Rotating Cylindrical Cutting Device for Plastic Container Covers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing container casings with rotating cylindrical cutting devices face inefficiencies due to high torque requirements, premature dulling of cutting edges, and incomplete cutting of materials like high-density polyethylene, leading to increased manufacturing costs and potential spillage.

Innovation Solution

A container casing with a rotatable cylindrical cutting device featuring multiple teeth inclined such that the foremost tooth contacts the container first, with subsequent teeth also engaging to distribute the cutting load, reducing torque and ensuring complete cutting through various materials without the need for a patch attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a cutting device with teeth arranged to gradually increase in height in the direction of rotation is used, then the foremost tooth can pierce the container shell first, but the high forces act mainly on the foremost blade causing it to dull during cutting and reduce cutting efficiency

Engineering Contradiction:
Improvecutting initiationVSAvoidcutting efficiency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The cutting edge is segmented into multiple teeth (at least three) arranged at different heights, where each tooth contributes to the cutting process. The teeth are positioned so that during rotation, multiple teeth simultaneously engage the container shell material, distributing the cutting forces across multiple segments rather than concentrating them on a single foremost tooth.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The teeth are designed with different local properties - specifically different heights and angular positions - so that each tooth is optimally positioned to engage the material at different stages of the cutting process. This local variation in tooth geometry ensures that multiple teeth participate in cutting, with each tooth experiencing appropriate loading conditions for its position in the rotational sequence.

Inventive Principle:
Principle #3Local quality

2Force

If high forces act mainly on the foremost blade during cutting, then the container shell can be pierced, but this leads to unwanted bending or angling of the front tooth relative to the container shell and increase in torque to be applied

Engineering Contradiction:
Improvecutting forceVSAvoidtorque requirement
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The cutting force is segmented and distributed across multiple teeth arranged at different angular positions around the cutting device. Instead of one tooth bearing the full cutting load, the force is divided among at least three teeth that engage the material sequentially or simultaneously during rotation, reducing the torque required for each individual tooth and overall operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cutting action occurs periodically as multiple teeth pass through the cutting zone during rotation. Each tooth delivers a cutting impulse in sequence, creating a periodic cutting action that smooths out force peaks and reduces the maximum torque required compared to a single-tooth impact cutting mechanism.

Inventive Principle:
Principle #19Periodic action

3Ease of manufacture

If known cutting devices are used on low-density polyethylene containers, then cutting can be made easily, but the material density and thickness are not sufficient to reliably store contents over long periods

Engineering Contradiction:
Improvecutting easeVSAvoidstorage reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The cutting device parameters have been changed to accommodate higher density materials. The teeth are designed with specific height variations, angular positions, and geometric configurations that enable effective cutting of high-density polyethylene and other dense materials. These parameter changes include optimizing tooth pitch, height distribution, and engagement angles to match the mechanical properties of denser container materials that provide better long-term storage reliability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2739539B1Container cover with rotating closure
Publication Date: 2016.02.24 ROBERT BOSCH GMBH
  • EP2739539B1 patent drawingFigure 1A~1B
  • EP2739539B1 patent drawingFigure 2A~2B
  • EP2739539B1 patent drawingFigure 3A~3B

AI summary

The present invention discloses a container cover produced from a plastics film, having a rotating closure which has a rotatable cylindrical cutting device (100, 300), wherein the latter has a lower rim (110) on which at least one cutting edge section (120) is arranged, and wherein said at least one cutting edge section (120) has at least three teeth (130) which are located on a line extending in an inclined manner in relation to the bag, and wherein the front-most tooth in the direction of rotation comes first into contact with the plastics film during the cutting operation. The cutting device (100, 300) is characterized in that the inclination of the line on which the teeth (130) of each cutting edge section are located is selected such that, in the case of at least approximately maximum deformation of the plastics film before the latter is perforated by the front-most tooth, at least two following teeth of the same cutting edge section (120) are in direct contact with the plastics film.