Clamping Disc Freewheel Locking for Power-Loss Grip Holding
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Solution Overview
Problem
Existing locking mechanisms in orthopedic devices, such as upper extremity prostheses, struggle to maintain gripping force after power loss without continuous energy input and often require complex designs that are costly and difficult to manufacture.
Innovation Solution
A clamping roller locking mechanism with asymmetrical clamping discs having freewheel and locking sides positioned differently for each disc, allowing selective rotation direction control through drive and output projections, using an odd number of discs and recesses for adjustable locking force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional freewheel mechanism is used to maintain gripping force after power loss, then the locking function is achieved, but the device complexity increases and manufacturing becomes more difficult
Solution Approach 1:
The locking mechanism is divided into multiple independent clamping discs (at least three) with recesses and clamping rollers, where each disc segment independently contributes to the locking function. This segmentation allows the complex locking behavior to be achieved through simple, repeatable modular units rather than a single complex mechanism.
Solution Approach 2:
The clamping discs feature asymmetrical recesses with distinct freewheel sides and locking sides. The freewheel side has a larger surface area allowing free rotation, while the locking side has a smaller surface area that engages with the housing to prevent rotation. This asymmetry enables the freewheel/locking dual function without additional complex components.
2Force
If a wrap spring locking mechanism is used to lock the drive train against external forces, then the locking force is achieved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The clamping rollers automatically perform the locking function without requiring external actuation or complex control systems. When external forces are applied to the output shaft, the clamping rollers are forced into the locking sides of the recesses, self-activating the locking mechanism. This eliminates the need for wrap springs or other active locking components.
3Ease of manufacture
If multiple identical clamping discs are used with uniform recess positions, then the manufacturing is simplified, but the locking force cannot be scaled effectively
Solution Approach 1:
The clamping discs are designed with different local configurations - specifically, the recesses are positioned at different angular locations on different discs. This allows each disc to contribute differently to the overall locking force, enabling scalable locking capability while maintaining relatively simple manufacturing of individual disc components.
4Speed
If the recesses are made large enough to prevent clamping roller contact with the housing, then free rotation is enabled, but the locking function is lost
Solution Approach 1:
The recesses are designed with asymmetrical dimensions: the freewheel side has a larger surface area that prevents clamping roller contact with the housing, enabling free rotation. The locking side has a smaller surface area that allows the clamping roller to contact the housing, enabling the locking function. This asymmetry resolves the contradiction between free rotation and locking capability.
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
Enables efficient, energy-saving operation by maintaining gripping force without continuous power and simplifies manufacturing with fewer components, ensuring free rotation when driven and locking when externally torqued.
Implementation Method 1
the clamping roller is clamped between the clamping disc and the housing... rotation of the clamping disc relative to the housing is not possible
Implementation Method 2
They have a freewheel side large enough to prevent a clamping roller from coming into contact with the housing, and a locking side small enough to allow a clamping roller to come into contact with the housing
Data Source
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AI summary
The invention relates to a jamming roller lock comprising a housing (22) and at least two, preferably three clamping disks (2), which are arranged in the housing (22) in rotatable fashion and each have at least one recess (4), in which a jamming roller (20) is situated, at least one driving projection (12) and at least one driven projection (14), wherein the clamping disks (1) are arranged and embodied in such a way that a rotation of the clamping disks (2) is possible by driving the driving projections (12) and a rotation of the clamping disks (2) is prevented when driving the driven projections (14).