Screw-In Back Bolt Anchoring for Stress-Free Thin Curtain Wall Panels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for installing curtain walls, such as adhesive-based attachment and expandable anchor bolts, face limitations in long-term durability, stress concentration, and incompatibility with ultra-thin panels, and are complex and costly.
Innovation Solution
A screw-in back bolt method involving drilling an anchor bolt hole, injecting adhesive, placing a spreadable back bolt sleeve, and locking it with a limit screw, which combines mechanical locking and chemical adhesion for secure panel installation without internal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If adhesive-based attachment is used to install curtain wall panels, then the installation process becomes complicated and construction is difficult, but the bearing force distribution is poor and long-term durability is compromised
Solution Approach 1:
The connection system is segmented into distinct functional components: the anchor bolt hole for mechanical anchoring, the adhesive layer for chemical bonding, and the back bolt sleeve with limit screw for structural support. This segmentation allows each component to perform its specialized function optimally, simplifying the overall installation process while ensuring long-term durability through multiple independent load-bearing mechanisms.
2Strength
If expandable anchor bolt is used to install curtain wall panels, then mechanical anchoring is achieved, but stress concentration occurs inside the panel increasing burden on panel structure strength
Solution Approach 1:
Instead of expanding the anchor bolt within the panel hole (which causes stress concentration), the invention inverts the approach by using a back bolt sleeve that expands at the back of the panel through the limit screw mechanism. The expansion force is applied in the opposite direction, away from the panel interior, thereby achieving mechanical anchoring without internal stress concentration.
3Strength
If expandable anchor bolt is used for curtain wall installation, then anchoring effect is generated, but ultra-thin panels cannot be installed due to insufficient strength margin
Solution Approach 1:
The invention transitions the expansion dimension from within the panel thickness (which would compromise ultra-thin panels) to the back surface dimension. The back bolt sleeve expands radially outward at the back of the panel, utilizing the counterbore space rather than consuming panel thickness, thereby enabling installation on ultra-thin panels while maintaining anchoring strength.
4Reliability
If conventional installation methods are used, then basic anchoring is achieved, but the construction process is complex and material costs are high
Solution Approach 1:
The invention merges the adhesive bonding function and mechanical anchoring function into a single integrated back bolt assembly. The back bolt sleeve with limit screw combines the roles of anchor, expander, and locking mechanism, eliminating the need for separate expandable anchor bolts and reducing construction steps while maintaining both adhesive and mechanical anchoring reliability.
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 method enhances panel installation strength, simplifies the process, reduces material costs, and supports thin panels without stress, offering a robust and cost-effective solution for curtain wall construction.
Implementation Method 1
injecting an adhesive into the anchor bolt hole
Implementation Method 2
screwing a limit screw of the back bolt into the back bolt sleeve so that the back bolt sleeve is spread... generate a pulling-resistant force through a shearing friction effect
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A screw-in back bolt comprises a back bolt sleeve and a limit screw. A front end of the back bolt sleeve is an expandable portion that can be expanded by the limit screw. The limit screw (3) can be screwed in from a rear end of the anchor bolt sleeve until the limit screw is secured in place. The expandable portion of the back bolt sleeve (2) is provided with one or more conical surfaces. A method for installing a panel based on the screw-in back bolt comprises: drilling an back bolt hole in a back of the panel; injecting an adhesive into the back bolt hole; placing the back bolt sleeve into the back bolt hole; and screwing the limit screw into the back bolt sleeve to expand the anchor bolt sleeve. A curtain wall comprises the panel and the screw-in anchor bolt.