Distorted Thread Fastener for Vibration-Resistant Electrical Terminal
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Solution Overview
Problem
Existing devices for fixing electrical connection lugs to supports in aircraft applications lack resistance to vibrations, leading to screw loosening, and require access to both sides of the support for assembly, which increases complexity and weight when trying to prevent loosening with lock washers.
Innovation Solution
A device with a distorted thread in the locking portion, achieved by permanent deformation during manufacturing, which creates a braking force to prevent screw loosening due to vibrations, and allows single-sided assembly by using a ring and pin assembly with conical shapes and radial deformation to secure the lug without additional support access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a screw and nut assembly with lock washers is used to prevent screw loosening under vibrations, then the resistance to vibrations is improved, but the weight and number of parts increase unacceptably
Solution Approach 1:
The thread geometry is changed from a standard circular helix to a distorted profile with variable pitch and non-circular cross-section. This parameter change in the thread shape creates asymmetric engagement that prevents loosening under vibration while maintaining a single-component design without additional washers or fasteners
Solution Approach 2:
The distorted thread introduces asymmetry in the engagement between screw and support. The non-uniform pitch and non-circular thread profile create different mechanical characteristics in tightening versus loosening directions, providing inherent resistance to vibration-induced loosening without requiring symmetric lock washers
2Reliability
If a traditional screw and nut assembly is used to fix the terminal, then the electrical connection is achieved, but access to both sides of the support is required during assembly
Solution Approach 1:
The nut component is extracted from the assembly, leaving only the screw with an integrated distorted thread that performs both fastening and locking functions. This extraction eliminates the need for a second side access while maintaining reliable electrical connection through the terminal clamping mechanism
3Reliability
If the support surface is stripped and protected against corrosion, then good electrical contact is ensured, but the assembly process becomes more complex and requires access to both sides
Solution Approach 1:
The corrosion protection layer is extracted from the necessary components, replaced by the distorted thread mechanism that achieves both electrical contact and vibration resistance without requiring surface preparation or protective coatings on the support
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 device provides a lightweight, vibration-resistant electrical connection that prevents screw loosening and allows for single-sided assembly, reducing the number of parts and weight, making it suitable for aircraft applications.
Implementation Method 1
the engagement of the external thread of the screw with the internal thread of the bore tends to restore the initial shape of the thread, and consequently to deform the locking portion. The deformation of the locking portion creates a braking force on the external thread of the screw.
Implementation Method 2
the engagement of the external thread of the screw with the internal thread of the bore tends to restore the initial shape of the thread, and consequently to deform the locking portion
Data Source
Figure 1~2B
Figure 3~4
Figure 5~6
AI summary
The invention concerns a device (1) for fixing an electrical connection terminal (6) to a support (2), comprising a ring (7) designed to be received in a hole (5) formed in the support (2) and a pin (8) designed to be forcibly inserted into the ring (7) to cause the deformation of the ring (7) in such a way as to embed the ring (7) in the hole (5), the pin (8) having a threaded bore (21) designed to receive a fixing screw (9) for fixing the terminal (6) to the ring (7), the threaded bore (21) having an inner thread (25) with which an outer thread (26) of the screw (9) engages, characterised in that the pin comprises a locking portion (19) in which the inner thread (25) of the bore (21) is deformed, in such a way that the engagement of the outer thread (26) of the screw (9) with the inner thread (25) of the bore (21) in the locking portion results in the locking of the screw (9) in the pin (8).