US20010000392A1 - EMI shielded vent panel and method - Google Patents

EMI shielded vent panel and method Download PDF

Info

Publication number
US20010000392A1
US20010000392A1 US09737195 US73719500A US2001000392A1 US 20010000392 A1 US20010000392 A1 US 20010000392A1 US 09737195 US09737195 US 09737195 US 73719500 A US73719500 A US 73719500A US 2001000392 A1 US2001000392 A1 US 2001000392A1
Authority
US
Grant status
Application
Patent type
Prior art keywords
frame
medium
surface
fig
side
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
US09737195
Other versions
US6362417B2 (en )
Inventor
Jonathan Mitchell
Charlene Andersen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Parker Intangibles LLC
Original Assignee
Parker-Hannifin Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Images

Classifications

    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00Screening of apparatus or components against electric or magnetic fields
    • H05K9/0007Casings
    • H05K9/0041Ventilation panels having provisions for screening

Abstract

An electromagnetic interference (EMI) shielded vent panel construction for disposition over an opening of an electronics enclosure. The panel includes an electrically-conductive medium having an outer periphery supported within an electrically-conductive frame. The frame is configured as having a generally C-shaped cross-sectional profile and includes an elongate end wall having an interior an exterior surface, and a pair of oppositely-disposed side walls extending from the end wall interior surface. Each of the side walls has an outer surface, one of which is disposable about the opening of the enclosure in electrically-conductive adjacency with the surface thereof, and an inner surface spaced-apart a first predetermined distance from the inner surface of the other of the side walls. The outer periphery of the medium is received intermediate the inner surfaces of the side walls such that each extends over a corresponding edge portion of the medium faces. Along with the medium, an electrically-conductive gasket is disposed intermediate the inner surface of a first one of the side walls and the edge portion of a first one of the medium faces. The gasket extends along substantially the entire perimeter of the frame and is deflectable between the side wall inner surface and the corresponding edge portion of the medium face. As assembled, the frame is compressed to space each of the side wall inner surfaces a second predetermined distance apart deflecting the gasket into a collapsed orientation providing electrical grounding contact between the frame and the medium.

Description

    RELATED CASES
  • [1]
    1. This application is a divisional of pending U.S. application Ser. No. 09/243,778, filed Feb. 3, 1999, which claims priority to U.S. Provisional application Ser. No. 60/074,929, filed Feb. 17, 1998, the disclosures of which are expressly incorporated herein by reference.
  • BACKGROUND OF THE INVENTION
  • [2]
    2. The present invention relates broadly to an electromagnetic interference (EMI) shielded or grounded panel assembly including a porous, electrically-conductive shielding media and an electrically-conductive frame for supporting the media, and more particularly to such an assembly which is adapted to cover a corresponding ventilation opening in an electronics housing or other enclosure enclosures and which accommodates the flow of cooling air into the enclosure while maintaining electrical continuity and EMI shielding effectiveness across the opening.
  • [3]
    3. The operation of electronic devices such as televisions, radios, computers, medical instruments, business machines, communications equipment, and the like is attended by the generation of electromagnetic radiation within the electronic circuitry of the equipment. As is detailed in U.S. Pat. Nos. 5,202,536; 5,142,101; 5,105,056; 5,028,739; 4,952,448; and 4,857,668, such radiation often develops as a field or as transients within the radio frequency band of the electromagnetic spectrum, i.e., between about 10 KHz and 10 GHz, and is termed “electromagnetic interference” or “EMI” as being known to interfere with the operation of other proximate electronic devices.
  • [4]
    4. For attenuating EMI effects, shielding having the capability of absorbing and/or reflecting EMI energy may be employed both to confine the EMI energy within a source device, and to insulate that device or other “target” devices from other source devices. Such shielding is provided as a barrier which is interposed between the source and the other devices, and most often is configured as an electrically conductive and grounded housing or other enclosure, such as a room, which surrounds the EMI generating circuitry of the source device. However, when such circuitry is contained within the confined space of an enclosure, it often is necessary to provide a cooling or ventilation means to dissipate the heat which is ohmicly or otherwise generated by the circuitry. Most enclosures therefore are formed with one or more air intake and/or exhaust openings or ports for natural or forced convective circulation of air between the interior of the enclosure and the ambient environment.
  • [5]
    5. Left uncovered, such openings would represent a discontinuity in the surface and ground conductivity of the enclosure, with the result of a decrease in the EMI shielding effectiveness of the enclosure. Accordingly, shielded vent panels have been proposed for covering the openings in an manner which allows for the ventilation of the enclosure while electrical continuity, i.e., grounding, across the vent opening is maintained. In basic construction, such vent panels, which are sized to span the corresponding opening in the enclosure, conventionally are formed as including a sheet of a porous, electrically-conductive shielding media, and an electrically-conductive frame member configured to support the media as extending about the outer periphery thereof. The media, which may be an expanded metal mesh or, alternatively, a honeycombed-structured or other cellular structured metal foil, is received in or otherwise is attached to the frame, which typically is provided as an extruded aluminum or other metal profile. The frame, in turn, may be fastened to the enclosure over the opening thereof with screws or the like, with a compressible, electrically-conductive seal or gasket optionally provided for improved electrical contact between the frame and the enclosure.
  • [6]
    6. However, for electrical continuity to be maintained across the opening, good electrical contact must be provided not only as between the frame and the enclosure, but also as between the media and the frame. In this regard, conventional panels may employ a C-shaped frame channel including a V-shaped or other projection integrally formed within one of the sides of the channel. With the peripheral edges of the media being received within the channel, the sides thereof are compressed to cause the projection to penetrate into the media and thereby establish good electrical contact. Vent panels of such type are marketed commercially by the Chomerics Division of Parker-Hannifin Corp. (Woburn, Mass. under the tradenames “Cho-Cell™,” “Shield Cell®,” and “Omni Cell®.” Alternatively, the media may be fit into the frame and then bonded thereto using a conventional joining technique such as resistance welding, brazing, soldering, or the like.
  • [7]
    7. Another method of attaching the media to the frame involves using the gasket typically provided between the frame and the enclosure to hold the filter media in place. As is described in commonly-assigned U.S. Pat. No. 5,032,689, the frame in such method may be integrally-formed as including a ridge over which the gasket is press-fitted for its retention about the periphery of the frame. The gasket, in turn, may be configured to overlap the media for securing the media to the frame.
  • [8]
    8. U.S. Pat. No. 3,580,981 discloses another shielding vent panel wherein an electrically conductive textile is positioned about the periphery of the media for contact between the media and the frame which may have an L-shaped or generally Z-shaped profile. To assure good conductivity, the frame, media, and textile are covered with an electrically-conductive coating or plating such as by immersion in a molten tin or metal bath. Other vents and materials therefor are described in U.S. Pat. Nos. 3,546,359; 3,553,343; 3,584,134; 3,821,463; and 4,616,101.
  • [9]
    9. In view of the continued proliferation of electronic devices, it is to be expected that continued improvements in EMI shielded vent panels would be well-received by industry, and particularly by semi-conductor manufacturers for use in the processing of silicon wafers and the like. A preferred seal construction would be economical to manufacture, but also would exhibit reliable shielding performance in assuring good electrical contact between the shielding media and the frame member.
  • BROAD STATEMENT OF THE INVENTION
  • [10]
    10. The present invention is directed to an EMI shielded vent construction including an electrically-conductive frame member having a generally U- or C-shaped profile including and end wall portions and a pair of side wall portions integral with the end wall portion, and an electrically-conductive, porous shielding medium member, which is supported by the frame member. With the periphery of the shielding medium member being received within the frame member intermediate the lateral or side wall portions thereof, the frame member may be compressed, such as within a hydraulic platen press or the like, to retain the medium member therein. However, in accordance with the present invention, a resilient, electrically-conductive strip gasket element further is provided as interposed between the medium member and one of the side wall portions of the frame member prior to the compression thereof. Such gasket member conforms under the applied pressure to any irregularities between the interfacing surfaces of the medium member and the frame member in ensuring that a substantially continuous conductive pathway is developed across those surfaces without the provision of an additional conductive coating or plating. Advantageously, the provision of the gasket member obviates the need to integrally form a contact projection within the frame member, and thus allows the frame member to be constructed of a roll formed aluminum or other metal channel rather than of a more costly extruded profile. The use of roll formed channel, moreover, allows a continuous length thereof to be folded or otherwise shaped into a rectangular, square, or other closed geometry and thereby eliminates the need for welds at the frame member corners.
  • [11]
    11. In one disclosed embodiment, the frame member is formed of aluminum or another metal, with the medium being formed of a layer of an aluminum or other metal foil which is folded, bent, or otherwise shaped into a cellular honeycomb structure to extend along a transverse axis intermediate a generally planar first and second face. Although the strip gasket element may be formed of any resilient, electrically conductive material such as a metal-filled elastomeric extrusion, or a foam extrusion sheathed in an electrically conductive mesh or fabric, an all-metal, knitted wire construction may be specified for economic or performance considerations. In a preferred construction, the compression of the frame member advantageously effects the compression of both the gasket and the peripheral edges of the medium to provide a greater surface area of electrical contact therebetween.
  • [12]
    12. It is therefore a feature of the present invention to provide an electromagnetic interference (EMI) shielded vent panel construction for disposition over a corresponding opening formed within a surface of an electronics enclosure. The vent panel includes an electrically-conductive medium having an outer periphery and extending along a transverse axis intermediate a pair of faces defining a thickness dimension. Such dimension is supported within an electrically-conductive frame having a perimeter defining a closed geometric area selected to circumscribe the opening of the electronics enclosure. The frame is configured as having a generally C-shaped cross-sectional profile and includes an elongate end wall having an interior surface and an exterior surface, and a pair of oppositely-disposed side walls extending from the interior surface of the end wall. Each of the side walls has an outer surface, one of which is disposable about the opening of the enclosure in electrically-conductive adjacency with the surface thereof, and an inner surface spaced-apart a first predetermined distance from the inner surface of the other of the side walls. The outer periphery of the medium is received intermediate the inner surfaces of the side walls such that each of said walls extends over a corresponding edge portion of the faces of the medium. Along with the medium, an electrically-conductive gasket is disposed intermediate the inner surface of a first one of the side walls and the edge portion of a first one of the medium faces. The gasket extends along substantially the entire perimeter of the frame and is deflectable between the inner surface of said first one of said side walls and the edge portion of said first one of the faces of said medium. As assembled, the frame is compressed to space the inner surface of each of the side walls thereof a second predetermined distance from the inner surface of the other of said side walls deflecting the gasket into a collapsed orientation effective to provide substantially continuous electrical contact between the frame and the medium.
  • [13]
    13. The present invention, accordingly, comprises the vent panel possessing the combination of elements and construction which are exemplified in the detailed disclosure to follow. Advantages of the present invention include a vent panel exhibits reliable EMI shielding and air flow characteristics. Additional advantages include a panel construction which is economical in allowing the use of a roll formed frame, and which ensures good electrical contact between the shielding medium and the frame without the need for a separate metal plating operation. These and other advantages will be readily apparent to those skilled in the art based upon the disclosure contained herein.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • [14]
    14. For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:
  • [15]
    15.FIG. 1 is a perspective view of a representative electronics enclosure including an EMI shielded vent panel according to the present invention.
  • [16]
    16.FIG. 2 is an exploded perspective view of the EMI shielded vent panel of FIG. 1 showing the frame, medium, and gasket elements thereof;
  • [17]
    17.FIG. 3A is an assembly view showing the bending of a roll formed channel to partially form the frame of FIG. 2;
  • [18]
    18.FIG. 3B is a continuing assembly view showing the medium of FIG. 2 being received within the frame of FIG. 3A;
  • [19]
    19.FIG. 3C is a continuing assembly view showing the assembled frame and medium of FIG. 3B with the gasket of FIG. 2 installed and prior to the compressing of the frame;
  • [20]
    20.FIG. 3D is a continuing assembly view showing the vent subassembly of FIG. 3C following the compression of the frame;
  • [21]
    21.FIG. 4 is an enlarged, generally schematic cross-sectional view of the vent subassembly of FIG. 3C taken through line 44 of FIG. 3C;
  • [22]
    22.FIG. 5 is an enlarged, generally schematic cross-sectional view of the vent assembly of FIG. 3D taken through line 55 of FIG. 3D;
  • [23]
    23.FIG. 6 is perspective view showing a portion of the vent assembly of FIG. 3D with a section of the frame member being cut-away to detail the compression of the gasket member therein; and
  • [24]
    24.FIG. 7 is an enlarged cross-sectional view taken through line 77 of FIG. 6 and illustrating the electrical contact between the gasket and medium.
  • [25]
    25. The drawings will be described further in connection with the following Detailed Description of the Invention.
  • DETAILED DESCRIPTION OF THE INVENTION
  • [26]
    26. Certain terminology may be employed in the description to follow for convenience rather than for any limiting purpose. For example, the terms “forward,” “rearward,” “right,” “left,” “upper,” and “lower” designate directions in the drawings to which reference is made, with the terms “inward,” “inner,” or “inboard” and “outward,” “outer,” or “outboard” referring, respectively, to directions toward and away from the center of the referenced element, and the terms “radial” and “axial” referring, respectively, to directions perpendicular and parallel to the longitudinal central axis of the referenced element. Terminology of similar import other than the words specifically mentioned above likewise is to be considered as being used for purposes of convenience rather than in any limiting sense.
  • [27]
    27. In the figures, elements having an alphanumeric designation may be referenced herein collectively or in the alternative, as will be apparent from context, by the numeric portion of the designation only. Further, the constituent parts of various elements in the figures may be designated with separate reference numerals which shall be understood to refer to that constituent part of the element and not the element as a whole. General references, along with references to spaces, surfaces, dimensions, and extents, may be designated with arrows.
  • [28]
    28. For the purposes of the discourse to follow, the precepts of the inventive EMI shielded vent panel, referenced at 10 in FIG. 1, herein involved are described in connection with its mounting onto a surface, 12, of a electronics enclosure, such as the EMI shielded housing shown in phantom at 14. Within this representative application, panel 10 is mounted using, for examples, screws, bolts, or other fastening members, over a corresponding opening formed within housing 14. Such opening generally will be formed as having a predefined outer margin, shown in phantom at 16, about which panel 10 is circumscribed to cover the opening in a manner providing ventilation without compromising the EMI shielding effectiveness of the housing 14. It will be appreciated, however, that aspects of the present invention may find utility in other EMI shielding applications. For example, panel 10 of the invention alternatively may be mounted onto the wall of an EMI shielded room for covering a ventilation opening thereof. Use within those such other applications therefore should be considered to be expressly within the scope of the present invention.
  • [29]
    29. Referring then to the remaining figures wherein corresponding reference characters are used to designate corresponding elements throughout the several views, EMI shielded vent panel 10 of FIG. 1 reappears in the exploded view of FIG. 2. As may be seen, in basic construction panel 10 includes an electrically-conductive, generally-planar medium, 20, having an outer periphery, 22, which is supported within an electrically-conductive frame, 24, along with a generally resilient, electrically-conductive gasket, 26. For illustrative purpose, frame 24 is shown to have a perimeter, the extent of which is referenced at 27, which defines a generally polygonal geometry sized to circumscribe the margins of a similarly dimensioned vent opening. Depending upon the configuration of the corresponding opening, however, the perimeter 27 of frame 24 may be of any closed geometry.
  • [30]
    30. As may be seen in the exploded view of FIG. 2, frame 24 preferably is formed from a length of an aluminum or other metal channel in a manner to be detailed hereinafter. Such channel may have, as is shown, a generally U- or C-shaped cross-sectional profile including an elongate end wall, 30, having an interior surface, 32, and an exterior surface, 34, and a pair of generally parallel, oppositely-disposed side walls, 36 a-b, extending from the interior surface 32 of the end wall 30. Each of the side walls 36 a-b, in turn, has an outer surface, 38 a-b, and an inner surface, 40 a-b, which is spaced-apart from the opposing inner surface 40 a oar 40 b of the other side wall 36 a or 36 b.
  • [31]
    31. The outer surface 38 a or 38 b of one or either of the side walls 36 a or 36 b is disposable about the opening of the housing 14 (FIG. 1) or other enclosure in an electrically-conductive contact adjacency with the surface 12 thereof. For lowering the impedance across the frame-housing interface, an electrically conductive seal or gasket member conventionally may be employed as mounted onto the confronting side wall outer surface 38 a or 38 b or as otherwise interposed between that surface and the housing surface 12. Such gasket may be constructed as having a resilient core element affording gap-filling capabilities which is either loaded, sheathed, or coated with an electrically conductive element. The resilient core element, which may be foamed or unfoamed, solid or tubular, typically is formed of an elastomeric thermoplastic material such as polyethylene, polypropylene, polyvinyl chloride, or a polypropylene-EPDM blend, or a thermoplastic or thermosetting rubber such as a butadiene, styrene-butadiene, nitrile, chlorosulfonate, neoprene, urethane, silicone, or fluorosilicone.
  • [32]
    32. Conductive materials for the filler, sheathing, or coating include metal or metal-plated particles, fabrics, meshes, and fibers. Preferred metals include copper, nickel, silver, aluminum, tin or an alloy such as Monel, with preferred fibers and fabrics including natural or synthetic fibers such as cotton, wool, silk, cellulose, polyester, polyamide, nylon, polyimide. Other conductive particles and fibers such as carbon, graphite, plated glass, or a conductive polymer material may be substituted. The gasket, alternatively, may be provided to be of an all-metal, knitted wire construction, or as a formed-in-place (FIP) bead of a curable, electrically-conductive silicone or urethane composition which is dispensed in a fluent state onto the surface of the frame or housing and then is cured in situ via the application of heat or with atmospheric moisture.
  • [33]
    33. As mentioned, the panel 10 is mountable onto surface 12 of housing 14 using screws, bolts, or other fastening members. In this regard, frame 24 may be provided has having a plurality of fastener-receiving apertures, one of which is referenced in phantom at 42, formed through side walls 38 a-b as indexed for registration with a corresponding aperture formed within the housing surface 12. Alternatively, frame 24 may be attached to the housing 14 using an electrically conductive adhesive, or otherwise as configured for an interference fit within the housing opening.
  • [34]
    34. Electrically-conductive medium 20 extends along a transverse axis, 50, intermediate a pair of opposing medium faces, 52 a-b, defining a thickness dimension therebetween which may range, typically, from about 0.25-1 inch (0.635-2.54 cm). Although medium 20 may be provided as a metal screen or expanded metal mesh, it more preferably is provided, as is shown in FIG. 2, as having a hexagonal, i.e., honeycombed, or other cellular structure which is “open” or otherwise porous to admit the flow of cooling air therethrough for the ventilation of the associated housing or other electronics enclosure. Such cellular structure of medium 20, which may be formed from a corrugated sheet of a 1-5 mil (0.039-0.197 mm) thick aluminum or other metal foil material, or otherwise as is described in U.S. Pat. No. 3,821,463, includes a plurality of cells, one of which is referenced at 54. Each of the cells 54 define a corresponding ventilation passageway of the medium 20 as extending through the thickness direction thereof generally along or parallel to the transverse axis 50 from, as is shown for cell 54, a first end, 56 a, which forms a segment of the medium face 52 a, and a second end, 56 b, which forms a segment of the medium face 52 b. As may be seen best with momentary reference to the assembled view of FIG. 3D, and with particular additional reference to the cross-sectional view thereof shown in FIG. 5, the thickness dimension of the outer periphery 22 of medium 20 is received intermediate the inner surfaces 40 a-b of side walls 36 a-b such that each of the walls 36 a-b extends over a corresponding edge portion, referenced in FIG. 5 at 60 a-b, respectively, of the medium faces 52 a-b.
  • [35]
    35. Optionally, a dust filter (not shown) may be employed in conjunction with medium 20 as disposed parallel thereto in a series arrangement relative to the air flow direction. Such filter may be formed of a screen or a high porosity foam or the like which allows for sufficient air flow therethrough while reducing the transmission of dust or other airborne contaminants into the enclosure. The filter may be attached to the outside, relative to the enclosure, of the frame in a conventional manner, but preferably is made to be removable for easier cleaning and replacement.
  • [36]
    36. Returning to FIG. 2, it further may be seen that electrically-conductive gasket 26 is provided to extend along substantially the entire frame perimeter 27 and medium outer margin 22 as interposed between, for example, the inner surface 40 a of side wall 36 a and the edge portion 60 a of medium face 52 a. In this regard, and as may be seen best with momentary reference again to the cross-sectional view of FIG. 5, gasket 26 is deflectable between the side wall inner surface 40 a and the medium face 52 a from a normal orientation to a collapsed orientation effective to provide, in accordance with the precepts of the present invention, substantially continuous electrical contact between the frame 24 and the medium 20.
  • [37]
    37. In the preferred embodiment of the invention illustrated in FIG. 1, gasket 26 is provided as a single length of an electrically-conductive strip material. For lowering the electrical impedance across the frame-medium interface, such material preferably exhibits gap-filling capabilities, and, as before, may be of a construction including a resilient core element which is either loaded, sheathed, or coated with an electrically conductive element. The resilient core element, which again may be foamed or unfoamed, solid or tubular, may formed of an elastomeric thermoplastic material such as polyethylene, polypropylene, polyvinyl chloride, or a polypropylene-EPDM blend, or a thermoplastic or thermosetting rubber such as a butadiene, styrene-butadiene, nitrile, chlorosulfonate, neoprene, urethane, silicone, or fluorosilicone. Conductive materials for the filler, sheathing, or coating include metal or metal-plated particles, fabrics, meshes, and fibers. Preferred metals include copper, nickel, silver, aluminum, tin or an alloy such as Monel, with preferred fibers and fabrics including natural or synthetic fibers such as cotton, wool, silk, cellulose, polyester, polyamide, nylon, polyimide. Other conductive particles and fibers such as carbon, graphite, plated glass, or a conductive polymer material may be substituted.
  • [38]
    38. In an particularly economical construction, however, gasket 26 is provided to be formed of a continuous metal wire which, depending upon the application, may be aluminum, Monel (nickel-copper alloy), or Ferrex® (tin-platted, copper-clad steel) sized to a diameter of between about 0.002-0.006 inch (0.05-0.15 mm). The wire may be knitted into a plurality of spring-like interlocking loops to form a mesh, which mesh then may be rolled, drawn, or otherwise formed into a compressible strip having a rectangular or round cross-section of a nominal widthwise dimension or diameter ranging between about 0.062-0.5 inch (1.57-12.7 mm). Wire mesh strip gaskets so formed generally are highly resilient in exhibiting a compression/deflection response of between about 50-80%. Commercial gaskets of such type are marketed by the Chomerics Division of Parker-Hannifin Corp. (Woburn, Mass.) under the tradename “Mesh Strip®.”
  • [39]
    39. With continuing reference to FIG. 2, and looking sequentially to FIGS. 3A-3D, a preferred method of assembly is described in further accordance with the present invention. Advantageously, by virtue of the described construction of panel 10, frame 24 may be economically formed from a single length of a metal channel, such as the channel 80 depicted in FIG. 3A which extends intermediate a mitered first end, 82, and correspondingly-mitered second end, 84. Channel 80 may be provided as a conventionally roll formed from a 25-60 mil (0.63-1.52 mm) thick sheet of aluminum or another metal. Roll forming is a cold working process which, as described in U.S. Pat. Nos. 4,354,372; 5,272,899; 5,527,625; 5,640,869, is well known in the metal forming arts.
  • [40]
    40. In the preferred embodiment shown in FIG. 3A, channel 80 is provided as having three spaced-apart pairs of generally V-shaped notch pairs, 86 a-c, each of which notch pairs extends from the inboard edges, 88 a-b, of side walls 36 a-b through a portion thereof. As is shown in FIG. 3A, channel 80 is bendable or otherwise foldable through each of the notch pairs 86 a and 86 b to form the corners 87 a and 87 b, respectively, of a generally U-shaped subassembly into which, as is shown in FIG. 3B, medium 20 may be received. Thereafter, and as is shown in phantom at 89 in FIG. 3B, channel 80 then may be folded through notch 86 c to form the corner 87 c shown in FIG. 3C, and to dispose second end 84 in diametrically opposed adjacency with first end 82 to define the corner 87 d and the interface 86 d between the opposing channel ends 82 and 84.
  • [41]
    41. For securing the ends 82 and 84 thereof, channel 80 further may be provided as having a tab, best seen at 90 in FIG. 2, integrally formed at second end 84 as an extension of end wall 30. Tab 90 includes a fastener receiving hole, 92, which is disposable in registration with a corresponding hole 94 formed into end wall 30 at first end 82. As is shown in phantom at 90′, tab 90 is foldable inwardly about end wall 30 to complete the corner 87 d and to overlap first end 82 disposing, as is shown at 92′, hole 92 in registration with hole 94. Lastly with respect to the assembly of frame 24, a rivet or other fastening member, referenced at 96 in FIG. 3C, may be received through the registered holes 92 and 94 for joining channel ends 82 and 84 and thereby securing the perimeter 27 of frame 24 into a closed geometry.
  • [42]
    42. With frame 24 being assembled as in FIG. 3C such that medium 20 is supported therein, gasket 26 then may be installed within the subassembly by being press fit or otherwise inserted intermediate, for example, the inner surface 40 a of side wall 36 a and the face 52 a of medium 20. Without departing from the precepts of the present invention, however, gasket 26 alternatively may be inserted intermediate the inner surface 40 b of side wall 36 b and the face 52 b of medium 20. A pair of such gaskets, moreover, may be employed with one disposed intermediate each of the side wall inner surfaces 40 a-b and the confronting medium face 52 a-b.
  • [43]
    43. For accommodating the installation of gasket 26, and with additional reference to the somewhat schematic cross-sectional view of the assembly of FIG. 3C shown in FIG. 4, it will be appreciated that channel 80 preferably is provided such that the confronting inner surfaces 40 of side walls 36 are spaced apart a first predetermined distance, referenced in FIG. 4 at d1, sized to receive the thickness dimension of the outer periphery 22 of medium 20 and the widthwise extent of gasket 26. In this regard, channel 90 may be roll formed with side wall 36 a being oriented such that the inner surface 40 a thereof defines a generally obtuse angle, referenced at θ1, of preferably between about 92°-100° with the interior surface 32 of frame end wall 30 corresponding to an angle of between about 2°-10° with the medium face 52 a. As also is shown in FIG. 4, the other side wall 36 b may be oriented such that the inner surface 40 b thereof defines a generally right angle, referenced at α, with the frame end wall interior surface 32.
  • [44]
    44. Following the installation of gasket 26 the panel subassembly shown in FIG. 3C may be compressed under a force, referenced 98, directed generally normal to the outer surfaces 38 a-b of side walls 36 a-b to form the final panel assembly 10 shown in FIG. 3D. Such compression may be effected within a conventional platen press operated under a pressure which may range from about 300-1000 psi (2070-6895 kPa). As may be seen best with additional reference to the somewhat schematic cross-section view of assembly 10 shown in FIG. 5 and to the cut-away perspective view of the panel detail 100 shown in FIG. 6, frame 24 is compressed such that the side wall inner surfaces 40 a-b are spaced-apart a second predetermined distance, referenced in FIG. 5 at d2, with side wall 36 a being re-oriented to dispose the inner surface 40 a thereof at a generally right angle, referenced at θ2, relative to the interior surface 32 of frame end wall 30. In such orientation of frame 24, and with gasket 26 being disposed over the first ends 56 a of a linear progression, referenced at 102, of cells 54 extending generally along the outer periphery 22 of medium 20, gasket 26 is compressed by up to about 50% of its original widthwise extent or diameter into a collapsed orientation effective to provide substantially continuous electrical contact between frame 24 and medium 20. In this regard, the provision and deflection of gasket 26 has been observed to lower the electrical impedance across the frame-medium interface by 10% or more, but without requiring the penetration of the medium by an extrusion-formed projection of the frame or the need for a separate conductive coating or plating applied to the gasket.
  • [45]
    45. Advantageously, and as may be seen best in FIG. 6, the first ends 56 a of the cells 54 in progression 102 under gasket 26 may, in the compressed orientation of the frame 24, be inwardly deflected concomitantly with the compression of gasket 26. With reference to the cross-sectional view of FIG. 7, it may be seen that as deflected, the first ends 56 of the cell progression 102 of FIG. 6 assume a folded orientation presenting a generally planar contact surface, 104, with gasket 26. Such surface 104, which may be disposed, as is shown, generally perpendicular to the transverse axis 50 of medium 20, increases the area of electrical contact between medium 20 and gasket 26, and thereby lowers the impedance across the frame-medium interface.
  • [46]
    46. Thus, a EMI shielded vent construction for electronics enclosures is described which exhibits reliable EMI shielding in ensuring the grounding of the enclosure across the vent opening. Such construction additional is exceptionally economical to manufacture in allowing the use of a roll formed frame, and in ensuring good electrical contact between the shielding media without the need for a separate metal plating. These use of a roll formed frame construction additionally eliminates the need and expense of having to provide welded frame joints at the corners of the panel.
  • [47]
    47. As it is anticipated that certain changes may be made in the present invention without departing from the precepts herein involved, it is intended that all matter contained in the foregoing description shall be interpreted as illustrative and not in a limiting sense. All references cited herein are expressly incorporated by reference.

Claims (8)

    What is claimed is:
  1. 1. A method of making an electromagnetic interference (EMI) shielded vent panel for disposition over a corresponding opening formed within a surface of an electronics enclosure, the opening having a predefined outer margin and said method comprising the steps of:
    (a) providing an electrically-conductive medium having an outer periphery and extending along a transverse axis intermediate a pair of faces defining a thickness dimension therebetween, said medium have a plurality of ventilation passageways extending through said thickness direction generally along said transverse axis;
    (b) supporting the thickness dimension of the outer periphery of said medium within an electrically-conductive frame having a perimeter defining a closed geometry configured to circumscribe the opening of the electronics enclosure, said frame having a generally C-shaped cross-sectional profile including an elongate end wall having an interior surface and an exterior surface, and a pair of oppositely-disposed side walls extending from the interior surface of said end wall, each of said side walls having an outer surface and an inner surface spaced-apart a first predetermined distance from the inner surface of the other of said side walls, the outer periphery of said medium being received intermediate the inner surfaces of said side walls such that each of said walls extends over a corresponding edge portion of the faces of said medium, with the outer surface of one of said side walls being disposable about the opening of the enclosure in electrically-conductive adjacency with the surface thereof;
    (c) disposing an electrically-conductive gasket intermediate the inner surface of a first one of said side walls and the edge portion of a first one of the faces of said medium, said gasket extending along substantially the entire perimeter of said frame and being deflectable between the inner surface of said first one of said side walls and the edge portion of said first one of the faces of said medium; and
    (d) compressing said frame to space the inner surface of each of said side walls thereof a second predetermined distance from the inner surface of the other of said side walls deflecting said gasket into a collasped orientation effective to provide substantially continuous electrical contact between said frame and said medium.
  2. 2. The method of
    claim 1
    wherein said medium is provided as a metal foil material which is corrugated into a plurality of cells, each of said cells extending along the transverse axis of said medium from a first end forming a segment of the first one of the faces of said medium to a second end forming a segment of the second one of the faces of said medium, and defining one of said ventilation passageways extending through said medium.
  3. 3. The method of
    claim 2
    wherein said gasket is disposed in step (c) over the first ends of a progression of said cells extending along the outer periphery of said medium, and wherein said first ends of said progression of said cells are deflected in step (d) under said gasket into a folded orientation presenting an electrical contact surface with said gasket disposed generally perpendicular to the transverse axis of said medium.
  4. 4. The method of
    claim 1
    wherein said gasket is disposed in step (c) as a strip of a resilient, knitted wire mesh material.
  5. 5. The method of
    claim 1
    wherein said frame is provided in step (b) as a rolled-formed, metal channel which extends from a first end to a second end, said channel being folded intermediate said first and said second end to form said frame.
  6. 6. The method of
    claim 1
    wherein a first one of said side walls of said frame of step (b) is oriented such that the inner surface thereof defines a generally obtuse angle with the interior surface of said end wall with said gasket being disposed in step (c) intermediate the inner surface of said first one of said side walls and the edge portion of said first one of the faces of said medium, and wherein said frame is compressed in step (d) to dispose the inner surface of said first one of said side walls generally perpendicular to the interior surface of said end wall.
  7. 7. The method of
    claim 6
    wherein the second one of said side walls of said frame of step (b) is oriented such that the inner surface thereof is disposed generally perpendicular to the interior surface of said end wall.
  8. 8. The EMI shielded vent panel made by the method of
    claim 1
    .
US09737195 1998-02-17 2000-12-15 EMI shielded vent panel and method Active US6362417B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US7492998 true 1998-02-17 1998-02-17
US09243778 US6211458B1 (en) 1998-02-17 1999-02-03 EMI shielded vent panel and method
US09737195 US6362417B2 (en) 1998-02-17 2000-12-15 EMI shielded vent panel and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09737195 US6362417B2 (en) 1998-02-17 2000-12-15 EMI shielded vent panel and method

Publications (2)

Publication Number Publication Date
US20010000392A1 true true US20010000392A1 (en) 2001-04-26
US6362417B2 US6362417B2 (en) 2002-03-26

Family

ID=22122503

Family Applications (2)

Application Number Title Priority Date Filing Date
US09243778 Active US6211458B1 (en) 1998-02-17 1999-02-03 EMI shielded vent panel and method
US09737195 Active US6362417B2 (en) 1998-02-17 2000-12-15 EMI shielded vent panel and method

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09243778 Active US6211458B1 (en) 1998-02-17 1999-02-03 EMI shielded vent panel and method

Country Status (3)

Country Link
US (2) US6211458B1 (en)
CA (1) CA2318433A1 (en)
WO (1) WO1999041963A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030201111A1 (en) * 2001-08-21 2003-10-30 Dell Products L.P. Perforated EMI gasket
US6680847B2 (en) * 2000-12-22 2004-01-20 Emc Corporation Electronic circuitry enclosure with air vents that comply with emissions and safety standards
WO2013138265A1 (en) * 2012-03-13 2013-09-19 Parker-Hannifin Corporation Deflectable conductive gasket with environmental seal
WO2016182871A1 (en) * 2015-05-08 2016-11-17 Laird Technologies, Inc Soft and/or flexible board level shields and related methods

Families Citing this family (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE69627909D1 (en) * 1995-01-17 2003-06-12 Vlt Corp Regulation of gepseicherten in the transformers of switching power supplies energy
US7071409B2 (en) * 1998-03-06 2006-07-04 Hoffman Enclosures, Inc. Electrical enclosure having improved sealing and shielding component and method of manufacture thereof
US6188014B1 (en) * 1998-03-06 2001-02-13 Hoffman Enclosures, Inc. Electrical enclosure having improved sealing and shielding component and method of manufacture thereof
CN101427618B (en) * 1998-12-15 2011-04-20 万加德产品股份有限公司 Electromagnetic interference shielding device
CN1207952C (en) * 1999-04-13 2005-06-22 西门子公司 Device for cooling electric module and technical appliance
DE19928580B4 (en) * 1999-06-22 2005-08-25 Reinz Dichtungs-Gmbh Flat gasket and method of manufacturing a gasket
US6411102B1 (en) * 2000-01-07 2002-06-25 International Business Machines Corporation Apparatus for testing various structural parameters of an electro-magnetic radiation barrier
US6646197B1 (en) * 2000-05-02 2003-11-11 Nortel Networks Limited High performance EMI shield for electronic equipment
US6384325B1 (en) * 2000-06-01 2002-05-07 Hewlett-Packard Company Ventilation port and EMI wave-guide for electronic equipment
US6449150B1 (en) * 2000-11-13 2002-09-10 Cisco Technology, Inc. Method and system for cooling a card shelf
US6501015B2 (en) * 2001-01-22 2002-12-31 Marconi Communications, Inc. Vented cap for equipment pedestal
US6626264B1 (en) * 2001-10-30 2003-09-30 Igt Radio frequency shielded and acoustically insulated enclosure
JP2005512336A (en) 2001-12-04 2005-04-28 レアード テクノロジーズ,インコーポレーテッド The method and apparatus of the Emi shielding
US6610922B1 (en) 2001-12-20 2003-08-26 Cisco Technology, Inc. Apparatus for securing an electromagnetic shield in a conductive casing
CN1276698C (en) * 2002-02-19 2006-09-20 S&K聚合物技术株式会社 High polymer microcellular foam conductive gaskets and method for preparing thereof
CA2428848A1 (en) * 2002-05-16 2003-11-16 Parker-Hannifin Corporation Emi shielding vent panel
US20040014421A1 (en) * 2002-07-19 2004-01-22 Raymer Paul H. Return air pressure relief vent
US6852924B2 (en) * 2002-07-30 2005-02-08 Lsi Logic Corporation EMI sealed removable latching cover
US20040047121A1 (en) * 2002-09-10 2004-03-11 John Hope Apparatus for EMI/RFI hardening of off-the-shelf computers
WO2004032580B1 (en) * 2002-10-03 2004-07-22 Laird Technologies Inc Emi-absorbing air filter
US7038124B1 (en) * 2002-11-19 2006-05-02 Laird Technologies, Inc. Two-piece EMI shielding vent panel
DE20306848U1 (en) * 2002-12-04 2003-08-14 Shuttle Inc Decoration window for a computer case
US6992885B2 (en) * 2003-07-21 2006-01-31 Datastor Technology Co., Ltd. External connection device for a storage device
EP1738625B1 (en) * 2004-01-29 2010-11-10 Laird Technologies, Inc. Ultra-low height electromagnetic interference shielding enclosure
US7183500B2 (en) * 2004-06-30 2007-02-27 Intel Corporation Electromagnetic interference (EMI) filter with passive noise cancellation
US7230827B2 (en) * 2005-04-20 2007-06-12 Dell Products L.P. Method and apparatus for venting a chassis
WO2007053651A3 (en) * 2005-11-01 2009-05-14 Amy L Boyce Emi vent panels including electrically-conductive porous substrates and meshes
US20070103862A1 (en) * 2005-11-10 2007-05-10 David Costello Chassis with positive pressure
US7492610B2 (en) * 2006-06-23 2009-02-17 International Business Machines Corporation Apparatus for improving server electromagnetic shielding
JP4518097B2 (en) * 2007-04-13 2010-08-04 ソニー株式会社 The front structure of the information processing apparatus
US7854781B2 (en) * 2007-04-30 2010-12-21 International Business Machines Corporation Mount for air filter and bezel assembly
US20090147464A1 (en) * 2007-12-10 2009-06-11 William James Anderl Ventilation Assembly for Computer Hardware Systems
US9393853B2 (en) * 2009-10-26 2016-07-19 The Eastern Company Vent apparatus
US20130135840A1 (en) * 2011-11-29 2013-05-30 Hon Hai Precision Industry Co., Ltd. Container data center
US20140077672A1 (en) * 2012-09-19 2014-03-20 A. Love II Grayling Data center rack door
US9101049B2 (en) * 2013-01-02 2015-08-04 Mcafee Inc. Opacity baffle to prevent viewing of internal structures in secure electronic equipment
RU2533687C1 (en) * 2013-04-25 2014-11-20 Сергей Иванович Петренко Device for reduction of electromagnetic background induced by electronics and operation mode of device
US9370132B2 (en) 2013-08-27 2016-06-14 Parker-Hannifin Corporation Homogeneous EMI vent panel and method for preparation thereof
US9345182B2 (en) * 2013-08-27 2016-05-17 Parker-Hannifin Corporation EMI shielding vent panel frame
RU2543077C1 (en) * 2013-10-18 2015-02-27 Общество с ограниченной ответственностью "Защита Информации" Ventilation panel for electronic device and method of making same
US9832918B2 (en) * 2015-08-13 2017-11-28 Arc Technologies, Inc. EMR absorbing server vent

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3553343A (en) 1968-11-19 1971-01-05 Sprague Electric Co Ventilation aperture for shielded enclosures
US3584134A (en) 1968-11-21 1971-06-08 Lectro Magnetics Inc Shielded air vents
US3546359A (en) 1969-06-18 1970-12-08 Gichner Mobile Systems Inc Rfi shielded vent
US3580981A (en) 1969-10-14 1971-05-25 Tech Wire Prod Inc Electrically conductive ventilating panel
US3821463A (en) 1970-03-06 1974-06-28 Metex Corp Electromagnetic shielding material
JPS6032532B2 (en) 1978-03-08 1985-07-29 Hitachi Metals Ltd
US4381421A (en) * 1980-07-01 1983-04-26 Tektronix, Inc. Electromagnetic shield for electronic equipment
US4616101A (en) 1984-07-13 1986-10-07 U.S. Philips Corporation Ventilation panel for electromagnetic shielding
US4851608A (en) * 1987-05-08 1989-07-25 Technical Wire Products, Inc. Electromagnetic shielding media and methods for manufacturing the same
US4857668A (en) * 1988-04-15 1989-08-15 Schlegel Corporation Multi-function gasket
US5032689A (en) * 1989-08-15 1991-07-16 Halligan Brian S EMI/RFI shielding vent and method of use
CA2077429C (en) 1992-09-02 1999-03-30 Ernest R. Bodnar Roll formed metal member
US5272899A (en) 1992-09-17 1993-12-28 Mcdonald Steel Corp. Method and apparatus for hot roll forming inside U-shaped channel section
JP3195718B2 (en) 1994-08-25 2001-08-06 昭和飛行機工業株式会社 Honeycomb ventilation body for electromagnetic shielding
JP3500742B2 (en) 1994-12-07 2004-02-23 アイシン精機株式会社 Method of manufacturing a gradual change roll moldings
WO1997032459A1 (en) 1996-02-28 1997-09-04 The Whitaker Corporation Shielding device for ventilation panels of electronic instruments and method for manufacture thereof
US5910639A (en) * 1997-03-20 1999-06-08 Kunkel; George M. Air vent panels for electromagnetic shielding
US5928076C1 (en) * 1997-09-25 2001-04-24 Hewlett Packard Co Emi-attenuating air ventilation panel
US5991163A (en) * 1998-11-12 1999-11-23 Nexabit Networks, Inc. Electronic circuit board assembly and method of closely stacking boards and cooling the same

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6680847B2 (en) * 2000-12-22 2004-01-20 Emc Corporation Electronic circuitry enclosure with air vents that comply with emissions and safety standards
US20030201111A1 (en) * 2001-08-21 2003-10-30 Dell Products L.P. Perforated EMI gasket
WO2013138265A1 (en) * 2012-03-13 2013-09-19 Parker-Hannifin Corporation Deflectable conductive gasket with environmental seal
US9635790B2 (en) 2012-03-13 2017-04-25 Parker-Hannifin Corporation Deflectable conductive gasket with environmental seal
WO2016182871A1 (en) * 2015-05-08 2016-11-17 Laird Technologies, Inc Soft and/or flexible board level shields and related methods
WO2016182643A1 (en) * 2015-05-08 2016-11-17 Laird Technologies, Inc. Soft and/or flexible board level shields and related methods

Also Published As

Publication number Publication date Type
CA2318433A1 (en) 1999-08-19 application
WO1999041963A1 (en) 1999-08-19 application
US6211458B1 (en) 2001-04-03 grant
US6362417B2 (en) 2002-03-26 grant

Similar Documents

Publication Publication Date Title
US3277230A (en) Shielding gaskets with fastening means
US3351699A (en) Raceway for electrical cables and wires adapted to retain rf energy
US3413406A (en) Shielded gasketing and seamed jacketing utilizing the same
US3502784A (en) Gasket
US6426881B1 (en) Shielding arrangement for inter-component shielding in electronic devices
US5115104A (en) EMI/RFI shielding gasket
US5012041A (en) Screened window for shielded enclosure
US4864076A (en) Electromagnetic shielding and environmental sealing device
US6374912B1 (en) Deep drawn enclosure with integrated heatsink and fastening details
US6137051A (en) EMI shield/ gasket enclosure
US7173822B2 (en) Techniques for providing ventilation and EMI shielding to electronic circuitry using a panel member with brimmed holes
US6025991A (en) Electronic apparatus having heat dissipating arrangement
US5599027A (en) Gasket assembly for sealing electromagnetic waves
US6852924B2 (en) EMI sealed removable latching cover
US5262588A (en) Electromagnetic interference/radio frequency innterference seal
US4934666A (en) Coiled spring electromagnetic shielding gasket
US6534706B1 (en) EMI shield having flexible fingers with nonlinear slits
USRE34393E (en) Enclosure for housing electronic components
US5522602A (en) EMI-shielding gasket
US3969572A (en) Electromagnetic interference shielding gasket for light-weight equipment enclosures
US7446265B2 (en) Board level shielding module
US20020173265A1 (en) Modular fan system for an enclosure
US5724234A (en) Slotted shield can
US5105056A (en) Electromagentic shielding with discontinuous adhesive
US4613530A (en) Multiple pane glass unit with electrically conductive transparent film for use as radiation shield

Legal Events

Date Code Title Description
AS Assignment

Owner name: PARKER-HANNIFIN CORPORATION, OHIO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MITCHELL, JONATHAN E.;ANDERSEN, CHARLENE;REEL/FRAME:011422/0692

Effective date: 19980324

AS Assignment

Owner name: PARKER INTANGIBLES LLC, OHIO

Free format text: MERGER;ASSIGNOR:PARKER HANNIFIN CUSTOMER SUPPORT INC.;REEL/FRAME:015215/0522

Effective date: 20030630

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12