Variable-Pitch Threaded Fastener for Self-Locking Without Seizing
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Solution Overview
Problem
Conventional threaded connections, such as screws and nuts, lack self-locking capabilities, especially under high temperatures and in applications requiring adjustable fit, leading to issues like loosening, jamming, or breakage, and often necessitate additional components like locknuts which can be difficult to access.
Innovation Solution
A self-locking threaded connection element with a variable pitch thread design, applicable to both bolts and nuts, which maintains a secure fit without jamming or breaking, allowing for use without additional nuts and compatibility with existing threads, achieved through specific variations in thread pitch along the length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional threaded connections are used, then the structure is simple and easy to manufacture, but the connection lacks self-locking capability and loosens under high temperatures
Solution Approach 1:
The patent applies different thread pitch values to different sections of the same thread. The first section has a first pitch value while the second section has a second pitch value different from the first. This local variation in thread geometry creates differential friction forces that generate self-locking capability without requiring additional components, thereby improving reliability while maintaining relatively simple manufacturing.
2Reliability
If additional locking components like locknuts are used, then self-locking capability is achieved, but the device complexity increases and accessibility becomes difficult
Solution Approach 1:
The patent merges the locking function directly into the threaded connection element itself by implementing variable pitch threads. Instead of using separate locking components like locknuts or washers, the locking mechanism is integrated into the thread geometry through pitch variation along the thread length. This reduces the number of components and simplifies the overall device structure while maintaining reliable locking capability.
Solution Approach 2:
The variable pitch thread design enables the threaded connection to lock itself automatically through differential friction forces generated by the pitch variation. The thread structure serves its own locking function without requiring external locking components or additional assembly steps, making the system self-sufficient and reducing overall complexity.
3Reliability
If variable pitch thread is applied, then self-locking is achieved without additional nuts, but the manufacturing precision requirements increase
Solution Approach 1:
The patent changes the pitch parameter along the length of the thread, creating sections with different pitch values. This parameter variation is designed to generate differential friction forces that produce self-locking. While this does require controlled manufacturing precision, the principle of changing a single geometric parameter (pitch) rather than complex multi-parameter variations makes the manufacturing process relatively straightforward compared to other self-locking mechanisms.
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 self-locking threaded connection element provides a secure, adjustable, and reliable fit in various applications, reducing manufacturing costs, extending the lifespan of machinery, and eliminating the need for additional locking components, especially in high-temperature conditions.
Implementation Method 1
a variable pitch is applied, when making the thread, along the length thereof, which enables self-locking to be obtained
Data Source
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AI summary
The self-locking threaded connection element, which can be a screw or a nut, and which comprises a thread with a set of several turns, characterised in that the thread comprises a thread pitch which varies from one turn to another, which enables the element to be self-locking, without seizing.