CA1306925C - Exhalation duct - Google Patents

Abstract

ABSTRACT

An exhalation duct is formed from a gas impermeable covering layer having spacer material extending through the length of the duct to define a substantially cylindrical opening. A
lower end of the duct is formed with a plurality of exhalation holes or openings in the covering layer and an elastic end receiving the air supply hose of a self-contained air supply breathing apparatus. The upper end of the exhalation duct seals to an exhalation valve of breathing apparatus to direct exhalation air from the mask, entirely through the duct, for discharge through the holes formed in the lower end. In operation, the lower end of the exhalation duct is positioned within the torso area of a protective hood jacket to prevent internal fogging of the hood jacket mask.

Description

The present invention relates generally to apparatus for protecting workers from percutaDeous poisoning and toxic environments. More particularly, the invention relates to an exhalation duct for a hood jacket worn over self-contained breathing apparatus to enable the wearer to perform tasks within a toxic environment without fogging the mask of the breathing apparatus.
It is an object of the present invention to provide apparatus for venting exhaled air from an enclosed hood forming part of a protective garment whIle preventing fogging of the hood lens and minimizing any exposure of the wearer to outside contaminated air.
The present invention also provides an exhalation duct that can be easily worn within a hood-jacket as part of a protective ensemble, i.e., a rocket fuel handler suit, rubber boots, rubber gloves, and a self-contained breathing apparatus worn within the hood-jacket. It is inexpensive to manufacture, comfortable to wear, and vents exhaled breath from the hood interior to within the jacket portion of the protective garment.
Different forms of exhalation ducts can be used to accommodate various types of breathing apparatus.
Other objects of the invention are realized in a preferred embodiment of this invention with an exhalation duct that is generally flexible along its length and has one end with sealing means providing sealing contact with the exhalation valve of a face mask of a breathing apparatus, and an opposite end provided with openings for directing exhalation gas outwardly from the duct. The inner diameter of the duct is greater than the 13~6~
outer diameter of an air supply hoæe extending through the duct and sealing end for connecting the inlet valve of the breathing mask to a source of bottled air carried on the wearer's back.
Preferably, the exhalation duct is formed of a spacer material defining a generally cylindrical duct. The spacer material has sufficiently rigid properties in the radial direction of the duct so as to maintain the interior region of the duct open along its entire length, i.e., without blockage. A protective covering is provided around the spacer material. The lower or discharge opening of the duct may be provided with vent holes for venting exhalation air into the jacket portion of the garment.
The lower end of the duct also preferably includes an elastic end opening to enable easy insertion of the air supply hose through the duct for suhseguent connection to the BA mask.
The upper sealed opening of the duct may take different forms depending upon the particular configuration of the exhalation valve and air supply connector of a BA type mask. In one embodiment, the sealed opening includes a seal member having a first opening connectable to the exhalation valve located below the face mask and a second smaller opening through which the air supply hose extends for connection to the mask. In another embodiment, the upper sealed opening is a valve cover formed of flexible material adapted to fit entirely around the mask regulator. A corrugated rubber or flexible hose is attached to ;the exhalation valve cover and has an inner diameter greater than the outer diameter of the air supply hose.
The exhalation duct of the present invention may be utilized with any type of protective garment wherein a BA mask is .

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worn by the user wherein fogging of the mask exterior is a problem.
Other aspects of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of thls invention simply by way of illustration of the best mode contemplated for carrying out the invention. As will be reali~ed, the invention is capable of other embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawing and description will be regarded as illustrative in nature and not as restrictive.
The invention will now be described with reference to the accompanying drawings in which:
Figure 1 is a perspective view of a hood-jacket and the exhalation duct of the present invention worn in combination with a BA mask;
Figure 2 is a front plan view of the hood-~acket;
Figure 3 is a rear plan view of the hood-~acket ; 20 illustrating various primary and secondary seals of the jacket;
Figure 3A is a partial perspective rear view of the interior of the hood portion depicting the neck collar barrier and cone seal configuration;
Figures 3B, 3C and 3D are partial perspective views of the cone seal configuration in open, partially closed and fully closed positions, respectively; and Figure 3R, located on the same sheet as Figure 3A, is a partial perspective side elevational view of the cone seal of , , ~

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Figure l7.
Figure 4 is a side elevational view of a first embodiment of an exhalation duct in accordance with the present invention;
Figure 5 is a sectional view taken along the :Line 5-5 of Figure 4;
Figure 6 is a sectional view taken along the line 6-6 of Figure 5;
Figure 7 is a detailed top plan view of the sealing end of the exhalation duct of Figure 4;
Figure ~ is a detailed plan view of the venting lower end of the exhalation duct of Figure 4;
Figure 9 is a sectional view taken along the line 9-9 of Figure 8;
Figure 10 is a cross-sectional view of the duct of Figure 4;
Figure 11 is a view of the manner in which the spacer material and cover forming the exhalation duct are sealed together along the length of the duct;
20Figure 12 is a detailed bottom plan view of the sealln~
end of the Figure 4 exhalation duct;
Figure 13 is a perspective view of a type of BA mask used in conjunction with the exhalation duct of Figure 4;
Figure 14 is a detailed side plan view of an exhalation duct in accordance with a second embodiment of the present invention;
Figure 15 is a sectional view taken along the line 15-15 of Figure 14;

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Figure 16 is a perspective view of a type of BA mask worn in conjunction with the ~igure 14 embodiment of the invention;
Figure 17 is a perspective view of a third type of mask;
Figure 18 is a detailed elevational view o~ an exhalation duct in accordance with a third embodiment of the invention worn in conjunction with the mask of Figure 17; and Figure 19 is a top plan view of the upper sealing end of the exhalation duct of Figure 18.
In Figures 1 - 3 there is disclosed a hood-jacket 10 formed with a hood portion 10b and iacket portion lOa preferal~ly made of panels of C~ILOROP~I,* fabric heat-sealed together to form a single protective garment. ~ood-~acket 10 as best illustrated in Figure 1, is worn over a self-contained air supply hreathing apparatus (such as the M23A1 type self-contained air supplied breathing apparatus) which breathing apparatus generally comprises an air cylinder 12 strapped to the wearer's back, a regulator assembly 14 having various instrument gauges (not shown in detail) strapped to the wearer's waist and a face mask 16 connected to regulator 14 with air hose 18 extending upwardly along the wearer's chest region for connection to an inlet valve 16a of the ; mask. As will he seen more fully below, hood-jacket 10 is designed to fit over the M23Al type BA illustrated in the drawings as well as other BAs. ~ood jacket 10 is also designed to fit any wearer, re~ardless of size.
As will be seen more fully below, hood-jacket 10 is preferably formed from panels of material resistant to toxic chemicals, which panels may be heat-sealed together along their * Trademark -- , :~ . .

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peripheries to form the basic garment of the hood-~acket. A
plastic vinyl material is used to form a visor 20 which is easily heat-sealed along its periphery to the fabric panels forming the hood portion lOb. The hood-~acket 10 is preferably of hip length and short-sleeved. There may be a large hump 22 (Figure 1) formed in the rear portion of the ~acket lOa to accommodate air cylinder 12 of the BA and to allow for forward bending.
There is a comhination closure in the back of jacket portion lOa, as best depicted in Figure 3, comprising a metal zipper 23 and a ~HLOROP~* zip-loc closure 25 for seaLable opening and closing of the jacket portion rear for air bottle replacement and donning/doffing of the garment.
In addition to the foregoing seals 23, 25, vapor leakage is in general mechan~cally reduced by two types of seals within hood-Jacket 10 of the invention. The first type, as will be seen below, encompasses the garment peripheries at the hip and sleeve ends. These seals incorporate cable drawstrings and are adjustable. The second type constitute internal collars, a few inches up from the ends of the sleeves and around the waist and 2n neck. These elastic collars are also self-ad~ustable. The elastic collar inside the hood, in the neck area, is designed to further reduce vapor infiltration into the area. This collar may ~ Lc Ro ~
have a frontal ~e~e~ closure which fastens around the ~A mask inlet air tube.
As discussed above, hood portion lOb is that portion of hood-jacket 10 which is worn over the head. Hood portion lOb is preferably a combination of chlorinated polyethylene plastic material and, in particular fabric panels 26 thereof which ma~ be * Trademark heat-sealed together as at 27 (Figure 3). The panels 26 are also heat-sealed to visor 20 as depicted in Figure 2. Visor 20, preferably made from such as polyvlnyl chloride (PVC*) o~
transparent optical quality, may constitute a major portion of hood lOb to provide for optimum viewing conditions by the wearer.
The torso or Jacket portion lOa of hood-jacket 10 is also formed of chlorinated polyethylene fabric panels 2fia that may be heat-sealed together at their peripheries (see Figure 3) as at 29 to form the basic jacket configuration. ~ pair of sleeves 30 ln also preferably formed of chlorinated polyethylene heat-sealable plastic material are heat-sealed to the fabric panels 26a of ~acket portion lOa (see, e.g., Figure 3). The hood ancl ~acket fabric panels 26, 26a and visor 20 are then heat-sealed together as depicted in Figure 2 to form the baslc outer garment of the hood-jacket. A chlorinated polyethylene fabric strip 33 (Figure 2) may be used to connect the hood or visor and jacket fabric panels together in heat-sealing relationship.
~ n anti-fog kit schematically shown at 35 may be fixed to a portion of fabric panels 26 of hood lOb outside seal 27 as depicted in Figure 3. More specifically, anti-fog kit 35 is secured to a grommet 37 heat-sealed to fabric panel portions 26 atop the hood and sècured thereto by string 37a. Anti-fog kit 35 consists of instructions, an anti-fog compound and a wiping cloth all enclosed in a plastic bag 35a. The compound is a medium hard wax-type substance that is applied like a crayon over the inner surface of visor 20 and gauge viewing windows 39 and 41 discussed infra~ The compound is then rubbed with the fingers to cover the entire areas and the excess is removed by means of the wiping * Trademark , )6~5 cloth. Its purpose is to reduce Eogging of the inside of visor surfaces for clearer ~ision.
Oval gauge window 39 and square gauge window 41 are both assembled in the front part of jacket portion 10a, as depicted in Figure 2. Their function is to allow the user to view the front mounted pressure gauges forming part of regulator 14 of the BA
worn beneath the hood-jacket 10. It is to be noted that each of the windows 39 and 41 is preferably made of the same PVC* material as visor 20 and heat-sealed into the fabric panels 26a of the jacket.
With reference now to Figure 3, the combination closure 25 is heat-sealed in the rear of jacket portion 10a and comprises an inner metal zipper 23 and an outer double channel ZIP-LOC*
plastic zipper (not shown in detail) 40 providing a good mechanical seal. The functions of zippers 23, 40 are to establish an opening in the rear of jacket portion 10a on each half thereof for donning/doffing the hood-jacket 10 and for access to air cylinder 12 for .replacement, without removing the garment. For a good air-tight seal, the two channels of ZIP-LOC* 40 are preferably filled with petroleum jelly on one side prior to donning. The ZIP-LOC* 40 may be opened by grasping adjacent pull tabs 42a and 42b starting at the bottom of the jacket to pull the ZIP-LOC* apart. The tabs 42a, 42b are mountd on reinforcement fabric strips 43 which overlap fabric panels 26 to provide a one inch in width heat seal all around the closure opening (Figure 3).
The double plastic channels 40 of the ZIP-LOC* plastic zipper are fixed to these reinforcement panels as depicted in Figure 3.
Waist draw cord 47 is pulled tight to the waist of the * Trademark .
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wearer and held ln place by a B-lock* fastener 49~ Waist collar barrier 5Q is pulled snug about the waist higher than the draw cord 47 and fastened hy means of hook and pile fasteners 51 and 53 sewn to the ends of the waist collar barrier. The waist collar b~rrier is preferably formed by a piece of elastic webbing positioned within a channel formed by an overlapping lower edge of the fabric panel at 57. Waist draw cord 47 is also formed within a channel formed by overlapping a piece of Eabric panel 26a and then heat-sealin~ the same together.
The neck collar barrier 70 is also defined by a piece of elastic wehhing 72 received within a closed channel 73 formed in a chlorinated polyethylene length of material 74 having heat-sealed overlapping edges which material is also heat-sealed to fabric panels 26a. The neck collar barrier 70 is thereby located inside hood-jacket 10 at the base of hood lOb to effect a seal between the inside of the jacket area and the hood.
The waist draw cord 47 and the sleeve draw cord 60 are the initial means of producing an air-tight seal. The waist collar barrier and the sleeve collar barrier 65 are secondary seals to prevent leakage into the jacket area. The waIst, sleeve and neck collar barriers are preferably made of a thinner chlorinated polyethylene material which are heat-sealed to the inside of the hood-jacket fabric panels 26, 26a in the areas shown and have elastic wehbing affixed to the inner portion which fits snug to those portions of the wearer's body. The neck collar barrier 70, which fits snuggly to the neck above the collar of the wearer's protective suit worn beneath, prevents any leakage in the jacket area from entering the hood area.

_ 9 _ * Trademark - ' , ' - ~l3~
Neck collar barrier 70 preferahly includes a split cone configuration lOO in the center oF the front portion of the barrier material. The purpose of the split cone is to provide a means of sealing around the air supply hose lô of the BA and the exhalation duct. The air hose 18 extends from the waist area up to the air mask 16 on the wearer's face. The exhalation duct hose (not shown) extends from the mask down into the chest area of the hood-jacket. A seal is effected around the air hose 18 and exhalation duct by the wrap around cone seal lOn and fastenetl in place by vertical and wrap around hook and pile fasteners.
More specifically, and with reference to Figures 3A-3~, the cone seal 100 is formed of neck collar barrier material (similar to the material forming collar 70) 102 folded into a cone shape having an upper diameter greater than the lower diameter.
The cone seal 100 is open as at 104, the opening being defined by two edges 106a and 106b extending the entire length of the cone.
A snap fastener having mating halves 108a and 108b are located at the top of each edge 106a and 106b, respectively~ and hook and pile fastener strips 110 and 112 (e.g., VRRCRO~) are secured on the inner vertical surface of seal material 102 adjacent the edges 106a and 106b. Tightening straps 114 having hook material 116 on one side and pile material 118 on the opposite side are vertically spaced ~rom each other and secured to lower and middle portions of the cone seal.
Once the air hose and exhalation duct are positioned through the center of the cone seal 100, the vertical sides or edges 106a and 106b are wrapped snugly around the air hose and exhalation duct and the open edges 106a and 106b are brought * TraAemark -- .

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together. The inside vertical hook and pile straps 110 and 112 contact each other and hold the cone in the Figure 3C position.
The fina] closure and seal is effected hy snapping the fastener halves 108a and lO~b together and wrapping the two adjustment and tightening straps 114 around the cone. The length of the straps 116 is sufficient so that the hook surface 116 on one side of the cone will contact the pile surface 118 on the other side so that the cone seal is Eully closed as depicted in Figure 3D in sealing contact with the air hose and exhalation duct.
The next seal 100 is secured to neck collar barrier 70 such as with stitching along the upper edges of the cone material 102. The cone suspends freely below the neck collar barrier 70 as depicted in Figure 3A and the partial side elevation view of Fi~ure 3R.
The hood-jacket 10 of our invention has a unique combination of internal seals, such as the cable draw cords and internal collar barriers, which together with the overall hood-jacket configuration achieve an extremely tight fit resulting in essentially no internal leakage. The hood jacket l0 and BA are designed to be worn over protective rubber suits which are in current use. There may be a very small amount of leakage depending on the physical activity of the wearer, which may get past the draw cord and collar barrier seals of the waist and sleeve and into the torso area. ~owever this occurs, it is contained between the outside of t~e protective suit and inside of the ~acket part of the garment and the neck collar barrier. There is no wearer's skin exposed in this area.
Because of the neck collar seal 70, there tends to be a , , : . , huildup of moisture inside the enclosed hood of the hood-jacket lO. This moisture disadvantageously causes fogging of the inside of the hood lens 20. The moisture buildup results from not only the perspiration of the skin of the wearer's head and neck, but also from the exhaled breath of the RA. Fogging caused by perspiration is somewhat controllable and, in any event, does not significan~ly contribute to the fogging problem. ~owever, exhaled breath, which contains more than 60~ moisture, is the most significant factor contributing to the Fogging problem. This can be eliminated by venting exhaled breath outside of the enclosed hood. Venting throu~h the hood wall to the outside involves sensitive valve assemhlies and possibly dangerous backflow of contaminated outside air, and is therefore disadvantageous.
To avoid the disadvantage associated with the apparatus of Figures 1 to 3 an exhalation duct 120, as shown in Figures 4 -7, has been designed for use in conjunction with the breathing apparatus depicted in Figure 13 (commonly known as a Mine Safety Appliances BA, Model 401). The exhalation duct 120 comprises a coverin~ 122 formed, for example, from a lightweight butyl coated cloth surrounding layers of spacer material 124 which may be very porous and substantially entirely enclosed by the cover 122. A
rubher seal 126 is formed at one end of exhalation duct 120. The rubber seal 126 will define the upper end of the exhalation duct located within the hood portion lOb of hood jacket 10. The rubber seal 126, as best depicted in Figure 12, includes a rubber sheet 128 formed with a first hole 130 adapted to receive the exhalation valve of the breathing apparatus and a second smaller hole 132 adapted to receive the inlet air hose 18 in sealing contact 6~
therewith.
The opposite or lower end 1~ is an elastic end provided with a series of vent or exhalation holes 136 formed within the covering 122.
In operation, the a1r supply hose 18 of the breathing apparatus is inserted through elastic end 134, through the spacer material 124 and out the sma]l hole 132 in the rubber seal 128 at the opposite or upper end. The air supply hose 18 is then reconnected to the mask and the large hole 130 of the rubber seal is stretched over the outlet valve of the mask, as described supra. The rubber seal 12~ is adjusted up over the air hose connector and outlet valve. It is then pushed flush to the face piece. The exhalation duct is then fitted through the cone seal 100 and stretched along the torso such that the elastic end 134 terminates proximate the lower chest or abdominal area of the wearer. Thus, in operation, exhaled air is captured by the rubber seal and directed through the porous circular spacer material layers 124 along the length of the duct 120 and out through the e~halation holes 136 into the torso area. The seal 128 and covering 122 prevents exhaust air from entering either the hood portion 10b or upper torso area of the hood ~acket portion 10a, i.e., the exhaled air is forced to flow entirely through the porous material of the exhalation duct until it reaches holes 1360 Incoming air is brought through the hose 18 into the ~àsk area as discussed supra.
The spacer material 124 has sufficiently rigid properties in the radial direction of the duct 120 so as to maintain the interior region of the duct open along its entire length, i.e., without blockage. The elastic end 134 enables easy insertion of the air supply hose through the duct for subsequent connection to the BA mask as discussed supra.
With reference to Figures 5-7, it can he seen that the upper portion of exhalation duct 120 is formed with a plurality of spacer material layers 124 to ensure that the generally cylindrical duct has sufficiently rigid properties in the radial direction thereof and in the upper portion so as to prevent blockage or excessive compression that might be caused by the cone seal lnO or by flattening of the up~er portion of the duct by the wearer's upper torso that might otherwise impede the flow of exhalation air from the mask to the elastic end 134. As depicted in Figure 6, the lower portion of the duct 120 may be formed with a single layer of spacer material 124.
The covering 122 may be stitched and heat-sealed to the outer periphery of seal 128, as depicted in Figures 5 and 12.
With reference to Figures 10 and 11, the covering 122 and spacer material layer 124 may be stitched together along their opposite longitudinal edges and heat-sealed to define a sealed seam ; 20 extending the length of the duct 120. With reference to Figure 9, the portion of duct 120 in the region of exhalation holes 136 May include a cloth material, such as butyl coated cloth that sandwiches the spacer material 124 in cooperation with covering 122. Edges 138 and 139 of cloth 140 and covering 122 respectively may overlap each other for stitching and heat-sealing together with elastic material 142 completing the elastic end 134 (Figure 9).
Figures 14-16 are illustrations of a second embodiment of an exhalation duct 145 according to the present invention which is substantially identical to exhalation duct 120 of the first embodiment except at its upper encl 147 providing sealing contact with a ~&~i~re Mark I BA depicted in Figure 16. Thus, with reference to Figure 15, the upper end 147 has the upper ends of covering 122 and spacer material 124 stitched and sealed together with further stitching and sealing at 149 to an annular rubber seal 150. The SURVIVAIRE* BA of Figure 16 has the exhalation valve in front of and slightly below the chin and the air supply hose connector directly below it. This duct 145 is assembled to the BA in the same manner as duct 120. The air supply hose of the BA is inserted through the spacer material and out through the rubber seal 147. However, after the air hose 18 is connected to the face mask, the ruhber seal 147 having a single central opening (not shown) is stretched over both the air hose connector and the exhalation valve and adjusted flush to the mask. Otherwise, the duct 145 functions exactly as that of the duct 120 of the first embodiment.
Figures 17-19 are illustrations of a third embodiment of the invention wherein an exhalation duct 155 is used in conjunction with a SCOTT PRESUR PAK* 4.5 breathing apparatus depicted in Figure 17. The principal end function of this duct 155 is the same as ducts 120 and 145, although the configuration is different. The regulator 157 of the Scott breathing apparatus is mounted on the front of the mask and appears as a cylindrical can in shape. The exhalation valve is loca~ed at the back and bottom of the air regulator 157, facing the mask. The exhalation duct 155 comprises an exhalation valve cover 159 of molded rubber *Trade Mark which fits over the entire air regulator 157 Inserted into the rubber cover through opening 160 defined by inturned edges 162. A
corrugated rubher hose 164 connected to an outlet opening 166 of valve cover 159 via bushing 168 and clamp 170 is adapted to extend through cone seal 164 to direct exhalation gas through the hose into the torso area. Although not shown, the valve cover 159 may have openings on either side of bushing 168 which respectively accommodate the smaller diameter air supply hose 18 and a purge valve.
It should be apparent from the preceding that this invention may be practiced otherwise than as specifically described and disclosed herein. Modifications may therefor he made to these specific embodiments disclosed here without departing from the scope of this invention and such as intended to be included within the appended claims.

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Claims (5)

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

1. Exhalation duct comprising a spacer material defining a generally cylindrical passage; a covering layer extending around the spacer material, said covering layer being gas-impermeable, one end of said duct having means for sealing the upper end thereof to an exhalation valve and the lower end of the duct having means for discharging air from the exhalation valve through at least one discharge opening in the lower end.

The exhalation duct of Claim 1, wherein the upper duct end sealing means includes a rubber seal member having first and second openings for respectively receiving an air supply hose and an exhalation valve of a breathing mask.

3. The exhalation duct of Claim 2, wherein the opposite end of the duct includes an elastic end for receiving therethrough the air supply hose, and wherein said at least one discharge opening is a plurality of openings formed in the covering layer substantially only at a lower end thereof.

4. The exhalation duct of Claim 1, wherein said sealing means includes an annular sealing member having a central opening adapted to fit around an exhalation valve of a breathing mask.

5. The exhalation duct of Claim 1, wherein the spacer material and covering layer is in the form of a corrugated rubber hose and wherein the sealing means is in the form of a molded rubber or the like valve covering having clamping means for securing an upper end of the hose to an outlet of said valve covering.