Screwdriver Split Shaft Oblique Contact Clamping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing screwdrivers for inner profile screws lack a reproducible clamping force, as the clamping force is dependent on material elasticity and tolerances, leading to inconsistent engagement with the screw head during surgical implantation.
Innovation Solution
A screwdriver design featuring a split shaft with oblique contact members and a screwable bushing, where the bushing's movement or rotation relative to the shaft allows for precise clamping of the inner profile recess, independent of screw head tolerances, using a contact ring to adjust the separation of split sections for consistent clamping force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a split shaft design with spring action is used to clamp the screw head, then the screwdriver can engage with the screw head, but the clamping force is not precisely defined and varies with tolerances
Solution Approach 1:
The patent changes the parameter of clamping force from being elasticity-dependent to being geometry-dependent. By using an oblique contact member that transforms axial movement into radial clamping force through geometric projection, the clamping force becomes a defined function of the applied axial force and the contact angle, rather than varying with material elasticity and tolerances.
Solution Approach 2:
The oblique contact member acts as an intermediary element between the axial movement and the radial clamping action. It mediates the force transformation from the shaft's axial displacement to the radial clamping force on the screw head, providing a predictable and reproducible force relationship independent of material properties.
2Ease of operation
If the shaft sections are separated by spring action, then engagement with the screw head is achieved, but the clamping force depends on material elasticity and tolerances
Solution Approach 1:
The shaft is segmented into separable sections that can move relative to each other. This segmentation allows the shaft to adapt to the screw head geometry while maintaining a defined clamping mechanism through the oblique contact member, separating the engagement function from the clamping force generation.
Solution Approach 2:
The patent changes the fundamental parameter of force generation from elastic deformation to geometric constraint. The oblique contact member creates a mechanical constraint that defines the clamping force through geometry rather than material elasticity, making the force reproducible and independent of material variations.
3Manufacturing precision
If a bushing is used to align shaft sections, then the shaft sections can be aligned, but the device complexity increases
Solution Approach 1:
The patent merges the alignment function and the clamping function into a single integrated mechanism. The oblique contact member simultaneously provides alignment guidance and generates the clamping force, eliminating the need for separate bushing components and reducing overall device complexity.
Solution Approach 2:
The oblique contact member serves multiple functions: it guides the alignment of shaft sections, transforms axial movement into radial clamping force, and maintains consistent contact pressure. This multi-functionality replaces what would traditionally require separate components for alignment and clamping.
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 screwdriver applies a reproducible clamping force, enhancing the secure engagement of the screwdriver with the screw head, reducing the risk of slippage during surgical procedures and improving the reliability of screwing operations.
Implementation Method 1
through a movement of the bushing relative to the shaft, the section of the shaft provided with the oblique contact member is split off from the other part, by clamping the inner profile recess with the outer profile head
Implementation Method 2
the screwdriver is designed with a screwable bushing that receives the shaft made from an elastic material
Data Source
AI summary
A screw driver for a screw having a drive socket having an axially extending shaft with a bifurcated tip, the tip having a cross-sectional profile for insertion into a cross-sectional profile of the screw socket. The shaft has a tapered section adjacent the bifurcated tip. A bushing is mounted on an outer surface of the shaft for axial movement therealong. The bushing has inwardly extending protrusions for engaging the tapered section on the shaft upon movement in the axial direction along the shaft in a direction away from the tip. This allows the selective capture or release of the screw by the shaft tip by axial movement of the bushing away from and towards the shaft distal tip.