastic force is achieved, but the mechanism becomes more complex and less mechanically simple
Solution Approach 1:
The patent extracts the force-generating function from a complex lever-and-tension-spring system and isolates it into a simple compression spring acting directly on a stop. By removing intermediate transmission elements and focusing solely on the essential force storage and release mechanism, the design achieves high force intensity with minimal mechanical complexity.
Solution Approach 2:
The compression spring serves multiple functions simultaneously: it stores elastic energy, provides the balancing force, and directly interacts with the oscillating housing through the stop. This self-contained arrangement eliminates the need for separate force transmission mechanisms, reducing overall system complexity while maintaining high force output.
3Ease of operation
If freedom of movement is maximized for the wearer, then user comfort and rehabilitation effectiveness are improved, but the load-balancing mechanism becomes less effective
Solution Approach 1:
The patent employs a dynamic oscillating housing that moves with the wearer's limb, allowing the load-balancing mechanism to adapt to varying movement amplitudes and velocities. The housing oscillates about a fixed axis while accommodating the natural range of motion, ensuring the spring remains engaged with the stop throughout the movement cycle and maintaining load-balancing effectiveness across the full spectrum of user activities.
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 mechanism achieves a compact design with high elastic force return, reducing bulk and enabling efficient load balancing with minimal transverse dimensions.
Implementation Method 1
at least one compression spring acting in a push ratio against the lever moving away from the first axis of oscillation
Implementation Method 2
the use of a very stiff compression spring able to return a particularly high intensity force
Implementation Method 3
the presence of a lever, allows the use of a very stiff compression spring able to return a particularly high intensity force while occupying a small footprint
Implementation Method 4
at least one flexible traction element having a first end integral with the connection element and a second end secured to the lever
Data Source
AI summary
An exoskeleton having a mechanism for elastically balancing loads applied to the exoskeleton is provided. The mechanism has a rigid connection element and a rigid housing mutually pivoted to one another about a first axis of oscillation and attachable to respective relatively rotatable parts of the exoskeleton. A lever is rotatably mounted to the rigid housing about a second axis of oscillation. A flexible traction element has a first end rotationally secured to the rigid connection element with respect to the first axis of oscillation and a second end secured to the lever at a securing point spaced from the second axis of oscillation. A compression spring exerts a thrust, away from the first axis of oscillation, against a portion of the lever intermediately between the second axis of oscillation and the securing point to the second end of the flexible traction element.