Double Thread Screw Reducing Resistance and Preventing Damage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional screws face high screwing resistance and risk of object damage due to incomplete cutting and accumulation of debris, leading to loose fastening and potential breakage.
Innovation Solution
A multi-threaded screw design with a second threaded section of smaller outer diameter and concavities on its circumference, which cuts and shatters debris to reduce resistance and securely embeds itself in the object by accommodating cuttings between threaded sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional threaded sections are used to fasten objects, then the screw can be screwed into the object, but the cuttings accumulate in the object and increase screwing resistance
Solution Approach 1:
The patent extracts the harmful cuttings from the screwing path by designing the second threaded section with a smaller outer diameter, creating clearance space between the shank and the object walls. This allows cuttings to be expelled outward rather than accumulating in the object, reducing screwing resistance and improving screwing speed.
2Ease of operation
If threaded sections push fibers away during screwing, then the screw can be inserted, but the holding force is insufficient and the screw turns back
Solution Approach 1:
The patent segments the threading function into two distinct threaded sections: the first threaded section with larger diameter pushes fibers away to enable easy insertion, while the second threaded section with smaller diameter and concavities provides enhanced gripping action to prevent backout. This segmentation allows each section to optimize its specific function without compromise.
Solution Approach 2:
The patent applies different geometric qualities to different parts of the screw threads. The first threaded section has a larger outer diameter suitable for initial insertion, while the second threaded section has a smaller outer diameter with concavities that create localized fiber catching zones, providing superior holding force at the critical engagement points.
3Productivity
If the shank is twisted by accumulated debris, then the screwing process continues, but the object is damaged or broken
Solution Approach 1:
The patent extracts cuttings from the harmful accumulation zone by designing the second threaded section to actively expel debris outward through the clearance space between the smaller diameter shank and object walls. This prevents debris from twisting the shank and damaging the object, maintaining screwing continuity without harmful side effects.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention pertains to a bimate screw (3) providing with a first threaded section (34) alternating with a second threaded section (36); wherein, the second threaded section (36) has a smaller outer diameter (d) than a diameter (D) of the first threaded section (34), and further a plurality of concavities (362) are disposed on each thread (361) of the second threaded section for defining two flanks (363, 363') therein. In this manner, both the first and the second threaded sections facilitate to sever and shatter cuttings so as to reduce the screwing resistance and prevent the object from being damaged under the accumulation of cuttings; simultaneously, the screw effectively attains to a good resistance of extraction from the object by the concavities receiving the remaining cuttings which are not guided out of the object (4).