Rotatable Sheet-Container Lock for Sequential Pull-Out Stability

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Solution Overview

Problem

Conventional pull-out lock devices for sheet containers in image-forming apparatuses have complex configurations that require movement control members and retainers to prevent multiple sheet containers from being pulled out simultaneously, leading to instability and potential apparatus tipping.

Innovation Solution

A pull-out lock device with a rotatable lock member that includes a contact member and a lock, allowing adjacent sheet containers to be locked or unlocked based on their position, using a simple configuration with a rotatable main body and rotation axis to prevent simultaneous pull-out.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a conventional pull-out lock device with movement control members and retainers is used to prevent multiple sheet containers from being pulled out simultaneously, then the sheet container stability is improved, but the device complexity increases

Engineering Contradiction:

Improvesheet container stabilityVSAvoidlock device complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The lock device is divided into independent functional components: a lock member with a lock portion, a contact member, and a rotation member. Each component performs a specific function, allowing the complex locking mechanism to be implemented through simple, modular parts that work together through mechanical interaction rather than a unified complex structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of using a retainer to actively hold the stopper member in place, the invention allows the lock member to rotate freely and use the contact member to passively engage with the sheet container. The locking action is achieved by the absence of contact (when lock portion moves away) rather than active retention, inverting the conventional approach.

Inventive Principle:

Principle #13The other way round (Inversion)

2Device complexity

If a simple rotatable lock member configuration is used, then the device complexity is reduced, but the reliability of preventing simultaneous pull-out may be compromised

Engineering Contradiction:

Improvelock device complexityVSAvoidpull-out prevention reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The lock member utilizes its own rotational movement and the natural contact between the contact member and sheet container to achieve locking and unlocking functions. The system is self-regulating through mechanical geometry rather than requiring external control mechanisms, maintaining reliability through inherent mechanical design.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The contact member acts as an intermediary between the lock member and the sheet container. It translates the rotational movement of the lock member into the linear locking/unlocking action, ensuring reliable force transmission and engagement while allowing the lock member to remain simple in structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If multiple sheet containers are allowed to be pulled out simultaneously, then the ease of operation is improved, but the apparatus stability deteriorates due to center of gravity shift

Engineering Contradiction:

Improvesheet container pull-out easeVSAvoidapparatus stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The lock member is positioned and configured to preemptively prevent the simultaneous pull-out of multiple sheet containers. By having the contact member already in position to engage with the sheet container, the system prevents the harmful effect of center of gravity shift before it can occur, rather than reacting after instability begins.

Inventive Principle:

Principle #9Preliminary anti-action

Data Source

PatentUS12410024B2Pull-out lock device for sheet container and image-forming apparatus including the same

Publication Date: 2025.09.09 SHARP KK

AI summary

In a lock member of a pull-out lock device, while two adjacent sheet containers are both located at an accommodated position in an image-forming apparatus main body, a contact member is in contact with one of the sheet containers and thus the lock member rotates around a rotation axis, and a lock moves to an unlock position to allow the other sheet container to move in a pull-out direction, and while the other sheet container is located at the accommodated position and the one of the sheet containers is pulled out from the accommodated position in the pull-out direction and thus the contact between the one of the sheet containers and the contact member is removed, the lock member rotates around the rotation axis and the lock moves to a lock position to prohibit the other sheet container from moving in the pull-out direction.