Support Bar Bearing Pin Design for Error-Tolerant Roll Insertion

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Solution Overview

Problem

Existing dispensing systems for low-value material webs, such as household paper and toilet paper, face instability and damage risks due to incorrect roll insertion, as the bearing journals are not robust enough to withstand forceful insertion attempts, despite having different designs on both sides for proper orientation.

Innovation Solution

A support rod with bearing pins at each end, where at least one pin has a non-rotational mating surface on a groove, allowing for rotatable arrangement on the support rod, ensuring the roll remains non-rotatable during dispensing and preventing material web withdrawal, while allowing the support rod to twist with the roll for easy insertion and secure holding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bearing journals are made robust to withstand forceful insertion attempts, then reliability improves, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveresistance to damage from incorrect insertionVSAvoidcomplexity of bearing journal design

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of making the bearing journal robust against incorrect insertion, the invention inverts the approach by making the bearing journal itself breakable. The bearing journal is designed with a breakable section that fractures under excessive force, thereby protecting the more critical components of the dispenser while still providing guidance for correct insertion.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The bearing journal is designed as a disposable component with a breakable section that is intended to fail under excessive force. This sacrificial element protects the permanent components of the dispenser from damage, allowing the bearing journal to be replaced rather than requiring the entire dispenser to be repaired or replaced.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If bearing journals are designed with non-rotational mating surfaces to prevent incorrect insertion, then reliability improves, but ease of operation deteriorates due to difficulty in insertion

Engineering Contradiction:

Improveprevention of incorrect roll insertionVSAvoidease of roll insertion

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

Instead of designing the bearing journal to resist incorrect insertion through robust non-rotational mating surfaces, the invention inverts the approach by allowing the bearing journal to break under excessive force. This maintains the guidance function for correct insertion while eliminating the resistance to insertion that would complicate operation.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The potential harm of forceful incorrect insertion is converted into a beneficial failure mode where the breakable bearing journal fractures to indicate incorrect insertion. This provides clear feedback to the user while protecting the dispenser, transforming a potentially damaging action into a useful error indication mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Stability of the object's composition

If the roll is held non-rotatably during dispensing, then stability improves, but the support rod cannot accommodate rotation during insertion

Engineering Contradiction:

Improvestability of roll position during dispensingVSAvoidease of roll insertion and support rod rotation

Core Design Contradiction:

Stability of the object's compositionVSEase of operation

Solution Approach 1:

The support rod is designed with dynamic characteristics, allowing it to rotate freely during insertion to accommodate the rolling motion of the roll. Once inserted and engaged with the bearing journals, the system transitions to a stable state where the roll is held non-rotatably during dispensing. This dynamic-to-static transition resolves the contradiction between insertion ease and dispensing stability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The support rod is segmented into distinct functional zones: a rotationally free section that allows the roll to rotate during insertion, and a constrained section that prevents rotation during dispensing. This segmentation allows the same component to fulfill both contradictory requirements at different stages of operation.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP2816941B1Dispensing system

Publication Date: 2017.04.26 HAGLEITNER HANS GEORG

Figure 1~5
Figure 6

AI summary

The invention relates to a support bar for a material web (12) wound onto a roller (3). Said support bar comprises, on each end, a bearing journal (4, 5) which is arranged on the longitudinal axis thereof. At least one of the two bearing journals (5) is provided with a fitting surface (9) which is not designed as a rotational surface and is rotatably arranged on the support bar (1). Said bearing journal (5) can be inserted into a guide (21) of a dispenser (20), said guide being continuous from the insertion position (15) to the dispensing position (10).