Twist-off Screw with Separable Clamping Section
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Solution Overview
Problem
Existing fastening means in screw connection technologies, such as those used in cable ladders for power engineering, face challenges in ensuring a mechanically stable and current-carrying connection, particularly when clamping electrical conductors, as they often fail to provide consistent clamping force due to varying material friction coefficients, leading to unreliable tearing and potential damage to insulating layers.
Innovation Solution
A fastening means with a separable clamping section and a first section, where the clamping section is separated by a radial puncture, allowing for controlled torque and frictional forces to ensure reliable tearing at the appropriate point, independent of the material's friction coefficient, ensuring consistent clamping force and preventing protrusion beyond the terminal body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lubricants or coatings are used to adjust friction behavior, then the clamping force can be controlled, but the production cost increases and operational reliability cannot be guaranteed under temperature fluctuations
Solution Approach 1:
The fastening means is divided into two separate sections: a clamping section that contacts the object to be clamped and a first section that is screwed into the threaded bore. This segmentation allows the frictional forces between the sections to be independent of the object material, eliminating the need for lubricants or coatings while ensuring consistent clamping force under varying temperature conditions.
2Strength
If the head friction is too high, then the screw may tear off before achieving required clamping force, but reducing friction requires additional production effort
Solution Approach 1:
By separating the clamping function into a distinct clamping section that rotates relative to the first section, the friction that could cause premature tearing is isolated to the interface between the two sections. This allows the clamping section to rotate freely against the object without transferring excessive frictional forces to the threaded connection, ensuring the screw achieves required clamping force without tearing off.
Solution Approach 2:
The clamping section is designed to rotate relative to the first section during the clamping process. This dynamic movement allows the clamping section to overcome static friction and engage properly with the object, while the relative rotation between sections prevents friction buildup that would otherwise cause premature tearing of the threaded connection.
3Reliability
If discrete predetermined breaking points are used, then the fastener can tear off at specific points, but the tearing is not reliable and may damage insulating layers
Solution Approach 1:
The fastening means utilizes dynamic relative rotation between the clamping section and the first section to control the tear-off process. As the clamping section rotates against the object, frictional forces build up until they exceed the connection strength at the puncture point, causing a controlled tear-off. This dynamic process ensures reliable tearing at the intended point without unpredictable damage to insulating layers.
Solution Approach 2:
The frictional forces between the clamping section and the first section are used as a controllable parameter to determine when tear-off occurs. By designing the friction characteristics of the clamping section, the tear-off torque can be precisely controlled to occur at the radial puncture point, ensuring reliable and clean separation without damaging surrounding insulating layers.
4Object-affected harmful factors
If the fastener is designed to tear off near the terminal body surface, then insulating layers are protected, but the connection point must be precisely controlled
Solution Approach 1:
The fastening means is segmented into a clamping section and a first section connected by a radial puncture. This segmentation creates a predetermined failure point that controls where the tear-off occurs. The clamping section remains attached to the terminal body while the first section tears off, ensuring the connection point is precisely at the puncture location and protecting insulating layers from damage.
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 solution provides a mechanically stable and current-carrying connection that is independent of the material's friction coefficient, ensuring reliable tearing and preventing damage to insulating layers, with a lower tear-off torque that ensures the fastener only separates when the required clamping force is achieved, maintaining the connection's integrity.
Implementation Method 1
the frictional forces occurring between the clamping section and the object to be clamped, and the effective friction radii
Implementation Method 2
a clamping section (10) separated from the first section (2) by a radial puncture (24)
Data Source
Figure 1
Figure 2~4
AI summary
The unit (1) has a section (2) with a thread (4), where the unit is shearable by an excess torque. A clamping section (10) is formed as a single piece with the section (2) in an output state of the unit and is separable from the section (2) in the case of screwing the unit. The clamping section is separable by another torque, which is smaller than the torque that is necessary for shearing the unit. The clamping section has a flat closed surface at its front surface (16), which is turned away from the section (2).