Prosthetic Knee Joint Switch Valve Adjustment Mechanism
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Solution Overview
Problem
The existing prosthetic knee joints with hydraulic systems face challenges in adjusting the switch valve's position effectively due to the pre-tensioning element being inside the hydraulic system, making it difficult to access and determine the required parameters for optimal damping and movement control, leading to inefficient switching between different flow resistances during various phases of the gait cycle.
Innovation Solution
Incorporating fluid connections within the valve housing and switch element to facilitate the transfer of hydraulic fluid between chambers, allowing for controlled movement of the switch element by applying a force to the spring element, which is pre-tensioned to exert a counter-force, thus enabling easier adjustment of the switch valve's position without additional installation space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the pre-tensioning element is placed inside the hydraulic system to control the switch valve, then the switching between different flow resistances is achieved, but the adjustment of the switch valve position becomes difficult due to inaccessibility
Solution Approach 1:
A telescopic adjustment mechanism is introduced as an intermediary component that extends through the valve housing to provide accessible adjustment of the switch valve position. The telescopic mechanism transmits adjustment forces from the external environment to the internal switch valve, overcoming the inaccessibility problem while maintaining the pre-tensioning element's function inside the hydraulic system
2Device complexity
If the pre-tensioning element is located inside the valve housing, then the hydraulic system is compact, but the parameters for optimal damping control cannot be easily determined or adjusted
Solution Approach 1:
The telescopic adjustment mechanism serves as a mediator that provides external access to the internal pre-tensioning element's adjustment parameters. By extending the adjustment interface outside the valve housing, the mechanism enables easy determination and adjustment of damping parameters while maintaining the compact internal structure of the hydraulic system
3Ease of operation
If additional components are added to enable switch valve adjustment, then the adjustability is improved, but the installation space requirements increase
Solution Approach 1:
The telescopic adjustment mechanism is nested within the existing valve housing structure, with the telescopic elements collapsing into the housing when not in use. This nesting approach provides the necessary adjustment functionality while minimizing the external footprint and installation space requirements of the overall valve assembly
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
This solution allows for precise control of the switch valve's position, providing the necessary damping for different phases of movement, enhancing the prosthetic knee joint's functionality by ensuring appropriate resistance and fluid flow, thereby improving the overall performance and usability of the prosthetic knee.
Implementation Method 1
the switch element is pre-tensioned by at least one pre-tensioning element arranged in the switch valve
Implementation Method 2
the prosthetic knee joint comprises at least one spring element that applies a counter-force to the switch element, which is oriented against the pre-tension
Implementation Method 3
hydraulic liquid, for example a hydraulic oil, flows from the flexion chamber into the extension chamber
Implementation Method 4
the speed at which the hydraulic fluid moves from the one chamber into the other chamber is decisive for the speed of the movement of the joint
Data Source
AI summary
The invention relates to a prosthetic knee joint with a joint lower part, a joint upper part and a hydraulic system with at least one switch valve, whereinthe hydraulic system comprises an extension chamber, a flexion chamber and at least one piston, the movement of which causes the volume of the extension chamber and/or the flexion chamber to change,the switch chamber comprises a valve housing and a switch element movably mounted therein, which can be brought into a first position and into a second position within the valve housing and divides an interior of the valve housing into a first chamber and a second chamber,the switch element is pre-tensioned by at least one pre-tensioning element arranged in the switch valve,the prosthetic knee joint comprises at least one spring element that applies a counter-force to the switch element, which is oriented against the pre-tension,wherein, within the valve housing and/or the switch element, at least one fluid connection is arranged between the first chamber and the second chamber.