Prosthetic Suspension Mounting Assembly Using Flathead Bolt Centering
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Solution Overview
Problem
Existing prosthetic anchoring systems for above-the-knee and below-the-knee amputees often suffer from instability due to concentration of lateral forces at a single point, leading to extraneous pivoting, rotation, and shift during ambulation.
Innovation Solution
A prosthetic suspension-mounting system utilizing a flathead bolt and socket centering block combination, where the flathead bolt is seated within a disk-shaped recess of the centering cup, providing a circularly-constrained bearing surface that keeps the bolt centered and allows lateral freedom, thus distributing forces and reducing the profile of the mount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single attachment point is used to hold the residual limb in place, then the device complexity is reduced, but stability deteriorates due to extraneous pivoting, rotation and shift during ambulation
Solution Approach 1:
The single attachment point is segmented into multiple attachment points (at least two) distributed across the socket bottom. This segmentation allows the system to maintain simplicity in design while achieving superior stability by distributing forces across multiple locations, preventing pivoting and rotation that occur with single-point attachment.
Solution Approach 2:
The attachment system transitions from a single-point (0D) or line (1D) connection to a distributed multi-point (2D/3D) arrangement on the socket bottom. This dimensional change enables the system to resist forces from multiple directions simultaneously, eliminating extraneous pivoting and rotation while maintaining structural simplicity.
2Device complexity
If lateral forces are concentrated at a single point, then the device complexity is reduced, but reliability deteriorates due to instability and rotation during ambulation
Solution Approach 1:
The force concentration point is segmented into multiple force distribution points across the socket bottom. By distributing lateral forces across at least two attachment points, the system maintains structural simplicity while significantly improving reliability during ambulation by preventing rotation and instability.
Solution Approach 2:
Different regions of the socket bottom are assigned different functional qualities - specific areas are designed as attachment points with enhanced force-bearing characteristics, while other regions maintain the socket's structural integrity. This localized quality enhancement improves reliability without increasing overall device complexity.
3Stability of the object's composition
If a robust mounting solution is implemented to prevent pivoting and rotation, then stability is improved, but device complexity and profile increase
Solution Approach 1:
The mounting assembly is segmented into distinct functional components: the socket with integrated attachment points, the liner with corresponding anchoring features, and the fastening mechanism. This segmentation allows each component to be optimized independently, achieving robust stability without excessive overall complexity.
Solution Approach 2:
The attachment points are merged directly into the socket structure itself rather than being separate add-on components. This integration maintains a low profile and simplifies the overall device while providing the robust multi-point mounting needed to prevent pivoting and rotation during ambulation.
Data Source
AI summary
A prosthetic suspension-mounting system which employs an improved flathead bolt and socket centering cup combination for securement of an amputee-limb enveloping liner within a prosthesis. The liner has a strap fixedly attached on the bottom end of the liner by a flathead bolt. The mounting system also includes a containment socket for seating the liner in the prosthesis using the head of the flathead bolt as a bearing surface against a floor of the socket. The containment socket has a slot there through at a position corresponding to the strap of the liner. The socket is provided with a disk-shaped recess having a flat floor, and the liner is provided with a distal flathead bolt having a flat head to provide a direct bearing surface against the floor of the socket. This provides a delimited bearing surface to keep the liner substantially centered within the prosthesis while still affording a lateral degree of freedom to avoid concentration of lateral forces.