Tool Holder Locking Groove Design to Prevent Tool Pull-Out
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tool holders with chucks for rotary tools experience axial migration during operation due to vibrations, leading to precision and dimensional accuracy issues, and potential safety hazards.
Innovation Solution
A tool holder design featuring a pull-out protection system with spherical locking elements and grooves, combined with rotatably mounted balls or cylindrical pins, which securely engage the tool shaft to prevent axial movement, utilizing a thermally expandable chuck mechanism for torque-resistant clamping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional chuck without locking elements is used, then the device complexity is low, but axial migration of the tool occurs during operation due to vibrations
Solution Approach 1:
The locking mechanism is segmented into separate locking elements (balls or cylindrical pins) that can be individually positioned in bearing bores, rather than using a continuous complex locking structure. This allows the locking function to be distributed and simplified while maintaining reliability.
Solution Approach 2:
The locking elements are designed with spherical heads and the locking grooves have corresponding spherical profiles. This spherical geometry enables automatic centering and reliable form-fitting engagement that prevents axial migration while maintaining simple structure. The curved surfaces provide smooth engagement and disengagement.
2Reliability
If locking grooves with narrow width are used, then the axial locking is secure, but tool insertion becomes difficult
Solution Approach 1:
The locking grooves are designed with a preliminary wider section at the insertion end that gradually transitions to the narrower locking section. This preliminary widening allows the tool to be easily inserted before the locking elements engage, separating the insertion phase from the locking phase.
Solution Approach 2:
The locking grooves are designed with a thread-like helical or curved course along the circumferential surface of the tool shank. This three-dimensional path allows the tool to be inserted axially while the locking elements engage through rotational movement, transforming the insertion operation from a purely axial action to a combined axial-rotational action that facilitates easier insertion.
3Manufacturing precision
If the chuck is designed without pull-out protection, then the manufacturing precision is high, but axial migration causes dimensional inaccuracy and safety hazards
Solution Approach 1:
The pull-out protection function is extracted as a separate, independent locking mechanism with discrete locking elements and locking grooves. This modular approach adds the safety function without fundamentally redesigning the entire chuck system, maintaining manufacturing precision while adding targeted protection.
Solution Approach 2:
The locking elements act as intermediary components between the chuck body and the tool shank. These intermediate elements provide the form-fitting connection that prevents axial migration and ensures dimensional accuracy, while being simple enough not to significantly increase overall system complexity.
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
Prevents axial migration of rotary tools, ensuring precise machining and safety by maintaining the tool within the chuck during operation, reducing waste and accident risks.
Implementation Method 1
The coil arrangement is connected to a high-frequency alternating current generator and induces eddy currents in the metallic sleeve section, which heat the sleeve section
Implementation Method 2
the sleeve section is quickly heated so that it expands thermally and the inside diameter of the receiving opening is increased
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
The holder (1) has a tool holding fixture, preferably a chuck, where a shank of a tool particularly rotary tool, is accommodated in the tool holding fixture. The pull-out preventing unit has a locking element and a locking groove (13), which corresponds to the locking element, receives the locking element and interacts with the locking element in a positively locking manner.