Mounting Screw with Segmented Thread for Sheet Metal
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Solution Overview
Problem
Existing mounting screws for sheet metal products are inefficient in terms of installation time, as they do not easily and quickly penetrate multiple metal sheets and provide adequate grip in both metal and wood materials, leading to prolonged assembly times for sheet roofing applications.
Innovation Solution
A chipless thread-forming mounting screw with a tapered tip part and frustoconical thread root, featuring a larger pitch shank part thread and fine tip part thread, along with asymmetrical thread angles, facilitates easy penetration through metal sheets and improved grip in wood, reducing metal chip formation and enhancing drilling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a mounting screw is designed to penetrate metal sheets easily, then penetration speed improves, but grip strength in wood material may deteriorate
Solution Approach 1:
The screw thread is segmented into two distinct parts: a tip part thread with fine pitch for penetrating metal sheets, and a shank part thread with coarse pitch for gripping wood material. This segmentation allows each part to be optimized for its specific function, resolving the contradiction between penetration speed and grip strength.
Solution Approach 2:
Different parts of the screw thread have different local qualities: the tip part has a finer pitch and frustoconical thread root for easy metal penetration, while the shank part has a coarser pitch for strong wood grip. This local differentiation enables the screw to excel at both penetration and gripping without compromise.
2Loss of time
If the pitch of the screw thread is increased for faster installation, then installation time reduces, but grip strength in wood material deteriorates
Solution Approach 1:
The thread pitch is segmented into two values: a fine pitch at the tip for rapid metal penetration and a coarse pitch at the shank for strong wood gripping. This resolves the contradiction by allowing fast installation through the fine-pitched tip while maintaining secure grip through the coarse-pitched shank.
Solution Approach 2:
The fine pitch at the tip provides more than enough penetration capability for quick installation, while the coarse pitch at the shank provides excessive grip strength for wood. This partial differentiation allows optimization for both speed and strength without requiring a compromise pitch throughout the entire thread.
3Ease of manufacture
If a standard thread profile is used, then manufacturing is simpler, but penetration efficiency through metal sheets deteriorates
Solution Approach 1:
The thread profile has different local qualities: the tip part features a frustoconical thread root and fine pitch for efficient metal penetration, while the shank part has a standard thread profile for easy manufacturing. This local differentiation maintains manufacturing simplicity while achieving superior penetration efficiency where needed.
Data Source
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AI summary
A mounting screw (1), comprising a head part (2), a tip part (3), the tip part (3) having a tapered shape tapering from the shank part (4) to the tip (5) of the screw, and comprising a tip part thread (6), said tip part thread (6) extending to the very end of the tip (5). The mounting screw (1) further comprises a shank part (4) between the head part (2) and the tip part (3), the shank part (4) comprising a shank part thread (7), wherein the pitch (P1) of the shank part thread (7) is larger than the pitch (P2) of the tip part thread (6), and the thread root of the tip part (3) being frustoconical in its shape.