Rotary Damper Nested in Rotation Shaft for Compact Sheet Feeding

Solution Overview

Problem

Existing sheet feeding apparatuses in image forming devices face space constraints due to the need for a rotary damper to reduce collision sounds when the cassette is drawn, as the damper requires a large space on the outer circumference of the rotation shaft, conflicting with the need for sheet storage space.

Innovation Solution

A space-saving rotary damper is integrated with the rotation shaft on the drawing direction side, reducing the rotary motion of the shaft and minimizing collision sounds by applying load torque through friction, allowing for a more compact design that doesn't occupy additional space on the outer circumference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a rotary damper is attached onto the rotation shaft to reduce collision sound, then the collision sound is suppressed, but the space for sheet storage is reduced

Engineering Contradiction:

Improvecollision soundVSAvoidsheet storage space

Core Design Contradiction:

Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The rotary damper is nested inside the hollow structure of the rotation shaft, utilizing the internal space of the shaft rather than occupying external space. This allows the damper to be integrated within the existing structural envelope, suppressing collision sounds while maintaining the external dimensions and sheet storage capacity of the cassette.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

Instead of placing the rotary damper in the radial direction (outer circumference) of the rotation shaft, the invention moves it to the axial direction by utilizing the hollow interior space of the shaft. This dimensional transition from radial to axial placement resolves the space conflict by using previously unused internal volume.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If a rotary damper is disposed on the outer circumferential surface of the rotation shaft, then the collision sound is reduced, but a large space is necessary in the cassette

Engineering Contradiction:

Improvecollision soundVSAvoidcassette space

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The rotary damper is nested inside the hollow structure of the rotation shaft, utilizing the internal space of the shaft rather than occupying external space. This allows the damper to be integrated within the existing structural envelope, suppressing collision sounds while maintaining the external dimensions and sheet storage capacity of the cassette.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Object-affected harmful factors

If the rotary damper is disposed on the back side of the image forming apparatus, then the collision sound is suppressed, but the engaging portion and rotary damper conflict for space on the rotation shaft

Engineering Contradiction:

Improvecollision soundVSAvoidspace arrangement

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of placing the rotary damper in the radial direction (outer circumference) of the rotation shaft, the invention moves it to the axial direction by utilizing the hollow interior space of the shaft. This dimensional transition from radial to axial placement resolves the space conflict by using previously unused internal volume.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The rotary damper is nested inside the hollow structure of the rotation shaft, utilizing the internal space of the shaft rather than occupying external space. This allows the damper to be integrated within the existing structural envelope, suppressing collision sounds while maintaining the external dimensions and sheet storage capacity of the cassette.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 suppresses collision sounds during cassette withdrawal without requiring additional space, ensuring a compact and efficient sheet feeding mechanism.

Implementation Method 1

a rotary damper joined with the rotation shaft on another end side in the axial direction and reducing rotary motion of the rotation shaft

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS11339015B2Sheet feeding apparatus and image forming apparatus

Publication Date: 2022.05.24 CANON KK

AI summary

A sheet feeding apparatus includes a storage portion, a sheet supporting portion, a feed portion, a drive portion to output driving force that lifts the sheet supporting portion, and a rotation shaft rotatably supported by the storage portion and including an engaging portion disposed on one end side in an axial direction of the rotation shaft. The engaging portion engages with the drive portion, and a pressing portion is fixed to the rotation shaft and presses the sheet supporting portion from below when the rotation shaft is rotated by the drive portion. A rotary damper joins with the rotation shaft on another end side of the rotation shaft and reduces rotary motion of the rotation shaft. The pressing portion is disposed between the engaging portion and the rotary damper in the axial direction.