Zigzag Support Webs for Three-Knife Trimmer Cutting Quality

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Solution Overview

Problem

Existing three-knife trimmers face challenges in achieving optimal cutting quality and minimizing setup time for processing individual books and small runs, as they often lack full-surface pressure, leading to cutting errors like mushroom cuts and requiring format-dependent adjustments that are time-consuming and impractical for small formats.

Innovation Solution

The solution involves a three-knife trimmer design with zigzag-shaped supporting webs between cutting bars and pressure bars, allowing for format-adjustable support that maintains full-surface pressure across the block, combined with a transport system that ensures continuous support and minimizes setup time by using a top and bottom belt with non-slip coatings and recesses for the spine area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If format-dependent tables and press plates are exchanged for each format, then cutting quality is optimized, but setup time increases making the machine unsuitable for very small runs and individual books

Engineering Contradiction:
Improvecutting qualityVSAvoidsetup time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The press plate is segmented into a base plate and multiple format-specific press plate sections that can be independently adjusted or removed. This allows the machine to maintain full-surface pressing capability for different formats without requiring complete plate exchanges, thereby reducing setup time while preserving cutting quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The press plate system is made dynamically adjustable through height-adjustable press rolls and movable press plate sections that can be quickly repositioned for different formats. This dynamic adjustment capability eliminates the need for time-consuming plate exchanges while maintaining optimal pressing contact for various book formats.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If support rails are used in the area of head and foot knives, then blocks are prevented from sagging, but full-surface pressure is not achieved and cutting quality suffers

Engineering Contradiction:
Improveblock stabilityVSAvoidcutting quality
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The support rails and press plate system are merged into an integrated structure where the press plate extends continuously across the full surface including areas behind the knives. This combination ensures both block stability during cutting and full-surface pressure application, eliminating the compromise between support and pressing quality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pressing system is extended into the dimensional space behind the cutting knives, creating a continuous press surface that provides both support and full-surface pressure. This dimensional extension allows the press plate to fulfill both stabilizing and quality-cutting functions simultaneously.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If filler pieces are used between gripper transport and cutting units, then flat block position is achieved for exact cut, but replacing filler pieces is not acceptable for individual products and very small runs

Engineering Contradiction:
Improvecut precisionVSAvoidproduction speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The press plate is designed as a universal component that serves multiple functions: it provides full-surface pressing, supports blocks of various formats, and eliminates the need for format-specific filler pieces. This multi-functional design allows rapid format changes while maintaining cut precision through consistent full-surface contact.

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

Solution Approach 2:

The system uses height-adjustable press rolls and movable press plate sections that can be quickly repositioned to accommodate different book formats. This parameter adjustment capability replaces the need for physical filler piece changes, maintaining cut precision across various formats while significantly improving production speed for individual books and small runs.

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

This design ensures high cutting quality by maintaining the block flat over its entire surface, preventing waves and bulging, and allows for rapid format changes, making it suitable for individual books and small runs without compromising cutting precision.

Implementation Method 1

the block is pressed over its entire surface during cutting

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

a plurality of zigzag-shaped supporting webs are arranged in the space between the pressure bars

Methodology Applied
Scientific EffectStructural support:

Implementation Method 3

a top and bottom belt with non-slip coatings

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2535153B1Three-knife trimmer
Publication Date: 2014.01.01 DGR GRAPHIC
  • EP2535153B1 patent drawingFigure 1
  • EP2535153B1 patent drawingFigure 2
  • EP2535153B1 patent drawingFigure 3~5

AI summary

A three-knife trimmer for book or brochure blocks is presented, in which a head-foot cut and front cut of the blocks are performed in one or two cutting stations using a shear cut against counter blades or a crush cut against cutting bars, with a total of three cutting units for head, foot and front, each consisting of knives, pressure bars, counter blades and the associated drive elements, a feed station, an output station and a transport device that transports the blocks from the feed through the two cutting positions to the output in indexed steps, in which the knives cut against cutting bars or counter blades, the block is held by pressure bars (3a) next to the knives during the head and foot cut and the front cut and, according to the invention, in the format-dependent variable free space between the cutting bars or counter blades.On the one hand, counter-knives and on the other hand, a plurality of zigzag-shaped support bars (1, 1a) are arranged in the space between the pressure bars (3a).