Apparatus for removably supporting a plurality of hot plug-connected hard disk drives

Abstract

A series of hard disk drives are secured atop molded plastic support trays slidably and removably received in opposing guide channel member pairs snap-fitted into opposite side walls of a sheet metal cage structure externally used in conjunction with a file server or other computer device. Snap-fitted into rear end portions of the trays are small printed circuit boards that are insertable into hot plug sockets at the rear of the cage. Forwardly projecting guard plates on the rear end of the cage block manual access to the board/socket interface, and the surface mounted grounding leads on the board extend rearwardly beyond its signal leads to enhance grounding safety during disk drive installation and removal. At the front end of each tray is a vertical support plate upon which LED indicating lights are conveniently mounted for the associated disk drive. Each guide channel member has a metal grounding clip portion that is pressed against the adjacent cage wall and is contacted by a grounding screw on the disk drive as the drive is slid into the housing, the grounding crew also functioning to prevent inadvertent upside-down installation of the drive. To assist in installing and removing each disk drive, its associated support tray is provided at its front corners with pivotable ejection latch members removably secured thereto using a molded connection structure that eliminates the requirement for attachment screws or rivets.

What is claimed is: 
     
       1. Apparatus for supporting and providing a plug connection for a disk drive, comprising: a housing cage structure having an open front end, a rear end wall having a plug socket thereon, and first and second opposite side walls extending between said open front end and said rear end wall, said first and second opposite side walls having facing surfaces;   first and second elongated guide channel members having open side portions with interiors, and generally U-shaped cross-sections along their lengths;   means for mounting said guide channel members on the facing surfaces of said first and second side walls in a parallel relationship in which said open side portions of the mounted first and second guide channel members face one another and said first and second guide channel members longitudinally extend toward said plug socket in a generally laterally aligned relationship therewith;   a support tray member having opposite side edge portions slidably and supportingly receivable in the interiors of said first and second guide channel members in a manner permitting said support tray member to be slid rearwardly along said first and second guide channel members to bring said support tray member to an operating position within said cage structure, said support tray member having a rear end portion and a top side portion disposed forwardly of said rear end portion;   a printed circuit board having a connector edge portion;   means for removably mounting said printed circuit board on said rear end portion of said support tray member for movement therewith in a manner such that when said support tray member is rearwardly moved through said cage structure to said operating position the connector edge portion of the mounted printed circuit board is conductively and removably received within said plug socket;   means for removably securing the disk drive to said top side portion of said support tray member for movement therewith; and   means for electrically coupling said printed circuit board to the disk drive.   
     
     
       2. The apparatus of claim 1 wherein: said printed circuit board has formed on said connector edge portion thereof a plurality of conductive, rearwardly extending signal traces electrically connectable to said plug socket in response to operative rearward insertion of said connector edge portion into said plug socket, and a plurality of conductive grounding traces electrically connectable to said plug socket in response to operative rearward insertion of said connector edge portion into said plug socket,   said grounding traces extending rearwardly beyond said signal traces, whereby, upon insertion of said connector edge portion into said plug socket a grounding connection is formed therebetween before a signal connection and, upon removal of said connector edge portion from said plug socket, the signal connection therebetween is broken before the grounding connection.   
     
     
       3. The apparatus of claim 1 wherein said means for removably mounting said printed circuit board on said rear end portion of said support tray member include: upwardly projecting clip means formed on said rear end portion of said printed circuit board and operative to engage said printed circuit board and provide for a releasable snap-on fit thereof on said rear end portion of said support tray member.   
     
     
       4. The apparatus of claim 3 wherein: said clip means include a spaced plurality of upwardly projecting resilient clip members positioned on a rear edge portion of said support tray member and being rearwardly deflectable to lockingly engage rear edge portions of said printed circuit board, and   said support tray member has wall means formed thereon and operative to protectively limit rearward deflection of said resilient clip members.   
     
     
       5. The apparatus of claim 3 wherein said means for removably mounting said printed circuit board on said rear end portion of said support tray member further include: a spaced plurality of holes extending transversely through said printed circuit board, and   a spaced plurality of upwardly projecting post portions disposed on said rear end portion of said support tray member and being receivable in said holes to essentially preclude edgewise movement of said printed circuit board relative to said support tray member.   
     
     
       6. The apparatus of claim 1 wherein: said support tray member is of a molded plastic construction.   
     
     
       7. The apparatus of claim 1 wherein: said support tray member has a plate member projecting upwardly from the front end thereof in front of the front end of the mounted disk drive,   said plate member has a plurality of disk drive indicating lights operatively mounted thereon, and   said apparatus further comprises wiring means, interconnected between said printed circuit board and said indicating lights, for transmitting electrical signals from said printed circuit board to said indicating lights.   
     
     
       8. The apparatus of claim 7 further comprising: wall means associated with said support tray member for forming thereon a wire passage, beneath the mounted disk drive, through which said wiring means extend.   
     
     
       9. The apparatus of claim 1 wherein: said housing cage structure has opposing channel portions formed on said open front end thereof and extending transversely to said guide channel members,   said support tray member has opposite front corner portions, and   said apparatus further comprises a pair of ejection latch members pivotally mountable on said opposite front corner portions and operative, when pivoted relative thereto, to engage said cage channel portions in a manner selectively creating an insertion or withdrawal force on said support tray member, and means for removably and pivotally mounting said ejection latch members on said opposite front corner portions of said support tray members.   
     
     
       10. The apparatus of claim 9 wherein, for each of said ejection latch members, said means for removably and pivotally mounting said ejection latch members include: a hole formed through the ejection latch member,   a post member formed on one of said front corner portions of said support tray and insertable through said hole, when the latch member is in a first pivotal orientation relative to the post member, to rotatably support the latch member on the post member,   first cooperating means on the post member and the latch member for preventing withdrawal of the post member from the latch member hole when the latch member is rotated about the post member away from said first pivotal orientation relative thereto, and   second cooperating means on said one of said front corner portions and the latch member for releasably blocking rotation of the latch member to said first pivotal orientation thereof after the latch member is operatively installed on the post member.   
     
     
       11. The apparatus of claim 10 wherein: said first cooperating means include a circumferentially spaced plurality of radially outwardly extending projections on an outer end portion of the post member, and a complementarily configured circumferentially spaced plurality of radially outwardly extending portions of the latch member hole through which said projections may be extended to outwardly overlie the latch member when it is in said first pivotal orientation relative to the post member, and   said second cooperating means include a stop surface on the latch member and a resilient locking portion disposed on said one of said corner portions of said support tray member, the locking portion being depressible to permit rotation of the latch member about the post member to said first pivotal orientation, and releasable to form an abutment for said stop surface to releasably preclude rotation of the latch member to said first pivotal orientation thereof.   
     
     
       12. The apparatus of claim 1 wherein: said printed circuit board has opposite side edge portions slidably receivable in said guide channel members and defining rearward extensions of said opposite side edge portions of said support tray member.   
     
     
       13. The apparatus of claim 1 wherein: said rear end wall of said housing cage structure has guard wall means projecting forwardly therefrom and operative to block manual access to said printed circuit board when it is adjacent said plug socket.   
     
     
       14. The apparatus of claim 13 wherein: said plug socket is horizontally elongated, and   said guard wall means include first and second guard plates projecting forwardly beyond said rear end wall of said housing cage structure above and below said plug socket.   
     
     
       15. The apparatus of claim 1 wherein: said housing cage structure is formed from a metal material,   said first and second guide channel members are formed from a plastic material, and   said apparatus further comprises sheet metal grounding clip members carried by said guide channel members and deformingly pressed against said first and second side walls of said housing cage structure, and metal grounding members secured to and projecting outwardly beyond opposite side portions of the mounted disk drive, said metal grounding members being configured and positioned to releasably engage said grounding clip members when said support member is rearwardly brought to said operating position thereof within said housing cage structure.   
     
     
       16. The apparatus of claim 15 further comprising: cooperating means on said grounding clip members and said guide channel members for providing a releasable snap-fit mounting connection between said grounding clip members and their associated guide channel members.   
     
     
       17. The apparatus of claim 1 further comprising: cooperating means on said guide channel members and said side walls of said housing cage structure for providing a releasable snap-fit attachment engagement between said guide channel members and said side walls of said housing cage structure.   
     
     
       18. The apparatus of claim 1 further comprising: cooperating means disposed on the disk drive and said side walls of said housing cage structure for preventing upside-down insertion of said support tray member fully into said housing cage structure.   
     
     
       19. The apparatus of claim 18 wherein said cooperating means include: an inward projection formed on one of said side walls of said housing cage structure, and   a stop member secured to and projecting outwardly from a side portion of the disk drive,   said inward projection being positioned to be engaged by said stop member, when said support tray member is partially inserted rearwardly into said guide channel members in an upside-down orientation, in a manner precluding further rearward insertion into said housing cage structure.   
     
     
       20. Apparatus for removably supporting a disk drive, comprising: a housing cage structure having an open front end, a rear end wall having a plug socket thereon, and first and second opposite side walls extending between said open front end and said rear end wall, and opposing wall channel portions formed on said open front end, said first and second opposite side walls having facing surfaces;   first and second elongated guide channel members having open side portions, and generally U-shaped cross-sections along their lengths;   means for mounting said guide channel members on the facing surfaces of said first and second side walls in a parallel relationship in which said open side portions of the mounted first and second guide channel members face one another and said first and second guide channel members longitudinally extend toward said plug socket in a generally laterally aligned relationship therewith and generally perpendicular to said opposing wall channel portions of said housing cage structure;   a generally flat support member having opposite front corner portions, and opposite side edge portions slidably and supportingly receivable in the interiors of said first and second guide channel members in a manner permitting said support member to be slid rearwardly along said first and second guide channel members to bring said support member to an operating position within said housing cage structure;   a pair of ejection latch members pivotally mountable on said opposite front corner portions of said support member and operative, when pivoted relative thereto, to engage said wall channel portions of said housing cage structure in a manner selectively creating an insertion or withdrawal force on said support member; and   means for removably and pivotally mounting said ejection latch members on said opposite front corner portions of said support member, said means for removably and pivotally mounting, for each ejection latch member, including:   a hole formed through the ejection latch member,   a post member formed on one of said front corner portions of said support member and insertable through said hole, when the latch member is in a first pivotal orientation relative to the post member, to rotatably support the latch member on the post member,   first cooperating means on the post member and the latch member for preventing withdrawal of the post member from the latch member hole when the latch member is rotated about the post member away from said first pivotal orientation relative thereto, and   second cooperating means on said one of said front corner portions of said support member and the latch member for releasably blocking rotation of the latch member to said first pivotal orientation thereof after the latch member is rotatably installed on the post member.   
     
     
       21. The apparatus of claim 20 wherein: said first cooperating means include a circumferentially spaced plurality of radially outwardly extending projections on an outer end portion of the post member, and a complementarily configured circumferentially spaced plurality of radially outwardly extending portions of the latch member hole through which said projections may be extended to outwardly overlie the latch member when it is in said first pivotal orientation relative to the post member, and   said second cooperating means include a stop surface on the latch member and a resilient locking portion disposed on said one of said corner portions of said support member, the locking portion being depressible to permit rotation of the latch member about the post member to said first pivotal orientation, and releasable to form an abutment for said stop surface to releasably preclude rotation of the latch member to said first pivotal orientation thereof.   
     
     
       22. The apparatus of claim 20 wherein said plug socket is a hot plug socket. .Iadd. 
     
     
       23.  For use in conjunction with a housing cage structure having an open end, and an end wall spaced inwardly apart from and facing the open end and having a plug socket thereon, disk drive apparatus insertable inwardly through the open housing cage structure end in a manner removably holding said disk drive apparatus therein and operatively coupling it to the plug socket, said disk drive apparatus comprising: a support tray member having a base wall with opposite top and bottom sides, a rear end portion, and a front end portion disposed forwardly of said rear end portion, said support tray member being rearwardly movable inwardly through the open housing cage structure end, toward the plug socket, to an operating position;   a printed circuit board having a connector edge portion;   mounting means for mounting said printed circuit board on one of said opposite top and bottom sides of said rear end portion of said base wall, in a parallel relationship therewith, for movement with said support tray member in a manner such that when said support tray member is rearwardly moved through the cage structure to said operating position said connector edge portion of the mounted printed circuit board is conductively and removably received within the plug socket;   securing means for securing a disk drive to one of said top and bottom sides of said front end portion of said base wall, forwardly of the printed circuit board, for movement therewith;   coupling means for electrically coupling said printed circuit board to the disk drive; and   support means associated with said support tray member and cooperatively engageable with a portion of the housing cage structure, in response to movement of said support tray member into the housing cage structure to said operating position, to removably support said support tray member within the housing cage structure. .Iaddend..Iadd.   
     
     
       24.  The disk drive apparatus of claim 23 further comprising: a hard disk drive secured by said securing means to said top side of said front end portion of said base wall forwardly of said printed circuit board. .Iaddend..Iadd.25. The disk drive apparatus of claim 24 wherein:   said printed circuit board is mounted on said top side of said front end portion of said base wall. .Iaddend..Iadd.26. The disk drive apparatus of claim 23 wherein:   said printed circuit board has formed on said connector edge portion thereof a plurality of conductive, rearwardly extending signal traces electrically connectable to the plug socket in response to operative rearward insertion of said connector edge portion into the plug socket, and a plurality of conductive grounding traces electrically connectable to said plug socket in response to operative rearward insertion of said connector edge portion into the plug socket, said grounding traces   
     
     
        extending rearwardly beyond said signal traces. .Iaddend..Iadd.27.  The disk drive apparatus of claim 23 wherein said means for mounting said printed circuit board on said rear end portion of said support tray member include: upwardly projecting clip means formed on said rear end portion of said printed circuit board and operative to engage said printed circuit board and provide for a releasable snap-on fit thereof on said rear end portion of said support tray member. .Iaddend..Iadd.28. The apparatus of claim 27 wherein:   said clip means include a spaced plurality of upwardly projecting resilient clip members positioned on a rear edge portion of said support tray member and being rearwardly deflectable to lockingly engage rear edge portions of said printed circuit board, and   said support tray member has wall means formed thereon and operative to protectively limit rearward deflection of said resilient clip members. .Iaddend..Iadd.29. The disk drive apparatus of claim 27 wherein said means for mounting said printed circuit board on said rear end portion of said support tray member further include:   a spaced plurality of holes extending transversely through said printed circuit board, and   a spaced plurality of upwardly projecting post portions disposed on said rear end portion of said support tray member and being receivable in said holes to essentially preclude edgewise movement of said printed circuit board relative to said support tray member. .Iaddend..Iadd.30. The disk drive apparatus of claim 23 wherein:   said support tray member is of a molded plastic construction. .Iaddend..Iadd.31. The disk drive apparatus of claim 23 wherein:   said support tray member has a plate member projecting upwardly from the front end thereof,   said plate member has a plurality of disk drive indicating lights operatively mounted thereon, and   said disk drive apparatus further comprises wiring means, interconnected between said printed circuit board and said indicating lights, for transmitting electrical signals from said printed circuit board to said indicating lights. .Iaddend..Iadd.32. The disk drive apparatus of claim 31 further comprising:   wall means associated with said support tray member for forming thereon a wire passage, disposed along the underside of said support tray member,   
     
     
        through which said wiring means extend. .Iaddend..Iadd.33.  For use in conjunction with a housing cage structure having an open end, and an end wall spaced inwardly apart from and facing the open end and having a plug socket thereon, disk drive apparatus insertable inwardly through the open housing cage structure end in a manner removably holding said disk drive apparatus therein and operatively coupling it to the plug socket, said disk drive apparatus comprising: a support tray member having a base wall with opposite top and bottom sides, a rear end portion, and a front end portion disposed forwardly of said rear end portion, said support tray member being rearwardly movable inwardly through the open housing cage structure end, toward the plug socket, to an operating position, said front end portion of said base wall having opposite side edge portions extending in front-to-rear directions;   a printed circuit board anchored to one of said top and bottom sides of said base wall and being positioned rearwardly of said front end portion of said base wall, said printed circuit board extending generally parallel to said base wall and having opposite side edge portions generally aligned with and forming rearward extensions of said opposite side edge portions of said base wall, said printed circuit board further having a rearwardly extending connector edge portion removably and operatively receivable in the plug socket;   a disk drive secured to one of said top and bottom sides of said front end portion of said base wall and being electrically coupled to said printed circuit board; and   support means associated with said support tray member and cooperatively engageable with a portion of the housing cage structure, in response to movement of said support tray member into the housing cage structure to said operating position, to removably support said support tray member within the housing cage structure, said support means including the aligned opposite side edge portions of said base wall and said printed circuit board. .Iaddend..Iadd.34. The disk drive apparatus of claim 33 wherein:   the housing cage structure has guide channel structures disposed therein, and   the aligned opposite side edge portions of said base wall and said printed circuit board are configured to be slidably and supportingly received in the guide channel structures. .Iaddend..Iadd.35. The disk drive apparatus of claim 33 further comprising:   a plate member projecting upwardly from a front end portion of said support tray member forwardly of said disk drive,   a plurality of disk drive indicating lights operatively mounted on said plate member, and   wiring means, interconnected between said printed circuit board and said indicating lights, for transmitting electrical signals from said printed circuit board to said indicating lights. .Iaddend..Iadd.36. The disk drive apparatus of claim 35 further comprising:   wall means associated with said support tray member for forming along an underside portion thereof a wire passage through which said wiring means extend. .Iaddend..Iadd.37. For use in conjunction with a housing cage structure having an open end, and an end wall spaced inwardly apart from and facing the open end and having a plug socket thereon, disk drive apparatus insertable inwardly through the open housing cage structure end in a manner removably holding said disk drive apparatus therein and operatively coupling it to the plug socket, said disk drive apparatus comprising:   a support tray member having a rear end portion and a top side portion disposed forwardly of said rear end portion, said top side portion having opposite front corner portions, said support tray member being rearwardly movable inwardly through the open housing cage structure end, toward the plug socket on the end wall of the housing cage structure, to an operating position;   a printed circuit board having a connector structure thereon;   mounting means for mounting said printed circuit board on said rear end portion of said support tray member for movement therewith in a manner such that when said support tray member is rearwardly moved through the cage structure to said operating position said connector structure of the mounted printed circuit board is conductively and removably received within the plug socket;   securing means for securing a disk drive to said top side portion of said support tray member for movement therewith;   coupling means for electrically coupling said printed circuit board to the disk drive;   support means associated with said support tray member and cooperatively engageable with a portion of the housing cage structure, in response to movement of said support tray member into the housing cage structure to said operating position, to removably support said support tray member within the housing cage structure;   a pair of ejection latch members pivotally mountable on said opposite front corner portions of said support tray member and operative, when pivoted relative thereto, to engage a portion of the housing cage structure in a manner selectively creating an insertion or withdrawal force on said support tray member; and   means for removably and pivotally mounting said ejection latch members on corner portions of said support tray member, said means for removably and pivotally mounting, for each ejection latch member, including: a hole formed through the ejection latch member,   a post member formed on one of said front corner portions of said support member and insertable through said hole, when the latch member is in a first pivotal orientation relative to the post member, to rotatably support the latch member on the post member,   first cooperating means on the post member and the latch member for preventing withdrawal of the post member from the latch member hole when the latch member is rotated about the post member away from said first pivotal orientation relative thereto, and   second cooperating means on said one of said front corner portions of said support member and the latch member for releasably blocking rotation of the latch member to said first pivotal orientation thereof after the latch member is rotatable installed on the post member. .Iaddend..Iadd.38. The disk drive apparatus of claim 37 wherein:     said first cooperating means include a circumferentially spaced plurality of radially outwardly extending projections on an outer end portion of the post member, and a complementarily configured circumferentially spaced plurality of radially outwardly extending portions of the latch member hole through which said projections may be extended to outwardly overlie the latch member when it is in said first pivotal orientation relative to the post member, and   said second cooperating means include a stop surface on the latch member and a resilient locking portion disposed on said one of said corner portions of said support member, the locking portion being depressible to permit rotation of the latch member about the post member to said first pivotal orientation, and releasable to form an abutment for said stop surface to releasably preclude rotation of the latch member to said first pivotal orientation thereof. .Iaddend..Iadd.39. For use in conjunction with a housing cage structure having an open end, and an end wall spaced inwardly apart from and facing the open end and having a plug socket thereon, disk drive apparatus insertable inwardly through the open housing cage structure end in a manner removably holding said disk drive apparatus therein and operatively coupling it to the plug socket, said disk drive apparatus comprising:   a support tray member having a base wall with a rear portion and a front portion disposed forwardly of said rear portion, said support tray member being rearwardly movable inwardly through the open housing cage structure end, toward the plug socket, to an operating position;   a printed circuit board mounted on a side of said rear portion of said base wall in a generally parallel relationship therewith and having a rearwardly projecting connector edge portion with a plurality of signal traces disposed thereon, and a grounding trace disposed thereon and extending rearwardly of said signal traces, said connector edge portion being removably receivable in the plug socket in response to rearward movement of said support tray member through the housing cage structure to said operating position;   securing means for securing a disk drive to said front portion of said base wall for movement therewith;   coupling means for electrically coupling said printed circuit board to the disk drive; and   support means associated with said support tray member and cooperatively engageable with a portion of the housing cage structure, in response to movement of said support tray member into the housing cage structure to said operating position, to removably support said support tray structure   
     
     
        within the housing cage structure. .Iaddend..Iadd.40.  The disk drive apparatus of claim 39 further comprising: a disk drive secured by said securing means to said front portion of said support tray member forwardly of said printed circuit board. .Iaddend..Iadd.41. The disk drive apparatus of claim 40 wherein:   said disk drive is a hard disk drive. .Iaddend..Iadd.42. The disk drive apparatus of claim 39 wherein:   said support tray member is of a plastic construction. .Iaddend..Iadd.43. Apparatus for supporting and providing a plug connection for a disk drive, comprising:   a housing cage structure having an open front end, a rear end wall having a plug socket thereon, and first and second opposite side walls extending between said open front end and said rear end wall, said first and second opposite side walls having facing surfaces;   first and second elongated guide channel members having open side portions with interiors, and generally U-shaped cross-sections along their lengths;   means for mounting said guide channel members on the facing surfaces of said first and second side walls in a parallel relationship in which said open side portions of the mounted first and second guide channel members face one another and said first and second guide channel members longitudinally extend toward said plug socket in a generally laterally aligned relationship therewith;   a support tray member having opposite side edge portions slidably and supportingly receivable in the interiors of said first and second guide channel members in a manner permitting said support tray member to be slid rearwardly along said first and second guide channel members to bring said support tray member to an operating position within said cage structure, said support tray member having a rear end portion and a top side portion disposed forwardly of said rear end portion;   a printed circuit board having a connector edge portion;   means for mounting said printed circuit board on said rear end portion of said support tray member for movement therewith in a manner such that when said support tray member is rearwardly moved through said cage structure to said operating position the connector edge portion of the mounted printed circuit board is conductively and removably received within said plug socket;   means for securing the disk drive to said top side portion of said support tray member for movement therewith; and   means for electrically coupling said printed circuit board to the disk   
     
     
        drive. .Iaddend..Iadd.44.  The apparatus of claim 43 wherein: said printed circuit board has formed on said connector edge portion thereof a plurality of conductive, rearwardly extending signal traces electrically connectable to said plug socket in response to operative rearward insertion of said connector edge portion into said plug socket, and a plurality of conductive grounding traces electrically connectable to said plug socket in response to operative rearward insertion of said connector edge portion into said plug socket,   said grounding traces extending rearwardly beyond said signal traces, whereby, upon insertion of said connector edge portion into said plug socket a grounding connection is formed therebetween before a signal connection and, upon removal of said connector edge portion from said plug socket, the signal connection therebetween is broken before the grounding connection. .Iaddend..Iadd.45. The apparatus of claim 43 wherein said means for mounting said printed circuit board on said rear end portion of said support tray member include:   upwardly projecting clip means formed on said rear end portion of said printed circuit board and operative to engage said printed circuit board and provide for a releasable snap-on fit thereof on said rear end portion of said support tray member. .Iaddend..Iadd.46. The apparatus of claim 45 wherein:   said clip means include a spaced plurality of upwardly projecting resilient clip members positioned on a rear edge portion of said support tray member and being rearwardly deflectable to lockingly engage rear edge portions of said printed circuit board, and   said support tray member has wall means formed thereon and operative to protectively limit rearward deflection of said resilient clip members. .Iaddend..Iadd.47. The apparatus of claim 45 wherein said means for mounting said printed circuit board on said rear end portion of said support tray member further include:   a spaced plurality of holes extending transversely through said printed circuit board, and   a spaced plurality of upwardly projecting post portions disposed on said rear end portion of said support tray member and being receivable in said holes to essentially preclude edgewise movement of said printed circuit   
     
     
        board relative to said support tray member. .Iaddend..Iadd.48.  The apparatus of claim 43 wherein said support tray member is of a molded plastic construction. .Iaddend..Iadd.49. The apparatus of claim 43 wherein: said support tray member has a plate member projecting upwardly from the front end thereof in front of the front end of the mounted disk drive,   said plate member has a plurality of disk drive indicating lights operatively mounted thereon, and   said apparatus further comprises wiring means, interconnected between said printed circuit board and said indicating lights, for transmitting electrical signals from said printed circuit board to said indicating lights. .Iaddend..Iadd.50. The apparatus of claim 49 further comprising:   wall means associated with said support tray member for forming thereon a wire passage, beneath the mounted disk drive, through which said wiring   
     
     
        means extend. .Iaddend..Iadd.51.  The apparatus of claim 43 wherein: said housing cage structure has opposing channel portions formed on said open front end thereof and extending transversely to said guide channel members,   said support tray member has opposite front corner portions, and   said apparatus further comprises a pair of ejection latch members pivotally mountable on said opposite front corner portions and operative, when pivoted relative thereto, to engage said cage channel portions in a manner selectively creating an insertion or withdrawal force on said support tray member, and means for removably and pivotally mounting said ejection latch members on said opposite front corner portions of said support tray members. .Iaddend..Iadd.52. The apparatus of claim 51 wherein, for each of said ejection latch members, said means for removably and pivotally mounting said ejection latch members include:   a hole formed through the ejection latch member,   a post member formed on one of said front corner portions of said support tray and insertable through said hole, when the latch member is in a first pivotal orientation relative to the post member, to rotatably support the latch member on the post member,   first cooperating means on the post member and the latch member for preventing withdrawal of the post member from the latch member hole when the latch member is rotated about the post member away from said first pivotal orientation relative thereto, and   second cooperating means on said one of said front corner portions and the latch member for releasably blocking rotation of the latch member to said first pivotal orientation thereof after the latch member is operatively   
     
     
        installed on the post member. .Iaddend..Iadd.53.  The apparatus of claim 52 wherein: said first cooperating means include a circumferentially spaced plurality of radially outwardly extending projections on an outer end portion of the post member, and a complementarily configured circumferentially spaced plurality of radially outwardly extending portions of the latch member hole through which said projections may be extended to outwardly overlie the latch member when it is in said first pivotal orientation relative to the post member, and   said second cooperating means include a stop surface on the latch member and a resilient locking portion disposed on said one of said corner portions of said support tray member, the locking portion being depressible to permit rotation of the latch member about the post member to said first pivotal orientation, and releasable to form an abutment for said stop surface to releasably preclude rotation of the latch member to   
     
     
        said first pivotal orientation thereof. .Iaddend..Iadd.54.  The apparatus of claim 43 wherein: said printed circuit board has opposite side edge portions slidably receivable in said guide channel members and defining rearward extensions of said opposite side edge portions of said support tray member. .Iaddend..Iadd.55. The apparatus of claim 43 wherein:   said rear end wall of said housing cage structure has guard wall means projecting forwardly therefrom and operative to block manual access to said printed circuit board when it is adjacent said plug socket. .Iaddend..Iadd.56. The apparatus of claim 55 wherein:   said plug socket is horizontally elongated, and   said guard wall means include first and second guard plates projecting forwardly beyond said rear end wall of said housing cage structure above and below said plug socket. .Iaddend..Iadd.57. The apparatus of claim 43 wherein:   said housing cage structure is formed from a metal material,   said first and second guide channel members are formed from a plastic material, and   said apparatus further comprises sheet metal grounding clip members carried by said guide channel members and deformingly pressed against said first and second side walls of said housing cage structure, and metal grounding members secured to and projecting outwardly beyond opposite side portions of the mounted disk drive, said metal grounding members being configured and positioned to releasably engage said grounding clip members when said support member is rearwardly brought to said operating position thereof within said housing cage structure. .Iaddend..Iadd.58. The apparatus of claim 57 further comprising:   cooperating means on said grounding clip members and said guide channel members for providing a releasable snap-fit mounting connection between said grounding clip members and their associated guide channel members. .Iaddend..Iadd.59. The apparatus of claim 43 further comprising:   cooperating means on said guide channel members and said side walls of said housing cage structure for providing a releasable snap-fit attachment engagement between said guide channel members and said side walls of said housing cage structure. .Iaddend..Iadd.60. The apparatus of claim 43 further comprising:   cooperating means disposed on the disk drive and said side walls of said housing cage structure for preventing upside-down insertion of said support tray member fully into said housing cage structure.   
     
     
        .Iaddend..Iadd.1.  The apparatus of claim 60 wherein said cooperating means include: an inward projection formed on one of said side walls of said housing cage structure, and   a stop member secured to and projecting outwardly from a side portion of the disk drive, said inward projection being positioned to be enraged by said stop member, when said support tray member is partially inserted rearwardly into said guide channel members in an upside-down orientation, in a manner precluding further rearward insertion into said housing cage structure. .Iaddend..Iadd.62. The disk drive apparatus of claim 33 wherein:     said disk drive is mounted on the top side of said front end portion of said base wall, and   said printed circuit board is mounted on the top side of said rear end   
     
     
        portion of said base wall. .Iaddend..Iadd.63.  For use conjunction with a housing cage structure having an open end, and an end wall spaced inwardly apart from and facing the open end and having a plug socket thereon, disk drive apparatus insertable inwardly through the open housing cage structure end in a manner removably holding said disk drive apparatus therein and operatively coupling it to the plug socket, said disk drive apparatus comprising: a support tray having a base wall structure with opposite top and bottom sides, a front end portion, a rear end portion having a downwardly offset top side portion, and a rear edge, said support tray being rearwardly movable inwardly through the open housing cage structure end, toward the plug socket on the end wall of the housing cage structure, to an operating position;   a printed circuit board having a connector edge portion;   mounting means for mounting said printed circuit board on said downwardly offset top side portion of said rear end portion of said base wall structure, in a parallel relationship therewith, with said connector edge portion of said printed circuit board projecting rearwardly beyond said rear edge of said rear end portion of said base wall structure, for movement with said support tray in a manner such that when said support tray is rearwardly moved through the cage structure to said operating position said connector edge portion of the mounted printed circuit board is conductively and removably received within the plug socket;   securing means for securing a disk drive to the top side of said front end portion of said base wall structure forwardly of said printed circuit board;   coupling means for electrically coupling said printed circuit board to the disk drive; and   support means associated with said support tray and cooperatively engageable with a portion of the housing cage structure, in response to movement of said support tray member into the housing cage structure to said operating position, to removably support said support tray within the   
     
     
        housing cage structure. .Iaddend..Iadd.64.  The disk drive apparatus of claim 63 wherein: said base wall structure of said support tray further has opposite side edge portions longitudinally extending in front-to-rear directions, and   said printed circuit board is generally vertically aligned with said opposite side edge portions of said base wall structure of said support tray. .Iaddend..Iadd.65. The disk drive apparatus of claim 64 wherein:   said printed circuit board has opposite side edge portions that generally define rearward extensions of said opposite side edge portions of said base wall structure of said support tray. .Iaddend..Iadd.66. The disk drive apparatus of claim 63 wherein:   said base wall structure of said support tray has opposite side edge portions longitudinally extending in front-to-rear directions, and   said support means include said opposite side edge portions of said base wall structure of said support tray. .Iaddend..Iadd.67. The disk drive apparatus of claim 63 further comprising a disk drive secured by said securing means to the top side of said front end portion of said base wall   
     
     
        structure. .Iaddend..Iadd.68.  The disk drive apparatus of claim 67 wherein: said disk drive apparatus further comprises a disk drive indicating light carried on a front end portion of said support tray, and   said coupling means include electrical wiring connected to said printed circuit board and having a first portion electrically coupling said printed circuit board to said disk drive, and a second portion extending between said disk drive and said base wall structure and connected to said disk drive indicating light. .Iaddend..Iadd.69. The disk drive apparatus of claim 63 wherein:   said disk drive apparatus further comprises a pair of ejection latch members pivotally carried on a front end portion of said support tray and being operative to engage the housing cage structure in a manner selectively creating an insertion or withdrawal force on said support tray. .Iaddend..Iadd.70. For use in conjunction with a housing cage structure having an open end, and an end wall spaced inwardly apart from and facing the open end and having a plug socket thereon, disk drive apparatus insertable inwardly through the open housing cage structure end in a manner removably holding said disk drive apparatus therein and operatively coupling it to the plug socket, said disk drive apparatus comprising:   a support tray having a base wall structure with opposite top and bottom sides, a front end portion having an upstanding front transverse wall, and a rear end portion having a rear edge, said support tray being rearwardly movable inwardly through the open housing cage structure end, toward the plug socket on the end wall of the housing cage structure, to an operating position;   a disk drive indicating light carried on said upstanding front transverse wall;   a printed circuit board having a connector edge portion;   mounting means for mounting said printed circuit board on a side of said rear end portion of said base wall structure, in a parallel relationship therewith, with said connector edge portion of said printed circuit board projecting rearwardly beyond said rear edge of said rear end portion of said base wall structure, for movement with said support tray in a manner such that when said support tray is rearwardly moved through the cage structure to said operating position said connector edge portion of the mounted printed circuit board is conductively and removably received within the plug socket;   securing means for securing a disk drive to the top side of said front end portion of said base wall structure forwardly of said printed circuit board;   wiring means for electrically coupling said printed circuit board to the disk drive and to said disk drive indicating light;   a pair of ejection latch members pivotally carried on said upstanding front transverse wall and being operative to engage a portion of the housing cage structure in a manner selectively creating an insertion or withdrawal force on said support tray; and   support means associated with said support tray and cooperatively engageable with a portion of the housing cage structure, in response to movement of said support tray into the housing cage structure to said operating position, to removably support said support tray within the   
     
     
        housing cage structure. .Iaddend..Iadd.71.  The disk drive apparatus of claim 70 wherein: said upstanding front transverse wall has a forwardly projecting portion, and   said pair of ejection latch members are pivotally carried on said forwardly projecting portion. .Iaddend..Iadd.72. The disk drive apparatus of claim 70 further comprising a disk drive secured by said securing means to said top side of said front end portion of said base wall structure, between said upstanding front transverse wall and said printed circuit board. .Iaddend..Iadd.73. The disk drive apparatus of claim 72 wherein a portion of said wiring means extends between said disk drive and said base wall structure and is interconnected between said printed circuit board and said indicating light. .Iaddend..Iadd.74. The disk drive apparatus of claim 70 wherein said printed circuit board is mounted on the top side of   
     
     
        said rear end portion of said base wall structure. .Iaddend..Iadd.75.  The disk drive apparatus of claim 70 wherein: said base wall structure further has opposite side edge portions longitudinally extending in front-to-rear directions, and   said support means include said opposite side edge portions of said base wall structure. .Iaddend.