Anchor Bolt with Segmented Taper Member for Crack Prevention
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Solution Overview
Problem
Existing anchor bolts can cause cracks in concrete walls due to the concentrated and vectorially opposite forces applied to the attachment bore, leading to a decrease in securing force.
Innovation Solution
The anchor bolt design features a taper member with inclined surfaces and abutment parts arranged in a triangular or pentagonal cross-section, distributing forces to prevent excessive expansion and cracking, with the abutment parts being pressed against the inner peripheral surface of the attachment bore to ensure secure fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If six abutment parts are arranged at the same height level on an equilateral hexagon taper member, then the anchor bolt can be firmly fixed in the attachment bore, but forces concentrate in a narrow longitudinal range causing cracks in concrete walls
Solution Approach 1:
The six abutment parts are divided into two groups of three, arranged at different height levels along the taper member. This segmentation distributes the expansion forces along the longitudinal axis of the attachment bore, preventing concentration in a narrow range and avoiding cracks in the concrete wall while maintaining firm fixation.
Solution Approach 2:
The abutment parts are arranged not only circumferentially (around the taper member) but also longitudinally (at different height levels). This adds a longitudinal dimension to the force distribution, spreading the expansion forces over a longer portion of the attachment bore and preventing localized stress concentration.
2Device complexity
If facing abutment parts push the inner peripheral surface in vectorially opposite directions, then the anchor bolt structure is simple, but excessive expansion occurs causing cracks
Solution Approach 1:
The abutment parts are arranged asymmetrically along the longitudinal axis, with three abutment parts at a first height level and three at a second height level. This asymmetric longitudinal arrangement prevents vectorially opposite forces from acting at the same location, distributing the expansion forces more evenly and preventing excessive localized expansion.
3Ease of manufacture
If the taper member cross section is an equilateral hexagon with six inclined surfaces, then the anchor bolt can be easily manufactured, but forces are concentrated causing cracks
Solution Approach 1:
The six inclined surfaces on the taper member are segmented into two groups of three, corresponding to the two height levels of abutment parts. This segmentation allows the taper member to be manufactured with standard machining processes while distributing the expansion forces along the longitudinal axis, preventing crack formation.
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 prevents cracks in concrete walls by distributing forces evenly, enhancing the securing force of the anchor bolt and ensuring stable fixation without excessive expansion of the attachment bore.
Implementation Method 1
outer peripheral surfaces of the abutment parts are pressed against the inner peripheral surface of the attachment bore so that the anchor bolt is fixed (secured) in the attachment bore
Data Source
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AI summary
An anchor bolt (40) according to the present invention has a taper member (7) threadably engaged with the rod (4), and three or five abutment parts (12) fitted over the taper member (7). The taper member (7) has a cross section in a form of an equilateral triangle or pentagon, and three or five inclined surfaces (10) at respective sides of the triangle or pentagon. The inclined surfaces (10) are inclined closer to a central axis of the taper member (7) toward a base end of the anchor bolt (40). Each abutment part (12) has an inner surface (11) which is inclined closer to the central axis of the taper member (7) toward the base end and which abuts the inclined surface (10) of the taper member (7). In a state in which the taper member (7) and the abutment parts (12) are inserted into the attachment bore (2), when only the taper member (7) is moved toward an opening of the attachment bore (2), the outer peripheral surface (15) of the abutment parts (12) are pressed against the inner peripheral surface (2a) of the attachment bore (2) so that the abutment parts (12) are fixed in the attachment bore (2).