Abstract:
A disk cage assembly into which multiple disk drives may be removably inserted is formed from two separate frames which are identical in shape and design and include complimentary mating features enabling the frames to be joined to form a symmetrical four-sided structure. The frames are symmetrical about a midpoint and are easily manufactured since all interior surfaces are accessible during the manufacturing process. A surface of the frames defines a plurality of channels into which modular disk drives may be inserted. In one embodiment, the frames are designed to accommodate a mid-panel which is securable within the structure and can be used to increase the number modular disk drives which can be disposed therein. The assembly may be formed from a number of different materials, including structural foam which can be used to help absorb vibrations among the disk drives within the assembly.

Description:
FIELD OF THE INVENTION 
     The invention relates to media drives, and, more specifically, to a cage assembly for accommodating multiple drives in a computer system. 
     BACKGROUND OF THE INVENTION 
     Computer systems typically include one or more drives for storage media such as magnetic disks, CD ROM disks or DVD disks. Such drives may accommodate either fixed or removable media. In more sophisticated computer systems, such as server platforms, multiple fixed disk arrays may be utilized to enhance the storage capacity and increase server performance. 
     Most computer manufacturers utilize a modular disk drive design which can be inserted and removed from the computer system. This configuration allows easier system assembly and maintenance, including removal and/or replacement of disk drives. Accordingly, disk drives are typically stacked in the physical housing of the computer system and are usually coupled to the same power and control signal sources. More specifically, computer manufacturers typically locate multiple disk drives within a box or frame-like assembly. Such assemblies require the interior surfaces thereof to have certain features to facilitate insertion and removal of disk drive modules. Unfortunately, a relatively complicated tooling process is required to manufacture the necessary features on the interior surfaces of the structure, often requiring a four-way collapsible core tool. Such manufacturing complexities increase the costs of the components, and, therefore, the costs of the overall computer system. Accordingly, a need exists for an assembly to house multiple disk drives which can be manufactured inexpensively and with simple tools. 
     Further, since many high-end computer systems are custom designed, with the number of disk drives being selectable by the purchaser, the housing or frame into which the disk drives are inserted typically accommodates multiple drives. With more sophisticated machines, large numbers of disk drives may be required, i.e., a dozen or more disk drives. Accordingly, a need exists for not only an assembly which can house multiple disk drives but for an assembly which can be configured with other similar assemblies to accommodate multiples of the maximum number of drives available in each specific assembly. 
     Additionally, current disk drives operate at extremely high RPM disk and are often stacked or adjacent within an assembly. Unfortunately, the motion of the read/write head as it traverses the surface of a spinning disk can cause “rotational vibration error” in adjacent drives. Such errors, induced by rotational vibration of a disk drive, actually diminish the tracking accuracy, and, therefore the data throughput, of the read/write head in adjacent drives. Accordingly, a further need exists for a disk drive assembly in which multiple disk drives may reside and which reduces the effects of unwanted vibrations among adjacent disk drives. 
     SUMMARY OF THE INVENTION 
     The present invention provides a cage-like assembly into which multiple disk drives may be easily inserted and removed. The assembly comprises a symmetrical four-sided box formed from two separate frames which are identical in shape and design and include complimentary mating features to enable joining to form the four-sided cage assembly. The frames can be manufactured, no matter how complex the surface features, since all surfaces are accessible and exposed during the manufacturing process. In one embodiment, the frames and/or the mid-panel may be formed of a structural foam or similar material to help prevent unwanted vibrations among adjacent drives during read/write operations. In another embodiment, the frames include surface features to allow positioning of adjacent assembly so that multiple disk drive banks may be accomplished using relatively few customized parts. In an another embodiment, the frames are L-shaped with one leg longer that another and are designed to receive a panel. The panel, as well as selected ones of the interior surfaces of the frames, include features which allow for removal and/or installation of modular disk drives. 
     According to a first aspect of the invention, an apparatus for accommodating multiple storage medium drives in a computer system comprises a housing formed from a pair of frames, each frame having identical features and dimensions and being symmetrical about a midpoint, each frame further comprising first and second legs joined together; the first leg having a mechanism for enabling attachment of the first leg to the second leg of another frame, the second leg having a mechanism for enabling attachment of the second let to the first leg of another frame, a surface on one of the first and second legs defining at least one channel into which a storage medium drive may be received. In one embodiment, a plurality of channels are defined in the surface of the frame for receiving a plurality of storage medium drives. In another embodiment, a mid-panel is securable within the housing and includes a surface defining a plurality of channels into which a plurality of storage medium drive may be received. In another embodiment, the frames may be made from structural foam to enhance absorption of vibrations within the housing caused by the storage medium drives. 
     According to a second aspect of the invention, a method for manufacturing an assembly for accommodating at least one storage medium drive in a computer system comprising (a) providing a pair of frames, each frame having identical features and dimensions and being symmetrical about a midpoint, each frame further comprising first and second legs joined together; the first leg having a mechanism for enabling attachment of the first leg to the second leg of another frame, the second leg having a mechanism for enabling attachment of the second let to the first leg of another frame, a surface on one of the first and second legs defining at least one channel into which a storage medium drive may be received; (b) attaching the second leg of one frame to the first leg of another frame; and (c) attaching the first leg of said one frame to the second leg of said other frame so as to form a four-sided assembly into which at least one storage medium drive may be received. In one embodiment, the method further comprises removably disposing at least one storage medium drive into the channels defined in the surfaces of the frames. In another embodiment, the method further comprises (d) providing a mid-panel securable within the assembly, the mid-panel having a surface defining at least one channel into which the storage medium drive may be received and (e) securing the mid-panel within the assembly. In yet another embodiment, the method comprises removably disposing at least one storage medium drive into the channels defined in the surfaces of the frames and the mid-panel. 
     According to a third aspect of the invention, an article of manufacture comprises a frame used for forming a housing for at least one storage medium drive, the frame being symmetrical about a midpoint and comprising: first and second legs; means for enabling attachment of the first leg to the second leg of another frame, means for enabling attachment of the second leg to the first leg of said another frame, and a surface on one of the first and second legs defining at least one channel into which a storage medium drive may be received. In one embodiment the frame has a unitary design and is formed of structural foam. 
     According to a fourth aspect of the invention, an apparatus for accommodating at least one storage medium drive in a computer system comprises: a housing formed from a pair of frames, each frame having identical features and dimensions and being symmetrical about a midpoint, each frame further comprising: first and second legs; means for enabling attachment of the first leg to the second leg of the other frame of the pair, means for enabling attachment of the second leg to the first leg of the other frame of the pair, and. means for receiving at least one storage medium drive. In one embodiment the means for receiving at least one storage medium drive comprises one or more channels defined in the surface of one of the first and second legs and into which one or more storage medium drives may be received. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and further advantages of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which: 
     FIG. 1 is a perspective view of a multi-part disk cage assembly in accordance with the present invention; 
     FIG. 2 is an exploded perspective view of the assembly of FIG. 1 illustrating the relationship of the frames, mid-panel and disk drive; 
     FIG. 3 is a perspective view of an L-shaped frame used in the cage assembly of FIG. 1; 
     FIG. 4 is an bottom view of the L-shaped frame of FIG. 3; 
     FIG. 5 is a side view of the L-shaped frame of FIG. 3; 
     FIG. 6 is a top view of the L-shaped frame of FIG. 3; 
     FIG. 7 is a side view of the L-shaped frame of FIG. 3; 
     FIG. 8 is a perspective view of a mid-panel for use inside the disk cage assembly in accordance with the present invention; 
     FIG. 9 is a top view of the mid-panel of FIG. 8; 
     FIG. 10 is a front view of the mid-panel of FIG. 8; 
     FIG. 11 is a side view of the mid-panel of FIG. 8; 
     FIG. 12 is a bottom view of the mid-panel of FIG. 8; 
     FIG. 13 is a perspective view of a multi-part disk cage assembly, without a mid-panel, in accordance with an alternative embodiment of the present invention; and 
     FIG. 14 is a perspective view of an L-shaped frame used in the cage assembly of FIG.  13 . 
    
    
     DETAILED DESCRIPTION 
     Referring to FIGS. 1-2, a disk cage assembly is shown in accordance with an illustrative embodiment of the invention. Assembly  10  comprises a housing  15  and a mid-panel  50  secured within the housing. A modular disk drive  70  is shown, for illustrative purposes only, inserted within assembly  10 . Disk drive assembly  70  is not part of the actual invention. 
     As illustrated in FIG. 2, housing  15  is formed by the joining of two identical, frames  20 A and  20 B, either of which may also be referred to hereafter simply as “frame  20 .” Each frame  20  has substantially identical, shape, features, dimensions and is symmetrical about a midpoint. When joined, frames  20 A and  20 B form the housing  15  into which mid-panel  50  is secured. In the illustrative embodiment, up to six modular disk drives  70  may be inserted into assembly  10 , with three on each side of panel  50 . 
     Referring to FIGS. 3-7, an L-shaped frame  20  is illustrated having a long leg  22  and a short leg  24 . In the illustrative embodiment, frame  20  has a unitary design which may be tooled from a single piece of material. A channel  28  extends along the a surface of long leg  22 . One or more threaded apertures  30  extend through long leg  22  from channel  28  to a surface of long leg  22  on the opposite side. A plurality of projections  26 , each containing a threaded aperture  27 , extend from the free end of long leg  22  to facilitate attachment of long leg  22  to the short leg  24  of a second frame  20 . As shown in FIGS. 1-2 and  4 , the bottom surface of long leg  22  of frame  20  includes a pair of mounting feet  38  having one or more threaded apertures extending through to facilitate mounting of assembly  10  to either a cabinet of a computer system or to other similarly designed assemblies  10 . 
     Short leg  24  of frame  20  includes a lip  29  at the free end thereof into which a plurality of threaded apertures  25  are formed. A plurality of projections  21  extend outward from lip  29 . In the illustrative embodiment, projections  21  have a shape which interlocks in a complimentary mating manner with projections  26  of long leg  22  of a second frame  20 . When threaded apertures  25  of short leg  24  of a first frame  20  and threaded aperture  27  of long leg  22  of a second frame  20  are aligned and secured with a screw or other fastener, the pair of frames  20  together form housing  15  of assembly  10 . A plurality of board mounts  32  extend from a side edge of short leg  24  to facilitate mounting of assembly  10  to a circuit board or backplane within the computer system. 
     The interior surface of short leg  24  of frame  20  includes a plurality of relief features  34  and  36  arranged in an alternating pattern to form a plurality of channels  35  into which modular disks drives  70  may be removably disposed. In the illustrative embodiment, a plurality of three complete channels  35  are defined within the interior surface of short leg  24 . As illustrated, selected edges of features  34  and  36  include one or more pinches  40 , e.g. opposed bumps, which help maintain the modular disk drive  70  in place upon insertion. The features  34  and  36  and the channels  35  defined therein on short short leg  24  of frame  20 , in conjunction with features of mid-panel  50  collectively define, in the illustrative embodiment, three bays, into which modular disk drives  70  may be received and removably disposed. It will be obvious to those reasonably skilled in the art that the size, shape and number of features  34  and  36 , and therefore the number of intermediate channels  35 , as well as the pinches or other features contained thereon, may vary according to the actual size, shape and profile of the modular disk drives  70  which are to be inserted within the drive bays of assembly  10 . For example, features  34  and  36  may be replaced with pairs of brackets or other structures on the surface of leg  24  which do not define channels as in the illustrative embodiment, but define structures into which a modular disk drive may be inserted. 
     In the illustrative embodiment, frames  20  may be manufactured, typically through an injection molding process, from any number of rigid materials including Noryl™, commercially available from General Electric, Plastics Division, Pittsfield, Mass. Other suitable materials from which frames  20  may be manufactured include plexiglass, polycarbonate ABS blends, structural foam, aluminum or cast metal. As explained hereinafter, structural foam has a smooth exterior surface but a randomly cavitated internal core which aids in absorbing vibrations and therefore helps dampen unwanted vibrations among disk drives  70 . Alternatively, frames  20  may be machined from a single piece of rigid material. 
     Referring to FIGS. 8-12, a mid-panel  50  in accordance with the present invention is illustrated. Mid-panel  50 , in the illustrative embodiment, may also have a unitary design and be injection molded from material similar to that from which frames  20  are made. Alternatively, mid-panel  50  may be machined from a single piece of rigid material. Other suitable materials from which mid-panel  50  may be made include natural or synthetic resins. 
     The top and bottom of mid-panel  50  include apertures  56  which, when aligned with threaded apertures  30  facilitate securing mid-panel  50  within the formed housing  15 . The opposing exterior sides of panel  50  include a plurality of features  54 , as illustrated, which collectively define a plurality of channels  52  which in conjunction with channels  35  of frame  20  define a plurality of bays into which disk drives  70  may be inserted. Like the features  34  and  36  of frame  20 , features  54  include along selected edges thereof pinches  55  which help maintain the modular disk drive  70  in place upon insertion. The features  54  may be similar or different to features  34  and  36  on short leg  24  of frame  20 , depending on the exterior configuration and shape of the modular disk drive  70 , however, the channels  52  should be substantially aligned with the channels  35  of frame  20  so the at the modular disk drive  70  will be aligned upon insertion into assembly  10 . 
     Referring to FIGS. 13-14, a disk cage assembly  110  is shown in accordance with an alternative illustrative embodiment of the invention. Assembly  110  comprises a housing  115  formed by the joining of two identical, frames  120 A and  120 B either of which may also be referred to hereafter simply as “frame  120 .” Each frame  120  has substantially identical, shape, features, dimensions and is symmetrical about a midpoint. When joined, frames  120 A and  120 B form the housing  115  into which a modular disk drive  70 . In the illustrative embodiment, up to three modular disk drives  70  may be inserted into assembly  110 . In the alternate embodiment of FIGS. 13-14, the mid-panel  50  has been eliminated and the dimensions of frame  120  adapted accordingly so that modular disk drive  70  may be inserted into channels  135  between long legs  124  of two joined frames  120 . 
     Referring to FIG. 14, a frame  120  is illustrated having a short leg  122  and a long leg  124 . In the illustrative embodiment, frame  120  has a unitary design which may be tooled from a single piece of material, similar to frame  20  as described above. A plurality of projections  126 , each containing a threaded aperture  127 , extend from the free end of short leg  122  to facilitate attachment of short leg  122  to the long leg  124  of a second frame  120 . As shown in FIGS. 13-14, the bottom surface of short leg  122  of frame  120  includes a pair of mounting feet  138  having apertures extending therethrough to facilitate mounting of assembly  110  to either a cabinet of a computer system or to other similarly designed assemblies  110 . 
     Long leg  124  of frame  120  includes a lip  129  at the free end thereof into which a plurality of threaded apertures  125  are formed. A plurality of projections  121  extend outward from lip  129 . In the illustrative embodiment, projections  121  have a shape which interlocks in a complimentary mating manner with projections  126  of the short leg  122  of a second frame  120 . When threaded apertures  125  of long leg  124  of a first frame  120  and threaded aperture  127  of long leg  122  of a second frame  120  are aligned and secured with a screw or other threaded fastener, the pair of frames  120  together form assembly  110 . A plurality of board mounts  132  extend from a side edge of long leg  124  to facilitate mounting of assembly  110  to a circuit board or backplane within the computer system. 
     The interior surface of long leg  124  of frame  120  includes a plurality of relief features  134  and  136  arranged in an alternating pattern to form a plurality of channels  135  into which modular disks drives  70  may be disposed. In the illustrative embodiment, a plurality of three channels  135  are defined within the interior surface of long leg  124 . As illustrated, selected edges of features  134  and  136  include one or more pinches  140 , e.g. opposed bumps, which help maintain the modular disk drive  70  in place upon insertion. As illustrated, selected edges of features  134  and  136  include one or more pinches  140 , e.g. opposed bumps, which help maintain the modular disk drive  70  in place upon insertion. The features  134  and  136  and the channels  135  defined therein on long leg  124  of frame  120 , in conjunction with the same features on the long leg of another frame  120  collectively define, in the illustrative embodiment, three bays, into which modular disk drives  70  may be received and removably disposed. It will be obvious to those reasonably skilled in the art that the size, shape and number of features  134  and  136 , and therefore the number of intermediate channels  135 , as well as the pinches or other features contained thereon, may vary according to the actual size, shape and profile of the modular disk drives  70  which are to be inserted within the drive bags of assembly  110 . In the illustrative embodiment, frames  120  may be manufactured from the same materials and by similar processes as frames  20 , as previously described. 
     It will be obvious to those reasonably skilled in the art that the actual design and shapes of those features along the free edges of legs  122  and  124  of frame  120 , as well legs  22  and  24  of frame  20  may be modified, as well as the techniques for securing the frames to form a housing. For example, in addition to screws or other threaded fasteners, pins, brackets, dowels, adhesive, thermobonding or other techniques may be utilized to secure the two symmetrical frames together to form assembly as essentially described herein. Accordingly, the illustrative embodiment disclosed herein should not be considered limiting. 
     Having described herein illustrative embodiments of the present invention, persons of ordinary skill in the art will appreciate various other features and advantages of the invention apart from those specifically described above. It should therefore be understood that the foregoing is only illustrative of the principles of the invention, and that various modifications and additions can be made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, the appended claims shall not by the particular features which have been shown and described, but shall be construed also to cover any obvious modifications and equivalents thereof.