Wood Screw Shank Elevations for Splitting Reduction
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Solution Overview
Problem
Existing screws with cylindrical shanks and wood threads face challenges in screwing behavior and explosive/splitting effects when engaging with wood materials, particularly hardwoods like construction beech, which affects their performance and holding power.
Innovation Solution
The screw design incorporates elevations with an oval or elliptical base, having a convexly curved surface, arranged at a distance from the thread flanks, which improves screwing behavior by enhancing material displacement and reducing explosive/splitting effects without compromising holding power. These elevations are strategically positioned along the shank, with varying angles and heights to support the screwing process and minimize material damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional screw designs with cylindrical shanks and wood threads are used, then the screw structure is simple and manufacturing is easy, but the screwing behavior is poor and explosive/splitting effects occur in wood
Solution Approach 1:
The screw shank is segmented into different functional zones: thread flanks for holding power, and raised sections with oval/elliptical bases for material displacement. This segmentation allows each zone to perform its specific function optimally without interfering with the other, resolving the contradiction between improved screwing behavior and structural simplicity.
Solution Approach 2:
The raised sections are strategically positioned at specific locations along the shank between thread flanks, creating local quality variations. These localized elevations with convex surfaces provide material displacement exactly where needed during screw insertion, while the rest of the shank maintains its simple cylindrical form for manufacturing ease.
2Ease of operation
If raised sections are added to improve material displacement and screwing behavior, then screw insertion is improved, but the screw structure becomes more complex
Solution Approach 1:
Instead of modifying the entire shank surface, only partial raised sections are added at specific intervals between thread flanks. This partial action provides sufficient material displacement for improved screw insertion while minimizing the increase in structural complexity and maintaining manufacturing feasibility.
3Ease of operation
If the raised sections are positioned close to thread flanks to enhance biting, then material displacement is improved, but the thread holding power is compromised
Solution Approach 1:
The raised sections are positioned in the spaces between thread flanks, creating local quality variations that enable material displacement for improved biting. The thread flanks themselves remain intact and unchanged, preserving their holding power function. This spatial separation resolves the contradiction between enhanced biting and maintained holding power.
Data Source
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AI summary
The invention relates to a screw having a cylindrical shank, wherein the shank is provided with a screw thread, in particular a wood thread, at least in some sections and wherein elevations from the cylindrical base surface of the shank are arranged between at least some thread flanks of the screw thread, wherein the elevations have an oval or elliptical base, wherein the elevations have a convexly curved surface, and wherein the elevations are arranged at a distance from the adjacent thread flanks of the screw thread.