Crank Mechanism Buffer for Cartridge Handling Reliability

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Solution Overview

Problem

Conventional library apparatus hand mechanisms using multiple motors for different movements result in a large, costly, and less reliable system, especially when trying to access cartridges in large-capacity storage systems, where positional errors become significant, leading to issues with cartridge handling and potential damage.

Innovation Solution

Incorporating a buffer mechanism within the crank mechanism of the hand mechanism, which includes a buffer block, slide shafts, and compression springs, allowing the hand mechanism to continue rotating and holding cartridges even when positioned closer than normal, thus preventing positional errors and cartridge damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the library apparatus is made large-capacity with increased storage rack size, then the storage capacity increases, but the positional error of the accessor increases leading to reliability degradation

Engineering Contradiction:

Improvestorage capacityVSAvoidcartridge access reliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent introduces a buffer mechanism with compression springs that absorb positional errors before they reach the cartridge. When the accessor position deviates due to large apparatus size, the buffer mechanism compensates by allowing controlled movement of the hand mechanism, preventing damage to the cartridge and maintaining reliable operation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Measurement precision

If multiple motors are used for different hand mechanism movements, then the control precision improves, but the device complexity and cost increase

Engineering Contradiction:

Improvepositioning precisionVSAvoidhand mechanism complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple motor functions into a single motor by using a crank mechanism that converts rotational motion into the complex multi-directional movements required for hand mechanism operation. This integration reduces the number of motors while maintaining precise control through mechanical advantage and kinematic coupling.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The crank mechanism acts as an intermediary between the single motor and the hand mechanism, translating simple rotational input into complex coordinated movements. This intermediary mechanism enables precise positioning without requiring multiple independent motors for each degree of freedom.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Speed

If the hand mechanism is positioned closer to the cartridge than normal, then the access speed increases, but the cartridge may be damaged due to excessive force

Engineering Contradiction:

Improveaccess speedVSAvoidcartridge damage risk

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The buffer mechanism with compression springs is positioned to absorb excessive force before it can damage the cartridge. When the hand mechanism approaches the cartridge too closely or with excessive speed, the springs compress to cushion the impact, preventing damage while allowing fast access operations.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent converts the potentially harmful excessive force into useful compression of the buffer springs. The energy from overly aggressive or fast positioning is transformed into spring compression, which then releases controlled force to gently position the cartridge, turning a harmful factor into a beneficial cushioning effect.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 buffer mechanism ensures reliable access and handling of cartridges in large-capacity systems by maintaining rotation and holding capabilities, reducing the need for retrying positions and enhancing the overall reliability of the library apparatus.

Implementation Method 1

a buffer mechanism within the crank mechanism of the hand mechanism, which includes a buffer block, slide shafts, and compression springs

Methodology Applied

Scientific EffectElastic potential energy storage and release: Spring

Data Source

PatentUS7466511B2Hand mechanism in a cartridge library apparatus being associated with a buffer mechanism to allow the hand mechanism to hold a cartridge even when the hand mechanism is not positioned at an optimal, normal position

Publication Date: 2008.12.16 FUJITSU LTD

AI summary

A library apparatus comprises a plurality of cartridges each containing a recording medium, a storage rack in which the plurality of cartridges is stored, at least one drive that records or reproduces data in or from the cartridge, and an accessor that holds the cartridge and transports the cartridge between the storage rack and the drive. Herein, a hand mechanism included in the accessor includes a buffer mechanism that, even if the advancement of the hand mechanism is stopped with the hand mechanism abutted against the cartridge within a predetermined range before reaching a normal position, allows the hand mechanism to hold the cartridge. The buffer mechanism is incorporated in a rotary base included in a crank mechanism. When external force is applied to a crank arm, the buffer mechanism moves a rotary shaft of the crank arm. Consequently, even if the hand mechanism approaches the cartridge storage rack too closely, the hand mechanism can access the cartridge without the necessity of retrying the advancement.