Gripping Tool with Retractable Roller for Variable Diameter Parts

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Solution Overview

Problem

Existing gripping tools for mechanical parts, such as ball joints and dowels, face challenges in handling cylindrical and spherical shapes of varying diameters due to their design limitations, which restrict their compatibility and robustness, especially in confined spaces and under mechanical stress.

Innovation Solution

A gripping tool with a bell and coaxial cage featuring retractable rotating rollers and guide means that allow radial displacement and inclination, enabling the tool to accommodate a wide range of diameters and absorb mechanical stresses, while maintaining a compact design and moderate cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional ball joint extractors are used to grip cylindrical parts, then gripping force is achieved, but the tool is limited to specific diameters and requires multiple tools in a box

Engineering Contradiction:
Improvecompatibility with various diametersVSAvoidneed for multiple tools in a box
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The ball joint extractor incorporates a retractable roller mechanism that allows the gripping surface to dynamically adjust its position. The roller can move radially inward and outward, enabling the same tool to accommodate ball joints of various diameters by changing the effective gripping radius, thereby eliminating the need for multiple fixed-size extractors

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The extractor is designed with a universal gripping mechanism that can handle multiple diameters through the retractable roller. The flange with multiple radial grooves and the ability to position the roller at different radii create a multi-functional tool that replaces an entire box of specialized extractors for different sizes

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If fixed-size extractors are used, then precise gripping is achieved for specific diameters, but the tool cannot adapt to future different diameters

Engineering Contradiction:
Improvegripping precision for specific diameterVSAvoidadaptability to different diameters
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The retractable roller mechanism allows dynamic adjustment of the gripping radius. The roller can be positioned at different radial locations along the flange, enabling precise gripping for various diameters while maintaining the precision needed for each specific size through controlled positioning

Inventive Principle:
Principle #15Dynamics

3Reliability

If standard ball joint extractors are used in confined spaces, then ball joints can be gripped, but the tool size limits accessibility in tight spaces

Engineering Contradiction:
Improvegripping reliabilityVSAvoidtool size for accessibility
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The extractor is segmented into modular components: a handle, a bell, a flange with multiple grooves, and a retractable roller. This segmentation allows the gripping function to be achieved with a more compact overall structure, reducing the volume needed while maintaining reliable gripping through the distributed groove and roller mechanism

Inventive Principle:
Principle #1Segmentation

4Reliability

If conventional extractors are used under mechanical stress, then gripping function is maintained, but the structure requires more parts reducing robustness

Engineering Contradiction:
Improvegripping function under stressVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple functions are merged into fewer components. The flange combines multiple radial grooves in a single piece, the roller serves both as the gripping surface and the adjustable element, and the elastic ring provides both retention and stress absorption. This merging reduces the total part count while maintaining reliable gripping under mechanical stress

Inventive Principle:
Principle #5Merging (Combining)

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 effectively grips mechanical parts of various diameters, enhancing robustness and ease of use, with a stable flange positioning and reduced part count, allowing for efficient handling in tight spaces and under mechanical stress.

Implementation Method 1

the cage and the guide means being arranged to allow the radial displacement of the retractable rotary roller from so that its axis can pass through the wall of the cage

Methodology Applied
Scientific EffectRadial displacement: Displacement

Implementation Method 2

the inner face of the bell being provided with at least one slope arranged to vary the center distance between the retractable rotary roller and the bell as a function of the angular position of the retractable rotary roller relative to the bell

Methodology Applied
Scientific EffectMechanical advantage through inclined plane: Inclined Plane

Implementation Method 3

the cage and the guide means being arranged to radially guide the retractable rotary roller during the variation of center distance

Methodology Applied
Scientific EffectMechanical guidance:

Implementation Method 4

elastic means provided between the retractable rotary roller and the cage and arranged to urge the displacement of the axis of the retractable rotary roller towards the axis of the cage

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2480379B1Gripping tool
Publication Date: 2013.11.06 GILLET OUTILLAGE
  • EP2480379B1 patent drawingFigure 1
  • EP2480379B1 patent drawingFigure 2~3
  • EP2480379B1 patent drawingFigure 4

AI summary

The invention relates to a tool for gripping (1) a mechanical part (4), comprising: a bell (3) provided with gripping means (2), a rotatably movable housing (5) coaxial to said bell (3), comprising at least one side window (54) and receiving said mechanical part (4), three bearing elements (7), one of which is a movable retractable rotary roller, said bell (3) being provided with at least one slope (31) for varying the center-to-center distance between said retractable rotary roller (7) and said bell (3) in accordance with the angular position of said retractable rotary roller (7), said housing (5) and said retractable rotary roller (7) being connected by guide means (55, 8) for guiding said retractable rotary roller (7), said housing (5) and said guide means (55, 8) enabling the radial movement of said retractable rotary roller (7) such that the pin thereof can pass through the wall of said housing (5).