Roller Tensioning Device Using Elastic Spring for Print Streak Prevention

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Solution Overview

Problem

Printers using rolls of paper face issues with streaks due to the continued rotary movement of paper rolls after printing, which existing solutions attempt to address with additional braking mechanisms, increasing costs and complexity.

Innovation Solution

A roll tensioning device with a tension spring arranged between the carrier axle and a sleeve, allowing the sleeve to rotate and tension the roll using the spring's restoring force, eliminating the need for additional braking and reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a brake is installed to stop the roller after printing, then the roller can be brought to a standstill, but this leads to increased costs and device complexity

Engineering Contradiction:
Improveroller stopping reliabilityVSAvoidbraking system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The roller is equipped with a tension spring that automatically tensions the medium and controls roller deceleration without requiring external braking intervention. The spring stores energy during roller rotation and releases it to maintain tension and control stopping, making the system self-regulating and eliminating the need for separate braking mechanisms

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The tension spring provides dynamic tensioning that adapts to the roller's motion state. As the roller rotates and decelerates, the spring dynamically adjusts the tension force applied to the medium, ensuring consistent tension throughout the stopping process without rigid mechanical constraints

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If an additional roller brake is installed to prevent continued rotation, then streaking is avoided, but manufacturing costs increase

Engineering Contradiction:
Improveprint quality uniformityVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The tension spring automatically maintains proper tension on the medium during roller deceleration, preventing streaking through self-regulating elastic force rather than requiring expensive additional braking components

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The tension spring changes the physical state of the medium from loose to tensioned during roller deceleration. By applying elastic restoring force, the spring maintains consistent medium tension parameters throughout the roller's motion, ensuring uniform print quality without additional braking hardware

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a slipping clutch is installed as a shaft-hub connection to avoid unwinding under web tension, then web tension control is improved, but device complexity and cost increase

Engineering Contradiction:
Improveweb tension controlVSAvoidshaft-hub connection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The tension spring attached to the carrier axle automatically controls web tension through its elastic properties. As the roller rotates or decelerates, the spring self-regulates the tension force applied to the medium, eliminating the need for complex slipping clutch mechanisms

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The tension spring dynamically adjusts web tension parameters based on roller motion. The elastic force of the spring automatically compensates for changes in roller speed and position, maintaining optimal web tension without requiring sophisticated mechanical connections

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 solution effectively prevents streaks by ensuring a cost-effective and efficient tensioning of the roll without additional braking, maintaining a simple construction and reliable operation.

Implementation Method 1

the roller is partially turned back in a simple manner by the restoring force of the tensioning spring

Methodology Applied
Scientific EffectElastic restoring force: Elasticity

Implementation Method 2

The design of the outer lateral surface of the sleeve and the inner lateral surface of the roller as a friction surface ensures in a simple manner that the inner lateral surface of the roller and the outer lateral surface of the sleeve are frictionally connected to one another

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2112105B1Roller tensioning device, printer and method for tensioning a roller
Publication Date: 2012.02.08 WINCOR NIXDORF INT GMBH
  • EP2112105B1 patent drawingFigure 1
  • EP2112105B1 patent drawingFigure 2~4
  • EP2112105B1 patent drawingFigure 5

AI summary

The roller tensioning device has a fixed carrier axis (1) and a casing (2) partially enclosing the carrier axis. A pretensioning device is arranged between the carrier axis and the casing. The pretensioning device is fixed at the carrier axis and at the casing. The casing is rotated at an angle around a longitudinal axis of the carrier axis. Independent claims are included for the following: (1) a printer with a printing unit; and (2) a method for tensioning a roller of a printing medium to be printed in a printer with a roller tensioning device.