Creasing Tools with Adjustable Shaft Positioning for Groove Shape Adaptation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing creasing devices for printed sheets or webs are inefficient in quickly and easily changing the groove shapes, particularly the curvature of grooves, which can lead to paper splitting and ink tearing issues, especially with envelopes having the wrong paper grain direction or made of paper with short fibers, and require time-consuming manual tool changes.

Innovation Solution

The method involves moving at least one pair of creasing tools with their shafts out of their working position to a new position, allowing for quick adjustments of the distance between groove pairs, with one pair fixed and the other adjustable based on book block thickness, and using actuators and a controller for automation, enabling easier operability and reduced manual intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If manual tool changes are used to adapt creasing tools to specific book and cover formats, then the groove shapes can be changed, but the changeover time increases significantly

Engineering Contradiction:
Improve groove shape adaptabilityVSAvoidchangeover time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent implements dynamic adjustability of the creasing tools by allowing the distance between the creasing tools and the pressing surface to be varied. The creasing tools can be positioned at different distances from the pressing surface to create grooves of different depths and shapes, enabling quick adaptation to various book formats without manual tool changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the geometric parameters of the creasing process by allowing adjustment of the groove depth, width, and curvature through mechanical positioning systems. The creasing tools can be moved along guides to achieve different pressing depths and angles, creating varied groove configurations for different cover types and book blocks.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If convex curvature grooves are used for back edges, then the creasing function is achieved, but paper splitting and ink tearing occur with certain envelope types

Engineering Contradiction:
Improvecreasing functionVSAvoidpaper splitting and ink tearing
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies different groove curvatures at different locations based on the specific requirements. The system can create convex curvatures for standard back edges while switching to concave curvatures for envelopes with specific paper grain directions or short fibers. This localized adaptation prevents paper splitting and ink tearing while maintaining effective creasing.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention allows reversal of the groove curvature from the conventional convex shape to a concave shape when needed. By inverting the curvature direction, the pressing force is distributed differently, preventing the paper fibers from splitting outward and avoiding ink tearing, particularly for envelopes with problematic paper characteristics.

Inventive Principle:
Principle #13The other way round (Inversion)

3Productivity

If multiple creasing tools are arranged on shafts to produce multiple grooves, then productivity increases, but the complexity of adjusting and maintaining the tools increases

Engineering Contradiction:
Improvemultiple grooves per operationVSAvoidtool arrangement complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent designs the creasing tools with multi-functionality, where each tool can perform multiple creasing operations by adjusting its position and angle. The same tool can create different groove types (convex, concave, straight) at various locations, reducing the need for multiple specialized tools and simplifying the overall system while maintaining high productivity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The creasing device is divided into modular tool units that can be independently adjusted and maintained. Each creasing tool is a separate module mounted on adjustable shafts, allowing individual optimization and simplifying maintenance. This segmentation enables complex multi-groove operations while keeping each tool unit relatively simple and easy to service.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2743072B1Creasing method
Publication Date: 2018.09.05 MULLER MARTINI HLDG
  • EP2743072B1 patent drawingFigure 1~1b
  • EP2743072B1 patent drawingFigure 2~2b
  • EP2743072B1 patent drawingFigure 3

AI summary

The method involves arranging multiple creasing tools (3-6) having tool pairs on the respective shafts (20,21,30,31) in a working position. Each tool is formed of an elevation and a recess which are arranged mirror-symmetrical relative to an imaginary center plane of the tool pairs. One of the tool pairs engaged with the shafts in a meshing state, is shifted from the working position to the new working positions, for introducing two spaced grooves (61,62) in a conveying direction of a creasing device (1). Independent claims are included for the following: (1) a creasing apparatus for introducing two spaced grooves in sheets of a printing material; and (2) a print processing apparatus.