CA2012293C - Emi/rfi shielding gasket - Google Patents
Emi/rfi shielding gasketInfo
- Publication number
- CA2012293C CA2012293C CA002012293A CA2012293A CA2012293C CA 2012293 C CA2012293 C CA 2012293C CA 002012293 A CA002012293 A CA 002012293A CA 2012293 A CA2012293 A CA 2012293A CA 2012293 C CA2012293 C CA 2012293C
- Authority
- CA
- Canada
- Prior art keywords
- core
- gasket
- mesh
- pressure sensitive
- sensitive adhesive
- 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.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0007—Casings
- H05K9/0015—Gaskets or seals
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Casings For Electric Apparatus (AREA)
- Sealing Material Composition (AREA)
Abstract
An EMI/RFI shielding gasket comprising a resilient elastomeric core enveloped with a fine, open format knit or braided wire mesh, and having a strip of pressure sensitive adhesive disposed lengthwise along a surface of the gasket.
This strip of adhesive allows the gasket to be removably fastened to an enclosure, circumventing the need for a metal clip and thus making the gasket lighter and less expensive than conventional gaskets.
This strip of adhesive allows the gasket to be removably fastened to an enclosure, circumventing the need for a metal clip and thus making the gasket lighter and less expensive than conventional gaskets.
Description
EMI/RFI SHIELDING GASKET
BACKGROUND OF THE INVENTION
The operation of conventional electronic equipment is typically accompanied by the generation of radio frequency and/or electromagnetic radiation in the electronic circuitry of the electronic system. If not properly shielded, such radiation can cause considerable interference with unrelated equipment. Accordingly, it is necessary to effectively shield and ground all sources of radio frequency and electromagnetic radiation within the electronic system.
In instances where the radiation-generating equipment is permanently housed in a container, efféctive shielding may be accomplished easily through proper construction of the enclosure. However, when the equipment housing is provided with a readily openable access panel or door, effective radio frequency interference (RFI) or electromagnetic interference (EMI) shielding presents more of a problem. Many electronic installations such as computer rooms have been made in the past without a full understanding of the effect of partially unshielded enclosures, such as access doors. Thus, manufacturers and users of older electronic equipment have attempted to upgrade the level of RFI/EMI shielding through retrofit installation of shielding devices around these access openings. To this end, it has been known to provide an RFI/EMI shielding device which may be a knitted wire mesh, knitted wire mesh over an elastomeric core, a conductive elastomeric and similar types of shielding devices.
Generally, these shielding devices are attached to the housing by rivets, welds, screws, etc. Preferably, a continuous, roll-formed strip metal clip, to which a shielding device has been attached, is used.
The clip is designed so that it may be placed over the edge of the door or panel and retained in place by frictional gripping action of the roll-formed clip. The configuration of the shielding device is such that the device attached to the clip, is brought into contact with a fised surface of the enclosure when the door or panel is closed, effectively sealing off the narrow gap otherwise typically provided between a door or panel and the oppositely facing surface areas of the housing.
For radiation frequencies between 30 megahertz and 3 gigahertz, it is known to utilize conductive mesh materials, supported internally by an elastomeric core or other similar element, in order to provide adequate shielding.- In the manufacture of conventional mesh shielded strips, a tubular sleeve of conductive wire is knitted in the form of a continuous tube closely about the esterior of a resilient core. Typically, this operation is performed twice, once to provide a tightly conforming inner mesh, and a second time to provide an outer tubular mesh. Both tubes surround and are supported internally by the resilient core. The thus shielded core is secured to a continuous mounting strip, clip or the like, for mounting upon the housing to be shielded.
Typically, this is done by providing sufficient slack in the outer mesh layer to enable a ~tail flange~ to be formed of the escess material, which can be secured in some form to a mounting means. A similar application in which the knit is wrapped around the core rather than knitted over the core is also known.
BACKGROUND OF THE INVENTION
The operation of conventional electronic equipment is typically accompanied by the generation of radio frequency and/or electromagnetic radiation in the electronic circuitry of the electronic system. If not properly shielded, such radiation can cause considerable interference with unrelated equipment. Accordingly, it is necessary to effectively shield and ground all sources of radio frequency and electromagnetic radiation within the electronic system.
In instances where the radiation-generating equipment is permanently housed in a container, efféctive shielding may be accomplished easily through proper construction of the enclosure. However, when the equipment housing is provided with a readily openable access panel or door, effective radio frequency interference (RFI) or electromagnetic interference (EMI) shielding presents more of a problem. Many electronic installations such as computer rooms have been made in the past without a full understanding of the effect of partially unshielded enclosures, such as access doors. Thus, manufacturers and users of older electronic equipment have attempted to upgrade the level of RFI/EMI shielding through retrofit installation of shielding devices around these access openings. To this end, it has been known to provide an RFI/EMI shielding device which may be a knitted wire mesh, knitted wire mesh over an elastomeric core, a conductive elastomeric and similar types of shielding devices.
Generally, these shielding devices are attached to the housing by rivets, welds, screws, etc. Preferably, a continuous, roll-formed strip metal clip, to which a shielding device has been attached, is used.
The clip is designed so that it may be placed over the edge of the door or panel and retained in place by frictional gripping action of the roll-formed clip. The configuration of the shielding device is such that the device attached to the clip, is brought into contact with a fised surface of the enclosure when the door or panel is closed, effectively sealing off the narrow gap otherwise typically provided between a door or panel and the oppositely facing surface areas of the housing.
For radiation frequencies between 30 megahertz and 3 gigahertz, it is known to utilize conductive mesh materials, supported internally by an elastomeric core or other similar element, in order to provide adequate shielding.- In the manufacture of conventional mesh shielded strips, a tubular sleeve of conductive wire is knitted in the form of a continuous tube closely about the esterior of a resilient core. Typically, this operation is performed twice, once to provide a tightly conforming inner mesh, and a second time to provide an outer tubular mesh. Both tubes surround and are supported internally by the resilient core. The thus shielded core is secured to a continuous mounting strip, clip or the like, for mounting upon the housing to be shielded.
Typically, this is done by providing sufficient slack in the outer mesh layer to enable a ~tail flange~ to be formed of the escess material, which can be secured in some form to a mounting means. A similar application in which the knit is wrapped around the core rather than knitted over the core is also known.
73702-3(S) While the prior art gaskets described above perform well, they are relatively costly to assemble onto the cabinet.
Also, the tightly knit wire mesh necessitates that a high closure force be used to seal the door, and the combination of the tightly knit mesh and the metal clip makes the gasket heavy, which is detrimental in aerospace and other applications where weight is a critical factor.
The present invention provides a novel and greatly improved mesh covered resilient core shielding gasket, which is inexpensive and lightweight and allows a low closure force.
SUMMARY AND OBJECTS OF THE INVENTION
It is an object of the invention to provide a shielding gasket which can be attached directly to an enclosure, without a clip, and subsequently easily removed for replacement.
Another object of the invention is to provide a shielding gasket which is lightweight and simple to manufacture.
A further object of the invention is to provide a shielding gasket which allows an enclosure door to be sealed with a low closure force.
According to one aspect, the present invention provides a shielding gasket comprising: a) an elastomer core; b) a knitted or braided wire mesh formed as a continuous tube surrounding said core; ;and c) a strip of pressure sensitive adhesive disposed on the surface of the gasket parallel to its length, in a manner such that the pressure sensitive adhesive bonds to the core through the mesh thereby securing the mesh to the core.
According to another aspect, the present invention .
73702-3(S) provides a method of shielding an enclosure comprising the steps of: a) forming a shielding gasket by a process comprising the sequential steps of: i. providing an elastomer core; ii. knitting or braiding a wire mesh over and surrounding said core; and iii.
applying strip of pressure sensitive adhesive to said gasket, parallel to its length, in a manner such that the pressure sensitive adhesive bonds to the core through the mesh, thereby securing the mesh to the core; and b) adhering said gasket to the surface of said enclosure via the pressure sensitive adhesive.
According to yet another aspect, the present invention provides an EMItRFI shielding gasket comprising: a) a resilient elastomeric core; b) a conductive metal mesh surrounding the core;
c) a metal foil strip the length of which is greater than its width, said strip having a pressure sensitive adhesive on its surfaces, and one surface of the metal foil strip being in contact with and bonded to the core by the pressure sensitive adhesive.
According to still another aspect, the present invention provides a method of shielding an enclosure comprising the steps of: a) forming a shielding gasket by a process comprising the sequential steps of: i. providing a resilient elastomer core;
ii. knitting or braiding a conductive metal mesh over and surrounding the core; and iii. applying to said gasket a metal foil strip the length of which is greater than its width, said foil strip having a pressure sensitive adhesive on at least two of its surfaces, such that one surface of the foil strip is bonded through the mesh to the core by the pressure sensitive adhesive;
and b) adhering said gasket to the surface of said enclosure via 20 ~ 2293 73702-3(S~
the pressure sensitive adhesive on the other surface of the foil strip.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a simplified perspective illustration of a typical cabinet with access door, for housing computer circuitry or the like.
Figure 2 is a perspective view, in cross section, of the shielding strip of the invention.
Figure 3 is a highly enlarged view of a selected area of figure 2, illustrating details of the wire mesh in one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figure 1, there is shown a typical metallic housing 1, utilized for computer circuitry and the like. The housing is typically provided with an access door 3 having a locking handle 2 on one side and provided with a suitable hinge means (not shown) on the opposite side. For effective RFI/EMI
shielding, the interface between the housing 1 and the door 3 is provided about its entire periphery with a 4a resilient strip of shielding material. The arrangement is such that, when the door 3 is closed, the resilient shielding strip will be contacted and compressed about the entire periphery of the door to provide good electrical contact all around.
In Figure 2 a perspective view, in cross-section, is shown of the shielding gasket of the invention. In this embodiment, a wire mesh 5 envelopes an elastomeric core 4.
The core and the gasket have a length that is greater than its width. The selected length is determined by the distance of the panel to be covered by the gasket. The width can be any width conventionally used, though generally from about 0.25 to about 1.0 inch. The height of the gasket can also be any height conventionally used, but is typically approsimately equal to the width. A strip of pressure sensitive adhesive 6 is disposed lengthwise on a surface of the thus formed gasket. In an alternate embodiment, a sheet of protective, releasable covering means (not shown) is provided adjacent the adhesive strip 6.
In a preferred embodiment of the invention, the wire mesh is formed of a nickel copper alloy wire such as Monel or a tin plated copper clad steel wire such as Ferrex~. Other types of wire which can also be used include copper wire which has been plated with tin or other metals, silver plated nylon or other synthetic thread, and other suitable electrically conductive materials. In order be able to successfully apply the strip of pressure sensitive adhesive to the mesh surface, it is necessary to control both the thickness of the wire and the tightness of the knit. For optimal results, the wire is typically of a thickness of less than about 0.0050 inches, and .
preferably less than about 0.0045 inches. The tightness of the knit is generally controlled such that the wire is knit in an open format, having less than about 35 openings per inch, and preferably less than about 30 openings per inch.
The elastomeric core 4 may be formed from a variety of materials known in the gasket art. In a preferred embodiment, the core is of an elastomeric foam, such as a foamed elastomeric thermoplastic, foamed neoprene, foamed urethane or foamed silicone. This foam may be open or closed cell and may have a skinned surface if desired. Conventional unfoamed neoprenes, urethanes, silicones, thermopl~astic elastomers and other suitable materials in solid or hollow form may also be used. The core may be electrically conductive or nonconductive, as dictated by cost and shielding requirements.
The pressure sensitive adhesive is generally applied in tape form. It is preferred to use a double sided tape or a transfer adhesive tape. Depending on the compatibility of the adhesive with the elastomer core, the tape may be applied by hand, or using up to about 20 psi nip roll pressure to promote bonding of the adhesive to the core. It is preferred that the adhesive be electrically conductive, in order to ensure optimal shielding. However, conventional pressure sensitive adhesives may be used as appropriate.
In one embodiment, the adhesive strip is provided with a protective, releasable covering means. This may be a siliconized paper or release film, or other conventional releasable covering material, and serves to protect the adhesive from contamination and facilitate storage and application of the gasket.
2(~12293 In another embodiment, a wide metal foil having pressure sensitive adhesive, preferably conductive, is applied to the gasket. The foil has a length that is greater than its width, however it is preferred that the width of the foil be greater than the width of the gasket. Preferably, the width of the foil is from two to four times the width of the gasket. The metal foil provides a larger ~footprint~ between the gasket and the surface to which it is bonded. The metal foil also tends to aid in the handling and placement of the gasket. Suitable metal foils include but are not limited to tinned copper, copper, aluminum, stainless steel, nickel, nickel plated metals, noble metal plated non-noble metals, such as silver coated copper, noble metals such as silver, and other such electrically conductive metal foils. THe foil thickness should be sufficient to allow the foil to support the gasket. Generally, a metal foil having a thickness from about 1 to about 10 mils is preferred, and more preferably a foil of from about 1 to about 3 mils.
In a further embodiment, the gasket is designed so that it requires a low closure force to form a EMI/RFI
shield. By n low closure force~ it is meant that the force required to close the door or panel while obtaining the necessary deflection of the gasket so as to ensure proper electrical mating of the door to the frame through the gasket is less than five pounds per linear inch. Preferably, the core of the gasket is formed of a light, highly resilient and conformable polyurethane foam which has a required closure force of one pound per linear inch or less.
In Figure 3 is shown the structure of mesh 5 in one embodiment of the invention. In this embodiment the wire is knit in an open format. In an alternate embodiment the wire may be braided. Both braiding and knitting of wire mesh is typically performed using equipmènt designed for this purpose and known to those skilled in the art.
While the mesh is shown as being knit or braided over the core, it can also be formed separately and wrapped around the core as is well known in the art. In that instance, one must make sure that the ends of the mesh are properly secured to each other or the gasket surface.
After manufacture of the gasket described above, the gasket would be applied around the periphery of an access door or other opening of an enclosure. The gasket could also be used in other shielding applications in which it could be useful. The gasket would typically be applied by stripping the release film (if present) from the adhesive and then pressing the adhesive strip against the substrate to which the gasket is applied. When the gasket requires replacement it can be easily removed by peeling it from the enclosure surface.
While preferred embodiments of this invention have been described in detail hereinabove, it is to be understood that many changes and modifications may be made by those skilled in the art without departing from the scope and spirit of this invention.
Also, the tightly knit wire mesh necessitates that a high closure force be used to seal the door, and the combination of the tightly knit mesh and the metal clip makes the gasket heavy, which is detrimental in aerospace and other applications where weight is a critical factor.
The present invention provides a novel and greatly improved mesh covered resilient core shielding gasket, which is inexpensive and lightweight and allows a low closure force.
SUMMARY AND OBJECTS OF THE INVENTION
It is an object of the invention to provide a shielding gasket which can be attached directly to an enclosure, without a clip, and subsequently easily removed for replacement.
Another object of the invention is to provide a shielding gasket which is lightweight and simple to manufacture.
A further object of the invention is to provide a shielding gasket which allows an enclosure door to be sealed with a low closure force.
According to one aspect, the present invention provides a shielding gasket comprising: a) an elastomer core; b) a knitted or braided wire mesh formed as a continuous tube surrounding said core; ;and c) a strip of pressure sensitive adhesive disposed on the surface of the gasket parallel to its length, in a manner such that the pressure sensitive adhesive bonds to the core through the mesh thereby securing the mesh to the core.
According to another aspect, the present invention .
73702-3(S) provides a method of shielding an enclosure comprising the steps of: a) forming a shielding gasket by a process comprising the sequential steps of: i. providing an elastomer core; ii. knitting or braiding a wire mesh over and surrounding said core; and iii.
applying strip of pressure sensitive adhesive to said gasket, parallel to its length, in a manner such that the pressure sensitive adhesive bonds to the core through the mesh, thereby securing the mesh to the core; and b) adhering said gasket to the surface of said enclosure via the pressure sensitive adhesive.
According to yet another aspect, the present invention provides an EMItRFI shielding gasket comprising: a) a resilient elastomeric core; b) a conductive metal mesh surrounding the core;
c) a metal foil strip the length of which is greater than its width, said strip having a pressure sensitive adhesive on its surfaces, and one surface of the metal foil strip being in contact with and bonded to the core by the pressure sensitive adhesive.
According to still another aspect, the present invention provides a method of shielding an enclosure comprising the steps of: a) forming a shielding gasket by a process comprising the sequential steps of: i. providing a resilient elastomer core;
ii. knitting or braiding a conductive metal mesh over and surrounding the core; and iii. applying to said gasket a metal foil strip the length of which is greater than its width, said foil strip having a pressure sensitive adhesive on at least two of its surfaces, such that one surface of the foil strip is bonded through the mesh to the core by the pressure sensitive adhesive;
and b) adhering said gasket to the surface of said enclosure via 20 ~ 2293 73702-3(S~
the pressure sensitive adhesive on the other surface of the foil strip.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a simplified perspective illustration of a typical cabinet with access door, for housing computer circuitry or the like.
Figure 2 is a perspective view, in cross section, of the shielding strip of the invention.
Figure 3 is a highly enlarged view of a selected area of figure 2, illustrating details of the wire mesh in one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figure 1, there is shown a typical metallic housing 1, utilized for computer circuitry and the like. The housing is typically provided with an access door 3 having a locking handle 2 on one side and provided with a suitable hinge means (not shown) on the opposite side. For effective RFI/EMI
shielding, the interface between the housing 1 and the door 3 is provided about its entire periphery with a 4a resilient strip of shielding material. The arrangement is such that, when the door 3 is closed, the resilient shielding strip will be contacted and compressed about the entire periphery of the door to provide good electrical contact all around.
In Figure 2 a perspective view, in cross-section, is shown of the shielding gasket of the invention. In this embodiment, a wire mesh 5 envelopes an elastomeric core 4.
The core and the gasket have a length that is greater than its width. The selected length is determined by the distance of the panel to be covered by the gasket. The width can be any width conventionally used, though generally from about 0.25 to about 1.0 inch. The height of the gasket can also be any height conventionally used, but is typically approsimately equal to the width. A strip of pressure sensitive adhesive 6 is disposed lengthwise on a surface of the thus formed gasket. In an alternate embodiment, a sheet of protective, releasable covering means (not shown) is provided adjacent the adhesive strip 6.
In a preferred embodiment of the invention, the wire mesh is formed of a nickel copper alloy wire such as Monel or a tin plated copper clad steel wire such as Ferrex~. Other types of wire which can also be used include copper wire which has been plated with tin or other metals, silver plated nylon or other synthetic thread, and other suitable electrically conductive materials. In order be able to successfully apply the strip of pressure sensitive adhesive to the mesh surface, it is necessary to control both the thickness of the wire and the tightness of the knit. For optimal results, the wire is typically of a thickness of less than about 0.0050 inches, and .
preferably less than about 0.0045 inches. The tightness of the knit is generally controlled such that the wire is knit in an open format, having less than about 35 openings per inch, and preferably less than about 30 openings per inch.
The elastomeric core 4 may be formed from a variety of materials known in the gasket art. In a preferred embodiment, the core is of an elastomeric foam, such as a foamed elastomeric thermoplastic, foamed neoprene, foamed urethane or foamed silicone. This foam may be open or closed cell and may have a skinned surface if desired. Conventional unfoamed neoprenes, urethanes, silicones, thermopl~astic elastomers and other suitable materials in solid or hollow form may also be used. The core may be electrically conductive or nonconductive, as dictated by cost and shielding requirements.
The pressure sensitive adhesive is generally applied in tape form. It is preferred to use a double sided tape or a transfer adhesive tape. Depending on the compatibility of the adhesive with the elastomer core, the tape may be applied by hand, or using up to about 20 psi nip roll pressure to promote bonding of the adhesive to the core. It is preferred that the adhesive be electrically conductive, in order to ensure optimal shielding. However, conventional pressure sensitive adhesives may be used as appropriate.
In one embodiment, the adhesive strip is provided with a protective, releasable covering means. This may be a siliconized paper or release film, or other conventional releasable covering material, and serves to protect the adhesive from contamination and facilitate storage and application of the gasket.
2(~12293 In another embodiment, a wide metal foil having pressure sensitive adhesive, preferably conductive, is applied to the gasket. The foil has a length that is greater than its width, however it is preferred that the width of the foil be greater than the width of the gasket. Preferably, the width of the foil is from two to four times the width of the gasket. The metal foil provides a larger ~footprint~ between the gasket and the surface to which it is bonded. The metal foil also tends to aid in the handling and placement of the gasket. Suitable metal foils include but are not limited to tinned copper, copper, aluminum, stainless steel, nickel, nickel plated metals, noble metal plated non-noble metals, such as silver coated copper, noble metals such as silver, and other such electrically conductive metal foils. THe foil thickness should be sufficient to allow the foil to support the gasket. Generally, a metal foil having a thickness from about 1 to about 10 mils is preferred, and more preferably a foil of from about 1 to about 3 mils.
In a further embodiment, the gasket is designed so that it requires a low closure force to form a EMI/RFI
shield. By n low closure force~ it is meant that the force required to close the door or panel while obtaining the necessary deflection of the gasket so as to ensure proper electrical mating of the door to the frame through the gasket is less than five pounds per linear inch. Preferably, the core of the gasket is formed of a light, highly resilient and conformable polyurethane foam which has a required closure force of one pound per linear inch or less.
In Figure 3 is shown the structure of mesh 5 in one embodiment of the invention. In this embodiment the wire is knit in an open format. In an alternate embodiment the wire may be braided. Both braiding and knitting of wire mesh is typically performed using equipmènt designed for this purpose and known to those skilled in the art.
While the mesh is shown as being knit or braided over the core, it can also be formed separately and wrapped around the core as is well known in the art. In that instance, one must make sure that the ends of the mesh are properly secured to each other or the gasket surface.
After manufacture of the gasket described above, the gasket would be applied around the periphery of an access door or other opening of an enclosure. The gasket could also be used in other shielding applications in which it could be useful. The gasket would typically be applied by stripping the release film (if present) from the adhesive and then pressing the adhesive strip against the substrate to which the gasket is applied. When the gasket requires replacement it can be easily removed by peeling it from the enclosure surface.
While preferred embodiments of this invention have been described in detail hereinabove, it is to be understood that many changes and modifications may be made by those skilled in the art without departing from the scope and spirit of this invention.
Claims (19)
1. A shielding gasket comprising: a) an elastomer core; b) a knitted or braided wire mesh formed as a continuous tube surrounding said core; ;and c) a strip of pressure sensitive adhesive disposed on the surface of the gasket parallel to its length, in a manner such that the pressure sensitive adhesive bonds to the core through the mesh thereby securing the mesh to the core.
2. The shielding gasket of claim 1 further comprising a releasable protective covering means adjacent said adhesive strip.
3. The shielding gasket of claim 1, wherein said mesh is formed from wire having a diameter of less than about 0.0050 inches.
4. The shielding gasket of claim 1, wherein said mesh is a knit fabric having less than about 35 openings per inch.
5. The shielding gasket of claim 1, wherein said core is of a material selected from the group consisting of: elastomeric thermoplastics, neoprene rubber, silicone, urethane, foamed elastomeric thermoplastics, neoprene rubber, foamed silicone and foamed urethane.
6. The shielding gasket of claim 1, wherein said core is formed of a solid silicone elastomer.
7. The shielding gasket of claim 1, wherein said adhesive strip is electrically conductive.
8. The shielding gasket of claim 1 wherein the elastomer core is a foamed urethane elastomer and the wire mesh is silver plated nylon.
9. A method of shielding an enclosure comprising the steps of: a) forming a shielding gasket by a process comprising the sequential steps of: i. providing an elastomer core; ii. knitting or braiding a wire mesh over and surrounding said core; and iii.
applying strip of pressure sensitive adhesive to said gasket, parallel to its length, in a manner such that the pressure sensitive adhesive bonds to the core through the mesh, thereby securing the mesh to the core; and b) adhering said gasket to the surface of said enclosure via the pressure sensitive adhesive.
applying strip of pressure sensitive adhesive to said gasket, parallel to its length, in a manner such that the pressure sensitive adhesive bonds to the core through the mesh, thereby securing the mesh to the core; and b) adhering said gasket to the surface of said enclosure via the pressure sensitive adhesive.
10. The method of claim 9 wherein said adhesive is electrically conductive.
11. The method of claim 9 wherein the elastomer core is a formed urethane elastomer and the wire mesh is silver plated nylon.
12. An EMI/RFI shielding gasket comprising: a) a resilient elastomeric core; b) a conductive metal mesh surrounding the core;
c) a metal foil strip the length of which is greater than its width, said strip having a pressure sensitive adhesive on its surfaces, and one surface of the metal foil strip being in contact with and bonded to the core by the pressure sensitive adhesive.
c) a metal foil strip the length of which is greater than its width, said strip having a pressure sensitive adhesive on its surfaces, and one surface of the metal foil strip being in contact with and bonded to the core by the pressure sensitive adhesive.
13. The EMI/RFI shielding gasket of claim 12 wherein the core is selected from the group consisting of: elastomeric thermoplastics, neoprene rubber, silicone, urethane, foamed elastomeric thermoplastics, foamed neoprene rubber, foamed silicone and foamed urethane; the mesh is a woven or braided material having less than 35 openings per square inch; and the metal foil strip is selected from the group consisting of tinned copper, copper, stainless steel, noble metal plated non-noble metals and noble metals.
14. The EMI/RFI shielding gasket of claim 12 wherein the pressure sensitive adhesive is electrically conductive.
15. A method of shielding an enclosure comprising the steps of: a) forming a shielding gasket by a process comprising the sequential steps of: i. providing a resilient elastomer core;
ii. knitting or braiding a conductive metal mesh over and surrounding the core; and iii. applying to said gasket a metal foil strip the length of which is greater than its width, said foil strip having a pressure sensitive adhesive on at least two of its surfaces, such that one surface of the foil strip is bonded through the mesh to the core by the pressure sensitive adhesive;
and b) adhering said gasket to the surface of said enclosure via the pressure sensitive adhesive on the other surface of the foil strip.
ii. knitting or braiding a conductive metal mesh over and surrounding the core; and iii. applying to said gasket a metal foil strip the length of which is greater than its width, said foil strip having a pressure sensitive adhesive on at least two of its surfaces, such that one surface of the foil strip is bonded through the mesh to the core by the pressure sensitive adhesive;
and b) adhering said gasket to the surface of said enclosure via the pressure sensitive adhesive on the other surface of the foil strip.
16. The method of claim 15 wherein the core is selected from the group consisting of urethane, elastomeric thermoplastics, neoprene rubber, silicone, and foams thereof; the mesh is a woven or braided material having less than 35 openings per square inch;
and the metal foil strip is selected from the group consisting of tinned copper, copper, stainless steel, and noble metal plated non-noble metals.
and the metal foil strip is selected from the group consisting of tinned copper, copper, stainless steel, and noble metal plated non-noble metals.
17. The method of claim 15 wherein the pressure sensitive adhesive is electrically conductive.
18. A shielding gasket comprising: a) an elastomeric core;
b) a wire mesh knitted or braided over and surrounding said core;
and c) a strip of pressure sensitive adhesive disposed on a surface of the gasket, parallel to its length, such that the adhesive bonds the mesh to the core; wherein the wire mesh is a knit fabric having less than about 35 openings per inch and is formed from wire having a thickness of less than 0.005 inches.
b) a wire mesh knitted or braided over and surrounding said core;
and c) a strip of pressure sensitive adhesive disposed on a surface of the gasket, parallel to its length, such that the adhesive bonds the mesh to the core; wherein the wire mesh is a knit fabric having less than about 35 openings per inch and is formed from wire having a thickness of less than 0.005 inches.
19. The shielding gasket of claim 18 wherein the elastomeric core is a foamed urethane elastomer and the wire mesh is silver plated nylon.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/337,491 US5028739A (en) | 1989-04-13 | 1989-04-13 | EMI/REI shielding gasket |
| US337,491 | 1989-04-13 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2012293A1 CA2012293A1 (en) | 1990-10-13 |
| CA2012293C true CA2012293C (en) | 1994-09-27 |
Family
ID=23320762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002012293A Expired - Fee Related CA2012293C (en) | 1989-04-13 | 1990-03-15 | Emi/rfi shielding gasket |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US5028739A (en) |
| EP (1) | EP0392821B2 (en) |
| JP (1) | JPH02296396A (en) |
| CA (1) | CA2012293C (en) |
| DE (1) | DE69006620T3 (en) |
Families Citing this family (74)
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| US5195232A (en) * | 1990-01-03 | 1993-03-23 | Integrated Power Components Inc. | Method of making electromagnetic interference filters |
| US5105056A (en) * | 1990-10-26 | 1992-04-14 | Schlegel Corporation | Electromagentic shielding with discontinuous adhesive |
| DE4037119A1 (en) * | 1990-11-22 | 1992-05-27 | Messerschmitt Boelkow Blohm | ARRANGEMENT FOR SEALING A DISCONNECTING OR CONNECTING JOINT BETWEEN TWO COMPONENTS, ESSENTIAL PLASTIC |
| JP2510404Y2 (en) * | 1990-11-29 | 1996-09-11 | 北川工業株式会社 | Electromagnetic shield gasket |
| JP2526820Y2 (en) * | 1991-05-24 | 1997-02-26 | 北川工業株式会社 | Knitted fabric for electromagnetic wave shielding |
| DE4128398A1 (en) * | 1991-08-23 | 1993-02-25 | Siemens Ag | CONTROL CABINET FOR SELECTIVE RECEPTION OF ELECTRICAL AND / OR ELECTRONIC DEVICES AND ASSEMBLIES |
| US6454267B1 (en) * | 1992-08-19 | 2002-09-24 | The Boeing Company | Corrosion resistant gasket for aircraft |
| US6719293B1 (en) * | 1992-08-19 | 2004-04-13 | The Boeing Company | Corrosion resistant gasket for aircraft |
| US5791654A (en) * | 1992-08-19 | 1998-08-11 | The Boeing Company | Corrosion resistant gasket in combination with aircraft antenna |
| DE4228427A1 (en) * | 1992-08-26 | 1994-03-03 | Siemens Ag | Control cabinet with sealing elements for sealing a door when closed |
| DE4307805C2 (en) * | 1993-03-12 | 1996-09-05 | Loh Kg Rittal Werk | RF-tight control cabinet with cabinet body and cabinet door |
| JP2710744B2 (en) * | 1993-06-08 | 1998-02-10 | 北川工業株式会社 | Gasket for electromagnetic wave shielding |
| JP2524471B2 (en) * | 1993-07-22 | 1996-08-14 | 日本電気株式会社 | EMI gasket |
| JPH0742190U (en) * | 1993-12-14 | 1995-07-21 | 芳郎 平岩 | A cushioning gasket that also prevents the intrusion of interference radio waves |
| US5443721A (en) * | 1994-02-10 | 1995-08-22 | Basf Corporation | Filter cartridge mounting assembly |
| US5512709A (en) * | 1994-02-28 | 1996-04-30 | Jencks; Andrew D. | Electromagnetic emission-shielding gasket |
| JP2690684B2 (en) * | 1994-04-14 | 1997-12-10 | 北川工業株式会社 | Sewing electromagnetic wave shield material |
| US5473110A (en) * | 1995-03-07 | 1995-12-05 | Unisys Corporation | Magnetically-attachable EMI shielding cover for attenuating electromagnetic emanation |
| WO1997008928A1 (en) * | 1995-08-25 | 1997-03-06 | Parker-Hannifin Corporation | Emi shielding gasket having a consolidated conductive sheathing |
| US5578790A (en) * | 1995-09-06 | 1996-11-26 | The Whitaker Corporation | Shielding gasket |
| US5904978A (en) * | 1995-12-15 | 1999-05-18 | W. L. Gore & Associates, Inc. | Electrically conductive polytetrafluoroethylene article |
| US5804762A (en) * | 1996-03-22 | 1998-09-08 | Parker-Hannifin Corporation | EMI shielding gasket having shear surface attachments |
| JP3794758B2 (en) * | 1996-05-20 | 2006-07-12 | 日本ジッパーチュービング株式会社 | Manufacturing method of irregular profile conductor |
| JP3306665B2 (en) * | 1996-08-05 | 2002-07-24 | セーレン株式会社 | Conductive material and method of manufacturing the same |
| US6210789B1 (en) | 1997-02-20 | 2001-04-03 | W. L. Gore & Associates, Inc. | Electrically conductive composite article |
| US6276026B1 (en) * | 1997-03-10 | 2001-08-21 | The Boeing Company | Aircraft hinge |
| JPH10294583A (en) * | 1997-04-16 | 1998-11-04 | Seiwa Electric Mfg Co Ltd | Electromagnetic wave shielding gasket |
| US6169666B1 (en) * | 1997-05-29 | 2001-01-02 | U.S. Philips Corporation | Electromagnetic shielding screen and circuit support having such a screen |
| US6222126B1 (en) * | 1997-09-08 | 2001-04-24 | Thomas & Betts International, Inc. | Woven mesh interconnect |
| US5945217A (en) * | 1997-10-14 | 1999-08-31 | Gore Enterprise Holdings, Inc. | Thermally conductive polytrafluoroethylene article |
| US6075205A (en) * | 1997-10-27 | 2000-06-13 | Parker-Hannifin Corporation | Tubular extrusion gasket profile exhibiting a controlled deflection response for improved environmental sealing and EMI shielding |
| US6054647A (en) * | 1997-11-26 | 2000-04-25 | National-Standard Company | Grid material for electromagnetic shielding |
| US6248393B1 (en) | 1998-02-27 | 2001-06-19 | Parker-Hannifin Corporation | Flame retardant EMI shielding materials and method of manufacture |
| US6188014B1 (en) * | 1998-03-06 | 2001-02-13 | Hoffman Enclosures, Inc. | Electrical enclosure having improved sealing and shielding component and method of manufacture thereof |
| US7071409B2 (en) * | 1998-03-06 | 2006-07-04 | Hoffman Enclosures, Inc. | Electrical enclosure having improved sealing and shielding component and method of manufacture thereof |
| US6255581B1 (en) | 1998-03-31 | 2001-07-03 | Gore Enterprise Holdings, Inc. | Surface mount technology compatible EMI gasket and a method of installing an EMI gasket on a ground trace |
| WO2000023513A1 (en) | 1998-10-22 | 2000-04-27 | Parker-Hannifin Corporation | Intumescent, flame retardant pressure sensitive adhesive composition for emi shielding applications |
| US20010003389A1 (en) * | 1999-02-16 | 2001-06-14 | C. James Bushman | High temperature static seal |
| KR200182453Y1 (en) * | 1999-11-22 | 2000-05-15 | 익스팬전자주식회사 | Conductive gasket for improving contact reliablity |
| KR200182519Y1 (en) | 1999-12-24 | 2000-05-15 | 익스팬전자주식회사 | Clip type conductive gasket |
| US6483023B1 (en) * | 2000-01-04 | 2002-11-19 | Fujitsu Network Communications, Inc. | Fabric wrapped over spring EMI gasket |
| US6309742B1 (en) | 2000-01-28 | 2001-10-30 | Gore Enterprise Holdings, Inc. | EMI/RFI shielding gasket |
| BR0017076B1 (en) | 2000-02-18 | 2014-09-02 | Parker Hannifin Corp | METHOD OF MANUFACTURING EMI SHELF TRAINING LOW CLOSURE FORM |
| US6348654B1 (en) | 2000-10-12 | 2002-02-19 | Parker-Hannifin Corporation | Compound waveform gasket for low closure force EMI shielding applications |
| US6519899B1 (en) * | 2000-10-31 | 2003-02-18 | Imedco Ag | Radio frequency shielded and acoustically insulated door |
| US6697248B1 (en) | 2001-02-06 | 2004-02-24 | Daniel Luch | Electromagnetic interference shields and methods of manufacture |
| US6671186B2 (en) * | 2001-04-20 | 2003-12-30 | Hewlett-Packard Development Company, L.P. | Electromagnetic interference shield |
| WO2002093996A1 (en) | 2001-05-10 | 2002-11-21 | Parker Hannifin Corporation | Manufacture of electronics enclosure having a metallized shielding layer |
| DE60206489T2 (en) | 2001-05-11 | 2006-07-13 | Parker-Hannifin Corp., Cleveland | Toothed seal for EMI shielding applications with low crimping forces |
| US6809254B2 (en) | 2001-07-20 | 2004-10-26 | Parker-Hannifin Corporation | Electronics enclosure having an interior EMI shielding and cosmetic coating |
| US20030091777A1 (en) * | 2001-08-14 | 2003-05-15 | Peter Jones | Clean release tape for EMI shielding |
| WO2003030610A1 (en) | 2001-10-02 | 2003-04-10 | Parker Hannifin Corporation | Emi shielding gasket construction |
| US6723916B2 (en) * | 2002-03-15 | 2004-04-20 | Parker-Hannifin Corporation | Combination EMI shielding and environmental seal gasket construction |
| US6781851B2 (en) * | 2002-05-30 | 2004-08-24 | Lucent Technologies Inc. | Electromagnetic interference shield |
| DE10231145A1 (en) * | 2002-07-10 | 2004-01-29 | Siemens Ag | Shielding device for electronic assemblies on a printed circuit board |
| KR100627169B1 (en) * | 2004-03-25 | 2006-09-25 | 주성숙 | Absorber of electric wave having shock-absorbing nature |
| US6943288B1 (en) * | 2004-06-04 | 2005-09-13 | Schlegel Systems, Inc. | EMI foil laminate gasket |
| US7470866B2 (en) * | 2004-11-18 | 2008-12-30 | Jemic Shielding Technology | Electrically conductive gasket |
| US7732714B2 (en) * | 2004-12-15 | 2010-06-08 | Jemic Shielding Technology | Electrically conductive gasket with paint masking |
| US20060180348A1 (en) * | 2005-02-16 | 2006-08-17 | Cloutier Bryan R | Flame retardant EMI shielding gasket |
| WO2006098528A1 (en) * | 2005-03-15 | 2006-09-21 | Sung Suk Ju | Conductive device for electronic equipment |
| WO2006104873A2 (en) * | 2005-03-30 | 2006-10-05 | Parker-Hannifin Corporation | Flame retardant foam for emi shielding gaskets |
| WO2006125045A2 (en) * | 2005-05-19 | 2006-11-23 | Parker Hannifin Corporation | Strip gaskets for emi shielding |
| EP2193702A1 (en) | 2007-10-02 | 2010-06-09 | Parker-Hannifin Corporation | Nano coating for emi gaskets |
| US20100052263A1 (en) * | 2008-09-03 | 2010-03-04 | Baker Hughes Incorporated | Electroplated resilient seal |
| WO2010036563A1 (en) * | 2008-09-26 | 2010-04-01 | Parker-Hannifin Corporation | Electrically-conductive foam emi shield |
| CN103098574A (en) * | 2010-07-20 | 2013-05-08 | 布雷迪转换公司 | Conductive grounding pad |
| WO2012174426A1 (en) * | 2011-06-17 | 2012-12-20 | Aviation Devices & Electronic Components, L.L.C. | Single-sided sticky gasket |
| US9739402B2 (en) | 2013-03-04 | 2017-08-22 | Eaton Corporation | Electrically conductive seals for fluid conveyance systems |
| US9345182B2 (en) | 2013-08-27 | 2016-05-17 | Parker-Hannifin Corporation | EMI shielding vent panel frame |
| US9370132B2 (en) | 2013-08-27 | 2016-06-14 | Parker-Hannifin Corporation | Homogeneous EMI vent panel and method for preparation thereof |
| US9447629B2 (en) | 2014-10-16 | 2016-09-20 | Hoffman Enclosures, Inc. | Strip gasket |
| GB201608437D0 (en) * | 2016-05-13 | 2016-06-29 | Sg Technical Systems Ltd | Sealed enclosures |
| US20220186835A1 (en) * | 2020-12-10 | 2022-06-16 | Laird Technologies (Shenzhen) Ltd. | Electrically and thermally conductive gaskets |
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|---|---|---|---|---|
| US3132204A (en) * | 1964-05-05 | Electrically conductive pressure sensitive adhesive tapes | ||
| US2519850A (en) * | 1945-03-22 | 1950-08-22 | Jr Adrian A Pierson | Radio shielding sealing gasket |
| US3029303A (en) * | 1958-12-02 | 1962-04-10 | Severino James | Adhesively secured electrical devices |
| US3247312A (en) * | 1963-12-26 | 1966-04-19 | Borg Warner | Shielding enclosure for electrical equipment |
| US3312769A (en) * | 1965-10-29 | 1967-04-04 | Borg Warner | R. f. seal for electromagnetic wave radiation shielding enclosure |
| US3413406A (en) * | 1967-04-10 | 1968-11-26 | Walter A. Plummer | Shielded gasketing and seamed jacketing utilizing the same |
| US3555168A (en) * | 1969-06-11 | 1971-01-12 | Tapecon | Shielding gasket |
| US3969572A (en) * | 1975-03-05 | 1976-07-13 | Ncr Corporation | Electromagnetic interference shielding gasket for light-weight equipment enclosures |
| US3965572A (en) * | 1975-10-21 | 1976-06-29 | Imperial-Eastman Corporation | Tube cutter |
| US4098633A (en) * | 1977-01-24 | 1978-07-04 | The United States Of America As Represented By The Secretary Of The Navy | Method of making radiation seal |
| US4247737A (en) * | 1979-03-29 | 1981-01-27 | Spectrum Control, Inc. | Electromagnetically shielded viewing window |
| FR2509949A1 (en) * | 1981-07-15 | 1983-01-21 | Aerospatiale | Electromagnetic tight and water-tight joint for shielding box - comprises supple rod surrounded by metallic braid and supple strips |
| US4659869A (en) * | 1983-06-20 | 1987-04-21 | Pawling Rubber Corporation | Clip-on strip for RFT/EMI shielding |
| US4652695A (en) * | 1983-06-20 | 1987-03-24 | Pawling Corporation | Mesh-covered core strip for high frequency RFI/EMI radiation shielding |
| DE3407657A1 (en) * | 1984-03-01 | 1985-09-05 | Siemens AG, 1000 Berlin und 8000 München | HIGH-FREQUENCY SEAL FOR HOUSING LATCHES AND DOORS |
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| JPS61187297A (en) * | 1985-02-14 | 1986-08-20 | 日本ジツパ−チユ−ビング株式会社 | Shielding tape and manufacture thereof |
| JPS61219199A (en) * | 1985-03-26 | 1986-09-29 | 株式会社ブリヂストン | Gasket for electromagnetic shield |
| CH668347A5 (en) * | 1985-06-28 | 1988-12-15 | Jakob Senn | GASKET ON HOUSING-EQUIPMENT WITH ELECTRICAL DEVICES. |
| US4791236A (en) * | 1987-07-10 | 1988-12-13 | The Zippertubing Co. | Releasable flexible conductive jacket |
| US4857668A (en) * | 1988-04-15 | 1989-08-15 | Schlegel Corporation | Multi-function gasket |
-
1989
- 1989-04-13 US US07/337,491 patent/US5028739A/en not_active Expired - Lifetime
-
1990
- 1990-03-15 CA CA002012293A patent/CA2012293C/en not_active Expired - Fee Related
- 1990-04-11 DE DE69006620T patent/DE69006620T3/en not_active Expired - Lifetime
- 1990-04-11 EP EP90303911A patent/EP0392821B2/en not_active Expired - Lifetime
- 1990-04-12 JP JP2095240A patent/JPH02296396A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| DE69006620T2 (en) | 1994-05-26 |
| CA2012293A1 (en) | 1990-10-13 |
| DE69006620T3 (en) | 1998-05-14 |
| JPH02296396A (en) | 1990-12-06 |
| EP0392821B2 (en) | 1997-12-17 |
| DE69006620D1 (en) | 1994-03-24 |
| EP0392821A2 (en) | 1990-10-17 |
| EP0392821A3 (en) | 1991-04-24 |
| EP0392821B1 (en) | 1994-02-16 |
| US5028739A (en) | 1991-07-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |