Plastic End Cap with Metal Spring Clip for Extruded Profiles
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Solution Overview
Problem
Existing end caps for extruded plastic profiles with hollow chambers require additional work steps such as screwing or gluing for secure attachment, which is inefficient and not suitable for all profiles without special screw channels or rotation prevention.
Innovation Solution
A plastic end cap with a metal spring clip and claw-like clamping lugs that securely attach to the profile's inner walls without screws or glue, featuring a fastening mandrel and depression for rotational security and additional plastic lugs for guidance, ensuring a firm and twist-resistant connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional clamping lugs with frictional anchoring are used, then the end cap can be easily installed, but the attachment is not secure enough and requires additional gluing or screwing
Solution Approach 1:
The attachment system is segmented into multiple functional elements: clamping lugs for radial retention, claw teeth for longitudinal anchoring, and a fastening mandrel with depression for rotational prevention. This segmentation allows each element to address a specific attachment requirement, achieving secure fixation without additional gluing or screwing steps.
Solution Approach 2:
The clamping lugs are designed as spring-elastic elements that dynamically adapt to the hollow chamber profile dimensions. This elasticity allows the lugs to exert continuous radial clamping force while accommodating manufacturing tolerances, maintaining secure attachment without requiring precise pre-adjustment or additional fastening steps.
2Reliability
If screws are used to mount end caps, then secure attachment is achieved, but additional work steps and special screw channels are required
Solution Approach 1:
The end cap attachment system is self-service in that the clamping lugs automatically engage and secure the end cap to the hollow chamber profile through elastic deformation and frictional anchoring. The claw teeth self-anchor into the profile wall during insertion, and the fastening mandrel with depression self-prevents rotation, eliminating the need for separate screwing operations or pre-formed screw channels.
Solution Approach 2:
The invention extracts the fastening function from the hollow chamber profile by integrating all necessary attachment elements (clamping lugs, claw teeth, fastening mandrel) directly onto the end cap. This eliminates the need for special screw channels or pre-prepared mounting features in the profile, simplifying both extrusion and installation processes.
3Ease of operation
If conventional end caps are used, then installation is simple, but rotational security is not provided
Solution Approach 1:
The fastening mandrel and its corresponding depression create an asymmetric geometric interface that inherently prevents rotation. The mandrel's shape does not match rotational symmetry with the depression, ensuring that the end cap can only be installed in one orientation. This asymmetric design provides rotational security while maintaining installation simplicity, as the anti-rotation feature is integrated into the basic insertion motion.
4Reliability
If claw teeth are added to clamping lugs, then firm positive attachment is achieved, but the structure becomes more complex
Solution Approach 1:
The claw teeth are merged with the clamping lugs to form an integrated attachment element. The claw teeth extend from the clamping lug structure, combining the radial clamping function with the longitudinal anchoring function in a single integrated component. This merging reduces the overall number of separate parts and simplifies the manufacturing process while achieving firm positive attachment through the combined action of clamping and clawing.
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 end cap provides a secure, rotation-proof closure of extruded plastic profiles without additional work steps, enhancing the attachment process and ensuring the cap cannot be easily removed, thus addressing the inefficiencies of existing solutions.
Implementation Method 1
The spring clip (6) is made of spring steel and essentially has the base area (22) and two clamping lugs (7, 7') protruding laterally and approximately perpendicularly from the base area (22). The spring clip is placed on the cap body (2) in such a way that the fastening spike (3) of the cap body penetrates the opening (23) in the base area (22) of the spring clip (6)
Implementation Method 2
the clamping lug with the means for clawing with appropriate pretension can be attached to one of the inner walls or one of the inner sides of the outer walls of the hollow chamber profile rests. This design of the clamping lugs and the means for clawing made of metal makes it possible for the means for clawing to be pressed so firmly and positively
Data Source
Figure 1~4
Figure 5
AI summary
An easily mounted end cap (1) is proposed for closing an open end region of an extruded plastic profile having several hollow chambers (20, 21). The end cap has a plastic body (2) and at least one clamping tab (7, 7'). The at least one clamping tab (7, 7') is made of metal and has means, in particular claw teeth (8), for gripping in a wall of one of the hollow chambers (20, 21). The end cap (1) is used, in particular, in casement windows to close the open end region of a sash frame profile (12) or a mullion profile.