Spacer Frame Corner Crimping for Leak-Resistant IGU Seals
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Solution Overview
Problem
Insulating glass units (IGUs) fail due to atmospheric water vapor infiltration at the frame corners, and existing manufacturing methods are inefficient and generate scrap, with manual operations limiting production rates.
Innovation Solution
An apparatus and method using crimping fingers and a double acting rack assembly to form folds at the corners of a spacer frame assembly, with an encoder measuring strip velocity and a controller accelerating the crimping assembly to ensure precise crimping, reducing manual labor and improving production efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If V-shaped notches are cut in the tube at corner locations to enable bending into mitered corner joints, then the frame can be assembled, but potential infiltration paths extend along the corner parting lines across the opposite frame faces
Solution Approach 1:
The crimping operation is performed preliminarily during the forming process to create interlocking corners before the sealant is applied. This preliminary crimping action forms the corners in a single continuous operation, eliminating subsequent infiltration paths that would exist if corners were assembled from separate pieces with visible parting lines.
Solution Approach 2:
The crimping fingers intentionally create controlled deformations and folds in the metal strip at the corners. These deformations, which might appear as defects, actually serve to interlock the corner sections and eliminate infiltration paths, converting potential weakness points into strength points for the seal.
2Ease of manufacture
If corner keys are inserted between adjacent frame element ends to form corners, then the frame can be assembled, but infiltration paths are formed by the junctures of the keys and frame elements
Solution Approach 1:
The invention extracts and eliminates the separate corner key component from the design. Instead of inserting discrete corner keys between frame elements, the crimping operation directly forms the corners by deforming the continuous metal strip, removing the source of infiltration paths at key-juncture locations.
3Adaptability or versatility
If manual operations are used for cutting, desiccant filling, and frame element end plugging, then the process is flexible, but production rates are greatly slowed
Solution Approach 1:
The crimping operation is integrated into the continuous forming process, allowing the metal strip to move continuously through the forming and crimping stations without interruption. This continuous operation eliminates the need for manual stopping, positioning, and handling operations, thereby dramatically increasing production rate while maintaining process flexibility.
Solution Approach 2:
Multiple operations that were previously performed separately and manually (cutting, desiccant filling, end plugging, corner formation) are merged into a single integrated automated forming and crimping process. The metal strip is formed and crimped in one continuous automated sequence, eliminating multiple manual handling steps.
4Ease of manufacture
If the frame is folded into final form with sealant applied, then the IGU assembly is completed, but the amount of sealant at frame corners is less than along frame sides, causing vapor leakage paths
Solution Approach 1:
The crimping operation is performed preliminarily to form interlocking corners before the sealant is applied. This preliminary corner formation ensures that the corners are structurally sound and properly aligned, allowing subsequent sealant application to uniformly cover all surfaces including corners, eliminating the sealant deficiency problem.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An apparatus and method is provided for forming folds at a corner in a spacer frame assembly used in the construction of insulating glass unit windows. The apparatus comprises a carriage supporting first and second crimping fingers. The crimping fingers are spaced about a path of travel for the passage of metal strips during operation. The apparatus comprises an encoder to determine a velocity of the strips, and a motor coupled to a ball screw assembly. The ball screw assembly moves the carriage during operation along the path of travel. The apparatus comprises an electrical gearing arrangement for accelerating the carriage along the path. The electrical gearing arrangement includes a controller and a double acting rack assembly, the controller being coupled to the motor, the encoder, and the double rack assembly. The double rack assembly simultaneously actuates the fingers at a direction substantially transverse to the path.