The Economic Aspects Of Water Resources Information

A storage library with a simplified operating mechanism for computer back-up data cartridges. The cartridge is placed in a tray in an opening in a sealed storage chamber and transported into and removed from a multi-tier storage carrousel by a robotic arm. When a tape is to be retrieved, the arm moves the stored cartridge either to a module or directly to the window tray. A simple transmission operating the carrousel permits any cartridge to be moved to the storage-retrieval station in no more than two revolutions of the multi-carrousel central drive shaft. The use of a carrousel reduces the distance the arm must travel and decreases the time for storage or retrieval of a cartridge. Only two of seven axes have incremental positioning controls: the vertical lift and the carrousel rotation. All other axes have fixed travel distances. A cartridge gripper is compliant, readily adaptable to different cartridge configurations, and materially reduces the need for precision positioning.