Abstract:
An EMI-efficient system for mounting internal peripheral devices such as disk or tape drives inside a computer enclosure so that the drives may be removed and replaced easily. A drive bracket guide is mounted to a computer enclosure chassis, a peripheral device is mounted to a drive bracket, and the drive bracket is inserted into an opening of the drive bracket guide. A socket support disposed at the end of the bracket guide opposite the opening fixedly supports a socket in position for receiving a mating socket on the drive. A locking insertion/ejection mechanism is coupled to the bracket and facilitates engagement/disengagement of the two sockets in the rear of the assembly. The bracket guide may be integrally formed on side walls of a drive cage to reduce potential for leaks of electromagnetic energy from the enclosure and to facilitate the creation of numerous bracket guides in a stack arrangement for housing multiple drives.

Description:
FIELD OF THE INVENTION 
     This invention relates to methods and apparatus for mounting internal peripheral devices inside a computer enclosure. More particularly, the invention relates to an EMI-efficient technique that facilitates easy removal and replacement of such internal peripheral devices. 
     BACKGROUND 
     One common method for mounting internal peripheral devices such as disk or tape drives inside a computer enclosure has been to fasten the drive directly to the enclosure chassis or to an appendage thereof, and to manually couple a ribbon cable between the drive and the drive&#39;s controller subsystem. This method may work satisfactorily for computers wherein only one or two drives are needed and wherein the drives are to be permanently housed within the enclosure of the computer. In many modern applications, however, a need exists to house as many as four or more drives in a single enclosure. Furthermore, a need exists to be able to remove and replace the drives easily and frequently, and to do so without introducing enclosure features that allow significant electromagnetic energy to escape from the computer. 
     It is therefore an object of this invention to provide a mechanism for mounting multiple drives inside a computer enclosure in a manner that makes it quick and easy to remove and replace the individual drives. 
     It is a further object of this invention to provide such a mechanism without introducing features to the computer&#39;s enclosure that would allow significant escape of electromagnetic energy from the computer. 
     SUMMARY OF THE INVENTION 
     The invention includes numerous aspects, each of which contributes to achieving these and other objectives. 
     In one aspect, a drive bracket guide is mounted to a computer enclosure chassis, a peripheral device is mounted to a drive bracket, and the drive bracket is then inserted into an opening of the drive bracket guide. A socket support disposed at the end of the drive bracket guide opposite the opening fixedly supports a socket in a position suitable for receiving a mating socket on the drive. The drive bracket and the drive bracket guide cooperate to put the two mating sockets into proper alignment so that insertion of the bracket into the guide causes the sockets to connect with one another automatically, thus obviating the need for manual attachment of a ribbon cable each time a drive is installed. 
     In another aspect, the drive bracket may be equipped with a locking insertion/ejection mechanism that further facilitates installation and removal of the drive bracket. The insertion/ejection mechanism is rotatably coupled to the drive bracket at a point of rotation. It includes a first prong disposed on one side of the point of rotation and a lever disposed on the other side of the point of rotation. The insertion/ejection mechanism is capable of being placed in an open and a closed position. The first prong, the lever and the point of rotation are disposed so that the first prong passes at least partially through the plane of a flange on the drive bracket guide when the drive bracket is inserted into the guide while the lever is in the open position. After the bracket has been so inserted, the first prong engages a back surface of the flange when the lever is then rotated from the open position into the closed position. The engagement of the first prong with the back surface of the flange and the rotation of the lever into the closed position tend to urge the drive bracket further into the drive bracket guide, thus facilitating the mating of the two sockets at the rear of the assembly. 
     In another aspect, the insertion/ejection mechanism includes a second prong adjacent to the first prong. The second prong is disposed so that it does not pass through the plane of the flange when the drive bracket is inserted into the bracket guide while the lever is in the open position. Rather, the second prong remains adjacent to a front surface of the flange when the lever is rotated into the closed position. When the lever is rotated from the closed position back into the open position, the second prong engages the front surface of the flange. The engagement of the second prong with the front surface of the flange and the rotation of the lever into the open position tends to urge the drive bracket out of the drive bracket guide, thus facilitating disconnection of the two sockets in the rear of the assembly and easing removal of the bracket from the bracket guide. 
     In another aspect, the lever of the insertion/ejection mechanism may be spring biased toward the open position, and the mechanism may be equipped with a locking feature. A resilient standoff member is mounted to the drive bracket at one end and has a catch formed at its other end. The lever of the insertion/ejection mechanism has a hole formed therein for lockingly receiving the catch when the lever is rotated into the closed position. When it is desired to remove the bracket from the guide, the resilient standoff member is moved to one side, allowing the catch to release. 
     In yet a further aspect, the drive bracket guide may be integrally formed on side walls of a drive cage. In such an embodiment, not only is the potential for electromagnetic energy leakage diminished, but also numerous bracket guides may be formed in a stack arrangement along the side walls of the cage. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a an isometric view of a drive mounting system according to a preferred embodiment of the invention. 
     FIG. 2 is an isometric view of the drive cage of FIG.  1 . 
     FIG. 3 is a front orthogonal view of the drive cage of FIG.  1 . 
     FIG. 4 Is a side orthogonal view of the drive cage of FIG.  1 . 
     FIG. 5 is an isometric view of the drive cage of FIG. 1 after having electrical sockets installed therein. 
     FIG. 6 is an isometric view of one of the drive brackets of FIG. 1 illustrating preferred installation of a drive therein. 
     FIG. 7 is an isometric view of the drive bracket of FIG. 6 with the drive removed. 
     FIGS. 8 and 9 are side and front orthogonal views, respectively, of the drive bracket of FIG.  7 . 
     FIGS. 10 and 11 are top orthogonal and isometric views, respectively, of the rotating member of one of the insertion/ejection mechanisms of FIG.  1 . 
     FIG. 12 is a top orthogonal view of the lever lock of one of the insertion/ejection mechanisms of FIG.  1 . 
     FIGS. 13 and 14 are back and front isometric views, respectively, of the lever lock of FIG.  12 . 
     FIG. 15 is an exploded isometric view illustrating the installation of the rotating member of FIG. 10 into the drive bracket of FIG.  7 . 
     FIG. 16 is an exploded isometric view illustrating the installation of the lever lock of FIG. 12 into the drive bracket of FIG.  7 . 
     FIG. 17 is a sectional view illustrating the completed installation indicated in FIG.  16 . 
     FIG. 18 is an isometric view of the spring of one of the insertion/ejection mechanisms of FIG.  1 . 
     FIG. 19 is an isometric view illustrating the installation of the spring of FIG. 18 into the insertion/ejection mechanism. 
     FIGS. 20 and 21 are front and top orthogonal views, respectively, illustrating the insertion/ejection mechanism in its closed position and the drive bracket installed within the drive cage. 
     FIGS. 22 and 23 are front and top orthogonal views, respectively, illustrating the insertion/ejection mechanism in its open position, and the drive bracket in the process of being install or removed from the drive cage. 
     FIGS. 24 and 25 are front and side orthogonal views, respectively, illustrating a preferred stacked arrangement of and EMI seal between the drive brackets when they are installed in the drive cage. 
     FIG. 26 is a sectional close-up view of the EMI seal illustrated in FIG.  25 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Drive Mounting System. FIG. 1 illustrates a drive mounting system  100  according to a preferred embodiment of the invention. Drive mounting system  100  includes a drive cage  102  and one or more drive brackets  104 . Each drive bracket  104  includes a locking insertion/ejection mechanism  106 . 
     Drive Cage. Drive cage  102  will now be described in detail with reference to FIGS. 2-5. Drive cage  102  is constructed using a conductive material such as steel and is adapted to be mounted to the chassis of a computer enclosure by conventional means such as rivets, screws or bolts. Preferably, drive cage  102  will be mounted to the chassis in such a manner that front portion  400  will be easily accessible after any external cosmetic enclosure components are swung out of the way or removed. Drive bay  102  includes bottom wall  216 , right and left side walls  200 ,  201 , a rear wall  300 , and a top portion  304 . In the embodiment shown, top portion  304  is an additional drive bay; in other embodiments, a top wall may be substituted for the additional drive bay and placed across drive cage  102  at height  306 . In either embodiment, drive cage  102  acts as a partial shield against leakage of electromagnetic energy from the computer enclosure in the area defined by front portion  400 . Moreover, because drive cage  102  includes a conductive wall on each of its interior sides, it is able to perform this electromagnetic interference (“EMI”) shielding function even when drive cage  102  is not populated with drive brackets. 
     In the embodiment shown, deformations are created in side walls  200 ,  201  to create four stacked drive bracket guides  218  disposed below top portion  304 . Drive bracket guides  218  include top guide protrusions  202  and bottom guide protrusions  204 . Together, top and bottom guide protrusions  202 ,  204  define a channel  206  through which an outer rail  604  of a drive bracket  104  may pass. The height of channel  206  should be just large enough to clear outer rail  604  of the drive bracket  104  so that protrusions  202 ,  204  will not only support bracket  104  but will also help to provide vertical alignment for bracket  104  within channel  206 . Likewise, the inside distance between right and left walls  200 ,  201  should be just large enough to clear the width of bracket  104  so that horizontal alignment is also provided. 
     Insertion stops  208  protrude into channel  206  to prevent bracket  104  from being inserted too deeply within drive cage  102 . When bracket  104  has been completely inserted, insertion stops  208  will engage notches  605  of bracket  104 , thus preventing further insertion. The hooked shape of insertion stops  208  enables them to engage the inner surface of outer rails  604  and thus retain outer rails  604  against right and left walls  200 ,  201  of drive cage  102 , providing additional horizontal alignment. Misinsertion stops  210  protrude into drive cage  102  above channel  206  so that, if bracket  104  is inserted too high, complete insertion will not be possible. (Misinsertion stops  210  will engage notches  605  and prevent further insertion.) In alternative embodiments, misinsertion stops  210  may be placed below channels  206 . In the embodiment shown, however, the function of bottom guide protrusions  204  is provided by bottom wall  216  for the bottom-most bracket guide in the stack; therefore misinsertion stops  210  are positioned above, not below, each of channels  206 . 
     Rear wall  300  includes a socket support  302  for each bracket guide  218 . In the embodiment shown, socket support  302  is the periphery of a hole in rear wall  300 . Preferably, a printed circuit board assembly having sockets  500  electrically connected to it is mounted to rear wall  300  by conventional means, such as by standoffs and screws or bolts. The mounting of the printed circuit assembly and the location of socket support  302  must be designed so that each socket  500  is accessible through the interior of drive cage  102  and will be aligned with a mating socket  613  when drive bracket  104  is inserted. 
     A flange  214  is formed along the front edge of left wall  201  of drive cage  102 . Clearance slots  212  are formed in flange  214  and in the front-most portion of wall  201 , as shown. The function of clearance slots  212  will be described in more detail below in the context of discussing insertion/ejection mechanism  106 . 
     Drive Bracket. Drive bracket  104  will now be described in detail with reference to FIGS. 6-9. Drive bracket  104  is constructed using a conductive material such as steel and may be formed from a single piece by folding. 
     Front panel  616  extends upward from frame  602  and includes an EMI flange  619  having a longitudinal recess  621  formed therein. A metallized fabric EMI gasket  618  is glued or otherwise fixed along recess  621 , as shown. Outer rails  604  extend upward along the outside length of frame  602  from front to back. Inner rails  606  extend upward along the inside length of frame  602 , substantially parallel with outer rails  604 . Each of outer rails  604  includes two screwdriver clearance holes  609 . Each of insides rails  606  includes two grommet retainer holes  608 . In the embodiment shown, grommet retainer holes  608  are open at the top to facilitate installation of rubber isolation grommets  610 . In other embodiments, the holes may be formed with no gaps, and the grommets may be inserted through the holes themselves. Each outer rail  604  has a rearward-opening notch  605  formed therein, for engaging insertions stops  208  and misinsertion stops  210  in drive cage  102 . A shoulder  614  is formed approximately midway down the length of each of outer rails  604 . Each shoulder  614  includes placeholder holes for storing disk mounting screws  612  when the screws are not in use. 
     Conductive fingers  620  are disposed at each side of front panel  616 . Each conductive finger  620  is bent slightly outward to enhance electrical contact between drive bracket  104  and drive cage  102  when drive bracket  104  is inserted into drive cage  102 . Each set of conductive fingers  620  creates an EMI gasket. 
     Two clearance slots  706  are formed at the corner of front panel  616  and side portion  623 , as shown. Clearance slots  706  are for receiving lever  1006  of insertion/ejection mechanism  106  (to be further described below). Holes  700 ,  702  and  704  are formed in front panel  616  for receiving lever lock  1200  of insertion/ejection mechanism  106  (also to be further described below). 
     Disk or tape drive  611  is installed into drive bracket  104  by inserting screws  612  through isolation grommets  610 . Screwdriver clearance holes  609  are aligned with grommet retaining holes  608  to allow screwdriver access to screws  612  during drive installation and removal. Preferably, drive  611  will have a socket  613  disposed at its rear, as shown, for engagement with a mating socket  500  supported on rear wall  300  of drive cage  102 . 
     Insertion/Ejection Mechanism. Insertion/ejection mechanism  106  will now be described in detail with reference to FIGS. 10-19. Insertion/ejection mechanism  106  includes rotating member  1000 , lever lock  1200 , hinge pin  1500  and spring  1800 . 
     Rotating member  1000  has two aligned points of rotation (hinge pin clearance holes)  1001  formed therein. Two sets of prongs  1002 ,  1004  are disposed on one side of points of rotation  1001 , and lever  1006  is disposed on the other side of points of rotation  1001 . Two kickstands  1010  extend radially away from points of rotation  1001  at approximately forty-five degrees relative to lever  1006 . Lever  1006  has a lever lock clearance hole  1008  formed therein for lockingly receiving and releasably retaining catch  1208  on lever lock  1200 . Lever  1006  also has a handle  1012  formed on one end, as shown, to facilitate movement of lever  1006  and to facilitate pulling drive bracket  104  out of drive cage  102 . In an embodiment, rotating member  1000  was constructed of steel; other suitable materials may be used. 
     Lever lock  1200  is designed to retain rotating member  1000  and hinge pin  1500  against front panel  616  of drive bracket  104 , and also to releasably retain lever  1006  in a closed position. Lever lock  1200  includes a hinge pin retaining hub  1202  and a hinge pin retaining arm  1204  disposed at one end of hub  1202 . Lever lock  1200  also includes a resilient standoff member  1206  having a catch  1208  formed on its end. Mounting hooks  1210 ,  1211  and a positioning stub  1212  are provided for engaging corresponding holes in front panel  616  of drive bracket  104 . (The engagement of mounting hooks  1210 ,  1211  with front panel  616  will be described in more detail below with reference to FIG. 17.) Handle  1214  is provided to facilitate installation of lever lock  1200  onto front panel  104 . In an embodiment, lever lock  1200  was constructed of molded plastic; other suitable materials may be used. Hinge pin  1500  was constructed of steel. Spring  1800  was constructed of blue spring steel. Other suitable materials may be used for either piece. It was found that a radius of approximately 3.8 mm and a thickness of approximately 0.005 inches for spring  1800  provided satisfactory results for biasing lever  1006  toward its open position while still enabling it to be moved to its closed position without undue force. 
     The installation of insertion/ejection mechanism  106  onto front panel  104  will now be described with reference to FIGS. 15-19. In step one (FIG.  15 ), rotating member  1000  is inserted into clearance slots  706  so that hinge pin clearance holes  1001  are disposed on the interior of drive bracket  104  at the corner. Hinge pin  1500  is then inserted through hinge pin clearance holes  1001 . After hinge pin  1500  is so inserted, rotating member  1000  may then be slid a small distance toward the center of front panel  616  in preparation for step two. 
     In step two (FIG.  16 ), lever lock  1200  is mounted to the interior side of front panel  616 . To do so, retaining hub  1202  is placed over hinge pin  1500  so that the top kickstand  1210  slides into the space between retaining arm  1204  and the top end of hub  1210 . Resilient standoff member  1206  and hook  1211  are both inserted into hole  706 , and hooks  1210  are inserted into holes  704 . At this point, positioning stub  1212  will not be aligned with holes  702 . To complete the step, lever lock  1200  is slid along the inside surface of front panel  616  until positioning stub  1212  snaps into hole  702 . After this has occurred, hooks  1210  will have engaged one edge of holes  704 , and hook  1211  will have engaged one edge of hole  700 , as shown in FIG.  17 . 
     In step three (FIG.  19 ), rotating member  1000  is placed in its open position, and spring  1800  is wedged into place as shown. Once spring  1800  is in position, leaf  1806  rests against the inside surface of lever  1006 , leaf  1804  rests against the outside surface of front panel  616 , shoulders  1808  rest against the inside of hooks  1210 , and protrusion  1802  is disposed between hooks  1210 . 
     Operation. The preferred operation of drive mounting system  100  will now be described with reference to FIGS. 20-26. To install a drive bracket  104  into drive cage  102 , lever  1006  is placed in its open position, as shown in FIGS. 22-23. Note that, in the open position, kickstands  1010  engage the inside surface of front panel  616  to prevent lever  1006  from opening too far. Outer rails  604  are inserted into channels  206  in drive a bracket guide  218 , and drive bracket  104  is pushed into drive cage  102 . Prongs  1004  will pass through clearance slots  706 , but prongs  1002  will not. Once prongs  1002  have engaged the front surface of flange  214 , prongs  1004  will have passed at least partially through the plane of flange  214 . Then, lever  1006  is moved to its closed position. As lever  1006  is closed, prongs  1004  engage the back surface of flange  215 . The movement of lever  1004  to the closed position, and the engagement of prongs  1004  with the back surface of flange  214 , tends to push bracket  104  further into drive cage  102 , preferably until socket  613  has mated with socket  500 . As lever  1006  nears the completely closed position, resilient standoff member  1206  bends back slightly as catch  1208  engages one side of hole  1008 . Once lever  1006  is in the completely closed position, standoff  1206  snaps back, and the bottom of catch  1208  engages the outside surface of lever  1006 , thereby retaining it in the closed position as shown in FIGS. 20-21. 
     To remove drive bracket  104  from drive cage  102 , catch  1208  is pulled back so that lever  1006  may spring open. As lever  1006  springs open, prongs  1002  engage the front surface of flange  214 . The user may then assist lever  1006  to the fully open position. The movement of lever  1006  to the open position, and the engagement of prongs  1002  with the front surface of flange  214 , tends to pull bracket  104  out of drive cage  102 , and helps to disengage socket  613  from socket  500 . 
     FIGS. 24-26 are provided to illustrate an EMI-reducing feature of an embodiment of the invention. Because of the stacked arrangement of drive bracket guides  218  in cage  102 , the drive brackets  104  populating cage  102  will reside immediately adjacent to one another, one on top of the other as illustrated by brackets  104 A and  104 B. When two drive brackets are so installed, the metallized foam gasket  618  on the lower bracket  104 B will form an EMI seal against the bottom of upper bracket  104 A. Flange  619  is tilted at angle  2600  (approximately 5-10 degrees) so that relative motion between brackets  104 A and  104 B does not peel away or roll. This aspect of the preferred embodiment allows metallized foam gaskets to be used in the application in lieu of more expensive or less effective types of EMI gaskets. 
     While the invention has been described in detail in relation to preferred embodiments thereof, the described embodiments have been presented by way of example and not by way of limitation. It will be understood by those skilled in the art that various changes may be made in the form and details of the described embodiments, resulting in equivalent embodiments that will remain within the scope of the appended claims.