Apparatus for electromagnetic interference and electrostatic discharge shielding of hot plug-connected hard disk drives

• US 5,673,172 A
• Filed: 01/05/1996
• Issued: 09/30/1997
• Est. Priority Date: 01/05/1996
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: McAuliffe, Barry S., Good, Lowell M., Hastings, Robert J., Varghese, Paily T.
• Primary Examiner(s): Phillips, Michael W.
• Application Number:
  US08/583,415
• Time in Patent Office: 634 Days
• Field of Search: 364/708.1, 439/928, 439/928.1, 174/35 R, 174/35 GC, 361/685, 361/692, 361/693, 361/816, 361/818
• US Class Current: 361/679.34
• CPC Class Codes: G06F 1/182 with special features, e.g. for use in industrial environments; grounding or shielding against radio frequency interference [RFI] or electromagnetical interference [EMI]
• CPC Class Codes: H05K 7/1418 Card guides, e.g. grooves H05K7/1425 takes precedence

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. Sheet metal electromagnetic interference and electrostatic discharge-suppressing housings enclose each hard disk drive, provide for ventilation of the hard disk drive and any associated electronic components through perforated portions thereof, and prevent transmission of electromagnetic interference through unperforated portions thereof. Each electromagnetic interference and electrostatic discharge-suppressing housing has grounding spring members mounted on a rear portion thereof, and resilient support members between the housing and the grounding spring members.

Claims

1. A shield for a disk drive of a type mountable on a support tray for insertion rearwardly into a sheet metal housing having opposing interior sides, the disk drive being susceptible to electromagnetic interference and electrostatic discharge from a source external thereto, the shield comprising:

an enclosure made of an electrically conductive material and having a top portion and opposing side portions;

means for mounting said enclosure to the support tray so that the disk drive is enclosed by said enclosure on the support tray;

means for electrically coupling said enclosure to the disk drive; and

means disposed on a rear portion of one of said enclosure opposing side portions for grounding said enclosure to the opposing interior sides of the sheet metal housing,

whereby the disk drive is electrically coupled and thereby grounded to the sheet metal housing when the support tray is inserted rearwardly into the sheet metal housing and is protected from the electromagnetic interference and electrostatic discharge.

2. The shield of claim 1, wherein the disk drive further has a drive circuit board mounted thereon, and said enclosure has a plurality of perforations therethrough for ventilation of the drive circuit board.

3. The shield of claim 1, wherein said mounting means comprises:

a plurality of slots formed in the support tray and extending therethrough; and

a corresponding plurality of downwardly extending tabs formed on bottom edges of said enclosure opposing side portions, said tabs being insertable into said support tray slots,

the disk drive being disposable on the support tray intermediate said enclosure opposing side portions.

4. The shield of claim 1, wherein said mounting means comprises a bottom portion on said enclosure, said bottom portion being disposed intermediate the disk drive and the support tray when the disk drive is mounted to the support tray,

whereby the disk drive is enclosed within said enclosure top, opposing side, and bottom portions when the disk drive is mounted to the support tray.

5. The shield of claim 1, wherein said electrically coupling means comprises:

a mounting rail on the disk drive, said mounting rail being electrically coupled to the disk drive;

an aperture formed through said enclosure and positionable proximate said mounting rail; and

an electrically conductive fastener, said fastener being installed through said aperture and fastenable to said mounting rail.

6. The shield of claim 1, wherein said grounding means comprises a sheet metal spring member resiliently outwardly biased to conductively contact one of the interior sides of the sheet metal housing when the support tray is inserted rearwardly into the sheet metal housing.

7. Apparatus for shielding a first disk drive from electromagnetic radiation radiating from an area on a second disk drive, the first and second disk drives being installed in a sheet metal cage structure, the sheet metal cage structure being conductively attached to earth ground, the apparatus comprising:

a housing for enclosing the second disk drive, said housing being made of an electrically conductive material and having perforated and unperforated portions, said unperforated portion overlying the area on the second disk drive from which the electromagnetic radiation originates when the second disk drive is enclosed by the housing;

means for electrically coupling said housing to the second disk drive; and

means for dissipating the electromagnetic radiation to earth ground.

8. The apparatus according to claim 7, wherein the second disk drive has an associated drive circuit board mounted thereon, the drive circuit board having a component which produces the electromagnetic radiation, and said unperforated portion of said housing overlies the component on the drive circuit board when the second disk chive is enclosed by the housing.

9. The apparatus according to claim 7, wherein said means for dissipating the electromagnetic radiation comprises an elongated strip of sheet metal, said sheet metal strip being conductively mounted to said housing, extending outwardly away from said housing, and capable of contacting the sheet metal cage structure,

whereby electromagnetic radiation present in said housing may be dissipated to earth ground at the sheet metal cage structure via said sheet metal strip.

10. The apparatus according to claim 9, further comprising means for biasing said sheet metal strip outwardly from said housing such that the resulting biasing force forces said sheet metal strip to contact the sheet metal cage structure when said sheet metal strip contacts the sheet metal cage structure.

11. The apparatus according to claim 9, wherein said means for dissipating the electromagnetic radiation further comprises a conductive fastener having a head portion, said fastener being securable to the second disk drive such that said head portion extends outwardly therefrom, and a conductive clip member mounted to an interior surface of the sheet metal cage structure such that when the second disk drive is operatively installed in the sheet metal cage structure said fastener head portion conductively contacts said clip member.

12. A shield to protect a first disk drive previously installed in a sheet metal housing from an electrostatic discharge produced when a second disk drive having static electricity thereon is initially being inserted rearwardly into the sheet metal housing adjacent the first disk drive, the shield comprising:

first means for surrounding the first disk drive with conductive material;

second means for surrounding the second disk drive with conductive material;

means for conducting the static electricity from the second disk drive to said second conductive material surrounding means;

means for electrically coupling said first conductive material surrounding means to the sheet metal housing;

means for electrically coupling said first conductive material surrounding means to the first disk drive; and

means mounted on a rear portion of said second conductive material surrounding means for conducting the static electricity from said second conductive material surrounding means to the sheet metal housing,

whereby when said rear portion of said second conductive material surrounding means is initially inserted into the sheet metal housing the static electricity is conducted to the sheet metal housing via said conducting means mounted on a rear portion of said second conductive material surrounding means and not to the first disk drive which is protected by said first conductive material surrounding means from the electrostatic discharge.

13. The shield according to claim 12, wherein said first and second means for surrounding the first and second disk drives with conductive material each comprise a sheet metal enclosure for substantially covering the outer surfaces of the first and second disk drives, respectively.

14. The shield according to claim 12, wherein said means for conducting the static electricity from said second conductive material surrounding means to the sheet metal housing comprises a spring member made of a conductive material, said spring member being conductively fastened to, and biased outwardly from, a rear portion of said second conductive material surrounding means so that said spring member engages the sheet metal housing when the second disk drive is initially inserted into the sheet metal housing.

15. Apparatus for supporting, providing a plug connection for, and shielding a disk drive, the apparatus 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 having facing surfaces;

first and second elongated guide channel members having open side portions and interiors along their lengths, said guide channel members being mounted on said 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 plug circuit board mounted 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 a rear portion of the mounted plug circuit board is conductively and removably received within said plug socket;

means for securing a disk drive to said top side portion of said support tray member for movement therewith;

means for electrically coupling said plug circuit board to the disk drive;

a conductive cover having a top portion and side portions, said cover being disposed on said support tray member for covering the disk drive;

two sheet metal grounding spring members, each of said sheet metal grounding spring members being mounted to a rear portion of one of said conductive cover side portions such that when said support tray member is slid rearwardly along said first and second guide channel members said sheet metal grounding spring members electrically couple to said housing cage structure facing surfaces;

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

cooperatively engageable means on said conductive cover for grounding the disk drive as said support tray member is being moved through said cage structure toward and away from said operating position.

16. The apparatus of claim 15 wherein:

said cooperatively engageable means comprises metal grounding members secured to and projecting outwardly beyond opposite side portions of said conductive cover, said metal grounding members being configured and positioned to releasably engage said grounding clip members when said support tray member is rearwardly brought to said operating position thereof within said housing cage structure to thereby continuously ground the disk drive while said plug circuit board is operatively connected to said plug socket.

17. The apparatus of claim 16 wherein:

said plug circuit board further comprises a conductive trace adjacent an edge portion thereof,

whereby, when said support tray member is slid rearwardly to said operating position within said cage structure, said conductive trace conductively contacts at least one of said sheet metal grounding clip members.