GARNITURE EN TOILE METALLIQUE

WIRE MESH GASKETING

Abrégé anglais

ABSTRACT
An arrangement for preventing electromagnetic
radiation from passing an access opening, in a sheet of elect-
romagnetically opaque material, having a closure of similarly
opaque material with a surface urged against the surface of
the sheet at the opening, comprising an elongated strip of
wire mesh gasket extending beside the opening in contact with the
surfaces, and being of generally circular cross section with
a fin extending laterally therefrom toward and through the
opening, and wear strips securing the fin to both surfaces of
the sheet at the opening.

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Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In combination:
a sheet of electromagnetically opaque material having
a polygonal access opening therein;
a gasket strip of woven wire electromagnetically opaque
material extending around the periphery of said opening, said
s-trip comprising, in cross section, a generally circular
portion from which a fin extends radially;
means securing said strip around said opening so that
said circular portion engages one surface of said sheet and
so that said fin engages both surfaces of said sheet, passing
through said opening to do so, said strip securing means
comprising resilient wear strips of generally U-shaped cross-
section substantially longitudinally co-extensive with said
edges of said opening and comprising in section first and
second legs extending in the same direction from a common bight
and mutually spaced to press said fin firmly against the
surfaces of said sheet, said circular portion being continuous
around the corners of said opening and being of greater
diameter than the thickness of a leg of said wear strip, to
enable compression of said circular portion and to limit the
amount of said compression;
and a closure of electromagnetically opaque material
larger than said opening and opposed thereto, so that when
said closure is pressed against said gasket strip said circular
portion thereof forms a continuous seal surrounding said opening.

Description

BRIEF _ M~ARY OE THE I _E_TION
The present invention comprises a procedure whereby
relatively unskilled personnel are able to install radiation-
-tight seals around openings of any size much more quickly and
inexpensively, withou-t any tooling or set--up charges, the
seals being capable of repair or replacement in the field
without special tools.
According to the invention, there is provided in
combination: a shee-t of electromagnetically opaque material
having a polygonal access opening therein; a gaske-t strip of
woven wire el.ectromagne-tically opaque material extending around
the periphery of said opening, said strip comprising, in cross
section, a generally circular portion from which a fin extends
radially; means securing said strip around said opening so
that said circular portion engayes one surface of sai.d sheet
and so that said fin engages both surfaces of said sheet,
passing through said opening to do so, said strip securing means
comprising resilient wear strips of generally U-shaped cross-
section substantially longitudinally co-extensive wi-th said
edges of said opening ancl comprising in section first and second
legs extending in the same direction from a common bigh-t and
mutually spaced to press said fin firmly against the surfaces
of said shee-t, said circular portion being continuous around
the corners of said opening and being of greater diameter than
the thickness of a leg of said wear strip, to enable compression
of said circular portion and to limit the amount of said com-
pression; and a closure of electromagnetically opaque material
larger than said openiny and opposed -thereto, so that when said
closure is pressed against said gasket strip said circuit
portion -thereof forms a continuous seal surrounding said open-
ing.



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BRIEF DESCRIPTION OF THE DRAWING
_ _ _ _ _ _ _ _ _ _ _ _
In -the drawing, in which like reference numerals
indicate corresponding parts throughout the several views,
FIGURE. 1 shows a radia-tion seal according to the inven-tion
installed around an access opening in a housing, FIGURE 2
is a fragmentary sectional view of a seal accordi.ng to -the
inventi.on in relation to a housing and a closure, and
FIGURE 3 is an enlarged, detailed vi.ew of a portion of
FIGURE 1.
DESCRIPTION _ T~IE PREFERRED EM~ODI~ENT
As is shown in the drawing, a cabinet or housing for
equipment producing electromagnetic radiation includes a



wall 20 having an access opening 21, with which a closure 22
cooperates by hinging, clamping, or other appropriate
measures.
A strip of woven wire gasket 24 is mounted to
surround opening 21. In cross-section, gasket strip 24
comprises a generally circular portion 25 from which a
fin 26 extends laterally toward and through opening 21,
being folded over the edge 27 of the opening. Gasket strip
24 may be preformed in the exact size to fit around opening
21, or may be made on the spot from a length of material,
the ends being mutually twisted and intertwined to form a
continuous bond, and the joint preferably being located at
a site other than a corner of the opening. In order to give
a more perfect configuration~ fin 26 only of strip 24 may be
mitered at the corners, as shown at 30 in FIGURE 3.
In order to secure gasket strip 24 in position, a
set of wear strips 31, 32, 33 and 34 are provided. These
strîps are of slightly less length than the sides of opening
21, and may be of nylon or other suitable material. They are
of U-shaped configuration in cross-section, comprising first
and second legs 35 and 36 extending in the same direction
from a bight 37. The spacing bet~een the legs is substantially
the same as the thickness of wall 20 plus twice the thickness
of fin 26. See FIGURE 2.
To install the seal, gasket strip 24 is placed at
opening 21 and fin 26 is passed through the opening and folded
along the surfaces of wall 20. Starting near one corner, a
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wear strip such as 34 is pressed over the fin and the end of
the wall, and this is continued unt~l the entire length of
the wear strip is tightly engaged. This is repeated at the
other edges of ~he openingr until the gasket strip is firmly
secured all around the opening. The wear strips come suffi-
ciently close to the corners to give adequate holding of the
gasket strip, but a mitered corner is not found necessary.
FIGURE 2 shows that the diameter of the gasket
strip is greater than the thickness of the wear strip r SO
that the gasket strip can be compressed between door surface
40 and housing surface 41, while the wear strip acts as a
mechanical stop to prevent undue compression of the gasket strip.
In one embodiment of the invention, the gasket strip
was of Monel Mesh material supplied by Tecknit, and the wear
strip was of molybdenum disulfide Filled Nylon, supplled by
Polymer Corp. For a housing of .060 to .090 thick gauge metal
the diameter of the gasket strip 24 was 3/16 inch and the width
of fin 26 was .750 inches. The dimensions of wear strips 31-34
were .23 x .32.
While the sPal has been shown as applie~ to the
housing around the opening, it can with equal satisfaction be
applied to the edge of a closure of proper dimensions.
From the above it will be evident that the invention
comprises an arrangement for sealing an opening against
passage of electromagnetic radiation without special

frames or fas-ceners f which can be accomplished readily and
inexpensively by xelatively unskilled labor.
- Various characteristics and advantages of the
invention ha~e b~en set forth in the foregoing description,
together with details of the structure and function of the
inventi~n, and the nov~l features thereof are pointed out in
the appended claims. The disclosure, however, is illustxative
only, and changes may be made in detail, especially in matters
of shape, size~ and arrangement of parts, within the principle
of the in~ention, to the full extent indicated by the broad
general meaning of the terms in which the appended claims
are expressed.