Expansion Unit Attachment Structure for Precise Positioning and Locking

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Solution Overview

Problem

Existing attachment structures for functional expansion units in electronic devices, such as image forming apparatuses, face challenges in easy and reliable attachment, often resulting in attachment failures due to misalignment and interference between components.

Innovation Solution

The attachment structure includes positioning shafts with circular cross-sections and positioning holes with both circular and elongated configurations, along with a lock mechanism featuring movable locks, springs, and stoppers, ensuring accurate alignment and easy attachment, while being covered by a common cover to prevent unauthorized detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional attachment structure is used, then the device can be assembled, but misalignment and interference between components occur resulting in attachment failures

Engineering Contradiction:

Improveattachment reliabilityVSAvoidpositioning accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The positioning hole is formed integrally with the lock-engageable part in the positioning lock member, establishing precise geometric relationships between positioning and locking features before assembly occurs. This preliminary integration ensures that when the functional expansion unit is attached, the positioning shaft aligns correctly with the positioning hole, preventing misalignment and interference issues during attachment

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent merges the positioning hole and lock-engageable part into a single integrated positioning lock member. This combination ensures that the positioning and locking functions work together seamlessly, eliminating the attachment failures that occur when these features are separate and potentially misaligned

Inventive Principle:

Principle #5Merging (Combining)

2Ease of operation

If the attachment structure is simplified, then assembly becomes easier, but positioning accuracy and alignment precision deteriorate

Engineering Contradiction:

Improveattachment easeVSAvoidalignment precision

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

By integrating the positioning hole and lock-engageable part into one component, the patent reduces the number of separate parts that need to be assembled while maintaining precise alignment. This integral structure guides the positioning shaft into correct alignment automatically during the attachment process, making assembly easy without sacrificing positioning accuracy

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The positioning lock member acts as an intermediary component that mediates between the functional expansion unit and the electronic device. Its integral design with the positioning hole and lock-engageable part ensures that alignment is achieved through the geometry of this single component, simplifying the attachment operation while maintaining precision

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12504710B2Functional expansion unit, electronic device, and image forming apparatus

Publication Date: 2025.12.23 RICOH CO LTD

AI summary

An attachment structure includes a positioning shaft of a functional expansion unit attachable to an electronic device; a lock member of the functional expansion unit; and a positioning lock member of the electronic device. The positioning lock member includes: a positioning hole into which the positioning shaft is insertable in an attachment direction; and a lock-engageable part engageable with the lock member. The positioning hole is formed integrally with the lock-engageable part in the positioning lock member.