Movable-Magnet Bit Holder for Secure Retention and Easy Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing bit holders for screwdriver tools have complex assemblies with many small parts, making manufacturing difficult and assembly cumbersome.

Innovation Solution

A bit holder design featuring a sleeve with a magnet that moves between positions to secure and partially eject bits, using a magnet retaining element and a simplified locking mechanism with fewer components, allowing for easy assembly and quick bit changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex locking mechanism with multiple small parts is used, then secure bit retention is achieved, but assembly complexity increases and manufacturing becomes difficult

Engineering Contradiction:
Improvebit retentionVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into a single integrated sleeve component. The sleeve incorporates the retaining tooth, spring mechanism, and bit engagement features all in one piece, eliminating the need for separate small parts that were previously required. This merging approach maintains secure bit retention while dramatically reducing assembly complexity and manufacturing difficulty.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sleeve is designed as a multi-functional component that simultaneously provides bit retention, spring biasing, and mechanical engagement features. By making the sleeve universal and multi-functional, the design eliminates the need for multiple specialized small parts, thereby reducing assembly complexity while maintaining reliable bit retention through its integrated features.

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

2Reliability

If multiple small parts are used in the locking mechanism, then bit retention functionality is achieved, but manufacturing ease deteriorates

Engineering Contradiction:
Improvebit retentionVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple small parts into a single integrated sleeve component that incorporates the retaining tooth, spring, and engagement features. This consolidation maintains all necessary bit retention functionalities while making manufacturing and assembly significantly easier by reducing the number of discrete parts that need to be manufactured and assembled.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If a simplified design with fewer parts is used, then assembly ease is improved, but bit retention reliability may be compromised

Engineering Contradiction:
Improveassembly easeVSAvoidbit retention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The integrated sleeve design combines multiple retention functions into one component, ensuring reliable bit retention through its built-in retaining tooth and spring mechanism while maintaining assembly ease by eliminating the need for multiple separate parts. The multi-functional design ensures that reliability is not compromised despite the reduction in part count.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sleeve is designed as a universal multi-functional component that performs bit retention, spring biasing, and mechanical engagement all within a single part. This multi-functionality ensures that bit retention reliability is maintained while achieving the simplification and assembly ease benefits of having fewer parts.

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

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 simplified design reduces assembly complexity, enhances ease of manufacturing, and ensures secure bit retention with fewer parts, facilitating quick and reliable bit changes.

Implementation Method 1

a magnet arranged to engage the bit

Methodology Applied
Scientific EffectMagnetic engagement: Magnetism

Implementation Method 2

a magnet spring arranged to urge the magnet from the first position towards the second position

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP4711084A1A bit holder
Publication Date: 2026.03.18 STANLEY BLACK & DECKER MEA FZE
  • EP4711084A1 patent drawingFigure 1
  • EP4711084A1 patent drawingFigure 2
  • EP4711084A1 patent drawingFigure 3a~3b

AI summary

A bit holder comprises a sleeve having a bore for receiving a bit and a through-hole in a wall of the sleeve connected to the bore. A magnet is arranged to engage the bit and wherein the magnet is moveable within the bore between a first position when the bit is seated in the bore and a second position when the bit is partially ejected from the bore. A magnet retaining element is mounted in the through-hole and arranged to protrude into the bore and engage a portion of the magnet when the magnet is in the second position.