Abstract:
For adding on to a tape automation system, a base unit is provided having at least one tape cartridge magazine having a plurality of tape cartridge receiving locations, a tape drive, a tape cartridge pickup which transports the tape cartridge from a tape cartridge receiving location after extraction to a tape drive in a first direction, a tape cartridge pickup guide along which the tape cartridge pickup travels, and an elevator system which moves the cartridge pickup guide in a second direction perpendicular to the first direction. The base unit has a removable cover. An add-on unit is provided having at least one tape cartridge magazine having a plurality of tape cartridge receiving locations. The cover is removed from the base unit and the add-on unit is placed on the base unit. The base unit elevator system is used to retrieve tape cartridges with the cartridge pickup from the add-on unit cartridge magazine and also from the base unit cartridge magazine.

Description:
BACKGROUND  
       [0001]     Automatic systems for handling many tape cartridges (cassettes) in conjunction with one or more tape drives are becoming more and more important in the world of data storage, such as tape back-ups for computer systems. Such systems are typically called a “loader” if the systems contain one tape drive and a small number (5-16) of tape cartridges; and are typically called a “library” if the systems contain two or more drives (and normally from 10 cartridges and upwards). These systems are designed to meet the need for reliable, low cost data backup and retrieval in modern data storage systems. With the systems, one is able to select any one of all the cartridges in the automation system and automatically insert it into one or more of the tape drives, and then later replace the selected cartridge with the next cartridge needed for the system operation. With such systems, operator handling, which is costly, as well as operator mistakes, can be drastically reduced.  
         [0002]     A common name for tape loaders and tape libraries is “tape automation systems”, which is used hereafter. Also in the following, the word “cartridge” is used to cover both tape cassettes and tape cartridges.  
         [0003]     Although the actual designs may vary significantly, a typical tape automation system  10  contains the following main items as shown in  FIG. 1 : a cabinet  100 , one or more tape drives  101 , one or more magazines  102  which each may contain a number of cartridges  103 , a cartridge picker (robot)  104  which can take any cartridge from the magazines  102  and put into one of the tape drives  101  or vice versa. An example of this system is shown in U.S. Pat. No. 6,829,116, which shows in detail a prior art rotating cartridge picker. Larger systems may also have a system for lifting the cartridge picker to a different height to allow it to pick a cartridge from another magazine, or from another position within the same magazine.  
         [0004]     Additionally, the tape automation systems contain some form of electrical control system  106  which controls the operation of the tape drive  101  and the cartridge picker  104 , as well as communicating with a connected host computer. A power supply  107  supplies electric power for the entire unit.  
         [0005]     The operation of a typical low end tape automation system having one tape drive  101  and just one or two magazines  102  is described hereafter, with reference to  FIG. 1 .  
         [0006]     The specially designed magazine  102  containing the tape cartridges  103  is placed inside the tape automation system  10 . the electrical control system  106  will (based on commands from the connected computer host), send signals to the cartridge picker  104  which moves along rail or rails  90 A,B to pick a specific cartridge  103  from the magazine  102  and insert it into the tape drive  101 . The tape drive  101  will then execute one or more active commands on the cartridge (reading/writing/winding etc.). When the tape drive  101  has finished its operations on the inserted cartridge  103 , it will eject the cartridge from the tape drive  101 . the cartridge  103  is then grabbed by the picker  104  and put back-into the magazine. Then the cartridge picker  104  will take another cartridge  103  from the magazine, place it into the tape drive  101 , and the operation continues. Note the cartridge picker operates in two main axis, Y and Y. The Y-direction is defined as the direction in and out of the tape drive, while Y is in the direction in and out of the magazines. In addition, the cartridge picker is able to rotate around its vertical axis (with a cartridge) so that the cartridge front either is positioned to be moved in or out of the tape drive (the X direction) or in or out of a room of the magazine (the Y axis).  
         [0007]     An automation system having several tape drives and magazines stacked on top of each other operates in the same manner, except that the picker  104  then has to move up and down between several levels of magazines and tape drives.  FIG. 2  shows how cartridges  103  are stacked above each other with a stack of magazines  102 . FIG. 15 of U.S. Pat. No. 6,829,116 also shows this. A small locking arm or finger  108  prevents the cartridge from falling out when the magazine is carried around. The magazine itself can be one single unit with storage rooms for all the specified cartridges, or the system can be designed to accept several magazines  102  (each typically with one or two levels of cartridges) stacked upon each other. Likewise the tape drives  101  ( FIG. 1 ) can be stacked upon each other. In this case, the automation system will normally be equipped with a cartridge picker  104  ( FIG. 1 ) that can move along all three main axis. In addition to the operation along the x and y axis described above in  FIG. 1 , the cartridge picker typically has a built-in elevator system to allow movement along the vertical Z-axis of a cartridge inside the picker  102  to a specific tape drive level or cartridge room level.  
         [0008]     Thus, in almost all low end automation systems, the cartridge picker is guided by a rail or a set of rails  90 A,B as shown in  FIG. 1 . These rails  90  are normally mounted to the bottom plate  80  of the automation unit  10 , and the cartridge picker  104  can run along the rails. To move to different heights within an automation system of the type shown in  FIG. 2 , the cartridge picker has a built-in elevator that can lift either almost the complete picker system or just the cartridge picker  104  itself up to the various heights within the automation system.  
         [0009]     Compared to using a single drive, the tape automation system makes it possible to increase total storage capacity with anywhere from a typical factor of 7 up to upwards of many 1000&#39;s for the largest and most complex systems, with human handling and interference being reduced to a bare minimum.  
         [0010]     Over the years, many forms and variations of automation systems have emerged; however, in the low end arena of the automation systems, more and more systems are now based on the same principle configuration as shown in  FIG. 1 .  
         [0011]     From a physical size point of view, these systems are designed to fit into 19″ wide racks, and come in fixed height sizes: 1U (as shown on  FIG. 1 ), 2U, 3U, 4U (as shown in  FIG. 2 ) and so on. Each “U” (=“unit”) means a height dimension of 1.75″ or 41.5 mm. A 1 U system typically contains one tape drive and 4-8 cartridges in one or two magazines (see  FIG. 1 ). The magazine stack shown in  FIG. 2  will typically be part of a 4 U level system. Except for the 1U systems, other systems (2U and above) normally need to have a picker system designed so that the portion of the picker handling the cartridge can be moved up and down between the various levels, (normally done with a built-in elevator in the picker).  
         [0012]     Low end systems are normally designed so that they are not expandable, meaning that they are designed for a fixed number of tape drives and cartridges. However, the actual number of drives and cartridges at the time of purchase may vary. For example, a typical 4U system may contain two magazine groups, each with 4 levels and 4 cartridges on each level. It may also have space for up to four drives. However, the user may elect to buy the system with just one drive and for example only one group of magazines and cartridges (in this example then 16 cartridges). The user may then later install more magazines to bring the total number of available cartridge slots up to the maximum (in this case 32) and also install more tape drives (in this case up to a maximum of 4).  
         [0013]     Should the user later need more capacity, he or she typically will have to buy a new automation system and connect this to the same computer. The two automation systems will operate independently of each other; however, both will (normally) be controlled by the same computer host.  
         [0014]     As shown in  FIG. 3 , there exist prior art low end automation systems that are designed to be stacked upon each other and have a special lift or elevator  111  at an end of the system, so that cartridges from one automation unit can be passed up or down to the other unit. Here, two complete automations systems  109  and  110  are stacked upon each other.  FIG. 3  shows the two units as seen from the side. At the back of the two units is mounted the “pass-thru” elevator  111 . This is a special unit which can lift a cartridge from system  109  up to system  110  or vice versa.  
         [0015]     This is done by the picker of system  109  first picking the cartridge to be moved out of its magazine slot and then placing the cartridge on a lift fixture inside the pass-thru elevator  111 . The elevator then moves the entire lift fixture upwards until the cartridge can be reached by the picker of system  110 . This picker then grabs the cartridge and either inserts it into one of the tape drives in system  110  or into a spare magazine slot of system  110 .  
         [0016]     The customer may add additional units on top of system  110  in order to increase capacity and performance of his or her system even further. In this case, an additional pass-thru elevator is also added on the back of the new unit to allow cartridges to be moved between all three system units.  
         [0017]     While such a system as described above allows the user to increase capacity and performance outside the limits given by the fixed size unit, it is from a cost point-of-view not very effective. Each automation unit contains all the normal elements required for an automation unit (including a picker) and in addition there is the cost of the pass-thru elevator.  
         [0018]     For very low end systems, it would be desirable to be able to have a low cost automation unit which can easily be expanded both with respect to number of cartridges and number of tape drives.  
       SUMMARY  
       [0019]     For adding on to a tape automation system, a base unit is provided having at least one tape cartridge magazine having a plurality of tape cartridge receiving locations, a tape drive, a tape cartridge pickup which transports the tape cartridge from a tape cartridge receiving location after extraction to a tape drive in a first direction, a tape cartridge pickup guide along which the tape cartridge pickup travels, and an elevator system which moves the cartridge pickup guide in a second direction perpendicular to the first direction. The base unit has a removable cover. An add-on unit is provided having at least one tape cartridge magazine having a plurality of tape cartridge receiving locations. The cover is removed from the base unit and the add-on unit is placed on the base unit. The base unit elevator system is used to retrieve the tape cartridges with the cartridge pickup from the add-on unit cartridge magazine. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a perspective view of a prior art tape automation system;  
         [0021]      FIG. 2  is a perspective view of a prior art tape automation system having a plurality of stacked tape magazines;  
         [0022]      FIG. 3  is a prior art tape automation system formed of two stacked automation units with a common elevator added at one end of the system;  
         [0023]      FIG. 4  is a perspective view of a tape automation system of the preferred embodiment having a base unit and an add-on unit where the base unit has an elevator with picker which secures both units;  
         [0024]      FIG. 5  is a cross-sectional view taken along lines V-V of  FIG. 4 ;  
         [0025]      FIG. 6  is a partial view of an elevator system used in  FIG. 5 ;  
         [0026]      FIG. 7  is a side view of the elevator system used in  FIG. 6 ;  
         [0027]      FIG. 8  is a detailed fragmentary view taken at section line VIII-VIII of  FIG. 9  of a pivot pin attachment used in the elevator system of  FIG. 7 ;  
         [0028]      FIG. 9  is a top view of the elevator system of  FIGS. 5, 6 , and  7 ;  
         [0029]      FIG. 10  is a plan view of the automation system of the preferred embodiment shown in  FIGS. 4 and 5  but without vertical guide rails;  
         [0030]      FIG. 11  is an alternative embodiment having vertical guide rails for the elevator system of  FIGS. 4 and 5 ; and  
         [0031]      FIG. 12  is a fragmentary side view showing the use of the vertical guide rails of  FIG. 11 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0032]     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the preferred embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and/or method, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur now or in the future to one skilled in the art to which the invention relates.  
         [0033]     As shown in  FIGS. 4 and 5 , with the preferred embodiment picker guide rails  121 A,B for picker  104  are moved up and down within an automation system  20 , and the system moving these rails is so flexible and effective that it allows the picker guide rails  121 A,B to be moved vertically beyond the height of the base automation unit  100 . By removing a top cover plate  5  of the base automation unit  100  and placing another add-on automation unit  142  having a removable cover  4  on top of the base unit  100  (without a bottom plate and without an additional cartridge picker), the guide rails  121 A,B of the base automation unit  100  may be moved to such a height that the picker can operate within the add-on automation unit  142 . It is also possible to provide one or more additional add-on automation units stacked upon the first add-on unit on base unit  100 . The cover  4  would then be removed from the first add-on unit before adding the second add-on unit.  
         [0034]     With the preferred embodiment, a user may begin with a very simple, low cost system, having a base unit  100  only typically 2 units (2U) in height. Then, when there is a need for more capacity, the user may buy another add-on unit  142  also two units (2U) in height (see  FIG. 4 ) and mount this on the top of the first base unit  100 . The top cover  5  on the base unit  100  must be removed before the add-on unit  142  is mounted on the top.  FIG. 5  shows this in more detail where the top cover of the base unit  100  has been removed and the new add-on unit  142  is mounted directly on top of the first base unit  100 . Front wall  143  of the add-on unit  142  matches directly with the front wall  140  of the base unit  100 . The same is true for the other three walls. Guide rails  144 A,B,C,D of the add-on unit  142  will match directly with guide rails  141 A,B,C,D of the base unit  100 , so that the two vertical rails together at each location act like one long vertical guide rail.  
         [0035]     The elevator drawing in  FIG. 5  is simplified in that a motor  134 , a spindle  131 , and beams  135  and  136  discussed hereafter in  FIG. 9  are not shown to keep the drawing clear.  
         [0036]     As shown in  FIG. 5 , the elevator system can lift guide rails  121 A,B along which picker  104  moves up into the add-on unit  142  and, for example, can pick a cartridge from one of compartments  103  in the top-most magazine  102 . The elevator system can then lower the guide rails  121 A,B and the picker  104  down to a suitable level for inserting the selected cartridge into a tape drive  101 .  
         [0037]     This add-on unit  142  can be made at lower cost than the base unit  100 , since it will not need an elevator system, a picker, or a tape drive. It will contain one or more magazines. It may contain a tape drive, however, if desired.  
         [0038]     Depending upon a height of the base unit  100  and the add-on unit  142 , it is also possible to even extend the system further with one or more additional add-on units. The limit is reached when arms  120 A,B and  123 A,B of the elevator system have moved so close together that the elevator system has reached its maximum practical height (due to requirements for stability of the guide rails  121 A,B). This maximum will vary with the dimensions of the total base unit  100 , the stability of the picker guide rails  121 A,B, vertical guide rails  141 A,B,C,D and  144 A,B,C,D, and vertical guide and stability of the elevator system itself.  
         [0039]     Thus this combined elevator system both represents a simple method to lift the picker  104  in automation system  20  to various height levels as well as also making it possible to design very low cost add-on units to the base unit. Without requiring elevators or a picker (or possibly even a tape derive), the cost savings for the add-on units can be significant.  
         [0040]      FIG. 6  shows a very simplified perspective drawing of the principle of the elevator system shown in  FIG. 5 . Here it is assumed that the cartridge picker  104  runs along the two guide rails  121 A,B. These guide rails can be moved higher or lower from the bottom plate  126  with the use of the simple elevator system, comprising the arms  120 A,B,  123 A,B, as well as the axle  125 . Axle  125  links at one end arms  120 A and  123 A with arms  120 B and  123 B at the other end. The axle  125  is mounted so it goes through a hole positioned approximately in the middle of each of the arms  120 A,B and  123 A,B. Moving the bottom ends of the arms  123 A,B and  120 A,B together on each side will lift the top ends of the same arms and therefore the guide rails  121 A,B upwards. Moving the bottom ends of the arms  123 A,B and  120 A,B away from each other will lower the guide rails  121 A,B. The guide rails  121 A,B are linked to the arms  120 A,B and  123 A,B with pins  124 A,B,C,D. The motor  134  of the elevator system for performing the movement of arms  120 A,B and  123 A,B by spindle  131  is not shown in  FIG. 6  or  7 , but is shown hereafter in  FIG. 9 . This elevator system can be made to lift the two guide rails  121 A,B high, and more specifically higher, than the height of the basic automation unit  100 .  
         [0041]      FIG. 7  and  FIG. 8 , together with  FIG. 6 , show the elevator system in detail.  FIG. 7  shows one side of the elevator system; the other side being identical. On the bottom plate  126  is mounted a pair of control rails  128 A,B. Each of these rails have two elongated openings  129 A,D or  129  B,C in which a respective bolt  130 A,B,C,D can slide. Bolts  130 A,B,C,D are mounted to the bottom ends of arms  120 A,B and  123 A,B.  FIG. 8  shows along section VIII-VIII of  FIG. 9  one of these bolts  130 C and the associated structure in a fragmentary view.  
         [0042]     As shown best in  FIG. 6 , an axle  125  passes through holes placed approximately in the middle of each arm  120 A,B and  123 A,B. Also as shown in  FIG. 6 , the upper guide rails  121 A,B are mounted to the top end of each arm pair  120 A,B and  123 A,B with respective bolts  124 A,B,C,D. The upper guide rails  121 A,B also have elongated respective openings  127 A,B,C,D (two in each rail) in which respective bolts  124 A,B,C,D can slide.  
         [0043]      FIG. 9  shows a bottom part of the elevator system seen from above. Only the bottom parts have been drawn in order to simplify the figure, and the upper picker rails  121 A,B are not shown for clarity.  FIG. 9  shows the bottom plate  126  with two control rails  128 A,B. The bottom ends of arms  120 A,B and  123 A,B are connected to the control rails  128 A,B with the bolts  130 A,B,C,D. The bolts  130 A,B,C,D (and thereby the bottom arm ends) can slide in the elongated openings  129 A,B,C,D of the control rails  128 A,B as shown on  FIG. 7 . The two bottom parts of arms  123 A,B are linked together with a beam  135 . This beam is connected to the ends of arms  123 A,B using the bolts  130 C,D so that the beam can rotate around the center of bolts  130 C,D. A hole  137  is drilled through beam  135 . This hole is equipped with internal screw threads. A spindle  131  with threads  133  corresponding to the internal threads in the hole  137 , is threaded through the hole  137 . This spindle  131  is connected to a motor  134  (preferably through a gear transmission system not shown here).  
         [0044]     As also shown in  FIG. 9 , the lower ends of arms  120 A,B are likewise linked together with another beam  136 . This beam is connected to the arms  120 A,B and the control rail  128 A,B with bolts  130 A,B, in the same way as already described above for arms  123 A,B. A hole  138  with internal screw threads is also drilled through beam  136 ; however, the threads are made in the opposite direction of the threads in hole  137 . The same spindle  131  goes through the hole  138  in beam  136 , however the threads  132  on this portion of the spindle go in the opposite direction of threads  133 . Therefore, spindle  131  has two sets of threads going in opposite directions and meeting at the spindle point which is approximately half way between beams  135  and  136 .  
         [0045]     The height of the picker guide rails  121 A,B can now be controlled by rotating the spindle  131  by the motor  134 . Rotating the spindle  131  counterclockwise (as seen from the motor  134 ) will move the two beams  135  and  136  towards each other. This will then move the upper ends of arms  120 A,B towards upper ends of arms  123 A,B and the guide rails  121 A,B will move upwards from the base plate  126 . The movement will be parallel to the base plate  126 .  
         [0046]     Likewise, rotating the spindle  131  clockwise (as seen from motor  134 ) will move the two beams  135  and  136  further apart. This again will lower the two guide rails  121 A,B towards the base plate  126 .  
         [0047]     As mounted onto the base plate of the automation system  20  shown in  FIGS. 4, 5  and  6 , this elevator system can now be used to move the cartridge picker  104  to various height levels within the automation system  20 . The picker  104  will be mounted on top of the guide rails  121 A,B and run along the guide rails to allow cartridges to be moved from the magazine compartments to the tape drive and vice versa. This is shown in  FIG. 10  (seen from above). The automation system  20  has the elevator system described in  FIGS. 7, 8 , and  9  mounted in the middle of the base unit  100 . For simplicity, only the two guide rails  121 A,B on the top of the elevator system are shown in  FIG. 10 . The picker  104  can move along the guide rails  121 A,B. It can take a cartridge out from one of the cartridge compartments  103  in the magazines  102  and insert it into the tape drive  101  or vice versa. The magazine may have cartridge compartments in several different height levels as shown in  FIG. 2 . The elevator system described here can lift the guide rails  121 A,B and thereby the picker  104  to the desired height level in order to reach a specific cartridge. Likewise, the same elevator system can lift the guide rails  121 A,B and thereby the picker  104  up and down to allow easy insertion (or removal) of a cartridge into one or more tape drives  101  in the automation system  20 .  
         [0048]     In  FIGS. 9 and 10  the vertical guide rails of  FIG. 5  are not provided. However, to increase the stability and accuracy of the positioning system, a set of special vertical guide rails  141 C,D may be mounted vertically on the front wall  140  of base unit  100  as shown in  FIGS. 5, 11 , and  12  (and similar vertical guide rails  141 A,B may also be mounted at the other end of the guiding rails  121 A,B near the tape drive  101 . Similar vertical guide rails  144 A,B,C,D are provided on the add-on unit  142  (see  FIG. 5 ) in matching positions so that they align with the base unit  100  vertical guide rails  141 A,B,C,D.  FIG. 11  shows the positioning of vertical guide rails  141 A,B,C,D seen from above, while  FIG. 12  shows the rail  141 D of unit  100  only seen from the side.  
         [0049]     While these vertical guide rails  141 A,B,C,D may be designed in many different forms depending upon how the vertical guide rails are made,  FIG. 11  shows a very simple U-form vertical guide rails  141 A,B,C,D which will guide and control the end of the picker guide rails  121 A,B as the elevator system moves the picker guide rails  121 A,B upwards or downwards.  
         [0050]     In principle, this elevator system described here may be used for many different forms of automation systems starting with low profile systems (like a 2U or 3U) and going up to at least 5U or 6U systems without experiencing any significant stability problems with the elevator guide rail system.  
         [0051]     While a preferred embodiment has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention both now or in the future are desired to be protected.