Non-conductive Collar for Developing Roller Shaft Insulation

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Solution Overview

Problem

In compact developing cartridges, ensuring insulation between the developing-roller shaft and other parts is challenging, and the arm of the collar struggles to bend due to reduced length.

Innovation Solution

The developing cartridge includes a housing, a developing roller with an electrically conductive shaft, an electrode made of conductive resin, and a first collar made of non-conductive resin. The first collar covers the end of the developing-roller shaft and includes a movable pawl that engages with the electrode, allowing for easier bending of the arm.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the developing cartridge is made more compact, then the size of the developing cartridge is reduced, but insulation between the developing-roller shaft and other parts becomes difficult to ensure

Engineering Contradiction:

Improvesize of developing cartridgeVSAvoidinsulation between developing-roller shaft and other parts

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent introduces a collar as an intermediary component between the developing-roller shaft and other parts. This collar is specifically designed with electrically non-conductive material to provide insulation, thereby maintaining reliable electrical isolation even when the developing cartridge is made compact. The collar acts as a mediator that prevents direct contact between the conductive shaft and other components.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The collar is made of composite material comprising electrically non-conductive resin, which provides both mechanical support and electrical insulation properties. This composite material approach allows the collar to fulfill multiple functions simultaneously - structural support and electrical isolation - without increasing the overall size of the developing cartridge.

Inventive Principle:

Principle #40Composite materials

2Volume of moving object

If the developing cartridge is made more compact, then the length of the arm of the collar is shorter, but the arm becomes difficult to bend

Engineering Contradiction:

Improvesize of developing cartridgeVSAvoidbending of arm of collar

Core Design Contradiction:

Volume of moving objectVSEase of operation

Solution Approach 1:

The patent changes the material parameter of the collar from conventional materials to electrically non-conductive resin, which has different mechanical properties including improved flexibility. This parameter change allows the arm to maintain adequate bending capability even when its length is reduced due to compact design requirements.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12271142B2Developing cartridge including electrically non-conductive collar covering end portion of developing-roller shaft

Publication Date: 2025.04.08 BROTHER KOGYO KK

AI summary

A developing cartridge includes: a housing accommodating developing agent; a developing roller including a developing-roller shaft extending in a first direction; an electrode made of an electrically conductive resin; and a first collar made of an electrically non-conductive resin. The electrode is positioned at one end portion of the housing in the first direction. The electrode is electrically connected to the developing-roller shaft. The first collar covers one end portion of the developing-roller shaft in the first direction. The first collar includes: a first arm extending in the first direction; and a first pawl configured to engage with the electrode. The first pawl protrudes from the first arm in a direction away from the developing-roller shaft. The first pawl is movable between: a first position at which the first pawl is in engagement with the electrode; and a second position at which the first pawl is separated from the electrode.