Thread Protection Sleeve for Fastening System Installation
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Solution Overview
Problem
Fastening systems where the fastener participates in forming the drilled hole are prone to thread damage from cuttings or the drill bit, requiring special precautions and increasing the complexity of the installation process.
Innovation Solution
A separate thread protection mechanism, such as a detachable plastic sleeve or viscous grease, is implemented to safeguard the internal thread, allowing for non-destructive removal and ensuring the thread is not forgotten, combined with a clearance angle and fastening geometry for improved cutting and anchoring performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fastener participates in forming the drilled hole, then the mounting hole can be created and the fastening element can be driven into it in one work step, but the thread is at risk of being damaged by cuttings or the drill bit
Solution Approach 1:
A thread protection sleeve is introduced as an intermediary component between the drill bit and the internal thread of the fastening element. The sleeve has a through-opening that allows the drill bit to pass through and form the hole, while simultaneously protecting the internal thread from damage by cuttings and the drill bit itself. After drilling, the sleeve is removed, leaving the protected thread ready for screw insertion.
2Reliability
If a thread protection is provided for the internal thread, then the sensitive internal thread is protected from damage, but the device complexity increases
Solution Approach 1:
The thread protection is designed as a separate, detachable sleeve component rather than an integrated part of the fastening element. This segmentation allows the protection function to be added independently, and the sleeve can be easily removed after drilling without requiring special tools or complex removal procedures. The sleeve is simply pulled off the fastening element after the drill bit passes through.
3Ease of operation
If the thread protector is detachably connected to the fastening element, then it can be removed non-destructively without tools, but the fixing structure adds complexity
Solution Approach 1:
The thread protection sleeve is preliminarily positioned on the fastening element before drilling, with its through-opening aligned to expose the internal thread protection area. The detachable connection (such as a friction fit or light snap-fit) holds the sleeve in place during drilling, and after the drill bit passes through, the sleeve is easily pulled off in the reverse direction without requiring tools or causing damage to the fastening element.
Data Source
Figure 1~2
Figure 3~6
Figure 7~8
AI summary
The mounting system comprises a driller (12) and a sleeve-like mounting element (22), which has a cutting edge (26) and a striking surface (24). The mounting element is acted upon by axially acting forces over the striking surface. The mounting element has an axial passage opening (34) with an internal thread (42), through which the driller is extended. A separate thread protection (43) is provided for the internal thread.