Pivotable Toner Agitator Assembly for Motor Torque Reduction

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Solution Overview

Problem

In electrophotographic image forming devices, the torque required to rotate a toner agitator assembly increases with larger toner cartridges, leading to potential motor stalling or damage due to packed toner, especially during shipment or storage, and current solutions either increase motor size or require user intervention to shake the cartridge.

Innovation Solution

A toner container with a pivotable toner agitator assembly biased by a double torsion spring, which folds counter to the rotational direction when resistance exceeds a threshold, reducing the radial length and torque required to rotate, thus preventing motor stalling and eliminating the need for user intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the toner cartridge size is increased to hold more toner, then the toner capacity is improved, but the torque required to rotate the toner agitator assembly increases

Engineering Contradiction:
Improvetoner capacityVSAvoidtorque required to rotate toner agitator
Core Design Contradiction:
Quantity of substanceVSForce

Solution Approach 1:

The toner agitator assembly is designed to dynamically change its configuration based on operating conditions. The agitator can fold from an extended operational position to a retracted position, changing its radial length and thus the torque it presents to the drive system. This dynamic adaptation allows the system to handle both large-toner-capacity containers and packed toner conditions without requiring excessive motor torque.

Inventive Principle:
Principle #15Dynamics

2Force

If the motor size is increased to provide sufficient torque, then the torque capability is improved, but the device size and cost increase

Engineering Contradiction:
Improvetorque capabilityVSAvoidmotor size
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

Instead of using a large motor capable of providing high torque throughout, the system uses a smaller motor paired with a dynamically configurable agitator. The agitator's ability to fold back reduces the torque demand during high-resistance conditions, allowing a smaller, more cost-effective motor to suffice.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The toner agitator assembly serves itself by automatically folding back when encountering high resistance from packed toner. This self-protecting mechanism eliminates the need for external control systems or larger motors, as the agitator autonomously adapts to prevent motor stalling or damage.

Inventive Principle:
Principle #25Self-service

3Force

If user intervention is required to shake the toner cartridge, then the torque issue can be temporarily resolved, but the ease of operation deteriorates

Engineering Contradiction:
Improvetorque availableVSAvoiduser intervention required
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The system eliminates the need for user intervention by incorporating an automatic torque-reduction mechanism. When the toner agitator encounters packed toner, it automatically folds back to reduce torque demand, preventing motor stalling without requiring the user to remove and shake the cartridge.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The mechanical design provides inherent feedback through the agitator's resistance to rotation. When packed toner increases resistance, the agitator naturally folds back, creating a self-regulating system that responds to operational conditions without external control or user input.

Inventive Principle:
Principle #23Feedback

4Productivity

If the toner agitator radial length is increased to improve toner mixing, then the mixing effectiveness is improved, but the torque required to rotate increases

Engineering Contradiction:
Improvetoner mixing effectivenessVSAvoidtorque required to rotate
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The toner agitator's radial length is made variable rather than fixed. During normal operation, the agitator extends to maximize mixing effectiveness. When resistance becomes excessive, the agitator automatically retracts, reducing radial length and torque demand. This dynamic adjustment maintains mixing effectiveness while preventing torque-related failures.

Inventive Principle:
Principle #15Dynamics

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 automatically reduces the torque required to rotate the toner agitator assembly when encountering packed toner, preventing motor stalling and damage, and maintains efficient operation without increasing motor size or requiring user intervention.

Implementation Method 1

A distal end of the toner agitator is positioned farthest from the rotational axis of the drive shaft when the toner agitator is in the extended position. The toner agitator is biased relative to the drive shaft in the operative rotational direction toward an extended position of the toner agitator.

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP3364253B1Toner agitator assembly
Publication Date: 2022.04.06 LEXMARK INTERNATIONAL INC
  • EP3364253B1 patent drawingFigure 1
  • EP3364253B1 patent drawingFigure 2
  • EP3364253B1 patent drawingFigure 3~4

AI summary

A toner container (100) according to one example embodiment includes a housing (102) having a reservoir (104) for storing toner and a drive shaft (132) positioned in the reservoir. The drive shaft is rotatable about a rotational axis in an operative rotational direction (136). A toner agitator (134) extends from the drive shaft in the reservoir. The toner agitator is rotatable around the rotational axis of the drive shaft as the drive shaft rotates. The toner agitator folds relative to the drive shaft counter to the operative rotational direction if resistance to rotation of the toner agitator provided by toner in the reservoir exceeds a threshold amount. The toner agitator is biased relative to the drive shaft in the operative rotational direction. A radial length of the toner agitator decreases when the toner agitator folds relative to the drive shaft counter to the operative rotational direction.