Wood Screw Head Cutting Areas for Burr Removal
Solution Overview
Problem
Conventional wood screws fail to effectively cut and scrape off wood burrs from the peripheral edge of drilled holes, leading to poor fastening due to protruding burrs and incomplete hole flushment, which hinders the screw's ability to achieve a tight fit with the wooden board.
Innovation Solution
The wood screw design incorporates cutting areas with grooves and rib walls on the head, forming cutting edges that efficiently cut and scrape off burrs, accommodating them in grooves to prevent protrusion, and includes a thread-free section and reaming helical units to reduce drilling resistance and enhance fastening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional wood screws use spaced apart ribs on the head, then the structure is simple, but the ribs can only lift up burrs and cannot effectively cut and scrape off all burrs, causing poor fastening effect
Solution Approach 1:
The head surface is segmented into multiple cutting areas, each containing multiple grooves that form cutting edges. This segmentation allows different zones to perform specific cutting functions, effectively removing burrs while maintaining a manageable structure.
Solution Approach 2:
Grooves are introduced as intermediary structures between the rib walls, forming cutting edges that act as mediators to effectively cut and scrape burrs. The grooves transform the simple rib structure into an effective cutting tool system.
2Volume of moving object
If conventional wood screws lack burr accommodation space, then the head structure is compact, but cut burrs stick out from the head, preventing flush fit and good fastening
Solution Approach 1:
The grooves are nested within the cutting areas on the head surface, creating embedded spaces that accommodate burrs. This nesting approach provides burr storage within the existing head volume without requiring external additions.
Solution Approach 2:
The cutting areas and grooves utilize the conical bottom surface dimension of the head, transforming the two-dimensional rib structure into a three-dimensional cutting and accommodation system that effectively manages burrs.
3Device complexity
If conventional wood screws lack effective burr cutting structures, then the head design is simple, but burrs protrude from the peripheral edge, rendering the head difficult to be flush with the board surface
Solution Approach 1:
Different regions of the head are given different local qualities: cutting areas with grooves and rib walls for burr removal, and smooth areas for surface contact. This local differentiation enables effective burr cutting while maintaining operational simplicity.
Data Source
AI summary
A wood screw includes a plurality of cutting areas radially disposed on a conical bottom surface of a head and a smooth area formed between the cutting areas. Each cutting area has at least two grooves, each of which has a base different from each smooth area and two rib walls protruding from the base. The rib walls of two adjacent grooves meet to form a first cutting edge. Each cutting area further has two outer walls protruding from the smooth area. Each outer wall meets one rib wall of the adjacent groove on a second cutting edge. The cutting edges cut and scrape off burrs attached to a drilled hole. The cutting edges cooperate with the grooves to permit a continuous cutting action simultaneously with an increasing accommodation area for scraped burrs and prevent the burrs from sticking out from the head. Thus, the fastening effect is promoted.