Movable Stopper Unit for Sheet Feed Tray Stability

Solution Overview

Problem

Existing image forming apparatuses face operability issues with sheet feed trays, requiring manual tool manipulation and user intervention to move screws between positions, leading to potential forgetfulness in returning the screw to its normal position.

Innovation Solution

A movable stopper unit with a regulating portion and an urging portion is integrated into the guide rail system, allowing the stopper to automatically move between a regulating and retracting position, preventing the sheet feed tray from falling and simplifying user interaction by eliminating the need for manual tool manipulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a screw is used to prevent the sheet feed tray from falling, then the tray can be securely held, but the user must manually manipulate the screw with a tool which reduces operability

Engineering Contradiction:

Improveprevention of tray fallingVSAvoidmanual tool manipulation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The stopper unit automatically returns to the regulating position after the tray is inserted, without requiring user intervention. The urging portion (spring) self-actuates to move the regulating portion back to its regulating position, making the system self-serving and eliminating the need for manual screw manipulation with tools.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The stopper unit transitions from a static screw position to a dynamic system where the regulating portion can move between a regulating position (abutting the tray) and a retracted position (allowing tray insertion). This dynamic movement is enabled by the urging portion that automatically returns the stopper to its regulating position.

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If the screw is retracted to allow tray removal, then the tray can be taken out, but the user must purposely return the screw to its normal position which increases complexity of operation

Engineering Contradiction:

Improvetray removalVSAvoidscrew position management

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The stopper unit automatically returns to the regulating position after the tray is inserted, without requiring user intervention. The urging portion (spring) self-actuates to move the regulating portion back to its regulating position, making the system self-serving and eliminating the need for manual screw manipulation with tools.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The urging portion is pre-configured to automatically return the regulating portion to the regulating position after tray insertion. This preliminary action ensures that the stopper is already in the correct position for the next operation, eliminating the need for users to manually reset it.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If a fixed stopper is used to hold the tray, then the tray cannot fall, but the tray cannot be easily removed for replenishment

Engineering Contradiction:

Improvetray stabilityVSAvoidtray removal for replenishment

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The stopper unit transitions from a static screw position to a dynamic system where the regulating portion can move between a regulating position (abutting the tray) and a retracted position (allowing tray insertion). This dynamic movement is enabled by the urging portion that automatically returns the stopper to its regulating position.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The user temporarily moves the regulating portion to the retracted position before tray removal, and the system preliminarily prepares for easy tray insertion by having the stopper automatically return to the regulating position after insertion, facilitating quick replenishment operations.

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

Enhances user operability by allowing easy drawing out and reinsertion of the sheet feed tray without tools, preventing accidental falls and ensuring the stopper returns to its regulating position automatically, thus improving usability and reducing the risk of user forgetfulness.

Implementation Method 1

an urging portion configured to urge the regulating portion to the regulating position

Methodology Applied

Scientific EffectElastic force: Elasticity

Data Source

PatentUS11360425B2Image forming apparatus and sheet storing apparatus

Publication Date: 2022.06.14 CANON KK

AI summary

An image forming apparatus includes a cassette, an image forming unit configured to form an image on a sheet fed from the cassette a set position, a guide rail configured to draw out the cassette from the set position, and a movable stopper unit that regulates a movement of the cassette in a draw-out direction by abutting with the cassette while the cassette is drawn out from the set position along the guide rail. The movable stopper unit includes a regulating portion movable between a regulating position where the regulating portion regulates a movement of the cassette within a moving trajectory of the cassette in moving in the draw-out direction and a retracting position where the regulating portion is located outside of the moving trajectory and does not regulate the movement of the cassette, and an urging portion configured to urge the regulating portion to the regulating position.