Screw With Segmented Crest Notches Reduces Drilling Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional screws face issues with high drilling torque due to entanglement with object fibers, accumulation of debris, and poor engagement, leading to increased difficulty in screwing and risk of damage or loosening.
Innovation Solution
The screw design features cutting threads with notches and grooves that provide multiple cutting points to effectively break fibers and reduce torque, while the notches and grooves accommodate debris for stable engagement, and auxiliary threads assist in the cutting operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional threads are used for cutting operation, then the screw can thread into the object, but the fibers entangle around the shank and drilling portion causing increased drilling torque
Solution Approach 1:
The thread crest is segmented into multiple crest portions by forming notches that extend from the thread crest to the thread root. Each crest portion is further divided into cutting edges by grooves. This segmentation prevents fiber entanglement by creating discrete cutting points that cleanly sever fibers rather than allowing them to wrap around the shank, thereby reducing drilling torque while maintaining threading capability.
Solution Approach 2:
Different regions of the thread are given different functions: the notches provide cutting action with sharp edges, the grooves accommodate debris and guide fiber separation, and the crest portions maintain structural integrity. This localized functional differentiation allows the thread to effectively cut fibers without entanglement while managing debris to reduce torque during the screwing operation.
2Ease of operation
If the screw presses directly on the object surface to enter, then the screw can initiate screwing, but the screwing operation slows down due to lack of fiber serving
Solution Approach 1:
The notches with sharp cutting edges are positioned at the thread crest to perform preliminary cutting action on the fibers as the screw advances. This preliminary fiber severing occurs before the fibers can entangle around the shank, enabling smooth screwing operation from initiation through completion without slowing down due to fiber resistance.
3Productivity
If the screw continues to screw downwards to complete threading, then the threading operation can be completed, but debris accumulates between the screw and object causing hindrance and potential damage
Solution Approach 1:
The grooves recessed into each crest portion serve as channels that extract and accommodate cutting debris during the screwing operation. By providing dedicated spaces for debris accumulation, the grooves prevent debris from accumulating between the screw and object surface, eliminating the risk of debris-induced damage or cracking while allowing the threading operation to complete smoothly.
Solution Approach 2:
The notches and grooves act as intermediary structures that manage the interaction between the screw and the object material. They provide controlled pathways for fiber separation and debris accommodation, mediating the cutting process to prevent harmful debris accumulation while maintaining effective threading completion.
4Productivity
If the screw engages with the object, then the screwing operation completes, but the engagement is ineffective causing loose, swaying, or falling off under external force
Solution Approach 1:
The segmented thread structure with multiple crest portions and cutting edges creates multiple engagement points with the object material. This segmentation ensures uniform distribution of loading and effective fiber serving throughout the threading process, resulting in tight and stable engagement that resists loosening, swaying, or falling off under external pulling or shaking forces.
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
This design significantly reduces drilling torque, enhances cutting efficiency, and ensures a stable and tight engagement with the object, increasing resistance to pulling-out forces.
Implementation Method 1
a plurality of notches formed at the thread crest to define a plurality of crest portions, alternating with the notches, and a plurality of grooves recessed on the crest portions... The first and second cutting edges cooperate with the upper and lower crest edges to provide multiple cutting points, thereby increasing the cutting efficiency, breaking fibers of an object effectively
Implementation Method 2
the notches and grooves help accommodate partial debris, thereby attaining a stable and tight engagement between the screw and the object
Implementation Method 3
the threads 14 continue to execute the cutting operation of the object, thereby threading the shank 11 into the object through the cutting action of the threads 14... attaining a stable and tight engagement between the screw and the object and increasing the ability of resisting the pulling-out force
Data Source
AI summary
A screw capable of reducing drilling torque includes a shank provided with cutting threads, and a head and a drilling portion respectively formed at two ends of the shank. Each cutting thread has two opposite flank surfaces converging at a thread crest. On the thread crest are recessedly formed notches alternating with grooves. Each groove has an upper crest edge and a lower crest edge meeting the flank surfaces respectively. Each notch has a first cutting edge and a second cutting edge meeting the flank surfaces respectively. The above cutting edges and crest edges cooperate to provide multiple cutting points, thereby increasing the cutting efficiency, preventing the improper entanglement of fibers, and reducing drilling torque for easier screwing. The notches and grooves accommodate and press partial debris for achieving a stable and tight engagement between the screw and an object and increasing the ability of resisting the pulling-out force.