T-Cork Partial Undercut for Axial and Rotational Locking
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Solution Overview
Problem
Existing T-corks face issues with insufficient strength in connections between disc-shaped components and foamable plastic stoppers, leading to non-functioning or violent fractures during axial or rotational movements, and require excessive foamable plastic for a tight fit, increasing production costs and complexity.
Innovation Solution
A method involving the production of T-corks with a concentric bore featuring a partial undercut, allowing for a flexible foamable plastic connection that ensures a positive axial fit and rotational movement, using an automated lathe for machining and injection molding to simplify the manufacturing process and reduce foam plastic volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the holes are widened by creating an undercut to increase contact surface, then the connection strength is improved, but the machining complexity and production time are increased
Solution Approach 1:
The connection structure is segmented into two functional zones: a cylindrical bore for axial positioning and an undercut region for rotational locking. This segmentation allows each zone to be optimized independently - the cylindrical part provides simple axial fit while the undercut portion provides rotational resistance without requiring complex overall geometry
Solution Approach 2:
The solution transitions from a simple cylindrical hole (one-dimensional radial symmetry) to a hole with an undercut feature that adds a second dimensional aspect - the radial expansion at the bottom of the hole. This dimensional change creates additional contact surface area and mechanical interlocking capability without significantly complicating the machining process
2Reliability
If a large quantity of foamable plastic is injected to achieve a tight fit, then the connection reliability is improved, but the production cost is increased
Solution Approach 1:
Instead of uniformly distributing foamable plastic throughout the entire hole volume, the undercut geometry concentrates the plastic material locally at the critical connection zone where mechanical interlocking is needed. The localized plastic injection into the undercut region provides sufficient anchoring strength without requiring excessive plastic quantity throughout the entire bore
3Strength
If the working carriage is moved back far to perform undercut machining, then the connection strength is improved, but the production cycle time is increased
Solution Approach 1:
The machining operations are merged into a single integrated process - the cylindrical bore and the undercut feature are created in one continuous machining sequence without requiring the working carriage to retract to extreme positions. The tool remains in the working area throughout, combining what would otherwise be separate positioning and machining operations into one efficient pass
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 method enhances the strength and reliability of T-cork connections, enabling secure axial and rotational movements while reducing the amount of foamable plastic needed, thus improving safety and reducing production costs.
Implementation Method 1
After being injected into the mold, the foamable plastic fills the remaining cavity and a firm connection is created between the disc-shaped component and the stopper made of the foamable plastic
Data Source
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AI summary
The invention relates to a method for manufacturing so-called T-corks, which consist of a disc-shaped component with a concentric bore and a plug molded onto it. The plug is produced by injection molding using a foamable plastic and is held against the disc-shaped component by axial positive locking. According to the method according to the invention, a positive-locking undercut is produced by machining and is created as at least one undercut that does not encompass the entire circumference of the coaxial bore. Accordingly, the T-cork according to the invention has at least one partial undercut through which positive locking exists between the disc-shaped component and the molded plug in both the axial and rotational directions.The invention also relates to a T-shaped cork with a child safety lock, which is designed using special undercuts and in conjunction with a stopper produced by injection molding.