Arcuate Creasing Blade Reducing Load and Time

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional creasing devices for sheet folding, such as saddle-stitched booklets, face challenges in producing uniform creases efficiently due to high processing time, increased load on creasing units, and environmental concerns like smoke and odor from laser-based methods, while also causing toner damage and uneven creasing.

Innovation Solution

A creasing device with a male blade and a grooved female blade, where the blades have an arcuate shape for point-to-point contact, reducing the driving load and enabling a uniform crease with a single stroke, and a drive unit that pivots the male blade to produce a crease.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a roller is moved across a sheet to produce a crease, then a crease can be produced, but the processing time increases

Engineering Contradiction:
Improvecrease uniformityVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The creasing blade is divided into multiple independent pressing portions that can contact the sheet at different positions simultaneously. This segmentation allows the entire crease line to be formed in a single stroke rather than requiring sequential rolling motion, thereby reducing processing time while maintaining crease uniformity through coordinated pressing of all portions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a linear rolling motion (one-dimensional contact progression) to a planar simultaneous pressing approach (two-dimensional contact). The creasing blade with multiple pressing portions contacts the sheet across its entire width at once, changing the contact dimension from sequential line-by-line to simultaneous area-wide pressing, which dramatically reduces processing time.

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

2Loss of time

If a creasing blade is pressed against the entire sheet at once, then processing time is reduced, but the load on the creasing unit increases

Engineering Contradiction:
Improveprocessing timeVSAvoidcreasing load
Core Design Contradiction:
Loss of timeVSForce

Solution Approach 1:

The creasing blade is divided into multiple independent pressing portions that distribute the total pressing force across different locations. Each portion applies force locally to its corresponding sheet region, segmenting the total load into manageable portions that can be applied simultaneously without overloading any single mechanism point.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the creasing blade are designed to contact specific regions of the sheet, allowing localized force application. This enables the system to apply sufficient pressing force at each local contact point while the overall load is distributed across multiple independent contact zones, reducing the burden on any single driving mechanism.

Inventive Principle:
Principle #3Local quality

3Loss of time

If the sheet conveying direction is rotated by 90 degrees to produce a crease parallel to the conveying direction, then processing time is reduced, but the footprint increases

Engineering Contradiction:
Improveprocessing timeVSAvoiddevice footprint
Core Design Contradiction:
Loss of timeVSArea of stationary object

Solution Approach 1:

The invention maintains the perpendicular crease orientation relative to the conveying direction (preserving compact footprint) while transitioning from sequential rolling contact to simultaneous planar pressing. This dimensional change in the contact mechanism allows the crease to be formed across the entire sheet width in a single stroke, achieving fast processing without rotating the conveying direction and increasing footprint.

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

4Force

If a creasing blade contacts the sheet multiple times at different portions, then the load is reduced, but unevenness develops between contacted portions

Engineering Contradiction:
Improvecreasing loadVSAvoidcrease uniformity
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The creasing blade is segmented into multiple pressing portions that contact the sheet simultaneously in a single stroke. This segmentation allows the load to be distributed across multiple portions without sequential contact, ensuring that each portion applies force at the same time, thereby maintaining uniformity across the entire crease line while reducing the load on each individual portion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

All pressing portions of the creasing blade contact the sheet continuously and simultaneously in a single stroke, maintaining continuous useful action across the entire crease line. This eliminates the intermittent contact and unevenness that would result from multiple sequential contact cycles, ensuring uniform crease quality while distributing the load across all portions.

Inventive Principle:
Principle #20Continuity of useful action

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 reduces processing time, minimizes load on the creasing unit, prevents toner damage, and produces a uniform crease with reduced environmental impact, enhancing productivity and creasing quality.

Implementation Method 1

a first member extending in a direction perpendicular to a sheet conveying direction and including a male blade, the male blade having a convex cross section and an edge portion of the male blade having an arcuate shape; a second member extending in the direction perpendicular to the sheet conveying direction and including a grooved female blade, the female blade allowing the male blade to be fitted thereinto with a sheet between the female blade and the male blade

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

the drive unit being further arranged to cause the male blade to pivot, thereby to produce a crease in the sheet with the edge portion having on arcuate shape

Methodology Applied
Scientific EffectPivoting Motion:

Implementation Method 3

a drive unit that brings the first member and the second member relatively into and out of contact with each other to cause a sheet stopped at a predetermined position to be pinched between the first member and the second member and creased

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2394943B1Creasing device and image forming system
Publication Date: 2015.09.16 RICOH CO LTD
  • EP2394943B1 patent drawingFigure 1
  • EP2394943B1 patent drawingFigure 2~4
  • EP2394943B1 patent drawingFigure 5~7

AI summary

A creasing device (A) for creasing sheets on a per-sheet basis, the creasing device (A) includes: a first member (6) extending perpendicularly to a sheet conveying direction and including a male blade (6-1), which has a convex cross section; a second member (7) extending perpendicularly to the sheet conveying direction and including a grooved female blade (7a), into which the male blade (6-1) to be fitted with a sheet between the female blade (7a) and the male blade (6-1); and a drive unit (40) that brings the first member (6) and the second member (7) relatively into and out of contact with each other to cause a sheet stopped at a predetermined position to be pinched between the first member (6) and the second member (7) and creased. An edge portion of any one of the first member (6) and the second member (7) has an arcuate shape.