Abstract:
An apparatus is disclosed to ensure positive latching of tape cartridges in tape library magazines. In one embodiment, such an apparatus includes a tape library defining a channel to receive a tape library magazine accommodating one or more tape cartridges. A protruding member is provided within the channel to urge the one or more tape cartridges into the tape library magazine as the tape library magazine slides into the channel. The protruding member may include a cam-like member, an arm, a roller, or other suitable structures to urge the one or more tape cartridges into the tape library magazine. The protruding member ensures engagement of a latching mechanism configured to retain the one or more tape cartridges within the tape library magazine. A corresponding system and method are also disclosed.

Description:
BACKGROUND 
     Field of the Invention 
       [0001]    This invention relates to apparatus and methods to ensure positive latching of tape cartridges in tape library magazines. 
       Background of the Invention 
       [0002]    A tape library is an automated data storage system used to store and retrieve data on magnetic tape cartridges. A tape library typically includes one or more tape drives for reading and writing information to magnetic tape cartridges, access ports for entering and removing cartridges from the tape library, and a moving robot (i.e., an accessor) to physically transport tape cartridges between storage cells, drives, and access ports. For example, the IBM 3572 is an LTO tape library that holds one tape drive and up to ten tape cartridges. The tape cartridges are placed in a magazine that can be inserted into or removed from a channel in the tape library. Once the magazine is inserted into the tape library, the tape cartridges are accessible to an accessor inside the library. 
         [0003]    The magazine used by the IBM 3572 employs “high density” slot technology, which enables two cartridges to be inserted into the same slot, also referred to as a “tier.” This enables much greater storage density in the tape library. Each high density slot is spring-loaded to enable a second cartridge to be pushed into the slot after a first cartridge is loaded. The first cartridge is pushed further into the slot by the second cartridge. When the second cartridge is removed, the first cartridge is pushed to the front of the slot by the spring, thereby allowing it to be grabbed by the accessor. In the IBM 3572, there are five slots in the magazine, each holding up to two cartridges. At the front of each slot is a latch that holds the tape cartridges against the spring. This latch maintains the tape cartridges at a correct position at the front of the slot so that they can be grabbed and manipulated by the library accessor. 
         [0004]    Unfortunately, because tape cartridges are inserted into the magazine by hand, operator error may cause problems with the magazine latching function. If the operator is not diligent in pushing a tape cartridge all the way into a slot, the latch may not close properly. This may create a partial latch condition. If a cartridge is not fully latched, the latch may open, allowing the tape cartridge to protrude out of the magazine beyond the latch point. This may occur when the magazine is subjected to shock or vibration, such as when the magazine is inserted into the tape library. If the latch opens when the magazine is inserted into the tape library, the protruding cartridge may prevent the removal of the magazine from the tape library. A protruding cartridge may also interfere with movement of the accessor inside the tape library, possibly causing an accessor movement error. Any of these scenarios has the potential to interfere with a scheduled backup and/or prevent a customer from accessing data on the tape library. In certain cases, the scenarios described above may damage the tape library, potentially causing loss of the tape library and/or the data contained therein. 
         [0005]    In view of the foregoing, what are needed are apparatus and methods to prevent cases of operator error that may cause the latching malfunction and associated problems described above. Ideally, such apparatus and methods will be simple, effective, and inexpensive. 
       SUMMARY 
       [0006]    The invention has been developed in response to the present state of the art and, in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available apparatus and methods. Accordingly, the invention has been developed to provide apparatus and methods to ensure positive latching of tape cartridges in tape library magazines. The features and advantages of the invention will become more fully apparent from the following description and appended claims, or may be learned by practice of the invention as set forth hereinafter. 
         [0007]    Consistent with the foregoing, an apparatus is disclosed to ensure positive latching of tape cartridges in tape library magazines. In one embodiment, such an apparatus includes a channel to receive a tape library magazine accommodating one or more tape cartridges. A protruding member is provided within the channel to urge the one or more tape cartridges into the tape library magazine as the tape library magazine slides into the channel. The protruding member may include a cam-like member, an arm, a roller, or other suitable structures to urge the one or more tape cartridges into the tape library magazine. The protruding member ensures engagement of a latching mechanism configured to retain the one or more tape cartridges within the tape library magazine. 
         [0008]    A corresponding system and method are also disclosed and claimed herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which: 
           [0010]      FIG. 1  is a perspective view showing one embodiment of a tape library receiving a tape library magazine; 
           [0011]      FIG. 2  is a perspective view showing one embodiment of a tape library magazine; 
           [0012]      FIG. 3  is a side view showing proper and improper engagement of a latching mechanism configured to retain a tape cartridge within a tape library magazine; 
           [0013]      FIG. 4  is a first cutaway top view showing a protruding member configured to urge a tape cartridge into a tape library magazine as the tape library magazine slides into a tape library; 
           [0014]      FIG. 5  is a second cutaway top view showing the protruding member urging the tape cartridge into the tape library magazine as the tape library magazine slides into the tape library; 
           [0015]      FIG. 6A  shows one embodiment of a cam-like protruding member to urge a tape cartridge into a tape library magazine; 
           [0016]      FIG. 6B  shows one embodiment of a protruding member incorporating a roller; 
           [0017]      FIG. 6C  shows one embodiment of a protruding member incorporating multiple rollers; 
           [0018]      FIG. 6D  shows one embodiment of a protruding member using a biasing member to urge the protruding member against a tape cartridge; 
           [0019]      FIG. 6E  shows one embodiment of a protruding member that acts as its own biasing member; and 
           [0020]      FIG. 6F  shows one embodiment of a protruding member using a cam wheel to urge a tape cartridge into a tape library magazine. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. 
         [0022]    Referring to  FIG. 1 , one example of a tape library  100  is illustrated. In this embodiment, the tape library  100  is configured to receive a magazine  102  holding multiple tape cartridges  104 . An accessor (not shown) within the tape library  100  may load/unload the tape cartridges  104  from the tape library magazine  102  and transport these tape cartridges  104  to and from a tape drive (not shown) for accessing data thereon. As shown in  FIG. 1 , the tape library magazine  102  may slide into a channel  106  of the tape library  100 . Once the tape library magazine  102  is fully inserted into the tape library  100 , the tape cartridges  104  may be accessible to the accessor inside the tape library  100 . 
         [0023]    Referring to  FIG. 2 , one embodiment of a tape library magazine  102  for use with a tape library  100  is illustrated. The illustrated tape library magazine  102  employs “high density” slot technology, which enables two tape cartridges  104  to be inserted into the same slot  200 , also referred to as a “tier”  200 . This enables much greater storage density in the tape library  100 . Each high density slot  200  is spring-loaded to enable a second tape cartridge  104  to be pushed into the slot  200  after a first tape cartridge  104  is loaded. The first tape cartridge  104  is pushed further into the slot  200  by the second tape cartridge  104 . When the second tape cartridge  104  is removed, the first tape cartridge  104  is pushed to the front of the slot  200  by the spring, thereby allowing it to be grabbed by the accessor. In the illustrated embodiment, there are five slots  200   a - e  in the tape library magazine  102 , each holding up to two tape cartridges  104 . The approximate position of the tape cartridges  104  within the tape library magazine  102  are shown with dotted lines. At the front of each slot  200  is a latch  202  that holds the tape cartridges  104  against the spring associated with the slot  200 . This latch  202  stops the tape cartridges  104  at a specified position at a front of the slot  200  so that they can be grabbed and manipulated by the library accessor. 
         [0024]    Referring to  FIG. 3 , unfortunately, because tape cartridges  104  are typically inserted into a tape library magazine  102  by hand, operator error may cause problems with the magazine latching function. If the operator is not diligent in pushing a tape cartridge  104  all the way into a slot  200 , the latching mechanism  202  may not close completely. This may create a partial latch condition. If a tape cartridge  104  is not fully latched, the latching mechanism  202  may open at unexpected times, allowing the tape cartridge  104  to protrude out of the tape library magazine  102  beyond the latch point. This may occur when the tape library magazine  102  is subjected to shock or vibration, such as when the magazine  102  is inserted into the tape library  100 . If the latch  202  opens when the magazine  102  is inserted into the tape library  100 , the tape cartridge  104  may protrude from the tape library magazine  102  in a way that prevents removal of the tape library magazine  102  from the tape library  100 . A protruding tape cartridge  104  may also interfere with movement of an accessor inside the tape library  100 , possibly causing an accessor movement error. Any of these scenarios has the potential to interfere with a scheduled backup and/or prevent a customer from accessing its data. In certain cases, the scenarios described above may damage the tape library  100 , potentially causing loss of the tape library  100  and/or the data contained therein. 
         [0025]      FIG. 3  is a side view showing one example of proper and improper engagement of a latching mechanism  202  configured to retain a tape cartridge  104  within a tape library magazine  102 . The latching mechanism  202   b  on the right-hand side of  FIG. 3  (shown in blow-up detail portion  300   b ) shows a properly engaged latching mechanism  202   b . The latching mechanism  202   a  on the left-hand side of  FIG. 3  (shown in blow-up detail portion  300   a ) shows an improperly engaged latching mechanism  202   a.  As shown in blow-up detail portion  300   b,  when properly engaged, the tape cartridge  104   b  may be pushed into the tape library magazine  102  sufficiently to enable the latching mechanism  202   b  to extend over the tape cartridge  104   b.  This will retain the tape cartridge  104   b  within the tape library magazine  102  and prevent the tape cartridge  104   b  from releasing or protruding from a side of the tape library magazine  102 . When functioning properly, the latching mechanism  202   b  may be disengaged, as needed, by the accessor and/or other robotics within the tape library  100  so that the tape cartridge  104   b  can be removed from the tape library magazine  102  and loaded into a tape drive for accessing data thereon. After data has been accessed, the tape cartridge  104   b  may be reloaded into the tape library magazine  102  and the latching mechanism  202   b  may be properly re-engaged. 
         [0026]    As shown in blow-up detail portion  300   a,  when improperly engaged, the tape cartridge  104   a  may not be pushed into the tape library magazine  102  sufficiently to enable the latching mechanism  202   a  to extend over the tape cartridge  104   a.  Such a scenario may occur if an operator is not diligent in pushing a tape cartridge  104   a  all the way into a slot  200 . In certain cases, the latching mechanism  202   a  may be partially engaged such that it only partially extends over the tape cartridge  104   a.  For example, the latching mechanism  202   a  may partially catch a curved edge of the tape cartridge  104   a,  or tenuously engage ridges or other surface elements on the tape cartridge  104   a.  In certain cases, the latching mechanism  202   a  may be misaligned or skewed as shown in the blow-up detail portion  300   a . A vibration, shock, or other movement, may be sufficient to jar the tape cartridge  104   a  loose from the tape library magazine  102 . This may allow the tape cartridge  104   a  to release or protrude from the tape library magazine  102  at unexpected or undesirable times, potentially causing the problems previously discussed. 
         [0027]    Referring to  FIGS. 4 and 5 , in order to prevent cases of operator error that may cause the latching malfunction and associated problems described above, a protruding member  400  may be placed within the channel  106  of the tape library  100  to urge tape cartridges  104  into the tape library magazine  102  as the tape library magazine  102  is slid into the channel  106 . This will ensure that the latching mechanisms  202  properly engage the tape cartridges  104  within the tape library magazine  102 . 
         [0028]      FIG. 4  shows a tape library magazine  102  as it is being slid into a tape library  100 . For illustration purposes, the tape library  100 , tape library magazine  102 , tape cartridge  104 , and protruding member  400  are shaded differently to show the position of various components relative to one another. In the illustrated example, the tape cartridge  104  is just coming into contact with the protruding member  400 . Furthermore, the tape cartridge  104  is not fully engaged by the latching mechanism  202 , possibly the result of an operator not sufficiently pushing the tape cartridge  104  into the tape library magazine  102 . In such a scenario, any vibration, shock, or movement, may be sufficient to jar the tape cartridge  104   a  loose from the tape library magazine  102 . In certain cases, the very act of inserting the tape library magazine  102  into the tape library  100  may create sufficient vibration to jar the tape cartridge  104   a  loose from the tape library magazine  102 . As previously discussed, this may cause the tape cartridge  104  to undesirably protrude from the tape library magazine  102 . 
         [0029]    As the tape library magazine  102  is slid into the tape library  100 , the tape cartridge  104  comes into contact with the protruding member  400 . In the illustrated embodiment, the protruding member  400  has a gradually sloped surface  502  to enable the tape cartridge  104  to slide along the protruding member  400  without catching thereon. In certain embodiments, the protruding member  400  is made of or coated with a material having a low coefficient of friction to reduce friction between the tape cartridge  104  and the protruding member  400 . As the tape cartridge  104  slides along the protruding member  400 , the tape cartridge  104  is pushed into the tape library magazine  102 , thereby allowing the latching mechanism  202  to fully engage the tape cartridge  104 . The height  500  of the protruding member  400  may be designed to push the tape cartridge  104  into the tape library magazine  102  a specified amount to engage the latching mechanism  202 .  FIG. 5  shows the tape library magazine  102  after the protruding member  400  has fully engaged the latching mechanism  202 . 
         [0030]    The shape and configuration of the protruding member  400  may vary in different embodiments. The illustrated shape and configuration is provided only by way of example and not limitation. For the purpose of this disclosure, any protruding structure that is designed to push a tape cartridge  104  into a tape library magazine  102  as the tape library magazine  102  is inserted into a tape library  100 , regardless of its shape or form, is deemed to be a “protruding member”  400  in accordance with the invention. 
         [0031]    Various ancillary structures may be used with the protruding member  400  or to improve operation of the protruding member  400 . For example, in certain embodiments, the protruding member  400  may be coupled to a biasing member (not shown) such as a spring, elastomeric member, or the like. This biasing member may press the protruding member  400  against the tape cartridge  104  with a desired amount of force. In certain embodiments, this force may be designed to overcome the spring force exerted by the tape library magazine  102  on the tape cartridge  104 . This will ensure that the tape cartridge  104  can be urged into the tape library magazine  102  to engage the latching mechanism  202 . 
         [0032]    The biasing member may also allow the protruding member  400  to be pushed away from the tape cartridge  104  and/or tape library magazine  102  when it comes into contact with more rigid structures. For example, when the latching mechanism  202  comes into contact with the protruding member  400 , the protruding member  400  may move in direction  504  to enable the latching mechanism  202  to slide past the protruding member  400 . Thus, the biasing member may enable the protruding member  400  to push against the tape cartridge  104  in addition to allowing the protruding member  400  to move away from more rigid structures. 
         [0033]    The same functionality may be used when removing the tape library magazine  102  from the tape library  100 . For example, a rear surface  506  of the protruding member  400  may, in certain embodiments, be sloped to enable structures to slide past the protruding member  400  when the tape library magazine  102  is removed from the tape library  100 . Similarly, the biasing member previously discussed may allow the protruding member  400  to move away from rigid structures such as the latching mechanism  202  when such structures move past the protruding member  400 . 
         [0034]    Referring to  FIGS. 6A through 6F , as mentioned above, a protruding member  400  in accordance with the invention may take on various shapes and forms. Several different embodiments of a protruding member  400  are illustrated in  FIGS. 6A through 6F . These embodiments are presented by way of example and not limitation. Furthermore, various features of the embodiments illustrated in  FIGS. 6A through 6F  may be combined into a single embodiment, or separated out into different embodiments. 
         [0035]    In general, a protruding member  400  in accordance with the invention may take the form of a cam that pushes against a tape cartridge  104  while allowing the tape cartridge  104  to slide past. In alternative embodiments, the protruding member  400  may be embodied as an arm, aided by a biasing member or other element, that pushes against a tape cartridge  104  while allowing the tape cartridge  104  to slide past. In certain embodiments, the protruding member  400  incorporates one on or more rollers to push against the tape cartridge  104  while reducing friction with the tape cartridge  104 . 
         [0036]      FIG. 6A  shows one embodiment of a cam-like protruding member  400   a  that pushes against a tape cartridge  104 . As shown, the protruding member  400   a  has a gradually sloped surface  502  to enable the tape cartridge  104  to slide along the protruding member  400   a  while being pushed into the tape library magazine  102 . A opposing surface  506  of the protruding member  400   a  may, in certain embodiments, also be sloped to enable structures to slide past the protruding member  400   a  when the tape library magazine  102  is removed from the tape library  100 . As previously mentioned, the protruding member  400   a  may in certain embodiments be made of or coated with a material having a low coefficient of friction to allow the tape cartridge  104  to easily slide along the protruding member  400   a.  The height  500  of the protruding member  400   a  may also be designed to push the tape cartridge  104  into the tape library magazine  102  an amount sufficient to engage a latching mechanism  202 . 
         [0037]      FIG. 6B  shows one embodiment of a protruding member  400   b  incorporating a roller  600 . The protruding member  400   b  has a shape similar to the protruding member  400   a  illustrated in  FIG. 6A , although other shapes and forms may be used. The roller  600  may push against a tape cartridge  104  while allowing the tape cartridge  104  to easily move past the protruding member  400   b.    
         [0038]      FIG. 6C  shows a protruding member  400   c  that is similar to the protruding member  400   b  illustrated in  FIG. 6B  except that the protruding member  400   c  incorporates multiple rollers  600 . These additional rollers  600  may further reduce friction between a tape cartridge  104 /tape library magazine  102  and the protruding member  400   c.    
         [0039]      FIG. 6D  shows one embodiment of a protruding member  400   d  that uses a biasing member  602  to press the protruding member  400   d  against a tape cartridge  104 , while also allowing the protruding member  400   d  to deflect away from the tape cartridge  104  and/or tape library magazine  102  when it comes into contact with more rigid structures. The spring-force generated by the biasing member  602  may be designed to overcome the spring force of the tape library magazine  102 , thereby enabling a tape cartridge  104  to be pushed into the tape library magazine  102 . Although the biasing member  602  illustrated in  FIG. 6D  is embodied as a compression spring, the biasing member  602  is not limited to compression springs. For example, the biasing member  602  may be embodied as a torsion spring, leaf spring, elastomeric member, or the like. Similarly, the biasing member  602  may linearly push the protruding member  400   d  against the tape cartridge  104  or the biasing member  602  may cause the protruding member  400   d  to pivot relative to an end (or other point) of the protruding member  400   d,  thereby making the protruding member  400   d  an arm or finger that pushes against the tape cartridge  104 . 
         [0040]      FIG. 6E  shows one embodiment of a protruding member  400   e  that also acts as a biasing member  602 . In the illustrated embodiment, the protruding member  400   e  functions like a leaf spring that pushes against the tape cartridge  104 . The protruding member  400   e  may flex away from the tape cartridge  104  and/or tape library magazine  102  when it comes into contact with more rigid members, such as the latching mechanism  202 . The dotted lines in  FIG. 6E  show the protruding member  400   e  in a compressed/flexed condition. Alternatively, or additionally, the protruding member  400  may be configured to act as a cantilever (i.e., a beam or member fixed at one end) that pushes against a tape cartridge  104  using its own built-in bias. Such a structure may also flex or bend away from more rigid structures. 
         [0041]      FIG. 6F  shows one embodiment of a protruding member  400  embodied as a cam wheel  604  with an off-center axis of rotation. When a tape cartridge  104  rolls along the cam wheel  604 , the cam wheel  604  will push the tape cartridge  104  into the tape library magazine  102  as it rotates. In certain embodiments, the cam wheel  604  is made of or coated with a material that can grip the tape cartridge  104  and cause the cam wheel  604  to rotate. As shown, the cam wheel  604  may, in certain embodiments, be provided within a recess  606  in the channel  106  of the tape library  100 . 
         [0042]    The protruding members  400   a - f  illustrated in  FIGS. 6A through 6F  are provided by way of example and not limitation. Other types of protruding members  400  are possible and within the scope of the invention. For example, it is contemplated that a protruding member  400  in accordance with the invention may be actuated by electrical current, hydraulic pressure, pneumatic pressure, or the like, to push a tape cartridge  104  into a tape library magazine  102  and thereby engage a latching mechanism  202 . 
         [0043]    The apparatus and methods disclosed herein, although described primarily in association with tape library magazines for insertion into tape libraries, may in other embodiments be extended to other types of magazines that carry items and are inserted into various types of devices. For example, the apparatus and methods disclosed herein may be applicable to magazines inserted into vending machines or to tools in a factory that dispense parts. Any type of application that requires positive latching of items within a magazine as the magazine is inserted into a device may utilize the apparatus and methods disclosed herein to ensure such latching. 
         [0044]    The apparatus and methods disclosed herein may be embodied in other specific forms without departing from their spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.