Under-Head Sealant Coating for Self-Tapping Screws
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing screw technologies for static metal and scaffolding construction face challenges in providing reliable strength, tightness against liquids, UV resistance, and ease of use, with self-forming or self-tapping threads often losing preload, being susceptible to errors, and having complex, cost-intensive manufacturing processes.
Innovation Solution
A screw with a self-forming or self-tapping thread and an elastic sealant coating on the screw head, which is dry to the touch and non-sticky, allowing for easy processing and storage, and providing a secure seal without the need for additional sealing devices like O-rings or washers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing ring is used to achieve tightness and strength, then sealing performance is improved, but the sealing ring can be lost or forgotten and deteriorate due to UV radiation leading to settling and loss of clamping force
Solution Approach 1:
The invention extracts the sealing function from a separate sealing ring component and integrates it directly into the screw head through a coating applied to the bearing surface. This eliminates the sealing ring as a separate part that can be lost or deteriorate, while maintaining the sealing function.
Solution Approach 2:
The invention merges the sealing function with the screw head structure by applying a coating to the bearing surface of the screw head. This combines the fastening function of the screw with the sealing function in a single integrated component.
2Reliability
If a sealing washer is used to achieve tightness, then sealing performance is improved, but the sealing washer can be damaged or destroyed during installation making it prone to failure
Solution Approach 1:
The invention removes the separate sealing washer component and integrates the sealing function directly into the screw head through coating application, eliminating the risk of washer damage during installation.
Solution Approach 2:
The sealing function is merged with the screw head structure through coating application, creating an integrated fastening and sealing component that cannot be damaged separately during installation.
3Reliability
If additional sealing devices like O-rings or washers are used to achieve reliable seal, then sealing performance is improved, but the manufacturing process becomes complex and expensive
Solution Approach 1:
The invention extracts the sealing function from separate sealing devices and integrates it directly into the screw head through coating application, eliminating the need for additional sealing components and simplifying the overall assembly.
Solution Approach 2:
The sealing function is merged with the screw head structure through coating application, creating a single integrated component that performs both fastening and sealing functions, thereby reducing device complexity.
4Reliability
If a coating of sealant is applied to the underside of the screw head to provide sealing, then sealing performance is improved, but the sealant may be sticky and difficult to process and store
Solution Approach 1:
The invention changes the physical and chemical parameters of the sealant coating, specifically selecting materials that are dry to the touch and non-sticky. This allows the coating to maintain sealing effectiveness while being easy to process and store.
5Ease of operation
If self-forming or self-tapping threads are used to ensure ease of use and error-free operation, then ease of operation is improved, but preload loss occurs and durability is reduced
Solution Approach 1:
The elastic sealant coating acts as an intermediary between the screw head bearing surface and the workpiece surface. It compensates for surface irregularities and maintains consistent contact pressure, preventing preload loss while maintaining ease of installation.
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 screw achieves reliable sealing and strength, minimizes preload loss, and is cost-effective to produce and use, while maintaining durability and resistance to transverse tensile forces and corrosion, ensuring a long-lasting secure connection.
Implementation Method 1
The sealant is elastic
Data Source
Figure 1~2
AI summary
The invention relates to a screw (10) and to a screw assembly. The screw comprises a screw head (11) and a screw shaft (16) projecting from a bottom side of the screw head (11), said screw shaft having a self-tapping or self-cutting thread (17), wherein the screw head (11) has a bearing surface (12) at the bottom side and at least one annular recess (14) extending around the shaft (16) between bearing surface (12) and shaft (16), wherein a coating (15) made of an elastic sealing agent is applied on the bottom side of the screw head (11).