Snap-fit Cap Assembly with Rotational Lifting Ramps

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Solution Overview

Problem

Contemporary bottle and cap combinations with sleek designs face challenges in achieving a close fit due to manufacturing tolerances and smooth surfaces, making it difficult to assemble and remove the cap, especially when using different materials like glass and plastic, and providing insufficient surface topography for gripping.

Innovation Solution

The cap assembly features adjustable inner and outer components with snap-fit engagement and downwardly directed ramps on the cap and upwardly directed ramps on the bottle, allowing the cap to be easily lifted from the bottle by rotating it, ensuring a snug fit and easy removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the gap between bottle and cap is minimized to provide a sleek appearance, then aesthetic quality is improved, but it becomes difficult for users to insert fingers under the cap to remove it

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidcap removal
Core Design Contradiction:
ShapeVSEase of operation

Solution Approach 1:

The cap assembly is divided into two functional zones: an outer cap portion that interfaces with the user's fingers for removal, and an inner cap portion that maintains the sleek seal against the bottle. This segmentation allows the outer portion to have a higher profile for finger insertion while the inner portion maintains minimal gap for aesthetics.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism (the dual-component cap structure with ramps) that mediates between the aesthetic requirement for minimal gap and the functional requirement for finger insertion. The ramps act as mechanical intermediaries that translate rotational motion into lifting force to overcome the tight seal.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If smooth surfaces are used for sleek design, then aesthetic quality is improved, but sufficient surface topography for gripping is not provided

Engineering Contradiction:
Improvesurface smoothnessVSAvoidgripping
Core Design Contradiction:
ShapeVSEase of operation

Solution Approach 1:

The cap assembly applies local quality by providing smooth surfaces only where aesthetic appearance is critical (the sealing surfaces against the bottle), while introducing textured or topographed surfaces on the outer cap portions that contact user fingers for gripping. This localized differentiation resolves the contradiction between smoothness and grip.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If close tolerance fit is achieved between cap and bottle, then manufacturing precision is improved, but the cap becomes difficult to remove

Engineering Contradiction:
Improveclose tolerance fitVSAvoidcap removal
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The cap assembly uses dynamics by incorporating ramps that convert rotational motion into vertical lifting force. During normal use, the cap maintains a static close-tolerance seal. During removal, the user rotates the cap, and the ramps dynamically transform this rotational input into upward motion that breaks the seal and enables easy removal.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The ramp structures are pre-configured in the cap and bottle designs to facilitate removal. When the user applies rotational force, the ramps are already positioned to convert this motion into lifting action, eliminating the need for finger insertion under the cap edge.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If different materials with varying tolerances (glass and plastic) are used, then material versatility is improved, but achieving a close fit becomes challenging

Engineering Contradiction:
Improvematerial compatibilityVSAvoidcomponent fit
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent addresses material tolerance variations by designing the cap and bottle with adjustable parameters. The dual-component cap structure allows for parameter adjustment in the radial direction (outer cap fit) and axial direction (inner cap seal position), enabling close fits despite variations in glass and plastic manufacturing tolerances.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3642129B1Containers with pull-off, snap-fit caps
Publication Date: 2022.02.16 ELC MANAGEMENT LLC
  • EP3642129B1 patent drawingFigure 1~2
  • EP3642129B1 patent drawingFigure 3~4
  • EP3642129B1 patent drawingFigure 5

AI summary

A combined bottle and cap assembly has a cap assembly secured to a bottle by snap-fit engagement. The cap assembly has downwardly directed ramps on an underside and bottle has upwardly directed ramps on a top wall. When the cap assembly is rotated relative to the bottle, the downwardly directed ramps cooperatively engage the upwardly directed ramps to lift the cap assembly from the bottle sufficiently to disengage the snap-fit engagement and allow cap assembly to be easily lifted from the bottle.