Abstract:
A manually operable ejector assembly is mounted on the front side of a carrier that supports a hot-pluggable disk drive for removable slidable insertion into a sheet metal cage structure portion of a computer system. The ejector assembly includes a main ejector lever which is pivotally spring-biased in a forward direction outwardly from the front side of the carrier, and is releasably held in a pivotally retracted position by a slide bar member that is spring-biased toward a retaining position in which it overlies a free end of the ejector lever. To remove the carrier from the cage, the slide bar member is slid away from the free ejector lever end, thereby permitting the lever to be spring-driven outwardly to an intermediate open position in which it conveniently forms a pull-handle but does not disconnect the drive from the backplane connector. The lever may be then pivoted further outwardly to exert a mechanically advantaged force on the cage to disconnect the drive from the backplane connector and permit the carrier to be pulled forwardly out of the cage. To reinstall the drive, the carrier is slidingly reinserted into the cage and the lever is pivoted inwardly to its retracted position to reconnect the drive to the backplane connector. As the lever reaches its retracted position it cammingly displaces the slide bar member which then snaps back over the free lever end to releasably hold the lever in its retracted position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to the mounting and support of hard disk drives for computers and, in a preferred embodiment thereof, more particularly relates to apparatus for removably supporting a plurality of hot plug-connected hard disk drives. 
     2. Description of Related Art 
     Hard disk drives for a file server or other type of computer are often mounted, in a vertically or horizontally stacked array, in a rectangular sheet metal “cage” structure which may be disposed within the computer housing or externally thereto. For operational convenience and flexibility, each disk drive is typically “hot plug” connected within the cage. This type of electrical connection permits any of the supported disk drives to be removed and re-installed within the cage without disturbing the operation of the other disk drives. 
     To effect this desirable hot plug connection of each of the disk drives, each disk drive is typically supported on a carrier structure which is slidably and removably insertable into the cage to mate an electrical connector carried on a rear portion of the drive or its carrier structure with a corresponding electrical connector on a back plane circuit board suitably supported at the rear interior side of the cage. Ejector mechanisms are typically associated with the carrier structures and are used to provide a mechanical advantage for the carrier to facilitate the insertion and removal of the carrier. These ejector mechanisms operate by interacting with the cage structure to provide such mechanical advantage, and have been provided in a wide variety of types and configurations. 
     Conventional ejector mechanisms tend to have one or more operational or configurational disadvantages including being relatively complex and cumbersome to use, requiring two-handed operation, being undesirably bulky, and having an at least somewhat counter-intuitive mode of operation. 
     From the foregoing it can be seen that a need exists for an improved pluggable device ejector mechanism that eliminates or at least substantially reduces the above-mentioned problems, limitations and disadvantages typically associated with conventional ejector mechanisms used on hot-pluggable disk drive carrier structures and other pluggable devices. It is to this need that the present invention is directed. 
     SUMMARY OF THE INVENTION 
     In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, a computer system is provided which includes a CPU unit having a microprocessor and a data storage section operative to store data retrievable by the microprocessor. The data storage section includes a housing in which a spced series of data storage devices, illustratively hot-pluggable hard disk drives, are removably supported using specially designed carrier structures upon which the individual disk drives are mounted. 
     Each carrier structure includes a body secured to the hard disk drive and being removably supported in the housing and forwardly withdrawable therefrom. The body has a front end portion which carries a specially designed, manual ejector latch assembly which is operative on the housing to releasably latch the body to the housing and forcibly and releasably couple an electrical connector associated with the disk drive to an electrical connector disposed within a rear portion of the housing. In a preferred embodiment thereof, the ejector latch assembly includes a lever member, a retaining structure, and a spring structure. The lever member is pivotable among three positions—(1) a closed position in which it is closely adjacent the front body portion, (2) an intermediate position in which it is pivoted forwardly beyond its closed position and in a leveraged engagement with the housing, and (3) an open position in which the lever member is pivoted forwardly beyond its intermediate position and out of leveraged engagement with the housing. The retaining structure is operative to releasably retain the lever member in its closed position, and the spring structure is operative to resiliently urge the lever member from its closed position toward its intermediate position. 
     Preferably, the lever member has a first end operative to engage the housing, and a second end. The retaining structure includes a retainer member secured to a free end of a resilient spring arm that resiliently biases the retainer member to a first position in which blocks the second lever member end in a manner holding it in its closed position. The retainer member may be moved to a second position in which it unblocks the second lever member end and permits the lever member spring structure to swing the lever member out to its intermediate position. The lever spring structure representatively includes a bifurcated spring member pivotable with the lever member and having a first arm engageable with the body when the lever member is in its closed position, and a second arm resiliently deflectable by the lever member when it is in its closed position. 
     With the body operatively inserted into the housing and the disk drive electrical connector releasably coupled to its associated housing electrical connector, the lever member is in its closed position and releasably retained in such position by the retainer member. To subsequently remove the disk drive/carrier assembly, the retainer is manually moved from its first position to its second position, thereby permitting the lever member spring structure to force the lever member outwardly from its closed position to its intermediate position in which it defines a convenient, easily graspable pull handle for the assembly. 
     The user then grasps the lever member and forwardly pulls it in a manner pivoting it outwardly to its open position and causing the lever to interact with the housing in a manner forwardly moving the body to uncouple the disk drive connector from its associated housing connector. A further forward pull on the lever member pulls the entire disk drive/carrier assembly out of the housing. 
     To operatively reinsert the disk drive/carrier assembly into the housing, the body, with the lever member in its open position, is simply inserted rearwardly into the housing to a supported position therein and the lever member is manually pivoted from its open position to its closed position to thereby cause the first lever member end to engage the housing and exert a mechanically advantaged forward force thereon which forcibly drives the body rearwardly and couples the disk drive and housing connectors. As the lever member pivotally reaches its closed position, its second end cams the retainer member outwardly to its second position, and then permits the retainer member to snap back to its first position over the second end of the lever member to releasably retain the lever member in its closed position in which it releasably latches the disk drive/carrier assembly in the housing. 
     The ejector latch assembly is of a simple and relatively inexpensive design, can be easily operated with one hand, is quite compact when the lever member is in its closed position closely adjacent the body portion of the assembly, and has an intuitive operational procedure and sequence. While the ejector latch assembly is illustrated and described herein as being utilized in conjunction with a hot-pluggable hard disk drive, it can also be advantageously use in conjunction with a variety or other types of pluggable electronic devices including, for example, circuit boards and CD ROM drives. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram of a representative computer system having incorporated therein a stacked hard disk drive/carrier array supported in a cage structure and embodying principles of the present invention; 
     FIG. 2 is a simplified, partially exploded perspective view of the cage structure and the plurality of disk drive/carrier assemblies operatively supported therein and hot plug-connected to backplane electrical connectors therein, with one of the disk drive/carrier assemblies having been removed from the cage structure; 
     FIG. 3 is an enlarged scale perspective detail view of an inner side portion of one of the vertical side walls of the cage structure; 
     FIG. 4 is an enlarged scale top plan view of the removed disk drive/carrier assembly; 
     FIG. 5 is an enlarged scale bottom plan view of the removed disk drive/carrier assembly; 
     FIG. 6 is an enlarged scale front end elevational view of the removed disk drive/carrier assembly; 
     FIG. 7 is an enlarged scale rear end elevational view of the removed disk drive/carrier assembly; 
     FIG. 8 is an enlarged scale right side elevational view of the removed disk drive/carrier assembly; 
     FIG. 9 is an enlarged scale left side elevational view of the removed disk drive/carrier assembly; 
     FIG. 10 is an enlarged scale exploded top, rear and right side perspective view of the removed disk drive/carrier assembly, with opposite heat sink wall portions of the carrier being pivoted outwardly to their disk drive release positions relative to a base wall portion of the carrier, and portions of the assembly having been removed for purposes of illustrative clarity; 
     FIGS. 11-13 are enlarged scale top, front and left side perspective views of the removed disk drive/carrier assembly, with a latch portion thereof respectively being in closed, partially opened, and fully opened positions thereof; 
     FIGS. 11A-13A are enlarged scale partial cross-sectional views through the removed disk drive/carrier assembly respectively taken along lines  11 A— 11 A,  12 A— 12 A and  13 A— 13 A of FIGS. 11-13; 
     FIG. 14 is an enlarged scale, partially cut away perspective view of part of the carrier portion of the removed assembly and illustrates a fiber optic cable-based LED indicating light transfer structure integrally incorporated into the carrier; 
     FIG. 15 is an enlarged scale partial exploded perspective view of the removed disk drive /carrier assembly and illustrates a heat sink support structure feature thereof; 
     FIG. 16 is an enlarged scale cross-sectional view through one of the cage-supported disk drive/carrier assemblies taken along line  16 — 16  of FIG. 2; 
     FIG. 17 is an enlarged scale front side elevational view of the cage structure and illustrates two of the disk drive/carrier assemblies supported and hot plug-connected therein; and 
     FIG. 18 is an enlarged scale detail view of the dashed circled area “A” in FIG.  17 . 
    
    
     DETAILED DESCRIPTION 
     Schematically illustrated in FIG. 1 is a representative computer system  10 , the components of which are interconnected as shown and include a computer, illustratively in the form of a tower type CPU unit  12 ; a monitor  14 ; a keyboard  16 ; and a pointing device, representatively in the form of a mouse  18 . In addition to various other components disposed therein, the CPU unit  12  has a data storage section, representatively a vertically stacked series of hard disk drives  20 , operative to store data that may be retrieved by a microprocessor  22  within the CPU unit  12 . 
     In the illustrated embodiment of the CPU unit  12 , the vertically stacked series of hard disk drives  20  are removably positioned within a support housing, representatively in the form of a sheet metal cage structure  24  positioned within the outer housing  26  of the CPU unit  12 , using specially designed carrier apparatus embodying principles of the present invention and subsequently described herein. Alternatively, the cage structure  24  could be located externally of the CPU housing  26  within a separate rack housing (not shown). Moreover, while the disk drives  20  have been representatively illustrated as being vertically stacked, they could also be positioned in a horizontally stacked array in which the cage  24  was rotated ninety degrees to one side instead of being vertically oriented. 
     The data storage section of the computer system  10 , with its vertically stacked array of hard disk drives  20  (representatively five in number), is shown in simplified, partially exploded perspective form in FIG.  2 . As illustrated, the sheet metal cage structure  24  functions as a support housing and representatively is of a vertically elongated rectangular configuration, having an open front side  28 , top and bottom walls  30  and  32 , left and right vertical side walls  34  and  36 , and a backplane structure  38  extending along its rear side. Ventilation holes  40  are formed in the top, left and right cage walls  30 , 34  and  36 , and a schematically illustrated fan  42  is operatively disposed behind the backplane structure  38  within the computer housing  26 . During operation of the CPU unit  12 , the fan  42  draws cooling air  44  into the interior of the cage structure  24  through its open front side  28  and its ventilation holes  40 , flows the air  44  along the disk drives  20  supported within the cage  24 , and then discharges the air outwardly through the rear of the cage  24  around the periphery of the backplane structure  38 . 
     The backplane structure  38  has a vertically elongated rectangular configuration, with a front side  46  from which a vertically spaced array of five male electrical connectors  48  (one for each of the five disk drives  20 ) forwardly project. To the left of each of the connectors  48  are three vertically stacked LED indicating lights  50 , 52  and  54 . As later described herein, these indicating lights are used to provide a visual indicia as to the operating state of each of the hard disk drives  20 . 
     Each of the disk drives  20  is supported on a specially designed carrier structure  60  which is used, as later described herein, to removably support the disk drives  20  within the cage  24  in a manner creating a hot plug connection for each drive to one of the backplane connectors  48 . To facilitate the removable support within the cage  24  of each of the carriers, portions  62  of the vertical left and right side walls  34 , 36  of the cage  24  are lanced inwardly to form for each carrier  60  a pair of front and rear guide rail sections  64  on each of the left and right cage side walls  34  and  36  (see FIGS.  3  and  16 - 18 ), with each of the guide rail sections  64  being defined by vertically facing pairs of the lanced-in cage wall portions  62 . For purposes later described herein, directly above each front pair of lanced-in wall portions  62  is an arcuate lanced-in wall portion  66 . 
     Each disk drive  20  (see FIGS. 10 and 15) has a generally rectangular configuration which is elongated in a front-to-rear direction, and further has front and rear end walls  68  and  70 , top and bottom side walls  72  and  74 , and left and right vertical side walls  76  and  78 . In each of the left and right side walls  76 , 78  a pair of threaded mounting holes  80 , 82  are formed near the bottom side of the disk drive respectively adjacent respectively adjacent its front and rear ends A circuit board  84  is operatively mounted on the bottom side of the disk drive  20 , and is electrically coupled thereto. The circuit board  84 , which forms a portion of the overall disk drive structure, has a female SCA connector  86  thereon which is centrally positioned at the rear end wall  70  of the disk drive and is releasably mateable , in a hot-plug manner, with a corresponding one of the backplane connectors  48  (see FIGS. 2 and 16) in response to operative insertion of the disk drive  20  into the cage  24  as later described herein. 
     Structure of the Carriers  60   
     The carrier structures  60  are used to support the hard disk drives  20  for removable sliding insertion into the interior cage  24  to supported operating positions in which the disk drives are releasably hot-plugged to the backplane connectors  48  received in the SCA connectors  86  of the inserted disk drives  20 . Each carrier structure  60  is of a unitary, no loose parts construction comprised of several components that are captively retained on one another so that none of the components can be separated from the structure and become misplaced, lost or easily damaged. 
     More specifically, and with reference now to FIGS. 4-18, each of the disk drive carriers  60  (see, in particular, FIGS. 10,  14  and  15 ) includes a perforated sheet metal bottom or base wall  90 ; left and right metal side wall heat sink structures  92  and  94 ; a molded plastic front bezel structure  96 ; and a molded plastic ejector latch assembly  98 . 
     Base wall  90  has front and rear end edges  100  and  102 , left and right side edges  104  and  106 , and an upturned rear end flange  108  having a rectangular opening  110  therein. For purposes later described herein, at the opposite rear corners of the base wall  90  are upturned rear edge tabs  112 . 
     Each of the left and right metal side wall heat sink structures  92  and  94  extends upwardly from its associated base wall  90  and has a relatively thin rectangular body section  114  which is horizontally elongated in a front-to-rear direction relative to the base wall  90  and is positioned adjacent one of the left and right base wall side edges  104 , 106 . The outer sides of the left and right side body sections  114  have formed thereon vertically spaced pluralities of elongated heat sink fin projections  116  that longitudinally extend in front-to-rear directions. 
     Along the bottom side edge of each of the left and right side walls  92 , 94  is an outwardly projecting mounting flange  118  which is slidingly receivable in the previously mentioned cage guide rail sections  64  to mount the carrier  60  (and thus the disk drive  20  which it supports) within the cage  24 . Front and rear disk drive mounting screws  120 , 122  are captives retained on each of the body sections  114  and extend therethrough from their outer sides to their inner sides  124 . For purposes later described herein, just forwardly of the front mounting screws  120  are a pair of outwardly projecting boss structures  126  formed on the outer sides of the left and right carrier side wall body sections  114 . Additionally, flanges  128 , elongated in a front-to-rear directions, are formed on the top side edges of the body sections  114 . 
     At the rear end of each of the side wall body sections  114  is an inturned tab  130  having a horizontal slot  132  formed therein. Top end portions  112   a  of the upturned base wall rear corner tabs  112  are slidingly received in the slots  132  which are substantially wider in left-to-right directions than the corresponding widths of the top tab end portions  112   a . The side wall body sections  114  have inturned transverse front end portions  114   a  each defined by a vertically spaced series of separated heat sink fins  134  joined at their inner ends by a vertical bar member  136 . 
     Front and rear resilient shock isolation feet  137   a , 137   b  (see FIGS. 5-9) are suitably secured to the underside of each of the side wall body sections  114  and project downwardly beyond its bottom side surface. Feet  137   a , 137   b  have rectangular configurations which are elongated in front-to-rear directions, with the feet  137   a  being positioned adjacent the junctures of the body sections  114  and their associated transverse front end portions, and the feet  137   b  being positioned adjacent the rear ends of the body sections  114 . 
     The molded plastic bezel structure  96  (see FIGS. 5,  6 ,  10  and  14 ) is positioned at the front end of the carrier  60  and has a hollow rectangular central section  138  with an open rear side  140  and a front wall  142  with a rectangular opening  144  therein. A translucent plastic plate member  146  with disk operating icons  148 , 150 , 152  thereon is received in the opening  144 . At the rear side of the central bezel section  138  is a bottom base plate portion  154  of the bezel which is elongated in left and right directions and underlies a front end edge portion of the metal carrier base wall  90 . A spaced series of posts extend upwardly from the bezel base plate portion  154  through corresponding holes in the metal carrier base plate  90  and are heat staked thereto as at  156 . 
     Hollow bosses  158 , 160  (see FIG. 11A) are respectively formed on left and right sides of the central bezel section  138  and are respectively received between the two lowermost heat sink fins  134  on the transverse front end portions  114   a  of the left and right heat sink walls  92 , 94  of the carrier  60 . Shouldered screws  162  extend vertically through the front end portions  114   a ,and the bosses  158 , 160 , and secure the front end portions  114   a  to the bezel  96  for pivotal motion relative thereto about vertical axes extending through the bosses  158 , 160 . 
     The ejector latch assembly  98  (see FIGS. 11-13A) includes an elongated molded plastic ejector lever member  164 ; a molded plastic retainer slide member  166 ; and a molded plastic bifurcated spring member  168 . The ejector lever member  164  has an inner end portion  170  with an inner side recess  172  formed therein, and a generally transverse, rearwardly inturned outer end portion  174  having an outer side notch  176  disposed at its juncture with the balance of the lever member. The retainer slide member  166  is formed integrally with an elongated spring arm structure  178  which, in turn, is formed integrally with a left side of the central bezel section  138  and extends between the two lowermost heat sink fins  134  on the left front corner of the carrier  60 . AS illustrated, the retainer slide member  166  is exposed on a left front side portion of the carrier  60 . 
     The bifurcated spring member  168  has an elongated inner side arm  180 , an elongated outer side arm  182  with a rounded projection  184  at its outer end, and an inner end portion  186  with a notch  188  formed therein. Inner end portions of the ejector lever  164  and the bifurcated spring member  168  are positioned between the two lowermost heat sink fins  134  on a right front corner portion of the carrier  60  and are pivotally secured to such heat sink fins  134  by a vertically extending shouldered screw  190 . The spring member  168  is pivotable relative to the lever member  164  in a manner such that the outer side arm  182  can swing into and out of the lever side recess  172 , and the outer end of the inner side arm  180  is forwardly adjacent the boss  160 . As illustrated, the notched inner end portion  186  of the ejector lever member  164  projects outwardly beyond a right front corner portion of the carrier  60  in a rightward direction. 
     Turning now to FIG. 14, a rearwardly facing exposed optical connector  192  is suitably mounted on the left rear corner of the carrier  60  in a cutout area  194  of the left inturned side wall tab  130 . The connector  192  extends forwardly through the cutout area  194  into a vertically enlarged portion of a horizontally elongated groove  196  formed in the inner side surface  124  of the body section  114  of the left heat sink side wall  92 . Three fiber optic cables  198 , 200 , 202  are operatively coupled at rear ends thereof to the connector  192  and longitudinally extend therefrom through the groove  196  to adjacent its front end near the front end section  114   a  of the left side wall heat sink structure  92 . At this point the fiber optic cables  198 , 200 , 202  turn rightwardly to a location directly behind the open rear side  140  of the central bezel section  138 . The cables then turn forwardly and connect to a lens structure  204  disposed within the interior of the central bezel section  138 . Lens structure  204  has three spaced apart, forwardly projecting sections  206 , 208 , 210  which are respectively associated with the front ends of the fiber optic cables  198 , 200 , 202 . The lens sections  206 , 208 , 210  have front ends which are located behind the plastic plate member  146  and respectively aligned with the drive operating icons  148 , 150 , 152  thereon (see FIG.  6 ). 
     Referring now to FIGS. 10 and 15, each of the carriers  60  also includes a pair of thermally conductive resilient heat transfer interface pad members  212  having horizontally elongated configurations. Pads  212  are adhered to the inner sides  124  of the side wall body sections  114 , with the left pad  212  being mounted over the groove  196  in the left body section  114 . Holes  120   a , 122   a  are formed in the pads  212  to permit passage of the captively retained mounting screws  120 , 122  therethrough. 
     Use and Operation of the Carriers  60   
     The operation, use and various advantages of the disk drive carriers  60  will now be described in detail with initial reference to FIGS. 10 and 11. To ready one of the carriers  60  for operative supporting connection to one of the hard disk drives  20 , the rear ends of the left and right side wall heat sink structures  92 , 94  are pivoted outwardly away from one another and the opposite left and right side edges  104 , 106  of the base wall  90 , as indicated by the arrows  214  in FIG. 10, to thereby increase the distance between the inner side surfaces  124  of the body sections  114 . The two side wall portions  92 , 94  pivot horizontally about the vertical shouldered screws  162  at the front of the carrier  60  (see FIG.  11 A), with the engagement of the rear corner tabs  112  with the inner end surfaces of the tab slots  132  serving to limit the extent of this outward pivoting. 
     The disk drive  20  is then simply placed atop the base wall  90  so that the disk drive threaded mounting holes  80 , 82  are aligned with the front and rear mounting screws  120 , 122  captively retained on the left and right side wall structures  92  and  94 . The side walls  92  and  94  are then pivoted back toward one another to their positions shown in FIGS. 4 and 5 in which they are parallel to the left and right side edges of the base wall  90 . Finally, the mounting screws  120 , 122  are simply screwed into the corresponding opposing disk drive side openings  80  and  82 . 
     This simple procedure securely mounts the disk drive  20  in the carrier  60  in a manner such that the bottom, opposite sides and opposite ends of the mounted disk drive are shielded by portions of the carrier structure against user hand contact with the mounted disk drive, while at the same time providing an appreciable degree of ESD shielding for the disk drive  20 . The completed disk drive/carrier assembly  20 , 60  may then be operatively inserted into the cage  24  (see FIG. 2) as later described herein. 
     When the disk drive/carrier assembly  20 , 60  is subsequently withdrawn from the cage  24 , the removal of the disk drive  20  from its carrier is effected simply by unscrewing the mounting screws  120 , 122  from the disk drive  20 , pivoting the carrier side wall structures  92 , 94  outwardly to their FIG. 10 release positions to facilitate removal of the disk drive, and then simply lifting the now freed disk drive  20  off of the top side of the base wall  90 . 
     As can readily be seen, both the installation of the disk drive  20  on its associated carrier  60 , and the subsequent removal of the disk drive  20  from its carrier  60 , can be carried out without the removal of any portion of the carrier  60  from the balance thereof. This is due to the unique “no loose parts” construction of the carrier  60  in which all of its components are captively carried by the balance of the carrier. Specifically, the front ends of the side wall structures  92 , 94  are captively and movably retained on the bezel  96 , the rear ends of the side wall structures  92 , 94  are captively and movably retained on the base wall  90 , the bezel  96  is captively retained on the base wall  90 , the latch assembly  98  is captively and movably retained on the bezel  96  and the right side wall structure  94 , and the mounting screws  120 , 122  are captively and movably retained on the left and right carrier side wall portions  92  and  94 . In this manner the potential for losing, misplacing or potentially damaging portions of carrier  60  in conjunction with mounting the disk drive on an associated carrier, or removing the disk drive therefrom, is substantially eliminated. 
     Each of the disk drive/carrier assemblies may be operatively installed within the interior of the cage  24  (see FIG. 2) by simply sliding the carrier mounting flanges  118  rearwardly into the appropriate opposing pairs of cage guide rail sections  64  (see FIGS. 3,  16  and  18 ), and then using the carrier&#39;s ejector latch assembly  98  to releasably mate, in a hot-plugged manner, the disk drive&#39;s rear-mounted SCA connector  86  (see FIGS. 10 and 15) with a facing one of the backplane connectors  48  (see FIGS.  2  and  16 ). The operation of the specially designed ejector latch assembly  98  will now be described with reference to FIGS. 11-13A. one of the disk drive/carrier assemblies  20 , 60  is shown in FIGS. 11 and 11A with its ejector latch assembly  98  in its fully closed, locked position to which it is moved, after the carrier  60  is slid into the cage  24 , to mate the disk drive/backplane connector pair  86 , 48  and releasably lock the disk drive/carrier assembly  20 / 60  in its operative position within the cage  24 . As illustrated, with the ejector latch assembly  98  in this position, the ejector lever member  164  longitudinally extends in a left-to-right direction and is compactly positioned closely adjacent the front side of the central bezel section  138 , with the inturned outer end portion  174  of the lever member  164  being received between the lowermost pair of heat sink fins  134  on the left front corner of the carrier  60 . 
     The outer end of the inner side arm  180  of the bifurcated spring member  168  is in abutment with the boss  160 , and the outer side arm  182  is received within the inner side recess  172  of the outer side arm  182 . The outer end projection  184  of the outer side arm  182  is engaging the front side surface of the recess  172  in a manner rearwardly bending the outer side arm  182 , thereby exerting a resilient forward pivotal biasing force on the ejector lever member  164 . The forwardly biased ejector lever member  164  is prevented from forwardly pivoting away from its fully closed position shown in FIGS. 11 and 11A by the retainer slide member  166 , a portion of which forwardly overlies the outer side notch area  176  at the outer end of the lever member  164  and releasably blocks forward pivoting of the lever member  164  relative to the front end of the carrier  60 . As illustrated, the inner or right end  186  of the bifurcated spring member  168 , adjacent the notch  188  therein, is received within an immediately adjacent vertical channel portion  36   a  of the right side wall  36  of the cage  24  (see FIG.  2 ). 
     When it is desired to remove the inserted disk drive/carrier assembly  20 , 60  from the interior of the cage  24 , and unplug the disk drive connector  86  from its associated backplane connector  48 , the user simply moves the retainer slide member  166  leftwardly, as indicated by the arrows  216  in FIGS. 11 and 11A, thereby leftwardly bending the spring arm structure  178  and shifting the retainer slide member  166  out of overlying, blocking engagement with the left end of the ejector lever member  164 . 
     This permits the previously deformed outer side arm  182  to forwardly pivot the ejector lever member  164  out to an intermediate position thereof (see FIGS. 12 and 12A) as indicated by the arrows  218  in FIGS. 12 and 12A. The pivotal movement of the lever member  164  from its fully closed position to its intermediate position does not unplug the disk drive connector  86  from its associated backplane connector  48 , but exposes the juncture of the elongated main lever body and its inturned outer end portion  174  to present a convenient pull handle structure to the user which he may grasp and pull forwardly with one hand. 
     BY manually pulling in a forward direction on the lever member  164  in its intermediate position shown in FIGS. 12 and 12 a , the lever member is forwardly pivoted outwardly to an opened position thereof shown in FIGS. 13 and 13 a . This movement of the lever member  164  to such opened position drives the inner end  186  of the bifurcated spring member  168  rearwardly against the vertical cage channel section  36   a  (see FIG. 13A) to forwardly drive the carrier  60  relative to the cage  24 , as indicated by the arrow  220  in FIG. 13A, to decouple the disk drive connector  86  from its associated backplane connector  48 . A further forward manual pull on the lever member  164  pivots the inner spring member end  186  out of leveraged engagement with the vertical cage channel section  36   a  and pulls the disk drive/carrier assembly  20 , 60  out of the cage  24 . 
     This process is simply reversed to easily and quickly install one of the disk drive/carrier assemblies  20 , 60  in the interior of the cage  24 . Specifically, with the lever member  164  in its fully opened position the carrier mounting flanges  118  (see FIGS. 10,  16  and  18 ) are slid rearwardly into opposing pairs of the cage guide rail structures  64  (see FIGS. 3,  16  and  18 ) until the inner end  186  of the bifurcated spring member  168  is adjacent the vertical channel section  36   a  (see FIG.  13 A). Lever member  164  is then rearwardly pivoted through its FIG. 13A opened position and its FIG. 12A intermediate position to its FIG. 11A locked position. 
     Via the leveraged interaction between the inner end  186  of the bifurcated spring member  168  and the vertical cage channel section  36   a  this drives the disk drive/carrier assembly  20 , 60  further rearwardly relative to the cage  24  to couple the disk drive connector  86  and its associated backplane connector  48  as the lever member  164  is rearwardly pivoted from its FIG. 13A position to its FIG. 12A position. As the lever member  164  is further pivoted from its FIG. 12A position to its FIG. 11A closed position, the lever member  164  engages and rearwardly bends the outer spring side arm  182 , and the curved outer side surface  222  of the lever member outer end portion  174  engages and leftwardly cams the retainer slide member  166  (thus leftwardly bending the spring arm structure  178 ) to permit the lever member end portion  174  to enter the space between the two lowermost heat sink fins  134  on the left front corner of the carrier  60 . upon entry of the lever end portion  174  into this space, the resiliently deformed spring arm structure  178  causes the retainer slide member  166  to snap rightwardly back into the outer end notch  176  of the lever member  164  to releasably retain the lever member  164  in its closed position, shown in FIGS. 11 and 11A, against the forward pivotal biasing force of the resiliently deformed outer side arm  182  of the bifurcated spring member  168 . 
     As can be seen from the foregoing, the overall ejector latch assembly  98  is of a simple, relatively inexpensive construction, and is easily useable with one hand, in a quite intuitive manner, to latch and unlatch the carrier  60  to and from the cage  24  and couple and decouple the connector pair  48 , 86 . The ejector latch assembly  98  in its closed orientation is also quite compact, but opens outwardly to define an easily graspable pull handle structure. While the ejector latch assembly  98  has been illustrated as being associated with a disk drive structure it could be alternatively utilized with a variety of other types of pluggable devices such as, by way of example, circuit boards and CD ROM drives. 
     In addition to its no-loose-parts construction and its improved ejector latch assembly, the carrier  60  is provided with several other advantages over conventionally configured carrier structures used to operatively support disk drives in support housings such as sheet metal cages. One of these additional advantages is the provision of substantially improved dissipation of disk drive operating heat. As will be recalled, the pivotable opposite side wall portions  92 , 94  of the carrier  60  are configured as heat sink structures, having integral fin portions  116 , 134  thereon. When one of the disk drives  20  is supported on its carrier  60  within the cage  24  (see FIG.  2 ), the operation of the fan  42  draws cooling air  44  inwardly through the front carrier fins  134  and along the supported disk drive, and inwardly through the cage ventilation holes  40  along the disk drive  20  and the carrier side wall cooling fins  116  to convectively dissipate disk drive operating heat from the disk drive/carrier assembly  20 , 60 . 
     This convective heat dissipation is very substantially augmented by the provision of the heat conductive thermal interface pad members  212  (see FIGS. 10 and 15) which are compressed between the carrier side wall members  92 , 94  and the facing left and right sides  76 , 78  of the disk drive  20 . The use of these pads  212  substantially increases the conductive heat transfer between the supported disk drive and the heat sink side wall portions  92 , 94  of the carrier  60  to thereby increase the overall disk drive operating heat transfer to the cooling flow of air  44  rearwardly through the interior of the support cage structure  24 . 
     Another advantage of the carrier structure  60  is the manner in which it provides a visual indication of the operational state of the disk drive  20  that it removably supports within the cage  24 . When the disk drive  20  is hot plug-connected to its associated backplane connector  48  within the cage  24 , the circuitry associated with the drive  20  (i.e., the electronics on its underlying circuit board portion  84 ) activates the three LED indicating lights  50 , 52 , 54  leftwardly adjacent the backplane connector  48  (see FIGS. 2 and 14) in accordance with the operational state of the disk drive  20 . When any of the three indicating lights  50 , 52 , 54  is activated, its light output is received by the optical connector  192  on the left rear corner of the carrier  60  and transmitted via the associated one of the three fiber optic cables  198 , 200 , 202  to the lens structure  204  at the front of the carrier  60  and then to the associated one of the three drive operating icons  148 , 150 , 152  via one of the lens sections  206 , 208 , 210  disposed in a central front end portion of the carrier  60 . 
     The unique positioning of the light transmitting elements  200 , 202 , 204  within the interior of the carrier  60 , as opposed to being routed externally along the outer side thereof or on the cage structure  24 , provides this transfer of the LED indicating light signals without increasing the outer spatial envelope of the carrier  60  or adding the complexity of placing the transfer elements on the cage structure. Additionally, due to the use of fiber optic cables as the light transmitting elements, neither the required bends in the elements to accommodate the central placement of the operating icons  148 , 150 , 152  nor the length of the transmitting element runs from the LED lights  50 , 52 , 54  to the operating icons  148 , 150 , 152  appreciably diminishes the light output intensity at the operating icons. 
     Illustratively, the hard disk drives  20  supported by the carriers  60  are high speed drives that operate in the 7,200 RPM to 12,000 RPM rotational speed range. This speed range refers to the rotational speed range of the platter portion of each drive around a rotational axis  224  of the drive (see FIG. 16) which is transverse to the base wall  90  of the carrier  60 . As is well known, this high rotational speed tends to cause self-induced rotational vibration of the drive about the axis  224  as indicated by the double-ended arrow  226  in FIG.  16 . If not suitably controlled, this rotational vibration  226  about the axis  224  can substantially degrade the performance of the supported disk drive  20 . 
     Conventional approaches to controlling this selfinduced operational vibration have included placing resilient vibration absorbing structures between the disk drive and its associated carrier, or simply increasing the size and mass of the carrier to better absorb this operational vibration of the disk drive. Neither of these previously proposed approaches has proven to be entirely satisfactory, the separate resilient shock absorbing system being an additional source of undesirable size, complexity and cost, and the increased size and mass of the carrier undesirably increasing the overall size of the stacked disk drive array. 
     In the specially designed carrier  60 , however, the self-induced rotational vibratory forces of its supported hard disk drive  20  about the axis  224  are very substantially reduced by using the two boss structures  126  on opposite sides of the carrier  60  (see FIGS. 16 and 17) to create on the cage-inserted carrier  60  two oppositely disposed interference fits between the boss structures  126  and the lanced-in carrier side wall portions  66  in response to insertion of the carrier  60  into the cage  24  as previously described herein. 
     These opposite interference fits between the cage  24  and the carrier  60  are offset in a front-to-rear direction relative to the rotational axis  224  of the supported hard disk drive  20 . Preferably, as shown in FIG. 16, such opposed interference fit locations are forwardly offset from the rotational axis  224 , but could alternatively be rearwardly offset therefrom. Because of this offset of the two opposed interference fit locations from the rotational axis  224  it can be seen that the cage  24  serves to strongly impede vibration induced rotation of the disk drive  20  in either direction about the drive&#39;s rotational axis  224 . The bosses  126  can be simply be integral metal portions of the cage side wall sections  92  and  94  or, as indicated in FIG. 16, be partially defined by suitable nonmetallic inserts  126   a  supported in base portions of the bosses  126 . 
     Another potential source of damage to the disk drives  20  arises from what is commonly referred to as non-operational shock damage. This type of shock damage to one of the carrier-supported disk drives  20  can arise when the carrier is removed from the cage  24  and placed on a horizontal work surface such as a table or work bench. For example, if the removed carrier accidentally slips out of a technician&#39;s hand and falls only a short distance onto the surface, or is placed on edge on the surface and then tips over onto the surface, the carrier-supported drive can be damaged from this type of non-operational shock. 
     In previously utilized, relatively low speed disk drives stacked in relatively low density arrangements, the non-operational shock problem was dealt with by placing resilient shock absorbing foot structures on the bottom sides of the drive carriers. Thus, if the carrier fell a short distance or tipped over onto a horizontal support surface, the feed absorbed the resulting non-operational shock and prevented resulting damage to the carrier-supported disk drive. However, with the growing trend toward stacking carrier supported disk drives in increasingly dense arrays, the additional stacking space required by even these small resilient shock-absorbing feet came to be unacceptable, with the result being that many computer manufacturers simply eliminated such feet and relied on labels placed on the disk drives and warning users of the drives to handle them very carefully to avoid non-operational shock damage thereto. 
     In the specially designed carrier  60 , however, the configurations of the disk drive/carrier assemblies  20 , 60  are related to one another in a unique manner permitting the previously described vibration isolation feet  137   a , 137   b  (see FIGS. 5-9,  17  and  18 ) to be placed on the bottom sides of the carriers  60  without appreciably increasing the overall stack height of a stacked array of disk drive/carrier assemblies  20 , 60  within the cage structure  24 . 
     Specifically, as best illustrated in FIG. 18, each disk drive/carrier assembly  20 , 60  is configured in a manner such that the top side edges of the top edge flanges  128  on the left and right carrier side wall structures  92 , 94  are downwardly offset from the top side of the disk drive  20  supported in the carrier  60  to thereby create in the assembly  20 , 60  front-to-rear extending depressed areas  228  (see FIGS. 17 and 18) outwardly adjacent top right and left corner portions of the supported disk drive  20 . 
     These depressed areas  228  define what may be termed nesting areas that downwardly receive the resilient support feet  137   a , 137   b  on the bottom side of the upwardly adjacent carrier  20 . For example, the support feet  137   a , 137   b  on the bottom side of the upper disk drive/carrier assembly  20 , 60   a  shown in FIGS. 17 and 18 downwardly nest in the opposite top corner depressed areas  228  of the lower disk drive/carrier assembly  20 , 60   b , with the bottom sides of the support feet  137   a , 137   b  on the upper disk drive/carrier assembly  20 , 60   a  being downwardly offset from the top side of the top side of the lower disk drive  20 . Thus, in each vertically successive pair of disk drive/carrier assemblies  20 , 60  the resilient shock absorbing feet  137   a , 137   b  in the upper assembly are received and nest within the outer spatial envelope of the lower assembly so that the desirable presence of the shock absorbing feet  137   a , 137   b  does not appreciably increase the stack height of the multi-disk drive array. While this unique nesting of the support feet has been representatively illustrated and described in conjunction with a vertically stacked array of carrier-supported disk drives, it will be readily appreciated that it could also be utilized to advantage in conjunction with a horizontally stacked array of carrier-supported disk drives as well. 
     The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.