Pretensioned Locking Assembly for One-Handed Surgical Fixation
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Solution Overview
Problem
Current pretensionable locking systems for medical instruments require additional effort from surgeons during surgery to fix the outer body onto the inner body, diverting attention from the surgical procedure.
Innovation Solution
A pretensionable locking system with a resilient retaining element on the outer locking body and a rigid bulge on the inner locking body allows for easy assembly and secure fixation by screwing the inner thread onto the outer thread, reducing the need for manual pressing and minimizing the risk of breakage and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer body is pressed onto the inner thread during surgery for final fixation, then secure fixation is achieved, but the surgeon's attention is diverted from the surgical procedure
Solution Approach 1:
The pressing action is performed preliminarily during assembly by the resilient retaining element automatically pressing the inner thread against the outer thread, so that during surgery only the screwing action is needed to achieve reliable fixation without diverting surgical attention
2Strength
If a resilient spring is used to pretension the inner thread of the sleeve, then the inner thread sits tightly between the spring and outer thread, but the spring may break or wear during use
Solution Approach 1:
The invention changes the material parameter from soft resilient material to hard wear-resistant material for the retaining element, while maintaining the pretensioning function through geometric design (ramp-shaped bulge) rather than material elasticity, thereby achieving both clamping force and resistance to breakage and wear
Solution Approach 2:
The locking system uses composite construction with the outer body made of wear-resistant material and the retaining element made of hard material, combining different material properties to achieve both pretensioning capability and resistance to breakage and wear
3Ease of operation
If the inner thread is shoved over the spring in longitudinal axial direction, then the outer body is prefixed, but the spring must be compressed radially inward which requires additional effort
Solution Approach 1:
The assembly process is simplified by performing the pressing action preliminarily during assembly rather than requiring compression during surgery, reducing the force required during surgical operation to only what is needed for screwing
Solution Approach 2:
The ramp-shaped bulge acts as an intermediary mechanical element that converts axial movement into radial pressing force, enabling the inner thread to be pressed against the outer thread automatically as the outer body is moved axially onto the inner body
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 system enables a one-handed operation, reduces the risk of breakage, ensures a constant clamping force, is easy to clean and disinfect, and can withstand torsional forces, thus enhancing surgical efficiency and safety.
Implementation Method 1
the outer locking body has a resilient retaining element that projects radially inward, and the inner locking body has a rigid bulge that projects radially outward, wherein in the pretensioned position, the retaining element lies against the bulge
Data Source
AI summary
A pretensionable locking system, a method for producing a locking system and a medical-technical instrument including a locking system. The locking system (2) includes a locking body (10) with an inner thread (12), and an inner locking body (20) with an outer thread (22). In a pretensioned position, the inner thread lies against the outer thread in a first longitudinal axial direction (80) and is pretensioned against the outer thread. In a locked position, the outer locking body is fixed on the inner locking body by screwing the inner thread onto the outer thread. The outer locking body has a resilient retaining element (14) that projects radially inward, and the inner locking body has a rigid bulge (24) that projects radially outward. In the pretensioned position, the retaining element lies against the bulge in a second longitudinal axial direction (85) that is opposite the first longitudinal axial direction.