Wood Screw Cutting Section for Tight Fit and Shear Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wood screws face challenges such as difficulty penetrating pre-drilled steel plates, large gaps between the structural girder and rod body due to reamer threads, and reduced shear stress resistance due to the occupation of rod body length by reamer threads, leading to potential breakage.
Innovation Solution
A wood screw design featuring a threadless rod body with a cutting unit between the threaded section and shank part, which breaks off wood fibers to reduce lateral resistance and forms a smooth inner cutting hole for tight contact, enhancing stability and bond strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a reamer thread is provided above the thread to drill wood material, then the screw can penetrate wood effectively, but the reamer thread occupies part of the rod body length, reducing the portion that can withstand shear stress and causing the screw to break easily
Solution Approach 1:
The rod body is divided into three distinct sections: a shank part with large diameter for shear resistance, a cutting section with cutting units for penetration, and a threaded section for bonding. This segmentation allows each part to perform its specific function optimally without compromising the others.
Solution Approach 2:
The cutting function is extracted from the rod body and concentrated into specific cutting units located at the cutting section. This extraction allows the main rod body to maintain its full length for shear stress resistance while the cutting units provide the necessary penetration capability.
2Ease of manufacture
If the reamer thread is directly formed on a smooth surface of the rod body, then the screw can be manufactured simply, but a large gap is formed between the structural girder and the rod body after screwing, reducing bonding strength
Solution Approach 1:
The cutting units perform preliminary cutting action on the wood material before the threaded section engages. This preliminary action creates a pre-formed hole that matches the shank diameter, ensuring tight contact and eliminating gaps between the screw and the wood material.
3Ease of operation
If a large diameter reamer thread is used to drill wood material, then the screw can effectively penetrate wood, but the screw is not easy to penetrate a pre-drilled steel plate when used with hardware components
Solution Approach 1:
Different sections of the screw have different diameters optimized for different functions: the cutting section has a smaller diameter for penetrating hard materials like steel plates, while the shank part has a larger diameter for withstanding shear stress in wood material. This local quality variation resolves the contradiction between penetration capability and hardware compatibility.
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 design allows for improved penetration and reduced gaps between the screw and object, enabling the wood screw to withstand higher tensile and shear stresses, thereby increasing overall stability and bond strength.
Implementation Method 1
the cutting unit allocated ahead of the shank part in the screw-in direction can break off the fiber structure of the wood material proactively so it can reduce a lateral resistance generated by the shank part of a larger diameter screwing into an object
Implementation Method 2
the thread (34) screws to the object so as to achieve efficiency of firmly screwing and locking the wooden work piece
Implementation Method 3
The threaded section has a thread spirally wound from the tapered part toward the screw head
Data Source
AI summary
A wood screw is disclosed herein. It comprises a screw head and a rod body integrally extended from the screw head and having a shank part and a screwing part, wherein the screwing part comprises a straight surface surrounded with a threaded section and a cutting section on which a cutting unit is formed, and wherein a root diameter of the shank part is larger than root diameters of the threaded section and the cutting section respectively, and larger than or equal to a maximum outer diameter of the cutting section defined by the cutting unit.