A multi-function gasket for electrical apparatus and the like, operation of which tends to generate or be adversely affected by electromagnetic and radio frequency interference (EMI/RFI), comprising: a continuously molded, resilient foam core having a sealed outer boundary layer when cured; a flexible, electrically conductive and substantially abrasion resistant sheath surrounding the foam core and bonded to the boundary layer as the foam expands within and fills the interior of the sheath during the molding; and, mounting structure for affixing the gasket. The apparatus may be sealed against EMI/RFI leakage, noise emission and enviromental infiltration through perimeter gaps of electrically conductive doors, access panels and the like by the actions and interactions of the sheath, the foam core and the boundary layer. The flexible sheath is continuously pressed into positive engagement with the conductive surfaces between which it is mounted by the resilient foam core, forming a continuous electrical path across the gaps and preventing EMI/RFI leakage through the gaps. The boundary layer prevents noise emission and environmental infiltration across the gaps. The sheath protects the boundary layer against damage from abrasion and the like.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to the field of gaskets and seals. More 
particularly, this invention relates to the fields of: gaskets for 
electrical apparatus and the like which are prone to generate, or be 
adversely affected by electromagnetic interference (EMI) and/or radio 
frequency interference (RFI) from gaps in shielded or conductive housings; 
seals which are intended to reduce or eliminate noise emission; and, seals 
which are intended to reduce or eliminate environmental contamination or 
infiltration. Most particularly, this invention relates to a field of 
hybrid or multi-function gaskets and seals which combine the protective 
features of preventing EMI/RFI leakage, preventing audible noise emission 
and preventing environmental infiltration. 
2. Description of Prior Art 
Electromagnetic interference (EMI) has been defined as undesired conducted 
or radiated electrical disturbances from an electrical or electronic 
apparatus, including transients, which can interfere with the operation of 
other electrical or electronic apparatus. Such disturbances can occur 
anywhere in the electromagnetic spectrum. Radio frequency interference 
(RFI) is often used interchangeably with electromagnetic interference, 
although it is more properly restricted to the radio frequency portion of 
the electromagnetic spectrum, usually defined as between 10 kilohertz 
(KHz) and 10 gigahertz (GHz). Comprehensive technical summaries are 
available from a number of sources. 
A shield is defined as a metallic or otherwise electrically conductive 
configuration inserted between a source of EMI/RFI and a desired area of 
protection, which has the capability of absorbing and/or reflecting 
EMI/RFI and reducing the energy levels thereof. As a practical matter, 
such shields normally take the form of an electrically conductive housing 
which is electrically grounded. The energy of the EMI/RFI is thereby 
dissipated harmlessly to ground. Such a shield may be provided to prevent 
EMI/RFI radiating from a source or to prevent EMI/RFI (generated randomly 
or by design) from reaching a target, or both. Most such housings are of 
necessity provided with access panels, hatches, doors and/or removable 
covers. 
The gaps between the panels, etc. and the housing provide an undesired 
opportunity for EMI/RFI to pass through the shield. The gaps also 
interfere with electrical currents running along the surfaces of the 
housings from EMI/RFI energy which is absorbed and is being conducted to 
ground. The gaps reduce the efficiency of the ground conduction path and 
may even result in the shield becoming a secondary source of EMI/RFI 
leakage, from gaps which act as slot antennas. 
Various configurations of gaskets have been developed over the years to 
close the gaps of such shields and to effect the least possible 
disturbance of the ground conduction currents. Each seeks to establish as 
continuous an electrically conductive path as possible across the gap(s). 
However, there are inevitable compromises between: the ability of the 
gasket to smoothly and thoroughly engage and conform to the surface of the 
housing adjacent the gaps; the conductive capacity of the gasket; the ease 
of mounting the gasket; the ability of the gasket to withstand abrasive 
wear and tear, as well as repeated compression and relaxation; and, the 
cost of manufacturing the gasket. 
Electrical or electronic apparatus are often prone to acoustically noisy 
operation, which may become quite annoying to those in audible range of 
the apparatus, even in the absence of any specific technical difficulty 
caused by the audible noise. Noise emission can of course also result in 
technical problems under certain circumstances. Audibly noisy apparatus 
are sometimes provided with seals to reduce noise emission, but such seals 
are often only marginally effective at best. Moreover, such seals are not 
effective to prevent EMI/RFI leakage. 
Electrical or electronic apparatus are also notoriously prone to damage or 
malfunction from environmental contamination or infiltration, the most 
common and perhaps most destructive contaminants being dust and moisture. 
Many electrical and electronic apparatus are provided with cooling fans, 
which are intended to draw air along a predefined path within the 
apparatus to maximize cooling. When the path is well defined, a filter can 
be used to collect dust and other debris prior to infiltration. 
Unfortunately, gaps of the kind described above too often provide 
alternate paths for contaminated air to enter the apparatus and eventually 
cause problems. Environmental seals, such as used in windows and doors 
have of course been known for some time, but such seals have never been 
capable of preventing EMI/RFI leakage. 
The following patents are illustrative of the kinds of gaskets which have 
been proposed to prevent EMI/RFI leakage. Even a cursory analysis of such 
prior art will reveal the inability of such gaskets to function as EMI/RFI 
gaskets and as environmental infiltration seals and as audible noise 
seals; the inability of such gaskets to be manufactured relatively 
inexpensively; and, the inability of such gaskets to withstand abrasive 
wear and tear. 
An RFI shielding gasket disclosed in U.S. Pat. No. 3,555,168 is formed as a 
conductive foil lamina bonded to a resilient foam backing by a flexible 
adhesive and is mounted by a pressure-sensitive adhesive on the back of 
the foam backing. The gasket is a flat member produced from flat layers of 
flat stock, rather than by extrusion or molding. In a preferred 
embodiment, the foam is a closed cell, medium density neoprene foam from 
0.015 to 0.500 inches thick. The resulting laminate is die cut to shape, 
and is said to be RFI tight and dust tight. A seal disclosed in U.S. Pat. 
No. 3,312,769 has a resilient core, preferably neoprene sponge, surrounded 
by a metallic mesh, preferably an alloy of nickel and copper such as 
Monel. There is no indication the the core is bonded to the metallic mesh 
in any fashion. A sealing gasket disclosed in U.S. Pat. No. 2,477,267 
comprises a resilient gasket having a network of electrically conductive 
wires embedded therein and therethrough, the wires having portions exposed 
on opposite surfaces, of the gasket. A seal disclosed in U.S. Pat. No. 
3,466,906 comprises a body of resilient plastic foam material having a 
plurality of interconnected open cells and a coating of electrically 
conductive material provided throughout the body on the surfaces of the 
plastic elements. A conductive coating is preferably applied by 
electroplating to form a conductive surface on the seal. A seal available 
from Chomerics Corporation is denoted by the trademark MESH STRIP. The 
seal is available as resilient, single and dual, all-metal strips or 
compressed shapes. The seal is also available with an elastomer core, in 
round or rectangular profiles, the core being solid or hollow. 
In so far as weather strip seals are of interest, mention is made of Q-LON 
brand weather strip seals manufactured and sold by Schlegel Corporation, 
assignee herein. The seals are formed by continuous molding processes 
wherein a foam core expands and cures in a travelling mold surrounded by a 
polyethylene or vinyl lamina, after which the lamina and foam adhere to 
one another. The continuous molding processes are described in U.S. Pat. 
Nos. 3,700,368 and 3,781,390. The seals may also be molded directly with 
or onto semi-rigid carriers used for reinforcing and/or mounting the 
seals. Such seals have never been capable of preventing EMI/RFI leakage, 
although such seals are generally acknowledged as superior environmental 
seals. 
A number of other problems are not apparent from such patent references. 
For example, most prior art gaskets require compression of at least 50% in 
order to reach maximum effectiveness. Gaskets according to this invention 
require only approximately 25% compression. This reduces the costs of 
cabinets, panels and the like, which do not have to be as robust as 
otherwise necessary to withstand prior art compression forces. Moreover, 
the compression can be adjusted for specific load requirements, by 
selectively altering gasket profiles and the density (mass) of gasket 
cores. 
As another example, the prior art is as yet unable to cope with signal 
radiation from rooms and building which are supposed to be "secure" 
against electronic surveillance techniques. When gaskets according to this 
invention are used for weatherstrips in doors and windows, rooms and whole 
buildings can be made more secure. 
The gasket disclosed herein is the first product capable of preventing 
EMI/RFI leakage, preventing audible noise emission and capable of 
preventing environmental infiltration; as well as being particularly 
resistant to damage from abrasion, even sliding contact; and, capable of 
manufacture by continuous molding processes in a wide variety of profiles 
and embodiments, including integral carriers. The gasket disclosed herein 
is the first such product to embody an EMI/RFI gasket in a form 
sufficiently corresponding to environmental seals to enable a cross-over 
of production and manufacturing technology which results in a 
multi-function hybrid gasket/seal solving all of the problems plaguing 
prior art EMI/RFI gaskets. 
SUMMARY OF THE INVENTION 
It is an object of the invention to provide improved gaskets for preventing 
EMI/RFI leakage. 
It is a further object of this invention to provide EMI/RFI gaskets which 
are also capable of preventing environmental infiltration or 
contamination. 
It is another object of the invention to provide EMI/RFI gaskets which are 
also capable of preventing audible noise emissions. 
It is yet another object of the invention to provide such a multi-function 
gasket in an integrally formed product. 
It is yet another object of the invention to provide such an integrally 
formed multi-function gasket in a form easily adapted to seal gaps in 
shield housings of all shapes, sizes and geometries. 
It is yet another object of this invention to provide such a gasket which 
can be manufactured by molding processes. 
It is yet another object of this invention to provide such a gasket which 
is substantially less prone to damage from abrasion and similar wear and 
tear. 
It is yet another object of the invention to provide such a gasket with a 
variety of integrally formed carriers to facilitate mounting and 
maintenance. 
These and other objects of the invention are accomplished by a 
multi-function gasket for shields housing electrical apparatus and the 
like, operation of which tends to generate or be affected by, EMI/RFI, 
comprising: a resilient core with a sealed outer boundary layer; an 
electrically conductive sheath; and, means for mounting the gasket. The 
core is preferably a continuously molded, resilient foam core having a 
sealed outer boundary layer when cured. The sheath is preferably a 
flexible, electrically conductive and substantially abrasion resistant 
sheath surrounding the foam core and bonded to the boundary layer as the 
foam expands within and fills the interior of the sheath during the 
continuous molding. The shield may be sealed against EMI/RFI leakage, 
audible noise emission and environmental infiltration through perimeter 
gaps of electrically conductive doors, access panels and the like by the 
actions and interactions of the sheath, the foam core and the boundary 
layer. The flexible sheath is continuously pressed into positive and 
thorough contact with the conductive surfaces, between which it is 
mounted, by the resilient foam core, forming a continuous electrical path 
across the gaps and preventing EMI/RFI leakage through the gaps. The 
boundary layer prevents noise emission and environmental infiltration 
across the gaps. The cellular nature of the foam inhibits audible noise 
propagation through the gasket itself. Moreover, the sheath protects the 
boundary layer, and the underlying foam core, against damage from abrasion 
and the like. 
The sheath is preferably a fabric, formed at least in part from 
electrically conductive fibers, or coated with an electrically conductive 
layer, or both. The metal surface, formed for example by electroless 
plating or sputtering, is not only highly resistant to damage from 
abrasion and the like, but is characterized by a relatively low 
coefficient of friction which enables the gasket to withstand sliding 
frictional contact. This provides an opportunity to mount the gasket in 
positions which are not appropriate for gaskets unable to withstand the 
rigors of sliding contact. The sheath may be provided with a coating on 
the interior surface thereof to inhibit bleeding of the foam through the 
sheath prior to curing. 
The ability to manufacture the gasket in accordance with continuous molding 
technology reduces the cost of manufacture and enables the gasket to be 
molded with a carrier, for example a semi-rigid plastic, by means of which 
the gasket may be conveniently reinforced and/or mounted. It will be 
appreciated that multi-function gaskets according to this invention can 
also be produced, for example, by shot molding techniques. Such other 
techniques are not now believed to be as efficient as continuous molding 
techniques. 
Multi-function shielding gaskets in accordance with this invention are 
preferably made from a compressible urethane foam core encapsulated within 
silver-coated nylon ripstop fabric. The conductive fabric is bonded to the 
foam as an integral part of the manufacturing process. The resilient 
urethane is formulated to provide minimum closing force with maximum 
attenuation. 
The excellent memory of the urethane foam permits it to return readily to 
its original shape after cycling and to adjust to cabinet door gap 
dimensions or irregular surfaces. Urethane wrapped in conductive fabric 
also assures shielding/sealing continuity. Corners are easily 
accommodated, and even cabinet hinges can be shielded and sealed. Further 
benefits include light, dust and noise sealing, as well as providing a 
solid protective barrier against the intrusion of moisture and humidity. 
EMI/RFI shielding/sealing gaskets offer an extremely high degree of 
shielding effectiveness. Test results (in accordance with the SAE-ARP 1705 
transfer impedance test) from a three-eighth inch (3/8") by three-eighth 
inch (3/8") in cross-section gasket with silver coated ripstop nylon, 
revealed attenuation, measured in decibels(dB) of approximately 80-90 dB 
from 1 KHz through 1 MHz; approximately 60-70 dB from 1 MHz through 100 
MHz; and, 55-60 dB from 100 MHz to 1 GHz. 
Multi-function gaskets according to this invention are durable, 
dimensionally stable and safe. There are no wire strands or metal fingers 
that can snag or break; no ends to fray, and ends do not require potting. 
There is no shrinkage under heat or stretching during installation. There 
are no sharp edges, metal or otherwise, which are often prone to break. 
Even more importantly, people are protected from nicks and cuts, and 
equipment is never vulnerable to loose foreign conductive material. 
Multi-function gaskets according to this invention provide very low closing 
force for cabinet doors and hatch covers. In fact, such closing forces can 
actually be reduced as much as ten times. Even so, the foam core enables 
the gasket to fill cavities and irregular spaces and thereby maintain 
shielding integrity. The very low closing forces greatly simplify the 
mounting problems heretofore experienced for such gaskets. Gaskets formed 
from relatively stiff metallic parts require substantial and robust 
mounting hardware. EMI/RFI gaskets according to this invention can, in 
very many instances, be mounted on flat surfaces by pressure-sensitive 
adhesives. In many instances, no special mounting grooves or hardware need 
ever be provided. Wherever appropriate, the urethane foam may be 
formulated as an unburnable char-foam, which will maintain at least an 
environmental seal, against passage of noxious gases and smoke even under 
the thermal loads of fire conditions. 
These and other objects and advantages of the invention will become 
apparent to those skilled in the art from the following detailed 
description of the preferred embodiments of the invention, shown in the 
accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The simplest embodiment of a multi-function gasket according to this 
invention is shown in FIG. 1 and generally designated by reference numeral 
10. The multi-function gasket 10 comprises a continuously molded foam core 
12, which is resilient and compliant over a wide range of temperatures and 
which exhibits good compression set characteristics, that is, the material 
will "spring back" even after repeated compression and decompression and 
even after long periods of compression. The foam core is covered by a 
sheath 14 formed from an electrically conductive fabric material. The 
sheath 14 is bonded to the foam core during a continuous molding process 
in which the foam blows or expands inside of the sheath, the sheath being 
wrapped around the foam as it enters a travelling mold. The ends 16 and 18 
of the sheath preferably overlap. This continuous molding process is 
described generally in commonly owned U.S. Pat. Nos. 3,700,368 and 
3,781,390, the teachings of which are incorporated herein by reference. 
Accordingly, this process will not be described in greater detail herein. 
The fabric may be conductive by reason of being formed directly from 
electrically conductive fibers or by reason of later treatment of the 
fabric by coating, or otherwise, with an electrically conductive material. 
The fabric may of course also be formed from a combination of electrically 
conductive fibers and after-treatment with an electrically conductive 
material. Examples of fabrics formed by weaving, braiding or knitting 
fabrics from conductive fibers are described in U.S. Pat. No. 4,684,762, 
the teachings of which are incorporated by reference. Another example is a 
silver coated fabric, woven first from 100% ripstop nylon and then made 
electrically conductive through a scouring and electroless plating 
process. The conductive material may also be applied by sputtering. This 
fabric material has been available in the market place for several years 
and is commonly made in both 30 denier (a unit expressing the fineness of 
silk, rayon, nylon and other yarns as a function of weight in grams per 
length; lower denier numbers indicating finer yarn)and 100 denier 
material. The specific processes by which these kinds of fabrics are made 
do not form part of this invention, and accordingly, are not described in 
detail herein. 
As the foam core cures, a sealed outer boundary level 20 forms on the outer 
surface thereof, facing the inner surface of the sheath 14. The outer 
boundary layer has an adhesive character which effects a strong bond 
between the foam core and the sheath. This bonding is sufficient for 
securing the sheath over the core. Under some circumstances, the pressures 
of molding and blowing forces some foam to bleed through the fabric before 
curing. Although this provides an even stronger bond between the core and 
the sheath, the electrical continuity of the sheath is compromised. When 
such bleeding is a problem, a supplemental layer or coating 22 on the 
interior surface of the sheath prevents the foam from bleeding or leaking 
through the sheath, before the core cures. Adhesion of the sheath is 
promoted, with or without the coating or layer 22, by reason of the 
surface roughness of the fabric, to which the foam or coating strongly 
adheres. The foam core and coating are preferably compatible with regard 
to adhering to one another. The weave of a typical fabric 14 is shown in 
enlarged scale in circle I. The layer 22 is shown in enlarged and 
exaggerated scale, for purposes of illustration, in circle II. The layer 
22 is also useful for bonding the overlapped edges 16 and 18 of the sheath 
to one another, at least remote from outer extreme edge 24. An adhesive 
strip 26 can be attached at the overlapped edges 16, 18, over extreme edge 
24. A flame retardant organic layer or coating 22, preferably urethane, is 
presently preferred. Flame retardant urethane formulations are available 
commercially. 
FIG. 2 illustrates a profile which is shaped somewhat differently of that 
of FIG. 1, but is otherwise structurally similar. Gasket 30 comprises a 
foam core 32 surrounded by electrically conductive sheath 34, the ends 36, 
38 of which overlap one another. A strip of pressure sensitive adhesive 40 
is provided for mounting the gasket. The gasket may be provided with a 
supplemental layer comparable to layer or coating 22 as shown in FIG. 1, 
to inhibit bleeding. The details of this aspect of the invention are the 
same in all of the illustrated embodiments, as in FIG. 1 Accordingly, 
these details are omitted from FIGS. 2-12 and from the following 
description. It will be appreciated by those skilled in the art that 
utilization of a layer or coating comparable to coating 22 will be more 
appropriate in certain circumstances than in others. 
A reinforced profile 46 is illustrated in FIG. 3. In this case, a foam core 
48 is molded onto a semi-rigid carrier 52, both of which are surrounded by 
conductive sheath 50. The carrier 52 imparts extra strength and some 
measure of rigidity. The plastic carrier may be formed from a number of 
suitable plastics, for example, polypropylene, as well as from paper, for 
example, kraft paper. It will be appreciated that the thickness of carrier 
52 is exaggerated in scale to facilitate illustration thereof, this being 
the case for all such carriers shown in the drawings. The actual thickness 
of the carrier will depend upon the material from which it is made, it 
being necessary to provide some rigidity and some flexibility. Even so, 
typical thicknesses are 0.015 to 0.040 inches. Gasket 46 may be provided 
with a pressure-sensitive adhesive 54 for purposes of mounting the gasket. 
Alternatively, in lieu of adhesive 54, the carrier may form mounting means 
for securing the seal in an inverted T-slot, as weatherstrips are 
sometimes mounted. 
The gasket 60 shown in FIG. 4(a) illustrates the large measure of freedom 
in design which can be achieved with multi-function gaskets according to 
this invention. The bun gasket 60 comprises a foam core 62 covered by 
electrically conductive sheath 64. Gasket 60 can be mounted by insertion 
into grooves of corresponding shape or by use of pressure-sensitive 
adhesive along almost any surface portion thereof. Gasket 60 is shown 
mounted in double grooved structure 66 in FIG. 4(b) as a sliding door 
seal. 
The gasket 70 shown in FIG. 5(a) illustrates an embodiment wherein a 
semi-rigid carrier is utilized for mounting the gasket in a kerf structure 
84, for example a door or window frame, as shown in FIG. 5(b). Gasket 70 
comprises a foam core 72 molded with or onto a semi-rigid carrier 76. 
Carrier 76 has a base portion 78 and a leg portion 80, defining a portion 
of the outer boundary of the gasket 70. Another leg 82 projects into the 
foam core 72. An electrically conductive sheath 74 surrounds both the core 
72 and the boundary portions of carrier 76. Carrier 76 of gasket 70 will 
typically be thicker than carrier 52 of gasket 46 to accommodate the 
compression mounting loads, which can be appreciated from FIG. 5(b). 
An alternative mounting structure is shown in FIG. 6. A gasket 90 has a 
substantially Z-shape cross section. A foam core 92 is molded onto and 
over a semi-rigid carrier 96 and a strip of magnetic material 108. The 
foam core 92, carrier 96 and magnetic strip 108 are surrounded by 
electrically conductive sheath 94. A metal clip 98 has a leg 102 for 
slipping over the edges of a metal panel, and is provided with a plurality 
of engagement prongs 104 along its length. The clip 98 also has a leg 100 
which is forceably bent over and pressably engages a portion of that leg 
of the seal 90 in which the carrier 96 is disposed. This ensures excellent 
electrical contact between the metal clip 98 and the electrically 
conductive sheath 94. The .provision of a magnetic strip 108 illustrates 
that secure electrically conductive contact can be effected in an 
alternative fashion to compression of the seal. Such a seal will be 
effective even where the gap in a shield to be sealed is between two parts 
which move relative to one another during operation of the electrical 
apparatus. Such movement is typical where heavy equipment is shock-mounted 
on springs or the like. Such a seal is also effective for sealing gaps of 
different or varying width. 
A gasket 110 having yet another configuration is shown in FIG. 7. Although 
the shape is different from the gaskets described herein before, the 
structural elements of the gasket 110 are essentially the same. A foam 
core 112 is molded over or with a semi-rigid carrier 116, both of which 
are surrounded by an electrically conductive sheath 114. The gasket may be 
mounted by means of pressure-sensitive adhesive 118. The gasket 110 may 
come as shown in FIG. 7, being mounted directly on a flat surface to which 
the adhesive will adhere. An alternative mounting arrangement for the same 
gasket is shown in FIG. 8. In FIG. 8, a gasket assembly 122 is formed by 
affixing gasket 110 to one leg 1 to 4 of a metal clip 126. 
A variation of the gasket assembly shown in FIG. 8 is illustrated in FIG. 
9. Gasket assembly 130 comprises two gaskets 46, as otherwise shown in 
FIG. 3, affixed to a metal clip 126. A comparison of FIGS. 1 through 9 
serves to highlight the tremendous design flexibility which is imparted to 
the field by reason of the structural interactions of the various 
components from which gaskets according to this invention are formed. 
Yet another mounting system is illustrated in FIGS. 10, 11 and 12. With 
reference first to FIG. 10, a gasket 140 has three foam core sections 142, 
144 and 146 molded over and with a semi-rigid carrier 150. The carrier 150 
has a stop or base portion 152, a segment 154 to inhibit longitudinal 
compression and a pair of deflectable fin portions 156. The three foam 
core sections and the carrier are surrounded by an electrically conductive 
sheath 148. The gasket 140 is adapted to be pressably inserted into a 
groove 162 of a door or panel 160, as shown in FIG. 11. The deflectable 
fin portions 156 of the carrier 150 inhibit movement of the seal out of 
its mounting position. The foam core sections 144 and 146 ensure good 
electrical contact between the electrically conductive sheath 148 and the 
corresponding engaged surfaces of the door 160 defining the groove 162. 
The door 160 may be all metal, as shown, or may be metal clad or may be 
formed from other conductive materials, for example, conductive plastics. 
Foam core portion 142 and that portion of the electrically conductive 
sheath 148 extending therearound, form a sealing tongue 158, which engages 
the surface of member 166. Member 166 may also be metallic, metal clad or 
formed from other conductive materials. Upon further closing of the gap 
and compression of the gasket, as shown in FIG. 12, sealing tongue 158 
folds around and presents a broad portion of itself for engaging and 
sealing against member 166. The base segment 152 of carrier 150 presents 
unwanted movement and compression of the gasket 140 further into the 
groove 162 as the compression load increases. 
Gasket 140 is particularly effective for doors. Even repeated sliding 
movement of the electrically conductive sheath 148 over the surface of 
member 166 does not noticeably degrade surface resistivity to any 
measurable extent. Gasket 140 is also useful because gaps of varied width 
may be sealed with the same part, whereas prior art seals might require 
three or more models of different dimensions to close gaps in the same 
range. 
Multi-function gaskets, according to this invention, may also be used in 
combination with a movable closure assembly forming a weatherstripped 
window, door or the like, wherein the multi-function gasket forms at least 
some of the weatherstripping, and further comprising means for 
electrically grounding the sheath. Electrical signals radiated on one side 
of the closure assembly will be blocked from radiating through 
weatherstripped gaps in the closure assembly sealed by the multi-function 
gasket, thereby inhibiting reception of the signals on the other side of 
the closure assembly by electronic surveillance techniques. The closure 
assembly will have a frame for a window, door or the like on which the 
weatherstripping may be mounted, and the frame may comprise means for 
electrically grounding the sheath. The frame may be formed at least in 
part from electrically conductive material in electrical contact with the 
sheath and in electrical contact with means for electrically grounding the 
frame. 
The variety of embodiments of EMI/RFI gaskets according to this invention, 
illustrated and described herein, have been presented to demonstrate the 
wide spread utility and flexibility of the invention. The variety of 
embodiments should not obscure the essential characteristics of all 
EMI/RFI gaskets made in accordance with this invention. An EMI/RFI gasket 
characteristic of this invention comprises: a resilient core, a flexible, 
abrasion resistant, electrically conductive sheath surrounding the 
resilient core and means for affixing or mounting the gasket. Gaskets may 
be optionally provided with semi-rigid carriers or reinforcing strips and 
may optionally be provided with magnetic strips to enhance sealing 
contact. The mounting means may include adhesives, resilient or 
spring-type clips or profiles of specific cross-section, adapted for 
insertion into grooves of corresponding shape. The resilient or 
spring-type clips may be embodied in exterior metal spring clips or 
internal profiles of carriers having deformable or deflectable locking 
ribs. Semi-rigid carriers may also be provided with apertures for 
receiving or engaging fastening members. 
The invention may be embodied in other specific forms without departing 
from the spirit or essential attributes thereof. Accordingly, reference 
should be made to the appended claims, rather than to the foregoing 
specification, as indicating the scope of the invention.