Dual-Interface Screw With Reverse-Threaded Extraction Grip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Screws often disengage from drivers during insertion or require excessive torque for extraction, leading to misalignment and difficulty in maintaining engagement, particularly in applications requiring high torque.
Innovation Solution
A dual interface screw element with a first engagement interface for insertion and a second reverse-threaded interface for extraction, allowing for separate torque application in both directions using complementary tools, ensuring secure engagement and alignment during insertion and extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single engagement interface is used for both insertion and extraction, then the device complexity is reduced, but the torque required for extraction may exceed the torque which can be delivered through the interface
Solution Approach 1:
The screw element is segmented into two distinct engagement interfaces: a first engagement interface for insertion and a second engagement interface for extraction. This segmentation allows each interface to be optimized for its specific function, enabling the extraction interface to handle higher extraction torques without requiring increased complexity in a single interface design.
2Reliability
If a strong forward axial force is applied to maintain reliable engagement during insertion, then the engagement reliability is improved, but the desired rearward extraction force is hindered
Solution Approach 1:
The invention inverts the engagement mechanism by providing a second engagement interface with reverse threading specifically for extraction. This allows the extraction operation to engage in the opposite direction, enabling rearward extraction force to be applied effectively without compromising the forward axial engagement reliability during insertion.
3Stability of the object's composition
If a magnetic bit is used to prevent screw disengagement, then the engagement stability is improved, but misalignment between driver and screw still occurs and non-magnetic materials are not solved
Solution Approach 1:
By segmenting the engagement interfaces and providing a dedicated first engagement interface for insertion with features such as alignment pins or tapered surfaces, the invention achieves precise alignment between driver and screw without relying on magnetic attraction, thereby solving both the stability and precision problems.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A dual interface screw element includes a screw body (10) with an external thread (12) and two distinct engagement interfaces (13, 15), one for inserting the screw and another for removing it. The removal engagement interface (15) includes a reverse thread (16) located in an axial recess (36) such that a complementary reverse-threaded tool (24) applying torque to extract the screw body is tightened against the second engagement interface. The screw is part of a system including an extraction tool (24) and an insertion tool (18). Applications include medical applications such as dental implants and bone screws, domestic applications such as headless wall mounting anchors, and a wide range of other industrial and aerospace applications.