Tube Cap Centering Projections for Screw Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed tube production often results in uneven radial clearance between the cap and neck during screwing, leading to cap misalignment, damage to the cover, and aesthetic defects, as well as increased torque requirements for sealing, which can cause the cover to tear or become unsightly.
Innovation Solution
Incorporating centering projections on the external or internal threads that are distributed regularly around the main axis, ensuring a residual radial clearance and maintaining a minimum clearance between the cap and neck, preventing the cap from becoming pinched and reducing frictional damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If radial clearance is provided between the cap and neck to allow easy screwing, then the cap can be easily screwed onto the neck, but the tab gets pinched and twisted between the cap and neck during high-speed production
Solution Approach 1:
The patent introduces a tab as an intermediary element between the cap and neck. The tab is folded back against the neck during assembly and protrudes radially to provide a grip for the user. This intermediary structure allows the cap to be screwed onto the neck while preventing direct pinching of the seal between the cap and neck, thus maintaining seal integrity during high-speed production
Solution Approach 2:
The tab is folded back against the neck before the cap is screwed onto the tube during production. This preliminary positioning of the tab prevents it from being pinched between the cap and neck during the screwing operation, thereby preventing damage to the seal before the sealing function is even activated
2Productivity
If the cap is screwed onto the neck at high speed to increase production rate, then productivity increases, but the tab is rotated and twisted by the cap causing damage to the seal
Solution Approach 1:
The tab serves as a mediator that absorbs the torsional stress during high-speed screwing. By positioning the tab radially protruding from the neck, it prevents the direct transmission of rotational force from the cap to the seal, allowing high-speed production without compromising seal integrity
Solution Approach 2:
The folded-back tab position during assembly acts as a cushioning mechanism that prevents the seal from being subjected to torsional stress during high-speed screwing. The tab absorbs the mechanical stress before it can reach the seal, enabling faster production rates
3Ease of operation
If radial clearance is provided between the cap and neck, then the cap can be easily screwed on, but the cap becomes tilted relative to the neck axis causing aesthetic defects
Solution Approach 1:
The tab structure acts as a positioning intermediary that guides the cap onto the neck in the correct angular position. The radial protrusion of the tab prevents the cap from becoming tilted during assembly, ensuring proper alignment while still allowing sufficient radial clearance for easy screwing
4Reliability
If high tightening torque is applied to ensure the tube is sealed, then the seal integrity is improved, but the plug fails in the angular sector accumulating all radial clearance
Solution Approach 1:
The patent applies different functional qualities to different parts of the cap-neck assembly. The tab is positioned to provide localized guidance and alignment at specific angular sectors, while allowing radial clearance in other sectors. This local differentiation enables proper cap alignment even when high tightening torque is applied to ensure seal integrity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to an assembly (16) for closing a tube (10), said assembly (16) comprising: - a neck (20) extending along a principal axis (A) to a free upper end edge (43), and having an external helical thread (32), - a cap (30) having an internal thread (40) complementary to the external thread (32) to allow the cap (30) to be screwed onto the neck (20), characterized in that it comprises means for centering the cap relative to the neck (20) during screwing, formed by at least one projection (46) extending from the thread root (32A) of one of the external or internal threads (32), a residual radial clearance (j1) remaining between the cap (30) and the neck (20) at the projections (46) in the screwed position of the cap (30) onto the bottle neck (20).