Abstract:
A vertical autoloader design enables multiple data cartridges to be selectively loaded into a drive while minimizing the device footprint. The structure of the vertical autoloader incorporates Geneva steps into the walls of the autoloader. The Geneva steps interface with gearing on a drive carriage to move the drive vertically. The data cartridges are inserted into slots on the front of the vertical autoloader, and the data cartridges not currently loaded into the drive can be removed and replaced while the autoloader is in operation. Further, the vertical autoloader includes prevent devices in the cartridge slots to ensure the data cartridges are loaded correctly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application claims priority from U.S. Provisional Application 60/720,767 filed Sep. 26, 2005. 
     
    
     TECHNICAL FIELD  
       [0002]     This invention relates to removable physical data storage devices, and more particularly to an autoloading device for data storage cartridges.  
       BACKGROUND  
       [0003]     A popular device for handling large amounts of information in a data processing system is an automated data cartridge loader (autoloader). Autoloaders store and manage large numbers of data cartridges containing media on which data is recorded. These cartridges are typically tape media, but recently autoloaders have been introduced using hard disk cartridges. One such autoloader is the SCSI Autoloader from Iomega Corporation, which incorporates its exclusive REV® drive and REV® disk cartridges in the autoloader design.  
         [0004]     One problem in the field of autoloaders is to increase the storage density while decreasing the equipment storage area required for the autoloaders. Autoloaders are widely accepted because they combine multiple data cartridges and a drive within a single chassis for higher data storage capacity. Typically, prior art autoloaders have an array of storage positions for data cartridges, one or more drives, and some type of automated changer or cartridge transport for picking or gripping a data cartridge and moving the data cartridge between a storage position and the drive. The robotic mechanism, often called a “picker”, is typically mounted to the autoloader chassis relative to the drive in order to move the data cartridges between a storage position and the drive.  
         [0005]     A typical picker mechanism automatically exchanges the individual data cartridges between their storage locations and the drive. Different types of data cartridge retrieval/transport mechanisms are used to accommodate the various data cartridge arrangements in different data cartridge library systems. One example of a data cartridge retrieval/transport mechanism utilizes a rotatable robotic arm with an optical sensor for selecting and retrieving the correct data cartridge and transporting the data cartridge to the one or more drives. Another example of a data cartridge retrieval/transport mechanism is a linear robotic mechanism that moves along an X-Y translation or about a pivot in a rotary motion to select, retrieve and transport data cartridges to the one or more drives. The drive is operable to read/write data from or to the media in the data cartridge. A host computer that communicates with a library control unit typically controls operation of the autoloader. In all of these architectures, the data cartridge retrieval/transport mechanism is a complex mechanism which must translate among the multitude of fixed data cartridge storage locations, moving in three dimensions to retrieve selected data cartridges for insertion into the drive. The complexity of this data cartridge retrieval/transport mechanism accounts for a significant component of the cost of the autoloader and requires a significant amount of space to implement.  
         [0006]     Therefore, there exists a need in the art of data storage for an autoloader that simplifies the storage and handling of large amounts of information, reduces the size of the system and space required for data storage, while at the same time being cost effective and simple.  
       SUMMARY  
       [0007]     A vertical autoloader design enables multiple data cartridges to be selectively loaded into a drive while minimizing the device footprint. The structure of the vertical autoloader incorporates Geneva steps into the walls of the autoloader. The Geneva steps interface with gearing on a drive carriage to move the drive vertically. The data cartridges are inserted into slots on the front of the vertical autoloader, and the data cartridges not currently loaded into the drive can be removed and replaced while the autoloader is in operation. Further, the vertical autoloader includes prevent devices in the cartridge slots to ensure the data cartridges are loaded correctly. 
     
    
     DESCRIPTION OF DRAWINGS  
       [0008]     These and other features and advantages of the invention will become more apparent upon reading the following detailed description and upon reference to the accompanying drawings.  
         [0009]      FIG. 1  illustrates the housing of an autoloader having interlocking tabs along all edges of the present invention (top and foreground side panel removed).  
         [0010]      FIG. 2  illustrates geneva steps molded into the side panel of the autoloader frame.  
         [0011]      FIG. 3  illustrates a drive carriage having geneva wheels for interacting with the Geneva steps shown in  FIG. 2 .  
         [0012]      FIG. 4  illustrates a detailed view of one of the geneva wheels of  FIG. 3 .  
         [0013]      FIG. 5  is a front view of the autoloader frame showing the cartridge slots. The bottom slot has a cartridge in it. In each slot, Prevent device tabs are present on either side, and a Prevent device cam is present in the center.  
         [0014]      FIG. 6  is a rear isometric view of the back side of the front panel and sleeve wall assembly. A cartridge is shown inserted and registered in the bottom slot. The Prevent device that controls cartridge orientation during insertion is just visible on the top of each horizontal plate.  
         [0015]      FIG. 7  illustrates the prevent device shown in  FIG. 6 .  
         [0016]      FIG. 8  is an isometric cross-section of the front panel showing the Prevent device in one of the slots.  
         [0017]      FIG. 9  is a rear isometric view of a cartridge being inserted. The prevent device is in the spring loaded up position. The slots on the underside of the cartridge can be seen to be aligned with the tabs on the end of the prevent device.  
         [0018]      FIG. 10  illustrates a cartridge inserted past the tabs but just engaging the cam.  
         [0019]      FIG. 11  illustrates the prevent device interacting with a cartridge that is inserted incorrectly.  
     
    
     DETAILED DESCRIPTION  
       [0020]     An autoloader using vertical movement can be used to minimize the footprint required for the device.  FIG. 1  illustrates the housing  100  of a vertical autoloader  110  having interlocking tabs  140  along all edges of the present invention (with the top and foreground side panel removed). The housing  100  comprises a bottom panel  130 , a front panel  120 , a back panel  115 , a first side panel  135  (a second side panel is not shown), and a top panel (not shown). The front panel  120  includes a cutout aperture  125  for the cartridge slots. The height of the vertical autoloader  110  may vary depending on the number of cartridges the autoloader  110  is designed to hold. The side panel  135  also includes a rib  155  which is used to ensure alignment of a drive carriage as will be described below.  
         [0021]     Prior art for the construction of a device like the vertical autoloader  110  consists of various sheet metal parts fastened together with screws to form a rigid support structure. Because of the limited types of features that can be made during the forming of a flat metal blank, additional parts are added as kinematic (typically guiding, locating or motive) features. Also, since the sheet metal structure is typically not visually appealing, the housing may be covered with additional, cosmetic, largely nonfunctional sheet metal or plastic facades.  
         [0022]     One embodiment of the vertical autoloader  110  improves on this by using molded plastic to form each of the panels of the housing  100 . The molded plastic components of the housing  100  may include interlocking tabs  140  to force the cosmetic enclosures into rigid alignment. Also, functional features such as a lifting mechanism  145  can be molded directly into the housing  100 .  
         [0023]      FIG. 2  illustrates Geneva steps as the lifting mechanism  145  molded into the side panel  135  of the housing  100 . The Geneva steps  145  may be included proximate both the front panel  120  and the rear panel  115  of the housing  100 . Complementary Geneva steps  145  are included on the second side panel (not shown). The complete Geneva steps  145  cooperate with a corresponding Geneva gear on a drive carriage and will be described below.  
         [0024]      FIG. 2  also shows the interaction of the interlocking tabs  140  to create the rigid housing  100 . As shown, tabs  140  on the side panel  135  may interface with corresponding cutouts  150  on the bottom panel  130 . Thus, the cost of forming the housing can be minimized while an attractive, rigid housing  100  is obtained. Interlocking tabs  140  are formed along all edges of all exterior parts. The tabs are shaped so that there is zero clearance between mating tabs. The net effect is to prevent any shearing motion between components. Therefore, the torsional stiffness of the assembled structure is very high without resorting to the use of sheet metal parts. Symmetry is exploited so that the two sides and the top and bottom are identical parts thus saving tooling costs and resulting in a lower part cost.  
         [0025]     Use of the interlocking tabs  140  eliminates many small fasteners that would normally be required to bind various pieces of sheet metal together to achieve the same structural integrity. In place of these many small fasteners, four long draw screws (not shown) may be used to pull the front panel  125  and rear panel  115  together to trap the tabs  140  and finish the assembly.  
         [0026]      FIG. 3  illustrates a drive carriage  300  having geneva wheels  305  for interacting with the Geneva steps shown in  FIG. 2 . The drive carriage  300  is adapted to hold a drive  310  which is moved vertically within the housing  100 . The drive  310  may be a tape drive or any type of drive that accepts removable cartridges. Preferably, the drive  310  is a REV® drive by Iomega Corporation. The REV drive accepts hard disk cartridges, which provides a faster, more reliable, and cheaper to tape drives and cartridges. The drive carriage  300  also includes a rib mating slot  315 . There is a slot  315  on each side of the carriage  300 . The vertical rib  155  ( FIG. 1 ) engages the mating slot  315  as the carriage moves vertically within the housing  100 . The vertical rib  155  and mating slot  315  assist the smooth movement of the carriage  300  due to forces on the carriage  300  from friction by the pins  325  sliding on the Geneva steps  145  in the side-panel.  
         [0027]      FIG. 4  illustrates a detailed view of one of the Geneva wheels  305  of  FIG. 3 . The Geneva wheels  305  include gearing  320  and pins  325 . The pins  325  on the Geneva wheels  305  engage the Geneva steps  145  on the side panels. A motor (not shown) is used to turn the Geneva wheels  305  using the gearing  320 . As the Geneva wheels  305  turn, the interaction of the pins  325  against the Geneva steps  145  causes the carriage  300  to move up and down depending on the direction of rotation of the Geneva wheels  305 . Not shown are two timing belts, one on either side, that keep the four wheels in synchrony. The precision of the molded Geneva steps  145  may be used to ensure proper alignment of a cartridge opening of the drive  310  with the cartridge to be loaded.  
         [0028]      FIG. 5  is a front view of the autoloader housing  100  showing cartridge slots  505 .  FIG. 6  is a rear isometric view of the back side of the autoloader housing  100  of  FIG. 5 . The bottom slot of autoloader housing  100  has a cartridge  510  installed for illustrative purposes. In each slot  505 , a prevent device  507  is installed. The prevent device  507  includes tabs  520  on each side, and a cam  525  in the center. A detailed view of the prevent device  507  and the tabs  520  and cam  525  is seen in  FIG. 7 .  
         [0029]      FIG. 8  is an isometric cross-section of the front panel showing the prevent device  507  in one of the slots. The prevent device  507  is installed on a sleeve plate surface  600  in each cartridge slot  125 . The prevent device  507  cooperates with the sleeve plate surface to control cartridge  510  insertion as will be described below.  
         [0030]      FIG. 9  is a rear isometric view of a cartridge  510  being inserted into a cartridge slot  125 . The prevent device  507  is in the spring loaded up position. Slots  610  on the underside of the cartridge  510  can be seen to be aligned with the tabs  520  on the end of the prevent device  507 . The bottom of a data cartridge may have a slot  610  on either side that extends from the front of the cartridge roughly one-third the length of the cartridge. The prevent device  507  has a tab  520  at either end that is aligned with the cartridge slots while the cartridge is being properly inserted. As the cartridge slides in, the tabs  520  slide into the slots  610  for a predetermined distance (approximately 15 mm for a REV cartridge). Once this distance is achieved, the cam  525  contacts the leading edge  615  of the moving cartridge. Because of the angle on the cam  525 , the prevent device  507  is forced to rotate downward, lowering the tabs  520  until they are flush with the sleeve plate surface  600  in the cartridge slot  505 . This moves the tabs  520  out of the way before they can engage the end of the slots  520  in the cartridge bottom.  
         [0031]      FIG. 10  illustrates a cartridge  510  inserted past the tabs  520  but just engaging the cam  525 . The tabs  520  have engaged the slots  610  in the bottom of the cartridge  510 . The leading edge  615  of the cartridge  510  has just contacted the center cam  525  which will lower the tabs out of the way before they can reach the end of the slots  610 .  
         [0032]      FIG. 11  illustrates the prevent device  507  interacting with a cartridge  510  that is inserted incorrectly. If the cartridge  510  is inserted in any other orientation, the tabs  520  of the prevent device  507  engages the leading surface  615 . Because the cartridge  510  is inserted incorrectly, the slots  620  are not properly positioned and therefore no slots  620  are available for the tabs  520  to slide. In the example of  FIG. 11 , the cartridge  520  is being inserted upside down. The tabs  520  contact the leading edge  620  of the inserting cartridge  520  before the cam  525  can be engaged to lower them out of the way. Thus, the cartridge  520  is stopped from being inserted by the prevent device  507 .  
         [0033]     A special case of unwanted cartridge orientation will now be discussed. Since the REV cartridge  520  is shorter in the direction of insertion than the width, putting the cartridge in sideways is more difficult to prevent than other orientations. However, it is possible for the cartridge  520  to be inserted upside down, sideways and skewed (to the extent allowed by the cartridge slot) such that only one of the prevent tabs  520  contacts the leading edge  620  of the cartridge  520 . In this case, the cam  525 , being positioned in the center of the prevent device  507 , is not contacted. Thus the tab  520  is not lowered, and insertion is prevented.  
         [0034]     Numerous variations and modifications of the invention will become readily apparent to those skilled in the art. Accordingly, the invention may be embodied in other specific forms without departing from its spirit or essential characteristics.