Sheet Skew Correction and Sorting Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional sheet processing apparatuses face challenges in achieving high accuracy and productivity due to increased motor load caused by frictional forces when correcting sheet skew and positioning for punching and sorting, leading to higher manufacturing costs.

Innovation Solution

The apparatus moves sheets without extra load by correcting lateral displacement and skew before punching, then shifting the sheet without contact with the abutment member to eliminate frictional forces, allowing for efficient sorting without increasing the drive system size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the skewed side of a sheet is brought into abutment with the abutment member to correct skew, then punching accuracy is improved, but frictional force increases causing extra load on the motor

Engineering Contradiction:
Improvepunching accuracyVSAvoidmotor load
Core Design Contradiction:
Manufacturing precisionVSForce

Solution Approach 1:

The sheet skew correction is performed in advance before the sheet enters the punching position. By using the abutment member to correct skew upstream and then allowing the sheet to be conveyed without continuous contact during punching and sorting, the frictional load is limited to the correction phase only, not the entire processing cycle.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sheet is separated from the abutment member after skew correction is achieved. The abutment member releases the sheet once the skewed side has been corrected, allowing the sheet to be conveyed and sorted without continuous frictional contact, thereby reducing the motor load during subsequent operations.

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If the sheet is held in contact with the abutment member during punching and sorting, then skew correction is maintained, but frictional force generates extra load requiring larger motor size

Engineering Contradiction:
Improveskew correction accuracyVSAvoidmotor size
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Skew correction is performed as a preliminary action before the sheet enters the punching and sorting phases. The abutment member corrects the skew upstream, and once correction is achieved, the sheet is released to be conveyed without continuous contact, avoiding the need for oversized motors to overcome continuous frictional resistance.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If continuous contact with abutment member is used for skew correction, then punching accuracy is improved, but productivity decreases due to increased processing time

Engineering Contradiction:
Improvehole positioning accuracyVSAvoidprocessing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The skew correction is executed as a quick preliminary action before the sheet enters the punching position. By limiting the abutment contact to only the correction phase and then releasing the sheet for rapid conveyance through punching and sorting, the processing time is minimized while maintaining hole positioning accuracy.

Inventive Principle:
Principle #10Preliminary 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

This approach enables high-accuracy post-processing without increasing motor size or manufacturing costs, enhancing productivity and reducing load on the drive system during sheet sorting.

Implementation Method 1

the skewed side of a sheet is brought into abutment with the abutment member, whereby the skew of the sheet side is corrected

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2168897B1Sheet processing apparatus, method of controlling the same, and image forming apparatus
Publication Date: 2011.11.09 CANON KK
  • EP2168897B1 patent drawingFigure 1
  • EP2168897B1 patent drawingFigure 2
  • EP2168897B1 patent drawingFigure 3

AI summary

A sheet processing apparatus (100) which is cable of moving a sheet (S) without applying extra load to the movement of the sheet in the case of laterally moving the sheet (S) for sorting after completion of punching of holes in the sheet (S). A sheet (S) is conveyed toward an abutment member (151,730). The sheet (S) comes into abutment with the abutment member (151,730), whereby skew of the sheet (S) is corrected. A punching unit (150) punches holes in the sheet (S) in abutment with the abutment member (151,730). A shift unit (108,M3) shifts the punched sheet (S) that has been punched by the puncher (150) in a direction intersecting with a conveying direction of the conveying unit. A controller (501) causes the shift unit to start shifting the sheet in response to separation between the punched sheet (S) and the abutment member (151,730).