Sheet Feed Cassette Curved Rail Mechanism

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Solution Overview

Problem

The existing sheet lifting and lowering mechanism in image forming apparatuses has a short pull-out distance and high cassette pull-out load, making it difficult to operate the sheet feed cassette efficiently.

Innovation Solution

An image processing apparatus with a sheet feed cassette, operation lever, sliding section, and main body rail section, where the operation lever rotates around a shaft, the sliding section slides along a curved main body rail section, and a ratchet-structured gear with a detachment mechanism is used to facilitate easy pull-out and reduce the pull-out force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the working part for depressing the sheet lifting and lowering tray is arranged in the cassette pull-out direction, then the sheet lifting and lowering function can be achieved, but the pull-out distance becomes short and the cassette pull-out load becomes heavy

Engineering Contradiction:
Improvesheet lifting and lowering operationVSAvoidcassette pull-out distance
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The patent applies a curved guide rail instead of a straight guide rail to extend the pull-out distance. The curved guide rail allows the cassette to move along an arc-shaped path, increasing the effective pull-out distance while maintaining the compact structure needed for the sheet lifting and lowering operation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent introduces a vertical dimension to the pull-out motion by using a curved guide rail that extends in the vertical direction. This allows the cassette to be pulled out not only horizontally but also vertically, effectively increasing the pull-out distance without increasing the horizontal footprint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the working part for depressing the sheet lifting and lowering tray is arranged in the cassette pull-out direction, then the sheet lifting and lowering function can be achieved, but the cassette pull-out load becomes heavy

Engineering Contradiction:
Improvesheet lifting and lowering operationVSAvoidcassette pull-out load
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The curved guide rail distributes the pull-out force over a longer distance and changes the direction of the force application. This reduces the peak pull-out load by allowing the force to be applied more gradually along the curved path rather than in a single abrupt motion.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The curved guide rail acts as an intermediary mechanism between the user's pull-out force and the cassette movement. It transforms the applied force into a controlled motion along the curved path, reducing the direct load on the cassette and making the pull-out operation easier.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a ratchet-structured gear with detachment mechanism is used, then accidental ejection due to vibration is prevented, but the device complexity increases

Engineering Contradiction:
Improveprevention of accidental ejectionVSAvoidcassette mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ratchet-structured gear with detachment mechanism provides automatic engagement and disengagement based on the cassette's position and operational state. The mechanism self-regulates to prevent accidental ejection during vibration while allowing easy detachment when properly operated, reducing the need for additional complex control systems.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3643649B1Image processing apparatus comprising a sheet feed cassette
Publication Date: 2023.01.04 TOSHIBA TEC KK
  • EP3643649B1 patent drawingFigure 1
  • EP3643649B1 patent drawingFigure 2
  • EP3643649B1 patent drawingFigure 3

AI summary

In accordance with an embodiment, an image processing apparatus comprises a sheet feed cassette (3), an operation lever (15), a sliding section (18), a sheet lifting and lowering tray (25), and a main body rail section (23). The sheet feed cassette (3) is housed to be capable of being pulled out from an apparatus main body. The operation lever (15) is arranged at the side of the sheet feed cassette and is rotatable around a shaft (16) positioned at the middle in a longitudinal direction. The sliding section (18) is arranged at the rear side of the shaft (16) of the operation lever (15). The sheet lifting and lowering tray can place a sheet and adjust an inclination thereof in conjunction with the operation lever. The main body rail section (23) is arranged in the apparatus main body and guides running of the sliding section (18) at the time of pulling out the sheet feed cassette.