Resilient Gripper for Twist-Lock Cap Opening Without Surface Damage

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Solution Overview

Problem

Existing auxiliary devices for opening twist-lock closures, such as screw caps, are either complex, prone to failure, expensive, and often damage the surface of the closure when opening or closing, especially when dealing with profiled plastic lids.

Innovation Solution

A simple and cost-effective auxiliary device with a base body featuring a curved inner wall and radially offset, sheet-shaped grippers made of resilient material, which engage gently with the closure cap's grooves to facilitate opening and closing without surface damage, and includes a spring action for secure engagement and acoustic feedback on closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If sharp-edged metal tongues are used to engage the closure cap, then the opening force is sufficient, but the surface of the plastic lid is damaged and grooves are destroyed

Engineering Contradiction:
Improveopening forceVSAvoidsurface damage
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The gripper is designed with differentiated local properties: the body portion has a larger cross-section for structural strength and engagement, while the free edge has a reduced cross-section with rounded corners for gentle contact. This local quality differentiation allows the gripper to exert sufficient opening force through its body while the rounded free edge prevents surface damage to the plastic lid.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The gripper is designed as a replaceable component that can be easily manufactured from resilient material. Instead of using expensive, complex mechanisms, the invention employs a simple, cost-effective gripper structure that can be replaced if worn, providing an economical solution to the surface damage problem.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Adaptability or versatility

If a strap made of lever is placed around the closure to lock by friction, then closures with different diameters can be opened, but the structure is complex and expensive to manufacture

Engineering Contradiction:
Improvecompatibility with different closure diametersVSAvoidstructural complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The base body is designed with a receiving opening that can accommodate closure caps of different diameters. The gripper, with its resilient material and spring action, adapts to various closure sizes and profiles, providing a universal solution that works with different closure types without requiring complex adjustable mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The gripper's resilient material allows it to change its physical parameters (shape, position) in response to different closure diameters. The spring action enables the gripper to compress and expand, adapting to various closure sizes while maintaining effective engagement, thereby achieving versatility without structural complexity.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the gripper has a large cross-section for strength, then it can exert sufficient force, but it cannot engage gently in grooves without damaging the surface

Engineering Contradiction:
Improvegripper strengthVSAvoidsurface damage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The gripper is designed with differentiated local properties: the body portion has a larger cross-section for structural strength and engagement, while the free edge has a reduced cross-section with rounded corners for gentle contact. This local quality differentiation allows the gripper to exert sufficient opening force through its body while the rounded free edge prevents surface damage to the plastic lid.

Inventive Principle:
Principle #3Local quality

4Object-affected harmful factors

If the gripper is made of resilient material with reduced cross-section at the free edge, then surface damage is prevented, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvesurface damageVSAvoidgripper geometry precision
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The gripper's resilient material allows it to change its physical parameters (shape, position) in response to different closure diameters. The spring action enables the gripper to compress and expand, adapting to various closure sizes while maintaining effective engagement, thereby achieving versatility without structural complexity.

Inventive Principle:
Principle #35Parameter changes

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 device allows reliable and repeated opening of twist-lock closures without damaging the surface, provides an audible indication of proper closure, and can be easily and inexpensively manufactured for long service life.

Implementation Method 1

the gripper consists of resilient material, with a surface of the gripper in the region of its protruding from the inner wall portion only line-shaped with the base body or the inner wall of the base body is in abutment

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

an audible noise is thus generated when the gripper slips through in the opening direction in a resilient manner from one recess into another recess

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

an audible noise is thus generated when the gripper slips through in the opening direction in a resilient manner from one recess into another recess

Methodology Applied
Scientific EffectAcoustic emission: Acoustic Emission

Data Source

PatentEP1798192B1Auxiliary device for unscrewing threaded caps
Publication Date: 2008.07.30 STIFTUNG BRANDI
  • EP1798192B1 patent drawingFigure 1~7
  • EP1798192B1 patent drawingFigure 4~6
  • EP1798192B1 patent drawingFigure 8~11

AI summary

Protruding inwards from the inner wall of a retaining opening (4) and aligned offset radially with reference to a vertical axis, a gripper (19) made of springy material in the shape of a blade has a straight free edge (21). A surface of the gripper maintains extended contact with a main body (3), i.e. the inner wall of the main body, in the area of its area protruding from the inner wall.