Asymmetric Threaded Joint for Cutting Tool Anchoring
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Solution Overview
Problem
Existing threaded joints in cutting tools face challenges in generating large tightening forces without damaging the thread ridges and require high dimensional accuracy, making them difficult to manufacture and prone to deformation under stress.
Innovation Solution
A threaded joint with conical threads and asymmetrical flank angles, where the pulling flank transfers tensile forces and the pressing flank absorbs compressive forces, allowing for stable anchoring and quick connection/separation of tool parts without damaging the threads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional threaded joints are used to connect tool parts, then the connection can be achieved with standard manufacturing processes, but the thread ridges are prone to deformation and damage under tightening forces
Solution Approach 1:
The patent applies asymmetry by designing thread flanks with different angles: the pressing flank has a larger angle than the pulling flank. This asymmetric configuration allows the thread profile to better distribute stresses during tightening and loosening operations, reducing deformation risk while maintaining connection strength
Solution Approach 2:
The patent changes the geometric parameters of the thread profile by specifying different flank angles instead of using symmetric threads. The pressing flank angle is set larger than the pulling flank angle, creating an optimized thread form that enhances durability without requiring extremely high manufacturing precision
2Force
If large tightening forces are generated to securely anchor the cutting body, then the connection strength improves, but the thread ridges may be damaged or deformed
Solution Approach 1:
The patent applies local quality by creating different surface characteristics on the thread flanks. The pressing flank has a larger angle optimized for force distribution during tightening, while the pulling flank has a smaller angle optimized for controlled loosening. This localized optimization allows large tightening forces without damaging the thread ridges
Solution Approach 2:
The asymmetric thread profile with different flank angles allows the thread to handle large tightening forces more effectively. The larger pressing flank angle distributes the tightening force over a broader area, reducing stress concentration and preventing thread ridge damage while maintaining secure anchoring
3Ease of manufacture
If the cutting body is made as a separate detachable part, then cost efficiency improves by reusing the basic body, but the interface design becomes complex and difficult to master
Solution Approach 1:
The patent applies segmentation by dividing the cutting tool into a basic body and a separate cutting body that can be independently manufactured and replaced. The threaded connection interface enables this segmentation while maintaining a relatively simple connection mechanism, achieving cost efficiency without excessive interface complexity
Solution Approach 2:
The threaded connection interface serves multiple functions: it provides mechanical attachment, allows for tool assembly and disassembly, and enables the cutting body to be replaced while keeping the basic body. This multi-functionality achieves cost efficiency through part reuse without requiring overly complex interface design
Data Source
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AI summary
A cutting tool, and a loose top therefore, includes two parts detachably connected to each other via a threaded joint in which co-operating male and female threads are included in the form of helicoidal ridges. The profile shape of each helicoidal ridge is defined by a top and two flanks, which delimit a helicoidal groove having a bottom. The first flank is inclined in relation to a center axis of the tool at a first angle that is smaller than a second angle of the second flank in relation to the center axis. Accordingly, the thread ridge is reinforced in comparison with thread ridges having a symmetrical profile shape, whereby larger tensile forces than compressive forces can be applied to the threaded joint while avoiding damage to the thread ridges.