Self-Tapping Screw Stop Flange Forming to Prevent Over-Threading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional self-tapping screws are prone to excessive feeding and locking, leading to wear or breakage due to improper assembly or operation, as the headless screw is easily over-torqued and not integrally formed with the shank.
Innovation Solution
A method of forming a stop flange on a self-tapping screw using two threading dies with notches and inserts that simultaneously thread and form an external thread and a stop flange, preventing excessive movement and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the headless screw is made separately and screwed into the shank, then the assembly process is simple, but the screw is easily over-torqued and worn out or broken
Solution Approach 1:
The invention merges the shank and headless screw into a single integral structure by forming the external thread and stop flange on the shank using threading dies. This eliminates the separate assembly step of screwing the headless screw into the shank, thereby preventing over-torquing and damage while maintaining manufacturing efficiency.
2Productivity
If the headless screw is easily fed and locked excessively, then the assembly is quick, but the screw is worn out or broken due to excessive movement
Solution Approach 1:
The invention applies preliminary action by forming the stop flange on the shank before assembly. The stop flange pre-establishes a physical limit that prevents excessive feeding and locking of the screw during operation, thereby protecting the screw from wear and breakage while allowing quick assembly.
3Reliability
If a stop flange is added to prevent excessive threading, then the screw reliability improves, but the manufacturing process becomes more complex
Solution Approach 1:
The invention combines the formation of the external thread and stop flange into a single integrated process using threading dies. The dies simultaneously create both features on the shank, eliminating the need for separate manufacturing steps and thereby preventing increased manufacturing complexity while ensuring screw reliability.
4Reliability
If the external thread and stop flange are formed simultaneously on the shank, then the screw is integrally formed and more durable, but the threading process requires more precise control
Solution Approach 1:
The invention uses threading dies as an intermediary tool that simplifies the simultaneous formation of the external thread and stop flange. The dies are designed with specific geometric features that automatically ensure proper dimensional relationships between the thread and stop flange, thereby reducing the precision control burden on the manufacturing process while achieving integral screw construction.
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 stop flange prevents excessive threading and locking, thereby reducing the risk of wear or breakage during operation by ensuring the shank is integrally formed with the external thread and stop flange, enhancing operational stability.
Implementation Method 1
each of the two threading dies having an external thread forming section... the external thread forming section of each of the two threading dies performs threading to form an external thread on the shank
Data Source
AI summary
A method for forming a stop flange on a self-tapping screw includes locating a shank of a self-tapping screw between two threading dies, fixing one of the two threading dies and moving the other one of the two threading dies to work the shank, the external thread forming section of each of the threading dies performing threading to form an external thread on the shank, inserting the insert and the recessed corner of each of the threading dies into a top of the external thread to form a groove in the shank, and the insert of each of the threading dies gradually squeezing downward an extruded portion that is formed during formation of the groove to form a stop flange on the shank. Thus, the shank is integrally formed with the stop flange, to stop an excessive movement of the external thread.