Bone Fixation Screw Head Spring Locking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bone fixation devices, such as trochanteric fixation implants, often experience screwdriver disengagement during insertion, prolonging procedure time and causing complications due to the lack of secure locking mechanisms.
Innovation Solution
A bone fixation device with a spring mechanism in the head that deflects radially outward to securely engage a spherical tip of the driving mechanism, providing a biasing force to lock the device in place, minimizing loosening and facilitating efficient insertion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional bone fixation device without a spring mechanism is used, then the device structure is simple, but the screwdriver is prone to disengagement during insertion, increasing procedure time and causing complications
Solution Approach 1:
The patent applies the dynamics principle by incorporating a spring mechanism that transitions from a static head structure to a dynamic one. The spring portion can deflect radially outward when force is applied, allowing the driving mechanism tip to be securely retained, and then returns to its original position to lock the driving mechanism in place. This dynamic behavior ensures reliable engagement while maintaining a relatively simple overall device structure.
Solution Approach 2:
The spring mechanism provides self-service functionality by automatically locking and unlocking the driving mechanism without requiring additional components or complex operations. When the driving mechanism is inserted, the spring deflects and naturally returns to retain the tip; when force is applied radially outward, the spring automatically releases the lock. This self-operating mechanism improves reliability without proportionally increasing device complexity.
2Productivity
If a secure locking mechanism is implemented, then disengagement is prevented and procedural efficiency is enhanced, but the device structure becomes more complex
Solution Approach 1:
The dynamic spring mechanism enables rapid engagement and disengagement of the driving mechanism, significantly improving procedural efficiency. The spring's ability to deflect and return provides instant locking upon insertion and quick release when needed, eliminating the time loss associated with screwdriver disengagement. The complexity added is minimal - primarily a slot and spring portion within the existing head structure.
Solution Approach 2:
The patent changes the physical state and position parameters of the head structure by introducing a slot that allows radial deflection of the spring portion. This parameter change enables the spring to move from a constrained position to a deflected position and back, creating the locking mechanism. The overall head geometry remains similar to traditional designs, so the increase in device complexity is minimal while productivity gains are substantial.
3Stability of the object's composition
If a spring mechanism is added to provide locking force, then engagement stability is improved, but the manufacturing complexity increases
Solution Approach 1:
The spring mechanism provides stable engagement through its dynamic locking action, where the spring's elastic force continuously maintains contact with the driving mechanism tip. This dynamic stability ensures the driving mechanism remains securely retained during insertion without requiring complex additional structures. The manufacturing process primarily involves creating a slot in the head and forming or installing a spring, which are relatively straightforward operations compared to creating complex mechanical locking systems.
Solution Approach 2:
The slot geometry and spring dimensions are designed to provide the necessary locking force while maintaining manufacturability. The slot can be created through standard machining or additive manufacturing processes, and the spring can be formed from wire or manufactured as an integrated feature. These parameter choices balance engagement stability with ease of manufacture, avoiding overly complex geometries that would significantly increase manufacturing difficulty.
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 spring mechanism effectively reduces the time and effort required for securely seating the bone fixation element by providing a stable locking mechanism, preventing disengagement and enhancing procedural efficiency.
Implementation Method 1
A slotted opening extends distally into the head by a predetermined distance, the opening defining a spring portion on a lateral side thereof, the spring portion being biased toward the central longitudinal axis and configured to be deflectable away from the central longitudinal axis upon application of a radially expansive force thereto.
Implementation Method 2
the spring portion being biased toward the central longitudinal axis and configured to be deflectable away from the central longitudinal axis upon application of a radially expansive force thereto
Data Source
Figure 1~3
Figure 4
Figure 5~6
AI summary
A bone fixation device comprises an elongated body extending from a head at a proximal end to a shaft at a distal end along a central longitudinal axis. A slotted opening extends distally into the head by a predetermined distance, the opening defining a spring portion on a lateral side thereof, the spring portion being biased toward the central longitudinal axis and configured to be deflectable away from the central longitudinal axis upon application of a radially expansive force thereto.