Sheet Feeder Stopper and Set Guide Alignment Mechanism

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Solution Overview

Problem

Existing sheet feeders often deform sheets due to reaction forces when feeding them, particularly causing bending issues with curled leading ends.

Innovation Solution

A sheet feeder mechanism that includes a stopper and set guide system, where the stopper rotates between a first position to restrict and a second position to permit sheet feeding, and the set guide moves between third and fourth positions to align and prevent contact with the pickup roller, reducing deformation risks by controlling the sheet's alignment and contact with the rollers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a flap is used to control sheet feeding by swinging between standby and feeding positions, then sheet feeding control is achieved, but the sheet receives reaction force causing deformation and bending

Engineering Contradiction:
Improvesheet feeding controlVSAvoidsheet deformation
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The patent extracts and removes the flap component from the sheet feeding mechanism. Instead of using a flap that swings and contacts the sheet, the invention uses a pickup roller that rotates to pick up sheets, eliminating the source of reaction force that caused sheet deformation while maintaining sheet feeding control through the roller's rotational motion

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent inverts the control mechanism from a passive flap that swings into position to an active pickup roller that rotates into engagement. The roller is driven by a motor to actively pick up sheets, reversing the cause-effect relationship and eliminating the harmful reaction force while achieving the same sheet feeding control function

Inventive Principle:
Principle #13The other way round (Inversion)

2Object-affected harmful factors

If the leading end of the sheet is curled, then the sheet is more likely to be deformed by reaction force, but preventing deformation requires additional alignment mechanisms

Engineering Contradiction:
Improvesheet deformation riskVSAvoidalignment mechanism
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies preliminary alignment action by using a guide plate positioned upstream of the pickup roller. The guide plate pre-aligns the sheets before they reach the pickup point, ensuring that even curled leading ends are properly positioned. This preliminary alignment prevents deformation during the picking process without requiring complex real-time correction mechanisms

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3002238B1Sheet feeder and method for the same
Publication Date: 2020.05.06 BROTHER KOGYO KK
  • EP3002238B1 patent drawingFigure 1
  • EP3002238B1 patent drawingFigure 2A~2B
  • EP3002238B1 patent drawingFigure 3A~3B

AI summary

A sheet feeder including a feed tray (20) configured to support a sheet placed thereon, a pickup roller (41) configured to rotate around a pickup roller axis (413) and feed the sheet placed on the feed tray in a sheet feeding direction, a stopper (44) movable between a first position where the stopper is close to the pickup roller and a second position where the stopper is farther from the pickup roller than when the stopper is in the first position, a driving mechanism (45) configured to move the stopper between the first position and the second position, and a set guide (43) having a first surface (431H) facing in a particular direction such as to become farther away from a surface of the pickup roller, the set guide being movable between a third position where the first surface is positioned downstream of all the surface of the pickup roller in the particular direction and a fourth position where the first surface is positioned upstream of at least a part of the surface of the pickup roller in the particular direction, wherein in response to the stopper being placed in the first position by the driving mechanism, the stopper comes into contact with the set guide, and the set guide is placed in the third position, and in response to the stopper being placed in the second position by the driving mechanism, the stopper is separated away from the set guide, and the set guide is placed in the fourth position.