Pivotable Roller Sheet Positioning in Knife Folding Machines

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Solution Overview

Problem

In knife folding machines, sheets tend to bounce back after hitting the stop, leading to reduced production output and inaccurate positioning due to kinetic energy rebound, especially at high speeds and with high grammages, where existing solutions like guide rollers and brushes are insufficient.

Innovation Solution

A device with rotatably and pivotably attached rollers that rest on the conveyor belt and sheet, adjusting their position based on the folding blade's movement to minimize friction and ensure precise alignment, using levers, pneumatic cylinders, and sensors to control the rollers' engagement and disengagement, thereby reducing bouncing and maintaining sheet alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If guide rollers are used to hold down sheets, then sheet guidance accuracy is improved, but at high speeds and high grammages the bouncing effect increases and guide rollers alone become insufficient

Engineering Contradiction:
Improvesheet guidance accuracyVSAvoidproduction output
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent employs a movable stop that can dynamically adjust its position and a folding blade with controlled movement to adapt to varying sheet conditions during the folding process, enabling effective handling of high-speed and high-grammage sheets that static guide rollers cannot manage

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If brushes are placed on the rear edge of folded sheets to fix position, then bouncing is reduced, but setting and positioning becomes time-consuming and symmetrical contact is difficult to achieve

Engineering Contradiction:
Improvesheet position stabilityVSAvoidbrush positioning complexity
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent removes the complex brush positioning system and replaces it with a streamlined movable stop mechanism that achieves sheet stabilization without requiring time-consuming adjustment of multiple brush elements, simplifying the manufacturing and setup process

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If sheets are run against a fixed stop at full production speed, then production output is maintained, but the sheet bounces back due to kinetic energy release reducing positioning accuracy

Engineering Contradiction:
Improveproduction speedVSAvoidfold position accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent uses a movable stop that can dynamically adjust its position and a folding blade with controlled movement to absorb and manage the kinetic energy of sheets running at full production speed, preventing bounce-back and maintaining fold position accuracy without sacrificing productivity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The movable stop is positioned and configured in advance to anticipate and cushion the sheet's kinetic energy before impact, reducing the rebound effect and ensuring accurate positioning while maintaining high production speeds

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 reduces settling times and ensures trouble-free folding by minimizing the sheet's rebound and maintaining precise alignment, even at high speeds and with high grammages, enhancing production efficiency and accuracy.

Implementation Method 1

At least one roller (5, 5') rests on the conveyor belt (2) or sheet (10) during the conveying process. This reduces bouncing of the sheet after hitting the leading edge stop (3).

Methodology Applied
Scientific EffectKinetic energy absorption: Damping

Implementation Method 2

This reduces bouncing of the sheet after hitting the leading edge stop (3) through the interaction between the roller and the sheet material.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP1900669B1Device for positioning the trailing edge of sheets
Publication Date: 2012.03.07 HEIDELBERGER DRUCKMASCHINEN AG
  • EP1900669B1 patent drawingFigure 1~2
  • EP1900669B1 patent drawingFigure 3
  • EP1900669B1 patent drawingFigure 4

AI summary

The device (100`) has a lower belt conveyor, and a roller (5`) overlying on the conveyor, where the conveyor conveys sheets (10) against a front edge guide. The roller is moved from an active position to an inactive position depending on the position of a folding unit (9), where the roller contacts the sheets in the active position, and detaches from the sheets in the inactive position. The roller is rotatably and pivotably fastened at a common support (12) by a lever, and a connecting rod is moved to and fro by a pneumatic cylinder. An independent claim is also included for a method for positioning a sheet in a combined folding and creasing machine.