Quick-Change Collet With Feedback for Secure Tool Clamping

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Solution Overview

Problem

Traditional collets do not provide feedback to users when a tool is being clamped, making it difficult to confirm securement during machining operations.

Innovation Solution

A collet design that includes an outer nut with a collet bore and a spring with extension portions that engage the output shaft or outer nut, providing tactile and audible feedback as the collet is tightened, indicating securement through engagement with the shaft's grooves or teeth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional collet is used to retain cutting implements, then the cutting implement is securely clamped to the output shaft, but the user receives no feedback to confirm securement during tightening

Engineering Contradiction:
Improvesecurement confirmationVSAvoidfeedback information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent incorporates a feedback mechanism consisting of a ball indicator visible through a window in the collet body and an auditory click mechanism. As the collet is tightened, the ball moves along a cam surface and drops into notches at specific intervals, providing both visual and auditory feedback to the user that the collet has reached predetermined tightening positions, thereby confirming securement of the cutting implement

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses a ball as an intermediary element that translates the internal tightening mechanism's movement into visible and audible signals for the user. The ball travels along a cam surface inside the collet body and its position is visible through a window, while its engagement with notches produces audible clicks, serving as a mediator between the tightening action and user perception

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the collet is tightened to ensure proper clamping, then securement is achieved, but there is risk of deformation without proper feedback guidance

Engineering Contradiction:
Improveproper clampingVSAvoiddeformation risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent incorporates predetermined tightening positions marked by notches in the cam surface at intervals corresponding to optimal clamping forces. These positions are established in advance during manufacturing, guiding the user to stop tightening at the correct point before deformation occurs, thereby ensuring proper clamping while preventing over-tightening damage

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The auditory click and visual ball position changes provide real-time feedback during tightening, informing the user when predetermined optimal clamping positions are reached. This feedback mechanism guides the user to apply the correct amount of force to achieve proper clamping without exceeding it and causing deformation

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If multiple cutting implements need to be changed for different profiles, then machining versatility is achieved, but tool changing time increases

Engineering Contradiction:
Improvecutting profile varietyVSAvoidtool changing time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent employs a modular quick-change system where the collet body, cutting implement holder, and retention mechanism are segmented into separable components. The cutting implement can be quickly released and replaced by manipulating release levers that disengage retention elements, allowing rapid tool changes between different cutting profiles without requiring complex disassembly procedures

Inventive Principle:
Principle #1Segmentation

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 collet design enhances user confidence by providing clear tactile and audible feedback during securement, reducing the likelihood of deformation and ensuring proper clamping of cutting implements.

Implementation Method 1

a spring having an extension portion engageable with an external part of an output shaft of the tool or an internal part of the outer nut to provide feedback to a user regarding securement of the collet

Methodology Applied
Scientific EffectMechanical feedback: Vibration

Data Source

PatentEP4389330A1Quick-change collet
Publication Date: 2024.06.26 TECHTRONIC CORDLESS GP
  • EP4389330A1 patent drawingFigure 1
  • EP4389330A1 patent drawingFigure 2
  • EP4389330A1 patent drawingFigure 3

AI summary

A collet (10) for a tool including an outer nut (18) having a grip and defining a collet bore configured to receive a chuck (26). The collet bore includes a collet engagement surface engageable with the chuck to selectively secure a tool accessory. The collet also includes a spring (30) having an extension portion engageable with an external part of an output shaft of the tool or an internal part of the outer nut to provide feedback to a user regarding securement of the collet.