Hinged Cap Anchoring for Incompatible Material Overmolding
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Solution Overview
Problem
Existing dispensing heads with hinge caps, commonly used in cosmetics and parapharmacy, face challenges in using different materials for the dispensing head and hinge cap that are incompatible with each other, limiting design flexibility and functionality.
Innovation Solution
Incorporating anchoring means such as grooves and tongues or hooks to ensure mechanical fixation of the hinge cap on the dispensing head, allowing for the use of incompatible materials and enabling overmolding for a strong and secure connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the hinge cap and dispensing head are made from incompatible materials to enable different colors and material properties, then design flexibility and functionality are improved, but the materials do not fuse together and adhere to each other, resulting in poor connection strength
Solution Approach 1:
The invention divides the connection interface into two separate anchoring systems: first anchoring means (protrusions) integrated into the dispensing head, and second anchoring means (corresponding recesses) integrated into the hinge cap. This segmentation allows incompatible materials to be mechanically interlocked without relying on material fusion or adhesion, thereby maintaining both design flexibility and connection strength.
Solution Approach 2:
The second anchoring means of the hinge cap are designed to engage within the first anchoring means of the dispensing head, creating a nested interlocking structure. This nesting arrangement ensures that the hinge cap is securely retained on the dispensing head through geometric interlocking, eliminating the need for material compatibility or adhesive bonding.
2Ease of manufacture
If the hinge cap is overmolded on the dispensing head to form a single-piece assembly, then manufacturing integration and leak prevention are improved, but using incompatible materials prevents proper adhesion and fusion
Solution Approach 1:
The overmolding process incorporates segmented anchoring features: the first anchoring means are formed as integral protrusions on the dispensing head during its molding, and the second anchoring means are formed as corresponding recesses on the hinge cap during its overmolding process. This segmentation enables the use of incompatible materials while maintaining mechanical interlocking and assembly integrity.
Solution Approach 2:
The anchoring means act as intermediary mechanical features that mediate the connection between incompatible materials. Instead of relying on direct material-to-material adhesion, the protrusion-recess interface serves as an intermediary mechanism that transfers and distributes mechanical loads, enabling secure connection despite material incompatibility.
3Reliability
If a lock with non-uniform height is used to overmold the cap on the dispensing head, then the cap can be secured, but an inclined junction is created and contact is limited to the plane level, reducing connection reliability
Solution Approach 1:
The anchoring means employ asymmetric protrusion and recess geometries that complement each other. The first anchoring means on the dispensing head feature protrusions with specific asymmetric shapes, while the second anchoring means on the hinge cap have corresponding asymmetric recesses. This asymmetric design creates uniform contact across the entire junction surface, maximizing connection reliability and eliminating the inclined junction problem.
Data Source
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AI summary
The invention relates to a dispensing head (103) for closing a vessel, mainly a tube or a vial, that comprises an outlet opening (135) and a hinged cap (104) for closing the opening (135) of the dispensing head, wherein the dispensing head (103) and the hinged cap (104) are made of a single piece. According to the invention, the hinged cap (104) is moulded over the dispensing head (103). In order to ensure the anchoring of the cap (104) onto the head (103) even when the materials are not compatible, anchoring means (138, 144) can also be provided.