Abstract:
Applicants&#39; invention includes an automated data storage system which includes one or more data storage libraries each of which includes one or a plurality of accessors which retrieve data storage media from a plurality of storage slots and deliver that retrieved data storage media to a data storage drive unit, where each of the plurality of accessors includes one or more attachment slots and a plurality of retractable wheels, and a maintenance robot which includes a plurality of wheels and an attachment device which is capable of insertion into, and subsequent removal from, the attachment slot(s) located on each of the accessors. Applicants&#39; invention further includes a method utilizing Applicants&#39; maintenance robot to remove one of Applicants&#39; accessors from a data storage library.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an automated data storage system having one or a plurality of data accessors, and an apparatus and a method to remove one of those data accessors from the automated data storage system. 
     BACKGROUND OF THE INVENTION 
     Automated data storage libraries are known for providing cost effective access to large quantities of stored data. Generally, data storage libraries include a large number of storage slots on which are stored portable data storage media. The typical portable data storage media is a tape cartridge, an optical cartridge, a disk cartridge, and the like. One (or more) accessor typically accesses the data storage media from the storage slots and delivers the accessed media to a data storage drive for reading and/or writing data on the accessed media. Suitable electronics both operate the accessor and operate the data storage drives to transmit and/or receive data from an attached on-line host computer system. 
     In a conventional automated data storage library, the storage slots are arranged in a planar orthogonal arrangement forming a “wall” of storage slots for holding data storage media. The plane may be a flat plane, or may be a cylindrical plane. To double the storage capacity, two “walls” of storage slots may be provided on either side of the accessor. 
     A number of different companies manufacture automated data storage libraries today, each model displaying various different features. One example is the IBM 3494 Data Storage Library. Some of the automated data storage libraries have dual or multiple accessors to provide a level of redundancy, in that, one accessor is the “active” accessor and the other may take over the accessor function and be the active accessor. 
     In many conventional libraries, one of the accessors is always the active accessor, and the other(s) is always spare. For example, in a dual accessor automated data storage library, the active accessor conducts all of the operations to access and move the data storage media, and the other accessor is the spare and is moved out of the active operation area. In other conventional libraries, multiple accessors may share the active operation and no accessors are spare. Occasionally, an accessor may become unavailable, for example, if a component of the accessor must be replaced or repaired. 
     SUMMARY OF THE INVENTION 
     Applicants&#39; invention includes a maintenance robot which can remove from Applicants&#39; automated data storage system an accessor having an attachment slot(s) and retractable wheels. Applicants&#39; maintenance robot includes a frame having a first support member pivotally connected thereto, a plurality of wheels rotatably mounted on said frame, and an attachment device mounted on the first support member. The attachment device is formed such that it can be inserted into, and subsequently removed from the attachment slot(s)located on the accessor. In one embodiment, the attachment device can be raised or lowered. 
     Applicants&#39; invention also includes an automated data storage system. Applicants&#39; automated data storage system includes at least one data storage library which includes a plurality of data storage media stored in a plurality of storage slots and at least one data storage drive for receiving said data storage media and reading and/or writing data thereon. Applicants&#39; automated data storage system further includes a first rail system located within the data storage library, and one or a plurality of accessors for accessing and transporting the stored media between the individual storage slots and the data storage drive. Each these accessors includes a plurality of retractable wheels and an attachment slot(s). Each of these data accessors are moveably disposed on the first rail system. 
     Applicants&#39; automated data storage system further includes a second rail system having a first end and a second end, with the first end located adjacent the first rail system. Applicants&#39; maintenance robot is movably disposed on the second rail system. 
     Applicants&#39; invention further includes a method to remove an accessor from Applicants&#39; automated data storage system. Applicants&#39; method includes the steps of: (i) positioning accessor on the first rail system adjacent the first end of the second rail system, (ii) positioning the maintenance robot on the second rail system adjacent the accessor, (iii) attaching the accessor to the maintenance robot, (iv) retracting the accessor&#39;s wheels, and (v) removing the maintenance robot and the attached accessor from the data storage library. In a separate embodiment, Applicants&#39; method also includes a step wherein the maintenance robot lifts/lowers the attached accessor to completely remove that accessor from the first rail system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood from a reading of the following detailed description taken in conjunction with the drawings in which like reference designators are used to designate like elements, and in which: 
     FIG. 1 a  is a side view of Applicants&#39; data accessor; 
     FIG. 1 b  is a perspective view of the robotic manipulator component of Applicants&#39; data accessor; 
     FIG. 2 is a side view of Applicants&#39; maintenance robot; 
     FIG. 3 a  is a side view of one embodiment of the support member component of Applicants&#39; maintenance robot; 
     FIG. 3 b  is a side view of one embodiment of the engagement rod component of Applicants&#39; maintenance robot; 
     FIG. 4 is a side view of a second embodiment of the support member component of Applicants&#39; maintenance robot; 
     FIG. 5 a  is a top view of Applicants&#39; automated data storage system illustrating the first step in Applicants&#39; method to remove a data accessor from a media storage library; 
     FIG. 5 b  is a top view of Applicants&#39; automated data storage system illustrating the second step in Applicants&#39; method to remove a data accessor from a media storage library; 
     FIG. 5 c  is a top view of Applicants&#39; automated data storage system illustrating the third step in Applicants&#39; method to remove a data accessor from a media storage library; 
     FIG. 5 d  is a top view of Applicants&#39; automated data storage system illustrating the fourth step in Applicants&#39; method to remove a data accessor from a media storage library; 
     FIG. 5 e  is a top view of Applicants&#39; automated data storage system illustrating the fifth step in Applicants&#39; method to remove a data accessor from a media storage library; and 
     FIG. 5 f  is a top view of Applicants&#39; automated data storage system illustrating the sixth step in Applicants&#39; method to remove a data accessor from a media storage library. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning to FIG. 1 a,  accessor  10  includes rectangular frame  16  which has first end  18 , second end  20 , top side  60 , and bottom side  62 . Applicants use the terms “top” and “bottom” for descriptive purposes only, and those terms should not be construed as limiting. Attachment slots  50  and  52  are internally disposed within frame  16  and extend outwardly to communicate with the surface of frame  16 . In the embodiment shown in FIG. 1 a , slots  50  and  52  have a rectangular cross section. In other embodiments, slots  50  and  52  have a circular, ovoid, triangular, square, trapezoidal, pentagonal, or hexagonal cross section. Slots  50  and  52  may have the same shape and size, or may have differing shapes and sizes. 
     Pillar  42  has a first end  40  and a second end  46 . First end  40  connects to bottom side  62  of frame  16  by way of an adhesive joint, a welded joint, metal screws, nuts and bolts, and the like. Wheel assembly  48  is rotatably disposed on second end  46 . Motor  90  is disposed adjacent second end  46  and connects to wheel assembly  48 . Operation of motor  90  in a first direction causes wheel  48  to rotate in a first direction. Operation of motor  90  in a second direction, i.e. the other direction, causes wheel  48  to rotate in a second direction. 
     Accessing mechanism  44  is movably disposed on pillar  42  such that accessing mechanism  44  travels bi-directionally along pillar  42  between first end  40  and second end  46 . FIG. 1 b  shows accessing mechanism  44  is greater detail. Robotic manipulator  49  is mounted on carriage  47  which can move vertically along pillar  42 . 
     Referring again to FIG. 1 a,  a first wheel assembly is disposed adjacent first end  18  of frame  16  such that guide wheel  22  is disposed above top surface  60 . The first wheel assembly comprises guide wheel  22 , retractable support  24 , power lead screw  26 , and gear motor  28 . Gear motor  28  is disposed on bottom side  62  of frame  16  adjacent first end  18 . One end of power lead screw  26  connects to gear motor  28  and the other end extends through frame  16  and connects to retractable support  24 . Retractable support  24  is disposed between power lead screw  26  and wheel  22 , such that retractable support  24  can be partially retracted into frame  16 . 
     Similarly, a second wheel assembly is disposed adjacent second end  20  of frame  16  such that guide wheel  30  is disposed above top surface  60 . The second wheel assembly comprises guide wheel  30 , retractable support  32 , power lead screw  34 , and gear motor  36 . Gear motor  36  is disposed on bottom side  62  of frame  16  adjacent second end  20 . One end of power lead screw  34  connects to gear motor  36  and the other end extends through frame  16  and connects to retractable support  32 . Retractable support  32  is disposed between power lead screw  34  and wheel  30 , such that retractable support  32  can be partially retracted into frame  16 . 
     Causing gear motor  28  to turn in a first direction causes wheel  22  to move in a first direction. Causing gear motor  28  to turn in a second direction, i.e. opposite to the first direction, causes wheel  22  to move in the opposite direction. Similarly, activation of gear motor  36  causes wheel  30  to move either upwardly or downwardly. 
     FIG. 2 shows maintenance robot  100 . Robot  100  includes frame  101  which is formed from top member  108 , bottom member  114 , first side member  116 , and second side member  106 . Applicants use the terms “top” and “bottom” for descriptive purposes only, and those terms should not be construed as limiting. First side member connects to first end  110  of top member  108  and to first end  117  of bottom member  114 . Second side member  106  connects to second end  112  of top member  108  and to second end  118  of bottom member  114 . The connections between top member  108 , bottom member  114 , first side member  116 , and second side member  106  may be formed by welding, mechanical attachments such as metal screws and/or nuts/bolts, adhesive joining, and the like. Top member  108 , bottom member  114 , first side member  116  and second side member  106  may be formed from any rigid material including metal, plastic, wood, and combinations thereof. In preferred embodiments, these members are formed from aluminum or stainless steel. In a most preferred embodiment, these members are formed of Stainless Steel Type-304. 
     First wheel  120  is rotatably disposed on top member  108  adjacent first end  110 . Second wheel  122  is rotatably disposed on bottom member  114  adjacent first end  117 . Third wheel  124  is rotatably disposed on top member  108  adjacent second end  112 . Fourth wheel  126  is rotatably disposed on bottom member  114  adjacent second end  118 . 
     First support member  130  has distal end  134  and proximal end  132 . Proximal end  132  is pivotably connected to top member  108  adjacent first end  110  such that first support member  130  can be rotated between a first position and a second position. In the first position, first support member  130  is folded against frame  101  such that first member  130  is parallel to, and adjacent, top member  108 . In the second position, first support member  130  has been rotated  90  degrees outwardly from frame  101  such that first support member  130  is substantially perpendicular to top member  108 . By substantially perpendicular, Applicants mean the angle formed by first support member  130  and top member  108  is about 90 degrees, plus or minus about 10 degrees. 
     Second support member  136  has top end  138  and bottom end  140 . Top end  138  connects to distal end  134  of first support member  130  using the attachment methods described above. Bottom end  140  is pivotably attached to first side member  116 . 
     An attachment device is disposed on first support member  130 . In the embodiment shown in FIG. 2, this attachment device comprises engaging rod  150  and engaging rod  156 . Engaging rod  150  has proximal end  152  and distal end  154 . Proximal end  152  is attached to first support member  130  such that distal end  154  extends outwardly from first support member  130  and away from frame  101 . Similarly, engaging rod  156  has proximal end  158  and distal end  160 . Proximal end  158  is attached to first support member  130  such that distal end  160  extends outwardly from first support member  130  and away from frame  101 . 
     Robot  100  is disposed between parallel rails  102  and  104  such that wheels  120  and  124  are movably disposed on rail  102  and wheels  122  and  126  are movably disposed on rail  104 . Motor  170  is disposed on bottom member  114  adjacent end  118 . External shaft  172  extends outwardly from distal end  171  of motor  170  and connects to wheel  126 . Causing motor  170  to rotate in a first direction causes wheel  126  to rotate in a first direction which causes frame  101  to move along rails  102  and  104  in a first direction. Causing first motor  170  to operate in the opposite direction thereby causes wheel  126  to rotate in a second direction which causes frame  101  to move along rails  102 / 104  in the second, i.e. opposite, direction. 
     Referring to FIG. 3 a , first support member  200  is pivotably connected to top member  108  of frame  101  (FIG.  2 ). Motor  202  is disposed on top member  108  adjacent end  110 . External rotatable shaft  206  extends outwardly from distal end  203  of motor  202 . Pivot gear  208  is disposed on first support member  200  adjacent end  205 . The distal portion of shaft  206  slidingly interconnects with pivot gear  208  such that rotation of shaft  206  in a first direction causes first support member  200  to rotate outwardly from frame  101 . Pivot gear  208  limits the outward rotation of first support member  200  to a second position wherein first support member  200  is substantially perpendicular to frame  101 . By substantially perpendicular, Applicants mean first the angle formed between first support member  200  and frame  101  is about 90 degrees, plus or minus about 10 degrees. Rotation of pivot gear  208  in a second direction, i.e. opposite from the first direction, causes first support member  200  to pivot inwardly toward frame  101 . Pivot gear  208  limits the inward rotation of first support member  200  to a first position wherein first support member  200  is adjacent to and parallel to top member  108 . In this first position, side  201  of first support member  200  faces away from top member  108 . 
     Motor  220  and rotatable gear  222  are disposed on side  201  of first support member  200 . Engaging rod  224  is mounted in an off-axis configuration to gear  222 . Gear  222  intermeshes with motor  220 , such that operation of motor  220  causes gear  222  to rotate 180 degrees between a first position (shown in FIG. 3 a ) wherein engaging rod  224  is disposed at the bottom of gear  222 , and a second position wherein engaging rod  222  is disposed at the top of gear  222  (not shown in FIG. 3 a ). 
     Similarly, motor  230  and rotatable gear  232  are disposed on side  201  of first support member  130  outwardly of motor  220 /gear  222 . Engaging rod  234  is mounted in an off-axis configuration to gear  232 . Gear  232  intermeshes with motor  230 , such that operation of motor  230  causes gear  232  to rotate 180 degrees between a first position (shown in FIG. 3 a ) wherein engaging rod  234  is disposed at the bottom of gear  232 , and a second position wherein engaging rod  232  is disposed at the top of gear  232  (not shown in FIG. 3 a ). 
     In the embodiment shown in FIG. 3 a , engagement rods  224  and  234  have a circular cross section. In other embodiments of Applicants&#39; invention, engagement rods  224  and  234  have an ovoid, triangular, square, trapezoidal, pentagonal, or hexagonal cross section. Engagement rod  224  may have the same cross section as does engagement rod  234 . In the alternative, engagement rods  224  and  234  may have differing cross sections. Referring to the embodiment shown in FIG. 3 b , engagement rod  224  is circular and has a proximal portion  226  having a first diameter d 1 , a middle portion  228  having a second diameter d 2 , and distal portion  232  having a third diameter d 3 . Notch  240  is disposed in middle portion  228  such that d 2  is smaller than either d 1  or d 3 . First diameter d 1  may equal third diameter d 3 , or d 1  may be either greater than or less than d 3 . Regardless of the cross section shape, i.e. square, rectangular, oval, ovoid, trapezoidal, pentagonal, or hexagonal, distance d 2  is shorter than either d 1  or d 3 . 
     In the embodiment shown in FIG. 4, proximal end  302  of first support member  300  is pivotably attached to top member  108 . Motor  330  is disposed on top member  108  adjacent end  110 . External rotatable shaft  332  extends outwardly from distal end  331  of motor  330 . Pivot gear  334  limits the outward rotation of first support member  300  to a second position wherein first support member  300  is substantially perpendicular to frame  101 . By substantially perpendicular, Applicants mean first the angle formed between first support member  300  and frame  101  is about 90 degrees, plus or minus about 10 degrees. Rotation of pivot gear  334  in a second direction, i.e. opposite from the first direction, causes first support member  300  to pivot inwardly toward frame  101 . Pivot gear  334  limits the inward rotation of first support member  300  to a first position wherein first support member  300  is adjacent to and parallel to top member  108 . In this first position, side  301  of first support member  300  faces away from top member  130 . 
     Vertically-movable member  312  is internally disposed within support member  300  such that outer surface  313  is contiguous with side  301  of member  300 . Although vertically-movable member  312  is shown having a trapezoidal shape in FIG.  4 . In other embodiments, vertically movable member  312  can have a square or rectangular shape. 
     Engagement rod  314  is disposed on side  313  of vertically-movable member  300 . Although engagement rod  314  is shown in FIG. 4 having a circular cross section, engagement rod  314  can also have a triangular, square, rectangular, pentagonal, or hexagonal cross section. In other embodiments of Applicants&#39; invention, engagement rod  314  may have a notched structure as shown in FIG. 3 b.    
     Motor  310  is disposed on the bottom of member  300  and connects to vertically-movable member  312 . Operation of motor  310  in one direction raises engagement rod  314  while operation of motor  310  in the opposite direction lowers engagement rod  314 . 
     Vertically-movable member  322  is internally disposed within support member  300  such that outer surface  323  is continuous with side  301 . Although vertically-movable member  322  is shown having a trapezoidal shape in FIG.  4 . In other embodiments, vertically movable member  322  can have a square or rectangular shape. 
     Engagement rod  324  is disposed on side  313  of vertically-movable member  300 . Although engagement rod  324  is shown in FIG. 4 having a circular cross section, engagement rod  324  can also have a triangular, square, rectangular, pentagonal, or hexagonal cross section. In other embodiments of Applicants&#39; invention, engagement rod  324  may have a notched structure as shown in FIG. 3 b.    
     Motor  320  is disposed on the bottom of member  300  and connects to vertically-movable member  322 . Operation of motor  320  in one direction raises engagement rod  324 , while operation of motor  320  in the opposite direction lowers engagement rod  324 . 
     The embodiment shown in FIG. 4 includes two engagement rods, namely rods  314  and  324 . In other embodiments, a single engagement rod or a plurality of engagement rods are used. In the embodiment shown in FIG. 4, engagement rods  314  and  324  have a similar size and shape. In other embodiments, the one or plurality of engagement rods used may have differing sizes and shapes. 
     FIG. 5 illustrates an embodiment of Applicants&#39; invention wherein a maintenance robot, formed as described above, removes an accessor, formed as described above, from a media storage library. FIGS. 5 a  through  5   f  illustrate the steps of Applicants&#39; method wherein maintenance robot  420  approaches accessor  406 , rotates support member  424  outwardly, attaches accessor  406  to support member  424 , rotates support member  424  inwardly, and carries accessor out of library  402 . Removal of an accessor may be required for a number of purposes, including routine maintenance, repair, and/or modification. 
     Referring to FIG. 5 a,  automated data storage system  400  is shown including media storage library  402  and maintenance bay  408 . Media storage library  402  includes a plurality of media storage slots  450  and  452  in which are stored a plurality of portable data storage media. Media storage library  402  further includes one or a plurality of data storage drives, such as drives  440  and  442 , for reading and/or writing data on the accessed media. 
     Rail system  404  is internally disposed within library  402 . In a preferred embodiment, rail system  404  includes two parallel rails. Rail system  410  is disposed internally within maintenance bay  408 , and has first end  412  and second end  414 . In a preferred embodiment, rail system  410  includes two parallel rails. 
     First end  412  of rail system  410  is disposed adjacent to, and substantially perpendicular with, rail system  404 . By substantially perpendicular with, Applicants mean the angle formed between rail system  404  and first end  412  of rail system  410  is about 90 degrees, plus or minus about 10 degrees. 
     Accessor  406  is movably disposed on rail system  404 , and travels bi-directionally along rail system  404  in the +/−Y direction. Accessor  406  is formed as described above, and as shown in FIG. 1 a.  Maintenance robot  420  is formed as described above and as shown in FIG. 2, and comprises frame  422  with pivotable support member  424  disposed thereon. Maintenance robot  420  is movably disposed on rail system  410  and travels bi-directionally along rail system  410  in the +/−X direction. 
     In FIG. 5 a  support member  424  is disposed in a first position wherein member  424  is adjacent to, and parallel to, frame  422 . In addition, maintenance robot  420  is shown disposed adjacent second end  414  of rail system  410 . 
     Referring now to FIG. 5 b , accessor  406  is positioned adjacent end  412  of rail system  410 , and maintenance robot  420  is positioned adjacent end  412  and adjacent accessor  406 . In the next step as shown in FIG. 5 c,  support member  424  is rotated outwardly from frame  422  until substantially perpendicular to frame  422 . “Substantially perpendicular” has the meaning recited above. For purposes of clarity, rail system  410  is not shown in FIGS. 5 c-   5   f.  As shown in FIG. 5 c,  engagement rods  430  and  432  are disposed on the surface of support member  424  having a facing relationship with accessor  406 . 
     As shown in FIG. 5 d,  robot  420  is next moved on rail system  410  (not shown in FIG,  5   d ) to insert engagement rods  430  and  432  into slots  50  (FIG. 1 a ) and  52  (FIG. 1 a ) disposed on accessor  406 . Referring now to FIG. 1 a , motors  28  and  36  are activated to retract wheels  22  and  30  from rail system  404 . Engagement rods  430  and  432  are then raised (or lowered depending on the orientation of accessor  406 ) to remove wheel  48  (FIG. 1 a ) from rail system  404 . 
     Referring to the embodiment shown in FIG. 3 a , motors  220  and  230  are activated and rotated in such a manner to either raise or lower engagement rods  224  and  234 , thereby raising or lowering accessor  406 , as required to remove wheel  406  from rail system  404 . Referring to the embodiment shown in FIG. 4, motors  310  and  320  are activated and operated in such a manner to either raise or lower engagement rods  314  and  324 , thereby raising or lowering accessor  406 , as required to remove wheel  48  from rail system  404 . 
     After retracting wheels  22  and  30 , and moving wheel  48 , accessor  406  is no longer disposed on rail system  404 . Rather, accessor  406  is now removably attached to maintenance robot  420 . 
     Referring now to FIG. 5 e,  support member  424  is rotated inwardly such that support member  424 , which now carries accessor  406 , returns to its first position, i.e. adjacent to and parallel to frame  422 . Referring to FIG. 5 f,  robot  420 , and the attached accessor  406 , are next moved to end  414  of rail system  410 , and thereby, out of library  402 .