Note: Descriptions are shown in the official language in which they were submitted.
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D I S POSABI.E RES PI RATOR
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to disposable respirators
more particularly of the foldable type which offer
protection against pneumoconiosis and fibrosis producing
contaminants.
Description of the Prior Art:
It is important to seek the protection of
one's respiratory system with a respirator when subjected
to unpleasant or noxious environments. However,
respirator wearing comfort, convenience of carrying
and freedom from maintenance are paramount to overcoming
the commonly encountered resistance to use.
In addition to a further-desire for co~pactness,
lightness of weight and comfort of face fit, a wearer's
ready acceptance of a particular respirator design
requires minimal resistance to breathing through
the face piece and avoidance of heretofore encountered
"hot and clammy" breathing atmosphere within the
face piece. This, in turn, requires adequate spacing
of the face piece around nose and mouth and avoidance
of collapse during inhalation.
Heretofore, the abo~e has been best attended
to with rigidly cupped and/or frame supported respira~or
structu7res of types exemplified ~y U.S. Patents Des. 248,497
and 3,521,630. These, however, suffer the disadvantages
of costly manu~acture, ungainliness in storage and
carrying by workers as well as a vulnerability to
. damage by crushing, particularly in the case o~ the
type of structure illustrated in U.S. Des. 2~8,497.
Frame supported structures, on the other hand, require
periodic cleaning of the support structure, tedious
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filter replacement a~d provision for clean storage
of the devices between times of use~
In view of the above, the more easily carried
foldable and disposable pocket respirator is attractive
5 to workers and suppliers alike. However, such devices
of which those of U.S. Patents Nos. Des~ 249,072
and 4,248F220 are exemplary, lack the effectiveness
of the c1lp-formed or frame-supported devices. In
particular, they lack the ease of application to
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- 10 the face, comfort of final fit, resistance to collapse
~ and air filtering capability of multiple layer filtering
- systems. Additionally, complicated plea~ing, stitching~
riviting and other assembly procedures needed to
produce prior art folded respirators render them
relatively difficult and costly to produce.
In view of the foregoing, an objective of
~~ the present invention is to provide improvements
in folded respirators and method of making same.
Another object is to provide for simple and
economical mass production of the respirators, more
particularly by use of a continuous multiply layered
web of disposable materials~
Still another object is to provide an end
product offering exceptional face-fitting and breathing
comfort with optimum air filtering efficiency.
Other objects and advantages of the invention
will become apparent from the following description
when taken in conjunction with the accompanying drawings.
IN THE DRAWINGS
~ig. 1 is an illustration, in pèrspective~
of a preferred embodiment of the invention;
Fig. 2 ;s an enlarged cross-section taken
along line 2-2 of Fig. 1;
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Fig. 3 is a fron~ elevational view o~ ~he
respirator of Fig~ 1 shown in a position of use;
Fig. 4 is a side vlew of the respirator of
Figs. 1 and 2 also shown in a position of use;
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Figs. 5 and 6 are diagrammatic illustrations
of a cross-section of a materials assembly used in
practice of the invention;
Fig. 7 is a plan view of the Figs. 5 and 6
assembly following a first heat sealing operation
of the invention;
Fig. 8 is a cross-sectional view taken along
line ~-8 of Fig. 7 wherewith results of the heat
sealing operation are-illustrated in diagrammatic
fash;on,
Fig. 9 is another plan view of the Figs~ 5
and 6 assembly illustrating an additional heat sealing
operation of the illustrated process; and
~ig~ 10 is a cross-sectional view taken along
line 10-10 of Fig. 9O
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DESCRIPTION OF T~E PREFERRED EMBODIMENTS
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Referring to the drawings, respirator 10 ~Fig~ 1~
is shown flat, i.e. folded, for convenience of packaging,
shipping and/or carrying in a worker's pocket as
a spare or when not needed on the ~ace. In Fi~s. 2
and 3, respirator 10 is opened and illustrated in
a position of use.
Body 12 oE the respirator comprises superimposed
top and bottom webs 14 and 16, of layered air-filtering
material. Each web preerably includes an outer
shell 18, an intermediate lofty filter medium 20
a~d inner scrim 22. The layers are edge or rim seaied
together leaving the intermediate matPrial generally
uncompressed and highly efficient in its intended
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air-filtering function. Ribs 24 and 2~ formed by
material heat sealing may be provided for body 12
shape retention and assurance reinforcement against
collapse during inhalation.
Essential to the accomplishment of secure
edge sealing of webs 14 and 16 is a selection of
materials which have heat-sealing compatibility.
The following are exemplary:
Outer shell structure 18 requires a material
capable of wi~hstanding direct handling abuses but
having a porosity permitting easy passage of inhaled
- and exhaled air. A mesh of polyester fibers with
a heat-sealable binder of polyvinyl chloride may
be used. Suitable commercially available products
are Stearns and Fos~er Type 4144X or W3499 polyes~er
non-woven media supplied by The Stearns and Foster
Company of Cincinnati, Ohio, USA and Union Wadding 7 oz.
polyester non-woven media supplied by Union Wadaing
Company of Pawtucket, Rhode Island, USA.
Inner filter medium 20, pre~erably maintained
in a somewhat lofty sta~e between lines of hea~ seallng
may comprise a random gathering of polyester fibers
with a thermoplastic medium. Vinyon and/or viscose
fibers may be used. A suitable commercially available
- 25 product is Riegel Stype S-03059-1 polyester 100 gram/sq.
meter supplied by Riegel Products Corporation of
Mil~ord, New Jersey, USA.
Scrim ~ which engayes the ~ace when worn
may oomprise a soft highly porous web or mesh of
polypropylene. A suitable commercially available
product is Snowpro Style #440-0827 polypropylene
filter media .8 oz/s~. yd. supplied by Snow Filtration
Company o~ Cincinnati, Ohio, USA.
It should be understood that in the combination
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: - of materials selected for webs 14 and 16, those happening
to be less responsive than others to sealing together
may, nevertheless, be readily ~oined to the others
having greater response to dielectric or other forrns
of heatirlg.
While edge and other heat sealing ope~ations
of the present invention are preferably performed
.. dielectrically with conventional apparatus well known
-;- to the artisan and not re~uiring discussion herein,
it should be understood that electrically or otherwise
heated dies and the like, with applied pressure and/or
ultrasonics.may also be used Furthermore, edge
and/or rib sealing of the present respirator structure .
- may employ adhesives if necessary or desired. Sti~ching~
., 15 which is presently ccnsidered least desirable, may
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. nevertheless be employed throughout or in partial
assembly of:the respirator~ -
. It should be understood that wh;le the abo~e
.. ; mentioned materials and sources of supply will provide
., 20 for successful practice of the invention, this information
is not to be taken as limitive or in any sense restrictive
to the invention. Those skilled in the art will
readily appreciate that various other commercially
available or specially prepared synthetic and/or
~ 25 natural fiber mediums, webs, meshes, shells or scrims
may be obtained or produced and used.
Referring more particularly to the respirator 10
shape, it can be seen from Figs. 1, 2 and 3 that
special curvilinear edge contours 28 and 30 have
- 30 been selected to provide a comfortable substantially
-. airtight seal about the nose, mouth and chin when
respirator 10 is positioned ~or wearing and held
by elastic headbands 32, 34. Remaining edges may
be rectilinear and angularly related as illustrated,
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right angularly related or comprise onl~ two acutely
angled sides or a sin~le semicircular side connecting
opposite ends of edges ~8 and 30.
An attached malleable chevron 36 ~acilitates
fitting and maintainin~ fit of the respira~or over
th~ nose. The chevron may be formed of a strip of
aluminum or its equivalent and cemented in place.
By pressing the chevron toward ~he nose after
application of the respirator ~he a~oresaid nasal
sealing may be readily accomplished. While the nose
area is-usually considered the most difficult to
fit and seal it can be readily attended to in this
manner.
As illustrated in Figs~ lt 2 and 3, respirator 10
may be quickly and-efficiently converted from its
folded, pocket carrying con~iyuration r~ig~ 1) to
a relatively rigid cupped con~iguration for wearing
by opening edges 28 and 30, placing the opening over
~he nose, mouth and chin~ slipping headbands 32, 34
~0 over the head and shaping chevron 36 against ~he
_ nose.
- Ri~s 24 and 26 lend rigidity to the opened
structurer assist in the prevention of collapse of
respirator body 12 during inhalation and retain ample
~~ 25 space between nose, mouth and respirator inner walls
to avoid undue overheating and/or "clamminess" of
the internal breathing atmosphere.
A pre~erred manner of constructing respirator 10
is illustrated diagrammatically in Figs~ 5-10. Therein
a mass production technique, using a continuous supply
(strip 42) of ma~erials, is demons~rated. I~ should
be clear, however, that this technique can be geared
to large or small production or, in fact, a one respirator
at a time operation.
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In Fig. 5, a schematic of layered materials
illustrates, in cross-section, the initial orien~ation
of materials used to produce webs 14 and 16 of respirators
according to the invention.
S In the illustrated orientation of materials 18, 20
and 22 used to produce each of webs 14 and 16, the
webs are separated at scrim sides with a dielectric
buf~er 38 (Fig. 6) and all three pieces are brought
together for subsequent heat-sealing operations,
e.g. by dielectric heating in conventional fashion
~ and not requiring detailed discussion herein. Those
- interested in such details, however, may refer to
literature on the subject of which Electronics for
Industry by ~.I. Be~dz is exemplaryD John Wiley ~ Sons, Inc
is the Publisher~
- If sealing with heated dies or the like is
selected, buffer 38 would accordingly comprise a
: suitable heat insulating material.
A preferred next operation is to heat seal
portions of top and bottom webs 14 and 16 along lines 4U
each having the configuration of one of edges 2~
and 30 of a respirator 10 to be producedO ~ig. 7
illustrates three such lines 40 from which three
respirator bodies 12 will ultimately be completed.
It should be understood, however, that similar
heat-sealed lines 40a will be produced on web 16
which is not visible in Fig. 7. In Fig. 8, hea~
seals 40 and 40a are illustrated diagramma~ically
as single lines each.
Buffer 38 is next removed or the strip 42
of web materials is advanced therebeyond as at Fig.
whereb~ heat sealing along lines 44, i.e. completely
through both webs 14 and 16 completes the respirator
ou~line in each case leaving heat seals 40 and 40a
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- se~arable. Fig. 10 ill~strates the seal alon~ lines 44.
Respirator bodies 12 are finally cut from
supply strip 42 by trimming through webs 14 and 16
alongr but outwardly of seals 40, 40a and 4~
Headbands 32, 34 (Figs. 1, 3 and 4) are then attached,
e.g. with cement, rivits, staples or by heat sealing.
Ribs 24, ~6 may be formed by heat sealing
in a proper position on supply strip 42 at the time
of forming seals 40, 40a (Figs. 7 and 8), e.g~ as
shown with single lines 24a, or subsequent to cutting
and removal of respirator bodies 12. In ~he latter
case, a suitable buf~er may be slipped in~o each
respirator body 12 to prevent the ribbing from connecting
the two webs 14 and 16 together.
l'; Lastly, i~ not at an earlier s~age of the
: process, chevron 36 (Fig. 1, 3 an~ 4) in flat form
is cemented in placeO
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Alternative fabricative procedures may include
reversing the order of effecting seals 4n 7 40a and 44,
- 20 precutting webs 14 and 16, i.e. before sealing the
edges; using heated dies and pressure to form
seals 40, 40a and 44 and/or seaLing ultrasonically.
Those skilled in the art will readily appreciate
that there are various other modifications and adaptations
- 25 of the precise forms of the invention here shown
which may sui~ particular requirements. Accordingly,
the foregoing illustrations are no~ to be interpreted
as restrictive of the invention beyond that necessitated
by the following claims.
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