Anchor Bolt Retainer Nut Wedge Rotation Control
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Solution Overview
Problem
Anchor bolts fail to anchor properly in base materials due to insufficient friction between the wedge and sleeve, leading to reduced expansion and anchoring capability.
Innovation Solution
An anchor bolt design incorporating a retainer nut with dimensions matching or exceeding the hole's central axis, which resists rotation and axially moves to urge the wedge toward the sleeve, enhancing frictional engagement and expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the wedge is designed to rotate freely on the stud, then the assembly is easier to install, but the wedge fails to generate axial movement to expand the sleeve
Solution Approach 1:
The retainer nut acts as an intermediary component between the stud and the wedge. It converts the rotational motion of the stud into axial movement of the wedge through its engagement geometry, while still allowing free rotation of the wedge on the stud during installation.
Solution Approach 2:
The retainer nut changes the motion parameter from pure rotation to combined rotation and axial movement. By engaging the wedge at an angle or through threaded interaction, it transforms the rotational input into the required axial displacement for sleeve expansion.
2Reliability
If friction between wedge and sleeve is increased to prevent rotation, then anchoring improves, but the wedge cannot rotate freely during installation
Solution Approach 1:
The retainer nut serves as a mediator that manages the friction relationship between the wedge and sleeve. It provides the necessary friction to prevent unwanted rotation during operation while allowing controlled movement during installation through its engagement mechanism.
Solution Approach 2:
The system transitions from a static friction relationship to a dynamic one where the retainer nut controls the interaction between wedge and sleeve. During installation, the nut allows movement; during operation, it maintains the friction needed to prevent rotation.
3Reliability
If the retainer nut dimension is made equal to or larger than the hole dimension, then wedge rotation is prevented, but the device complexity increases
Solution Approach 1:
The retainer nut performs multiple functions: it controls wedge rotation, transmits axial force to expand the sleeve, and maintains engagement with the stud. This multi-functionality justifies its size and reduces the need for additional components.
Solution Approach 2:
The retainer nut combines several functions into a single component: rotation control, force transmission, and expansion actuation. By merging these functions, the overall device complexity is reduced despite the nut's larger dimensions.
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
The solution ensures effective anchoring by increasing frictional engagement between the sleeve and the base material, preventing wedge rotation and ensuring proper expansion of the sleeve for secure attachment.
Implementation Method 1
The proper function of anchor bolts as described above in part relies on the presence of friction between the wedge and the sleeve to inhibit rotation of the wedge relative to the sleeve.
Implementation Method 2
Upon rotation of the stud, the wedge moves axially along the stud and, due to the abutment between the wedge and the sleeve, causes an expansion of the sleeve.
Data Source
AI summary
An anchor bolt for use in a hole in a base material is provided and includes a stud, a sleeve disposed about the stud and a retainer nut, disposed in operable communication with the stud and having a dimension measured from a central axis of the hole that is at least as large as a corresponding dimension of the hole.