Adjustable Knee Brace Telescoping Strut and Hinge Mechanism
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Solution Overview
Problem
Current adjustable postoperative knee braces lack ease of use and effectiveness in fitting different leg sizes and adjusting flexion and extension settings, as well as locking mechanisms, which are crucial for post-surgery and rehabilitation.
Innovation Solution
The knee brace incorporates telescoping struts with a latch assembly and a range of motion hinge, featuring a cam-based locking mechanism and movable latches, allowing for customizable fit and adjustable motion limitations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If telescoping struts are used to fit different leg sizes, then adaptability is improved, but device complexity increases due to the need for adjustable mechanisms
Solution Approach 1:
The telescoping strut employs a nested structure where one tube is inserted within another tube, allowing the brace to adjust to different leg sizes while maintaining a compact form. The inner tube telescopes within the outer tube, providing length adjustment without requiring complex external mechanisms.
Solution Approach 2:
The latch assembly uses a cam mechanism that converts rotational motion of the adjustment knob into linear motion to lock or unlock the telescoping tubes. This self-contained mechanism allows users to easily adjust and secure the strut length without requiring external tools or complex locking systems.
2Reliability
If a latch assembly with cam mechanism is used to lock telescoping struts, then locking reliability is improved, but device complexity increases
Solution Approach 1:
The cam mechanism utilizes a curved cam surface that rotates within a corresponding curved recess in the latch member. This curved geometry converts rotational input into linear locking motion, providing reliable engagement while maintaining a simple, compact structure. The cam profile is designed to ensure positive locking at the desired position.
3Measurement precision
If range of motion hinge with movable latch is used to limit flexion or extension, then control precision is improved, but ease of operation deteriorates
Solution Approach 1:
The range of motion control is divided into discrete angular positions marked on the hinge assembly. The movable latch engages with corresponding detents or notches at these marked positions, allowing precise control of flexion and extension limits. Each marked position represents a predetermined angle, enabling accurate range of motion limitation.
Solution Approach 2:
The adjustment mechanism uses a simple latch that can be manually moved along the hinge plate to engage different angular positions. This mechanical approach replaces complex electronic or motorized adjustment systems, maintaining ease of operation while achieving precise range of motion control through the marked positions and detent engagement.
4Reliability
If frictional force is used to lock strut members, then locking reliability is improved, but ease of operation deteriorates
Solution Approach 1:
The cam mechanism dynamically transitions the locking system between two states: locked and unlocked. When the adjustment knob is rotated, the cam rotates and uses its curved surface to push the latch member, overcoming static friction and releasing the locked position. Once released, a small movement secures the new position by engaging the friction lock again. This dynamic operation allows easy adjustment while maintaining reliable locking.
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 enables quick and easy adjustment of the brace to fit various leg sizes and provides effective immobilization or range of motion limitations, facilitating rehabilitation and postoperative care by ensuring a secure and adjustable fit.
Implementation Method 1
pivoting of the pivot member in one direction relative to the cam base selectively bears the cam base towards the strut member to apply a frictional force to lock the strut member and the receiver against relative telescoping movement
Data Source
AI summary
An adjustable knee brace for fitting a variety of leg sizes and adjustable to limit flexion or extension motion of a knee. The knee brace includes an adjustable length provided by a strut that telescopes within a receiver. A latch assembly mounted on the receiver selectively applies a frictional force to lock the strut member and the receiver against relative telescoping movement. An adjustable range of motion hinge is operatively associated with the telescoping strut. The hinge includes a hinge plate connected to the strut member and having a semi-circular peripheral edge defining a plurality of uniformly spaced apart keys. A range of motion stop is movably positionable relative to the semi-circular peripheral edge and includes a movable latch having teeth. The latch is movable away from the keys to an unlocked position in which the stop is movable relative to the keys, and the movable latch is movable toward and into engagement with the keys to a locked position in which the range of motion stop is not movable relative to the keys. The range of motion stop defines a limit of rotational movement of the range of motion hinge to limit extension or flexion motion of the knee.