Pull-In Apparatus Two-Step Locking to Prevent Erroneous Release

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Solution Overview

Problem

Existing pull-in apparatuses for image forming devices, such as printers, risk erroneous release of the locking mechanism, leading to unintended pivoting and increased user complexity and cost due to recovery procedures.

Innovation Solution

A pull-in apparatus with a locking mechanism that requires two specific actions to release the locking, preventing accidental pivoting, featuring a locking member and arm spring configuration that ensures stability and secure engagement of the cartridge tray within the apparatus body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a locking mechanism with a single action release is used, then the ease of operation is improved, but the reliability deteriorates due to erroneous release

Engineering Contradiction:
Improveease of operationVSAvoidreliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The release action is segmented into two distinct steps: first pressing the pressing portion to move the locking member, and then pulling the draw-out unit. This segmentation prevents accidental release by requiring deliberate sequential actions rather than a single inadvertent movement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking member is moved to a lock-release position as a preliminary action before the actual release can occur. This preliminary positioning of the locking member, achieved by pressing the pressing portion, ensures that the release is intentional and controlled, preventing erroneous release during normal operation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a recovery structure is provided for erroneous release, then the reliability is improved, but the device complexity and cost increase

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system automatically returns to its normal state through the spring's urging force when the locking member is repositioned during the proper two-step release sequence. This self-service mechanism eliminates the need for separate recovery structures or procedures, reducing device complexity while maintaining reliability.

Inventive Principle:
Principle #25Self-service

3Productivity

If a spring urging mechanism is used, then the productivity is improved through automatic pull-in, but the stability deteriorates due to potential unintended movement

Engineering Contradiction:
ImproveproductivityVSAvoidstability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The locking member and locking claw create a preliminary counter-action that prevents the spring's urging force from causing unintended movement. The locking mechanism engages before the spring can act, and the two-step release process ensures that the spring's force is only utilized when deliberately activated, maintaining stability while preserving automatic pull-in functionality.

Inventive Principle:
Principle #9Preliminary anti-action

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 erroneous release of the locking mechanism, enhancing stability and usability by requiring deliberate actions to engage and disengage the locking, thus preventing unintended cartridge tray movement and reducing operational complexity.

Implementation Method 1

an arm (92) that is pivotably held by a holder (91) and that pulls in the draw-out unit (40) in a pivot direction (R1) by being urged in the pivot direction (R1) by an arm spring (93)

Methodology Applied
Scientific EffectElastic potential energy conversion: Elasticity

Implementation Method 2

a locking member (94) that is held by the arm (92) so as to be pivotable and that restricts the pivoting of the arm (92) in the pivot direction (R1) by having an abutting portion (941) abut an abutted portion (911) provided on the holder (91)

Methodology Applied
Scientific EffectMechanical engagement: Mechanical Fastener

Data Source

PatentEP3736637B1Pull-in apparatus, image forming apparatus, sheet accommodating apparatus, and draw-out unit
Publication Date: 2021.12.29 CANON KK
  • EP3736637B1 patent drawingFigure 1
  • EP3736637B1 patent drawingFigure 2
  • EP3736637B1 patent drawingFigure 3A~3B

AI summary

A pull-in apparatus configured to pull in a unit (40) toward a predetermined position in an apparatus body (100A) includes an arm member (92), a restriction member (94), a first action portion (46sl) and a second action portion (46s2). The restriction member (94) is movable between a lock position at which the restriction member (94) restricts movement of the arm member (92) in a first direction and a lock-release position at which the restriction member (94) allows the movement of the arm member (92) in the first direction. Movement of the restriction member (94) from the lock position toward the lock-release position is restricted in a state in which the arm member (92) is at a stand-by position, and is allowed in a state in which the arm member (92) has been moved from the stand-by position in a second direction.