Tool Holder Radial Locking via Axial Insertion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing tool holders for hand-held machine tools, such as rotary hammers, face challenges in securely mounting tools with different shanks while ensuring safety and preventing the insert tool from tipping, especially when accommodating a wide range of tool designs.

Innovation Solution

A tool holder with an adjustable locking mechanism, featuring a blocking element and a locking element that moves radially between unlocked and locked positions, actuated by the insert tool's axial movement, utilizing a beveled adjustment surface and spring elements for secure engagement and release, allowing for easy use of various tool shanks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a simple tool holder design is used, then ease of operation is improved, but reliability of tool mounting deteriorates

Engineering Contradiction:
Improveease of useVSAvoidoperational reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The blocking element automatically actuates itself through the axial insertion movement of the tool shank. As the shank is inserted axially, it directly pushes the blocking element, which then triggers the locking element to move radially into the locked position. This self-actuating mechanism eliminates the need for separate manual locking operations while ensuring reliable tool mounting.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The locking mechanism transitions from a static design to a dynamic one where the blocking element and locking element can move relative to each other. The blocking element moves axially during insertion, while the locking element moves radially to engage with the tool shank. This dynamic behavior enables automatic locking and unlocking based on tool insertion and removal actions.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a complex locking mechanism is used, then reliability of tool mounting is improved, but device complexity increases

Engineering Contradiction:
Improvesecure mountingVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is divided into two independent but coordinated elements: a blocking element that responds to axial insertion movement, and a locking element that provides radial locking. Each element has a simple individual structure and function, but their combination achieves reliable automatic locking. The blocking element handles the actuation function while the locking element handles the securing function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blocking element serves as an intermediary between the tool shank insertion movement and the locking element actuation. It converts the axial movement of the shank into radial movement of the locking element through its geometric configuration, enabling automatic locking without complex control systems or multiple actuating components.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If automatic locking is implemented, then ease of operation is improved, but risk of tool tipping increases

Engineering Contradiction:
Improveautomatic lockingVSAvoidtool tipping risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The locking element is positioned and configured in advance within the tool holder structure. As the tool shank is inserted axially, the blocking element is actuated to move the locking element radially into the locked position before the tool is fully inserted. This preliminary locking action secures the tool early in the insertion process, preventing tipping during the remaining insertion distance and during operation.

Inventive Principle:
Principle #10Preliminary action

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

Ensures secure and reliable mounting of different tool shanks with enhanced safety by automatically adjusting the locking mechanism, preventing tool tipping and facilitating easy insertion and removal, while accommodating various tool designs within the tool holder.

Implementation Method 1

The blocking member is subjected to a force, in particular in the direction of the blocking position, by an associated spring element

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

The conversion of the axial adjustment movement of the blocking element into the radial transfer movement of the locking element between the unlocking and locking position is expediently carried out by means of a beveled adjustment surface on the blocking element

Methodology Applied
Scientific EffectMechanical conversion of movement direction: Wedge

Data Source

PatentEP2117751B1Tool holder for a mechanical tool, in particular a mechanical hand tool
Publication Date: 2017.08.23 ROBERT BOSCH GMBH
  • EP2117751B1 patent drawingFigure 1~2
  • EP2117751B1 patent drawingFigure 3~4
  • EP2117751B1 patent drawingFigure 5~6

AI summary

A tool holder (2) for a mechanical tool (1), in particular a percussion drill, comprises a tool gripper (3) into which an insert tool (4) can be inserted, and said insert tool (4) can be locked into the tool gripper by means of a locking unit. The locking unit comprises a locking element (7) which is adjustable between an unlocking position and a locking position. In addition, a blocking element (8) is held in the tool holder and can be displaced by the insert tool such that the movement of the locking element in the locking position is inhibited by the blocking element.