Sheet Processing Roller Reverse Rotation Alignment

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Solution Overview

Problem

Existing sheet processing apparatuses face issues with accurate leading-edge alignment of sheet bundles due to factors like sheet hardness, leading to misalignment and processing position discrepancies during the conveyance and folding processes.

Innovation Solution

A sheet processing apparatus featuring a roller pair and a sheet bundle conveyer, where the controller causes the sheet bundle to contact leading edges with the roller pair and rotates it in reverse to align the sheets, ensuring all leading edges align properly and preventing misalignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the leading edges of sheets contact the conveyance roller pair during conveyance, then the sheets are conveyed forward, but sheets with higher hardness may enter the nip of the roller pair causing leading-edge alignment inaccuracies

Engineering Contradiction:

Improvecontinuous conveyanceVSAvoidleading-edge alignment accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies reverse rotation of the conveyance roller pair to eject sheets that have entered the nip. Instead of continuing forward rotation that would pull harder sheets deeper into the nip, the system inverts the rotation direction to push the leading edges back out, thereby correcting alignment issues while maintaining continuous operation

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The system performs preliminary detection of sheet hardness and adjusts the roller pair rotation accordingly. Before sheets enter the nip, the system prepares to apply counter-action by rotating in reverse if hardness detection indicates potential entry issues, preventing misalignment before it occurs

Inventive Principle:

Principle #9Preliminary anti-action

2Manufacturing precision

If the sheet bundle is conveyed in a substantially loop shape and returned to the conveyance roller pair for leading-edge alignment, then alignment is improved, but processing time increases due to the loop conveyance

Engineering Contradiction:

Improveleading-edge alignment accuracyVSAvoidprocessing time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system performs leading-edge alignment as a preliminary action before the sheet bundle enters the main processing section. By aligning sheets at the entrance using reverse rotation, the bundle is prepared in advance, eliminating the need for time-consuming loop conveyance and subsequent realignment operations

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent extracts the alignment function from the main processing flow by performing it separately at the entrance using reverse rotation. This separates the alignment operation from the continuous conveyance process, allowing alignment to occur without interrupting the overall production flow or requiring loop conveyance

Inventive Principle:

Principle #2Taking out (Extraction)

3Manufacturing precision

If the roller pair rotates in reverse to align leading edges, then sheets that entered the nip are ejected, but the rotation direction changes may affect conveyance stability

Engineering Contradiction:

Improveleading-edge alignment accuracyVSAvoidconveyance stability

Core Design Contradiction:

Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The system uses periodic alternation between forward and reverse rotation of the roller pair. Reverse rotation is applied periodically only when alignment correction is needed, while forward rotation maintains continuous conveyance. This periodic action pattern maintains stability by minimizing disruption to the overall conveyance flow

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The roller pair rotation speed and direction are dynamically adjusted based on real-time detection of sheet characteristics and alignment status. The system transitions smoothly between forward and reverse rotation modes, maintaining conveyance stability through adaptive control rather than fixed rotation patterns

Inventive Principle:

Principle #15Dynamics

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 aligns the leading edges of sheet bundles, preventing wedge-shaped folds and longitudinal wrinkles, and improving productivity by allowing smooth conveyance and processing without stopping the rotation of conveyance rollers.

Implementation Method 1

a conveyance roller pair and a sheet bundle conveyance device that conveys a sheet bundle to the conveyance roller pair, causes a leading-edge of the sheet bundle to contact the conveyance roller pair

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentEP3543186B1Sheet processing apparatus and image forming system incorporating the same

Publication Date: 2022.09.21 RICOH CO LTD

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AI summary

A sheet processing apparatus (1) includes a roller pair (15, 117a) configured to convey a sheet, a sheet bundle conveyer (13, 15) configured to convey a sheet bundle to the roller pair (15, 117a), a controller (40) configured to cause the sheet bundle conveyer (13,15) to contact leading edges of sheets of the sheet bundle to the roller pair (15, 117a) and cause the roller pair (15, 117a) to rotate in reverse to align the leading edges of the sheets of the sheet bundle.