Surgical Rotary Tool Coupling Assembly Alignment

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Solution Overview

Problem

Existing surgical rotary tools face challenges in securely and efficiently attaching and detaching working elements like drill bits and burrs from high-speed motors, leading to alignment and vibration issues, which can affect the precision and effectiveness of surgical procedures.

Innovation Solution

A novel coupling assembly featuring a collet sleeve with multiple openings and collet balls, a cam element, and a biasing collar, which securely connects the working element to the high-speed motor, minimizing alignment and vibration issues while allowing for easy attachment and detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional coupling assembly is used to attach working elements to the high-speed motor, then the attachment can be achieved, but alignment issues and vibration problems occur that affect surgical precision

Engineering Contradiction:
Improvealignment precisionVSAvoidconnection stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The coupling assembly is divided into distinct functional segments: a collet sleeve with multiple openings for individual collet balls, a cam element with separate engagement surfaces, and a biasing collar. This segmentation allows each component to perform its specific function optimally - the collet balls provide precise radial positioning, the cam element provides axial positioning and locking, and the biasing collar maintains constant contact pressure, collectively eliminating alignment and vibration issues.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the working element is securely locked to prevent vibration, then connection stability is improved, but the attachment and detachment process becomes more complex

Engineering Contradiction:
Improveconnection stabilityVSAvoidcoupling mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coupling assembly employs self-service mechanisms where the biasing collar automatically maintains constant contact pressure on the cam element, ensuring secure locking without additional adjustment mechanisms. The collet balls automatically engage with the working element shaft when inserted, and the cam element's geometry ensures automatic axial positioning. This self-service approach provides reliable secure locking while keeping the attachment and detachment process simple and intuitive.

Inventive Principle:
Principle #25Self-service

3Reliability

If multiple locking mechanisms are added to prevent vibration and improve alignment, then connection reliability is improved, but the device complexity increases

Engineering Contradiction:
Improveconnection stabilityVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges multiple locking functions into a compact integrated assembly. The collet sleeve, collet balls, cam element, and biasing collar work together as a unified mechanism where the cam element simultaneously provides axial positioning and radial locking through its interaction with the collet balls. The biasing collar integrates the spring loading function directly into the assembly. This merging provides robust vibration prevention and alignment precision without significantly increasing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3137249B1Rotary tool with improved coupling assembly
Publication Date: 2020.06.03 GYRUS ACMI INC
  • EP3137249B1 patent drawingFigure 1
  • EP3137249B1 patent drawingFigure 2
  • EP3137249B1 patent drawingFigure 3

AI summary

A surgical device comprising: a handle assembly; a locking collar and a set of replaceable bits that load along an axis into the handle assembly; wherein the locking collar is fully removable from the handle assembly, the locking collar loads axially to a first position, and the locking collar rotates between the first position and a second position; wherein, in the first position, the locking collar is free to be axially removed from the handle assembly and the replaceable bits are free to be loaded or unloaded from the handle assembly; wherein in the second position, the locking collar is prevented from axial movement relative to the handle assembly and the replaceable bits are prevented from being received within, or removed from, the handle assembly.