Elastic Truncated Cone Roller for Sheet Conveying

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Solution Overview

Problem

Conventional sheet conveying devices struggle to accommodate a wide range of sheet types, including soft and hard sheets, due to limitations in existing roller structures, which often result in defective stacking or roller traces on hard sheets, and require complex and costly modifications.

Innovation Solution

A sheet conveying device featuring a pair of rollers with a driving roller and a driven roller, where the end portions have an approximately circular truncated cone shape and are made of an elastic material, allowing for adjustable sheet-strengthening force by elastic deformation, supporting both soft and hard sheets without leaving roller traces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional discharging rollers are used to convey soft sheets, then the sheets may be stacked, but the sheets bend during discharging resulting in defective stacking

Engineering Contradiction:
Improvestacking qualityVSAvoiddischarging quality
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The roller surface is divided into different regions with different properties: the central portion has a larger diameter and different hardness to provide sheet-strengthening force, while the end portions have a smaller diameter to reduce excessive force application. This local differentiation allows the roller to handle both soft and hard sheets appropriately in different regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The roller structure incorporates a gradual change in diameter from the central portion to the end portions, creating a continuous parameter transition. This diameter variation allows the roller to apply appropriate sheet-strengthening force to soft sheets in the central region while reducing force application to hard sheets at the ends, preventing both bending and roller traces.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If excessive force is applied by discharging rollers to hard sheets to prevent bending, then sheets can be stacked, but roller traces remain on the sheet resulting in low quality

Engineering Contradiction:
Improvestacking qualityVSAvoidsheet surface quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The roller applies different contact characteristics to different parts of the sheet: the central portion with larger diameter provides gentle support for sheet stacking, while the end portions with smaller diameter reduce excessive force that causes roller traces, thus maintaining surface quality while ensuring proper stacking.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The roller structure dynamically adapts to different sheet types through its diameter variation. When conveying hard sheets, the smaller end portions contact the sheet edges with reduced force, preventing roller traces, while the larger central portion provides sufficient support for stacking stability.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If conventional roller structures are used, then the structure is simple, but the apparatus cannot accommodate a wide range of sheet types

Engineering Contradiction:
Improveroller structureVSAvoidsheet type accommodation
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The roller is designed with a composite structure that enables it to handle multiple sheet types (soft sheets, hard sheets, thin paper, thick paper) with a single unified design. The diameter variation and hardness differentiation allow the same roller to adapt to different sheet properties without requiring replacement or modification.

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

Solution Approach 2:

The roller incorporates a composite structure with different hardness regions and diameter variations, combining multiple functional characteristics in a single component. This composite design allows the roller to provide both sheet-strengthening force for soft sheets and gentle contact for hard sheets, achieving universal applicability.

Inventive Principle:
Principle #40Composite materials

4Adaptability or versatility

If separate discharging rollers and discharging rings are used to change sheet-strengthening force, then different sheet types can be handled, but the apparatus becomes more complex and cost increases

Engineering Contradiction:
Improvesheet type handlingVSAvoidapparatus structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention integrates the functions of multiple separate components (discharging rollers and discharging rings) into a single unified roller structure. The diameter variation and hardness differentiation are built into the roller itself, eliminating the need for separate rings or multiple specialized rollers, thus reducing structural complexity and cost while maintaining versatility.

Inventive Principle:
Principle #5Merging (Combining)

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 prevents defective stacking of soft sheets and avoids roller traces on hard sheets, enabling the handling of a wide range of sheet types with improved alignment precision and image quality, while reducing complexity and cost.

Implementation Method 1

the end portions have an approximately circular truncated cone shape, surfaces of the center portion and the end portions are made of an elastic material

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2374744B1Sheet conveying device, sheet post-processing apparatus, and image forming apparatus
Publication Date: 2015.04.01 RICOH CO LTD
  • EP2374744B1 patent drawingFigure 1
  • EP2374744B1 patent drawingFigure 2~3
  • EP2374744B1 patent drawingFigure 4~5

AI summary

A sheet conveying device includes a first rotating shaft (601), a driving roller (602) fixed to the first rotating shaft (601), a driven roller (604) that faces and is pressed against the driving roller (602), and a second rotating shaft (603) supporting the driven roller (604). The driving roller (602) or the driven roller (604) includes a cylindrical center portion, and end portions (608) located at both ends of the center portion and having an approximately circular truncated cone shape. Surfaces of the center portion and the end portions (608) are made of an elastic material. An outer surface of the center portion is matched with outer surfaces of one end of the end portions (608), and a diameter of another end of the end portions (608) is larger than a diameter of the one end. The end portions (608) have a hollow (609) inside, and have a thin surface.