Variable Radius Knee Brace Spring for Constant Muscle Support
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Solution Overview
Problem
Existing knee braces primarily focus on lateral support for the joint rather than providing adequate muscle support, and some devices use complex and bulky fluid spring systems that are expensive.
Innovation Solution
A variable radius spring assembly for knee braces comprising upper and lower hinge pieces, a spring bracket, and an elongated spring element, which provides non-linear support to leg muscles by maintaining a constant force throughout the range of motion, enhancing muscle support without compromising the normal range of motion or comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional linear spring system is used to support leg muscles, then the device structure is simple, but the force required to compress the spring increases non-linearly with compression distance, making it uncomfortable and ineffective for full range of motion
Solution Approach 1:
The spring assembly uses a dynamic variable radius mechanism where the effective radius changes as the knee moves through its range of motion. The lower hinge piece rotates relative to the upper hinge piece, causing the catch's distance from the rotation axis to vary. This dynamic adjustment transforms the spring's mechanical advantage throughout the motion arc, maintaining substantially constant force requirements for compression while providing full range of motion support.
Solution Approach 2:
The invention adds a rotational dimension to the spring mechanism by introducing relative rotation between the upper and lower hinge pieces. This rotational degree of freedom creates a variable lever arm (radius) that changes with the knee angle, converting a simple linear spring compression into a two-dimensional motion system that maintains constant force characteristics.
2Force
If a fluid spring system is used to provide muscle support, then the device provides adequate muscle support, but the device becomes complicated, bulky, and expensive
Solution Approach 1:
The invention extracts and eliminates the complex fluid spring system from the knee brace design. By removing the hydraulic/pneumatic components and replacing them with a mechanical variable radius spring assembly, the patent achieves the same muscle support function with a much simpler, more compact structure that does not require bulky reservoirs, valves, or fluid management systems.
Solution Approach 2:
The patent replaces the fluid-based spring system with a purely mechanical solution. The variable radius spring assembly uses mechanical leverage and geometry changes to provide the necessary support force, eliminating the need for fluid pressure systems while achieving comparable or superior performance.
3Stability of the object's composition
If a knee brace provides lateral support to the joint, then the joint stability is improved, but the device does not provide adequate support and assistance to the leg muscles
Solution Approach 1:
The variable radius spring assembly performs multiple functions simultaneously: it provides lateral stability to the knee joint through the hinge connection while also delivering substantial muscle support through the spring's resistive force. The single assembly structure serves both as a stabilizing joint mechanism and as a muscle assistance system, eliminating the need for separate support mechanisms.
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 assembly offers ergonomic and robust support to leg muscles, providing lateral protection and support to the knee joint, suitable for daily activities and athletic endeavors, while requiring less input force and maintaining consistent energy storage.
Implementation Method 1
the spring element is secured to the spring bracket... the spring element extends downward from the spring bracket... the catch forces the spring element rearward and slides downward along the spring element... the spring element applies a substantially constant force throughout its travel returning to its undeflected state
Data Source
AI summary
In combination with a knee brace, the variable radius spring assembly of the present invention provides a full range knee orthotic with support to the leg muscles without compromising the range of motion and the patient's normal walk/gate. The assembly comprises upper and lower hinge pieces attached to upper and lower sections of the brace, a spring bracket, and an elongated spring element that extends downward from the upper hinge piece past a catch on the lower hinge piece. Two such assemblies are attached to a knee brace, one on the inner side and one on the outer side. As the lower leg, and the lower hinge piece, move rearward, the catch forces the spring element rearward and slides downward along the spring element. Consequently, the spring element has a non-linear response requiring approximately the same about of force to deflect the spring element throughout its range of rearward travel.