Screw Underside Cutters and Pockets for Fibrous Material Locking
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Solution Overview
Problem
Wood screws and screws for fibrous materials tend to loosen over time, despite being self-countersinking, which is a persistent issue in existing technologies.
Innovation Solution
A screw design featuring cutters on the underside of the head to countersink into the material and multiple pockets to receive and lock material, preventing loosening, by arranging cutters circumferentially and pockets radially inwardly to secure the screw.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a self-countersinking screw is used for fibrous material, then the screw can be inserted easily and efficiently, but the screw has a propensity to loosen over time
Solution Approach 1:
The screw head underside is segmented into multiple functional zones: circumferential cutters for material removal, radial pockets for material reception and locking, and threaded portions for engagement. This segmentation allows each zone to perform its specific function optimally - cutters create countersink while pockets prevent loosening through material interlocking
Solution Approach 2:
Different regions of the screw head underside are given different local qualities: the outer circumferential region has sharp cutting edges for efficient material removal, while the inner radial regions have pocket structures with varying depths and configurations for optimal material locking. This local differentiation resolves the contradiction by optimizing each region for its specific function
2Ease of operation
If cutters are added to the underside of the screw head to facilitate countersinking, then the screw can be easily inserted, but the device complexity increases
Solution Approach 1:
The countersinking function and the anti-loosening function are merged into a single integrated screw head structure. The cutters and pockets are combined in one component rather than being separate devices, simplifying the overall system while achieving multiple functions simultaneously
Solution Approach 2:
The screw head underside is designed as a multi-functional element that simultaneously performs material cutting (countersinking), material reception (pockets), and mechanical locking (threaded engagement). This multi-functionality reduces the need for additional components while solving multiple problems
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 effectively countersinks into fibrous materials and locks in place, reducing the likelihood of loosening over time by collecting material in the pockets, enhancing long-term stability.
Implementation Method 1
A plurality of cutters are arranged circumferentially on the underside of the head. The cutters are adapted to facilitate countersinking of the head by cutting away material from a surface of a fibrous material
Implementation Method 2
Multiple pockets are spaced radially apart and are disposed radially inwardly from the cutters for receiving at least some of the fibrous material when the screw is inserted into the fibrous material. The material that enters the pockets prevents the screw from loosening
Data Source
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AI summary
A screw has a generally flat washer-like head. On an underside of the head are a plurality of cutters or cutting wedges arranged circumferentially around the shank of the screw. The cutters cut or carve off material when the screw is inserted into a fibrous material like wood to thereby facilitate countersinking of the screw head. The cutters may be triangular or quadrilateral wedges. One or more pockets are disposed radially inwardly of the cutters for receiving fibrous material to help lock the screw in place, i.e. to prevent the screw from loosening over time. These pockets may circularly shaped pockets disposed circumferentially around the shank. Alternatively, a single annular pocket may be provided around the shank.