Window Frame Corner Assembly with Retractable Finger Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Window frames made from materials like wood or wood-based materials are prone to shrinking and warping due to temperature and humidity changes, leading to gaps and visible finger joints, which affect the cosmetic and functional integrity of the window, and existing solutions like over-moulding with polymers or using joint sealers either increase costs or compromise insulation.
Innovation Solution
A window frame design featuring interconnected first and second frame parts with retractable fingers that align in a way to display only a single joint line, allowing for movement without exposing gaps, and using connecting means like adhesive or fasteners for stability, ensuring the fingers remain hidden even during material expansion or contraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If frame parts are made from wood or wood-based materials, then the frame is cost-effective and flexible for production, but the frame material shrinks and warps due to temperature and humidity changes, causing gaps and visible finger joints
Solution Approach 1:
The patent applies dimensionality change by retracting the side surfaces of the fingers from the assembly plane into a second dimension (parallel to the assembly plane but offset). This allows the fingers to remain hidden even when gaps form between frame parts due to material movement, while maintaining the cost-effective wood or wood-based frame construction.
2Reliability
If fingers are retracted to reduce visibility, then the fingers are less visible when frame parts are close together, but the fingers become exposed when gaps form between frame parts
Solution Approach 1:
The patent extends the benefit of retraction by positioning side surfaces of multiple fingers (not just one) parallel to and retracted from the assembly plane. This creates a buffer zone that accommodates larger gaps between frame parts while keeping all fingers hidden, thereby increasing gap tolerance without sacrificing joint visibility.
3Reliability
If over-moulding with polymer is used to cover joints, then the joints are covered and fingers remain hidden, but the price increases and production flexibility decreases
Solution Approach 1:
The patent extracts the finger joint coverage function from the polymer over-moulding process and implements it through geometric retraction of the fingers themselves. This eliminates the need for expensive custom moulds for each frame size while maintaining joint coverage and finger hiding, thereby reducing production costs and increasing flexibility.
4Reliability
If joint sealer is used to cover gaps, then the gaps are covered and not visible, but the insulation performance decreases and production time increases
Solution Approach 1:
The patent implements preliminary action by designing the fingers to be retracted from the assembly plane during the frame construction phase itself. This pre-configured geometry automatically prevents gap visibility and eliminates the need for subsequent joint sealing operations, thereby reducing production time while maintaining gap coverage and insulation performance.
Data Source
Figure 1
Figure 2~4
Figure 3a~3b
AI summary
The present invention relates to a frame for a window delimiting an inner opening, the frame comprising a first frame part and a second frame part, which are interconnected in a corner assembly, each frame part having a main inner surface facing the inner opening and an outer surface facing away from the inner opening, and where the corner assembly displays only a single joint line at the main inner surfaces of the frame parts. The invention also relates to a method for for assembling a corner of a frame for a window.