Medical Screwdriver Tool with Cam-Actuated Split Tip

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing medical screwdrivers require counter-intuitive force application to secure screws, making the process tedious and risky, especially in medical procedures, due to the asymmetrical split end design which can lead to screws becoming loose or lost.

Innovation Solution

A tool with a driver shaft and actuator that moves between positions to open or close the tip's portions via a cam profile and drive projections, allowing intuitive forward pushing to secure fasteners, reducing the risk of misalignment and screw loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the bushing is moved away from the screw to clamp the screw, then the clamping force is improved, but the user must apply counter-intuitive force which increases operation difficulty and risk of screw loss

Engineering Contradiction:
Improveclamping forceVSAvoidoperation intuitiveness
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent inverts the traditional bushing movement direction. Instead of moving the bushing away from the screw to clamp (as in prior art), the actuator moves toward the tip to engage the cam profile and force the split portions together. This reversal makes the clamping action intuitive - pushing forward to clamp, pulling back to release - eliminating the counter-intuitive force application problem while maintaining strong clamping force

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If the bushing is pulled back to release the screw, then the screw can be removed, but the force required may outweigh the securing force causing accidental screw loss

Engineering Contradiction:
Improvescrew release capabilityVSAvoidscrew security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces a cam profile as an intermediary mechanism between the actuator and the split portions. The cam profile converts the actuator's linear motion into controlled radial movement of the split portions. During release, the actuator simply pulls back along the cam profile's guide groove, and the cam geometry automatically reduces clamping force progressively, preventing sudden screw loss while ensuring reliable release when fully retracted

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the split end design is used to enable screw clamping, then the fastening function is achieved, but the asymmetrical design creates counter-intuitive operation and increases screw loss risk

Engineering Contradiction:
Improvefastener engagement capabilityVSAvoidforce application direction
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies the inversion principle to the entire clamping mechanism operation. The actuator moves in the same direction as the desired clamping force (toward the tip), rather than opposite to it. The cam profile translates this forward motion into the necessary radial convergence of split portions, making the operation intuitive while maintaining the asymmetrical split design's fastening capability

Inventive Principle:
Principle #13The other way round (Inversion)

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 tool enables intuitive and reliable fastener securing with reduced risk of loss, improving ergonomics and visibility, and is compatible with various fastener sizes through a tapered cam profile and slot design.

Implementation Method 1

the actuator is configured to drive against a cam profile defined by grooves on the driver shaft

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

the pressure from the contact ring onto the shaft is reduced allowing the two parts of the split end of the shaft to move towards each other due to the elasticity of the material of the shaft

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3374131B1Tool for use with a fastener
Publication Date: 2023.03.08 LUNAR INNOVATION LTD
  • EP3374131B1 patent drawingFigure 1
  • EP3374131B1 patent drawingFigure 2
  • EP3374131B1 patent drawingFigure 3

AI summary

There is provided a tool for use with a fastener, more particularly, there is provided a medical screwdriver tool arranged to interact with a fastener. The tool has a driver body with a driver shaft, the driver shaft being associated with a tip configured for interaction with a fastener. The tool also having an actuator arranged for reciprocal movement with respect to a longitudinal axis of the driver shaft between a first position proximal the tip and a second position distal the tip. The tip has first and second portions. The tool is configured for moving said first and second portions from a closed condition to an open condition upon movement of the actuator from said second position to said first position.