Pneumatic Tearing Device for Paper Web Perforation

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Solution Overview

Problem

Existing devices for causing paper webs to tear off in rewinding machines are unreliable and require frequent costly maintenance, failing to ensure accuracy and stability at varying feeding speeds.

Innovation Solution

An apparatus using a pneumatic system with nozzles and solenoid valves to direct a jet of compressed air along a perforation line, assisted by rotating rollers, to accurately and reliably tear the paper web, reducing abrupt movements and vibrations, and simplifying maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional tearing devices are used, then the paper web can be torn off, but the system experiences frequent failures and requires costly maintenance

Engineering Contradiction:

Improvereliability of tearing deviceVSAvoidmaintenance cost and frequency

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The patent replaces complex mechanical tearing devices with a simple pneumatic system consisting of a nozzle and compressed air supply. The jet of compressed air directed at the perforation line causes the paper web to tear without requiring mechanical contact or complex moving parts, thereby eliminating frequent failures and reducing maintenance requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention uses a jet of compressed air delivered through a nozzle to achieve the tearing function. This pneumatic approach provides reliable operation without the mechanical complexity that leads to failures, maintaining high reliability while minimizing maintenance needs.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Measurement precision

If conventional tearing devices are used, then tearing can occur, but accuracy is compromised at varying feeding speeds

Engineering Contradiction:

Improveaccuracy of tearing positionVSAvoidperformance at varying feeding speeds

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

By replacing mechanical tearing mechanisms with a pneumatic jet system, the invention achieves consistent tearing accuracy regardless of feeding speed variations. The compressed air jet acts instantaneously on the perforation line without being affected by mechanical inertia or speed-dependent mechanical tolerances.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The pneumatic system allows for precise control of the tearing process by adjusting parameters such as air pressure and nozzle positioning. This enables accurate tearing at varying feeding speeds without compromising precision, as the pneumatic action can be rapidly adjusted to match different operational conditions.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If conventional tearing devices are used, then the tearing function is performed, but abrupt movements and vibrations occur that endanger system operation

Engineering Contradiction:

Improvesmooth operation without vibrationsVSAvoidvibrations and abrupt movements

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent eliminates abrupt movements and vibrations by replacing mechanical tearing devices with a pneumatic jet system. The compressed air delivers a controlled, smooth action on the paper web at the perforation line, avoiding the shocks and vibrations inherent in mechanical impact-based tearing mechanisms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The jet of compressed air acts as an intermediary between the control system and the paper web, providing a smooth, vibration-free tearing action. This pneumatic mediator transfers energy without the mechanical contact and impact that cause harmful vibrations and abrupt movements.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Ensures high accuracy and reliability in tearing paper webs at any feeding speed, with reduced maintenance costs and prolonged system lifespan, eliminating vibrations that could disrupt operation.

Implementation Method 1

a jet of compressed air is directed toward a perforation line

Methodology Applied

Scientific EffectCompressed air jet: Jet

Data Source

PatentUS9079738B2Apparatus for causing paper webs to tear off within rewinding machines

Publication Date: 2015.07.14 PERINI

AI summary

Apparatus for causing paper webs to tear off within rewinding machines, the web (2) being provided, at regular intervals, with transverse perforation which subdivide the web into sheets joined to each other but able to be separated in correspondence of said perforation lines, the apparatus comprising a device to cause the tearing of the web (2) upon the passage of a perforation line (p) which separates the last sheet of a log (RO) in the course of formation from the first sheet of the next log to be formed, characterized in that the tearing device is a pneumatic type device (SP) able to direct a jet of compressed air toward the line (p).