Dovetail Window Profile Groove Preserves Wall Thickness
Solution Overview
Problem
Existing window or door hollow profiles with rectangular fitting grooves weaken the material thickness during machining, leading to potential cracks and fractures due to the need for extensive flank machining for gear insertion.
Innovation Solution
A dovetail-shaped fitting groove with flanks forming an angle of 45° to 85°, preferably 60° to 80°, particularly 70°, reduces material removal to the shoulders, maintaining the wall thickness and ensuring a secure fit with parallel side surfaces for the cuff rail fitting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a rectangular fitting groove is used for accommodating faceplate fittings, then the groove can be easily machined, but the wall thickness of the window or door hollow profile is significantly weakened leading to cracks and fractures
Solution Approach 1:
The fitting groove is divided into two distinct parts: a dovetail-shaped main body for structural strength and localized shoulder areas for material removal. This segmentation allows the gear insertion area to be isolated to specific regions rather than requiring machining along the entire groove flanks, thus preserving overall wall thickness strength while still enabling gear installation.
Solution Approach 2:
The groove profile transitions from a uniform rectangular shape to a dovetail shape with localized shoulders. The shoulders create specific zones where material can be removed for gear accommodation, while the rest of the groove maintains full wall thickness. This local modification approach ensures that strength is preserved in critical areas while still providing the necessary clearance for gear insertion.
2Ease of operation
If the groove flanks are machined extensively for gear insertion, then the gear can be installed, but the material thickness is reduced causing structural weakness
Solution Approach 1:
The fitting groove is divided into two distinct parts: a dovetail-shaped main body for structural strength and localized shoulder areas for material removal. This segmentation allows the gear insertion area to be isolated to specific regions rather than requiring machining along the entire groove flanks, thus preserving overall wall thickness strength while still enabling gear installation.
Solution Approach 2:
The groove profile changes from symmetric rectangular flanks to an asymmetric dovetail shape with inclined sides and localized shoulders. This asymmetric design concentrates the material removal requirements to specific shoulder regions, allowing gear insertion while maintaining structural integrity in the main groove body where the material thickness is preserved.
Data Source
Figure 1~3
Figure 4~5
AI summary
The invention relates to a hollow window or door section (1, 11) comprising at least one mounting groove (2) for accommodating a covering rail fitting (3). The mounting groove (2) has lowered shoulders (2d) in the starting zone (8) of the groove flanks (2a, 2b) in order to accommodate a covering rail (7) that can be fixedly connected to the hollow window or door section (1, 11). In order to prevent the wall thicknesses from being reduced as a result of mounting conditions, the mounting groove (2) has a substantially dovetail-shaped profile from a cross-sectional view, and the groove flanks (2a, 2b) enclose an angle (a) ranging from 45° to 85°, preferably from 60° to 80°, especially preferably an angle of about 70°, along with the bottom (2c) of the mounting groove (2).