Coupling Mechanism for Smooth Sheet Feeding and Noise Reduction

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Solution Overview

Problem

Existing coupling mechanisms in image forming apparatuses, such as printers and copiers, face challenges in smoothly transitioning between forward and reverse rotation to manage sheet feeding, leading to potential damage and noise during paper cassette removal and handling, especially when friction forces are high or when the drive motor fails.

Innovation Solution

A coupling mechanism incorporating a drive transmission member, a coupling member with engagement protrusions and holding protrusions, and a biasing member that ensures controlled rotation and load management by engaging and disengaging the coupling member with the drive transmission member, preventing rapid reverse rotation and reducing wear on components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the coupling member is directly engaged with the drive transmission member without a biasing member, then the structure is simpler, but the engagement and disengagement control is poor leading to rapid reverse rotation and component damage

Engineering Contradiction:

Improveengagement control reliabilityVSAvoidcoupling mechanism structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A biasing member is introduced as an intermediary element between the coupling member and the drive transmission member. This biasing member applies a predetermined biasing force to ensure reliable engagement while allowing controlled disengagement, preventing rapid reverse rotation and component damage without significantly complicating the overall structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coupling mechanism is designed to dynamically transition between engaged and disengaged states. The biasing member enables the coupling member to automatically engage with the drive transmission member during normal operation and allows controlled disengagement when needed, providing dynamic control over the engagement state

Inventive Principle:

Principle #15Dynamics

2Reliability

If the engagement pin is always firmly engaged with the coupling member, then the drive transmission is more reliable, but the reverse rotation causes high friction forces and noise during cassette removal

Engineering Contradiction:

Improvedrive transmission reliabilityVSAvoidnoise and friction during reverse rotation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The engagement pin is designed to dynamically adjust its engagement state. During forward rotation, the pin is firmly engaged for reliable drive transmission. During reverse rotation or cassette removal, the pin can disengage from the coupling member, allowing the coupling member to rotate freely and reducing friction forces and noise

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The coupling mechanism is segmented into distinct functional zones: an engagement portion for reliable drive transmission during forward rotation, and a disengagement portion that allows the engagement pin to separate from the coupling member during reverse rotation, eliminating harmful friction and noise

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If the coupling member allows free reverse rotation, then noise and friction are reduced, but the drive transmission member may rotate in reverse causing operational issues

Engineering Contradiction:

Improvefriction and noise during reverse rotationVSAvoiddrive transmission control

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The coupling mechanism employs asymmetric design where the engagement pin and coupling member have specific geometric features that allow free rotation in the reverse direction (reducing friction and noise) while preventing or controlling reverse rotation of the drive transmission member. The biasing member applies unidirectional force to maintain engagement during forward rotation

Inventive Principle:

Principle #4Asymmetry

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 solution enables smooth and controlled sheet feeding, reduces noise during reverse rotation, and minimizes damage to components by managing loads and preventing excessive stress on the engagement pin, ensuring reliable operation even under high friction or motor failure conditions.

Implementation Method 1

a biasing member (43) which biases the coupling member (50) in a direction in which the coupling member (50) is engaged with the drive transmission member (25)

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS10061261B2Coupling mechanism, and sheet feed device and image forming apparatus including same

Publication Date: 2018.08.28 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

A coupling mechanism of the present disclosure includes a drive transmission member, a coupling member and a biasing member. The drive transmission member includes a shaft portion and an engagement pin. The coupling member includes a plurality of engagement protrusions and a holding protrusion which is smaller than the engagement protrusion. The holding protrusion makes contact with the engagement pin in a state where the engagement pin makes contact with the pressing surface. A load in a reverse rotation direction is applied from the holding protrusion to the engagement pin when the coupling member is reversely rotated.