Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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PORTABLE AIR FILTERING DEVICE FOR FACE MASKS
This invention relates to new and useful improvements in
portable air filtering devices for face masks.
~ asks with forced air means have heretofore been employed
to furnish filtered air to a user to protect the user from outside
polluted air. Such devices for example are shown in U.S. Patents
No. 3,112,745 and 3,~7,965. Apparatuses such as shown in these
patents as well as other patents have inherent disadvantages one
of which is that the ventilating protective devices are complex in
construction and bulky to wear. This is especially so for apparatus
of this type which is worn as complete head covers or hoods.
Another disadvantage of prior apparatuses is that a single portable
filtering unit cannot convenien~ly be adapted for use with other
types of face masks, thus limiting the device to a particular use.
The above disadYantages also make the prior devices costly to manu-
f~cture and uneconomical to market.
According to the present invention and forming a primary
objective thereof, a portable air filtering device is provided
which overcomes disad~antages of prior de~ices and in general compri-
ses a simplified, efficient lightweight and versatile structure.
One feature of the invention is that a filter blower unit has uni-
versal application to most types of face masks. In one application,
a head band which can be used with the filter blower unit has air
outlet means in the front thereof and such head band is arranged
for use with a mask of a structure providing a selected diffusion
of air such that no outside polluted air is admitted even though
the mask has spaces between it and the user's head. The llead band
has means for detachably supporting various types of safety masks or
shields so that a single head band can be used with various types of
masks or shields to suit the condition at hand. In other appli-
cations, the filter blower unit can be used with a respirator facemask or with an oxygen mask.
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The invention will be better understood and additional
objects and advantages will become apparent from the following
description taken in connection with the accompanying drawings
which illustrate a preferred form of the device.
Figure 1 is a side elevational view of a portable air filter-
ing device for face masks embodying principles of the present in-
vention;
Figure 2 is a rear elevational view of the invention taken
on the line 2-2 of Figure l;
10Figure 3 is a sectional view taken on the line 3-3 of
Figure l;
Figure 4 is a side elevational view of another application
of the present in~ention;
Figure 5 is an enlarged sectional view taken on the line
5-5 of Figure 4;
Figure 6 is a sectional view of adapter means providing use
of the invention in the manner shown in Figure 4 but with a different
form of face mask; and
Figure 7 is a side elevational view of still another appli-
cation of the present invention.
With particular reference to the drawings, a~d first toFigures l-3, a first concept of the invention comprises a head
band member lQ having a rear arcuate portion 12 arranged to engage
the back of the head and a front arcuate portion 14 arranged to
engage the front of the head. Arcuate portion 14 or rear arcuate
portion 12, or both, are preferably formed from a resilient or
stretchable materi.al which provides a good fit and adjustment on
the head. ~n inner lining 16 may be used if desired. The head
;band includes a lateral strap 18 which fits over the top of the
head. This strap as well as the head band may have conventional
size adjustment means, not shown, if desired.
`Front portion 14 is hollow and forms a passageway 20 for
the flow of filtered air. An outlet 22 for such passageway is in
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the upright front wall of the portion 1~
Head band portion 14 is provided with side extensions 24
having a telescoping connection with upper ends of a Y-shaped mani-
fold 26 connected to a flexible conduit 28. Conduit 28 connects
into a filter blower unit housing 30 in which is incorporated a
blower 32, a battery pack 34, and suitable conventional circuitry
including an on-off switch 36. Housing 30 has suitable means for
support on the body of the user in a convenient position and for
this purpose may include a clip 37 for engagement with the user's
10 belt.
Opposite ends of the housing have caps 38 threadedly mounted
thereon, and such caps have an apertured or mesh wall ~0 allowing for
the entrance of air to be filtered. Each cap 38 removably holds
a filter disc 42 therein for filtering the air to be supplied to
the head band. These filters are easily replaced by first unthreading
the caps 38, installing new filters, and then replacing the caps.
The threaded ends o:E the housing 30 are of the same size and thread
structure as that used on conventional respirator face masks so that
existing caps for such respirator face masks can be employed for the
20 caps 38 and the filters may comprise conventional disc-type filters
now used on existing face masks.
The head band 10 has side connections 44 of conven-tional design
for removably receiving a safety mask or sh.ield 46. The conllections
44 similarly have conventional means for holding the mask vertically
or in a pos.ition pivoted up away from the face. Such connec-ting
structur~ is well known in the art and is not detailed.
In the operation of the arrangement of Figures 1-3, forced
air from the blower 32 enters through the apertured caps 38 and
:Eilters 42 and is forcefully ejected through the opening 22. Since
30 the air is ejected perpendicularly against the mask, it diffuses
in all directions and discharges evenly around the open spaces
between the mask and the user's head. Since the air is diffused
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.evenly in all directions, an air barrier is provided around the
entire mask and thus no polluted air is drawn in through spaces
around the mask.
Any type of safety mask can thus be mounted on the head
band and a consumer can apply the type of mask which accommodates
a specific purpose. For best operation of the invention, it is
desired that ~he safety mask 46 have rearwardly turned portions 48
at the sides, a rearwardly turned portion 50 at the top, and a
rearwardly turned portion 52 at the bottom. Such mask structure
provides a substantially equal distribu~ion of air around the face
of the user to maintain filtered air in such face area at all times.
The ~ask 46 preferably has cut-back portions 54 on the
sides to allow the user to turn his head and ~urthermore has a bead
56 around the rearward edges for securement to a head cover, hood,
or the like.
Another concept of the invention comprises the use of the
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filter blower unit 30 with a respirator face mask 60, Figures 4 and 5,
such unit 30 using a blower 32, caps 38, filters 42, etc. the same
as in Figure 2. Mask 60 is of conventional construction and fits
in an air tight connection around the nose and mouth of the wearer.
.
This type of mask has a front threaded projection 62 arranged to
receive a cap 6~. In the conventional arrangement and use of such
a mask, the cap used therewith which is similar to cap 38 in Figure
2, houses a filter disc the same as filter disc 42. In the con-
cept o~ the present i~vention, however, a fllter disc is not used
in cap 64 since the air is already filtered in the filter blower
unit 30, although oE course an additional filter may if desired
be US ed in the mask.
Instead o~ using a conventional cap, the cap 64 comprises an
adapter cap arranged for threaded connection on the p-rojection 62
of the conventional mask and having a pipe elbow 66 arranged at
one end for plug-in connection with the hose 28. The other end of
elbow 66 has a swivel connection 67 with the cap 64. Thus, not
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only does a concept of the invention have means for supplying a
fresh layer of air across a person's face as in Figure 1 but such
fresh air could be supplied to a respirator face mask as in Figure
4.
In some conventional face masks 60', Figure 6, the project-
ion 62' has internal threads, and in order to apply the present in-
vention to such structure, an adapter ring 68 is employed having
a pair of external threaded portions 70 and 72, the threaded por-
tion 70 being of a structure to fit the internal threads of pro-
jection 62' and the threaded portion 72 being of a structure tofit the internal threads of a cap 6~ having the same structure as
the cap ~4 in Figures 4 and 5. Thus, the filter blower unit can
be applied to respirator face masks with internal threads at the
front.
A concept of the invention also can be associated with an
oxygen-type mask 74, Figure 7. Such type of mas~ fits around the
nose and mouth of a wearer but as distinguished from the mask 60
in Figure ~, no means for holding a filter is employed. The hose
28 of the filter blower unit 3~ is fitted onto a comlector 76 that
forms a part of the mask and which in conventional use is connected
to an oxygen line.
According to the present invention, ~iltering means is provi-
ded which can be used with substantially any type of face mask.
By the specific arrangement of air ejection from the head band in
the concept of Figure 1, an air barrier is provicled around the user's
face which, while allowing the safety mask or shield to be suitably
spaced from the face prevents any entrance of polluted air around
the mask. ~urthermore, since the air is ejected straight out and
difused, there are no uncomfortable currents of air flowing past
the face. ~nother feature of the present invention is that it
uses conventional on the market filters ~2 so that spec:ial filters
do not have to be purchased.
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- It is to be understood that ~he forms of our invention here-
in shown and described are to be taken as preferred examples of the
same and that various changes in the shape, size and arrangement of
parts may be resorted to without departing from the spirit of our
invention or the scope of the subjoined claims.
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