CA1088841A - Protective clothing - Google Patents
Protective clothingInfo
- Publication number
- CA1088841A CA1088841A CA215,913A CA215913A CA1088841A CA 1088841 A CA1088841 A CA 1088841A CA 215913 A CA215913 A CA 215913A CA 1088841 A CA1088841 A CA 1088841A
- Authority
- CA
- Canada
- Prior art keywords
- hood
- visor
- cowl
- wearer
- face opening
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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- Respiratory Apparatuses And Protective Means (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Protective headwear is described which provides protection against radio-active contaminants, or chemically or bacteriologically polluted atmospheres, (i.e. A B C
environment) This headwear protects a user's head and respiratory system, and is fabricated of a material resistant to the A B C environment. An A B C proof visor is mounted sealably in a from t portion of the headwear, frequently in the form of a hood, with the lower edge of the visor being detachable from the hood material. The visor can thus be lifted. The hood also has provisions to prevent the atmosphere outside the hood from reaching the head via the neck region. This arrangement permits the wearer to breathe acceptable air and/or oxygen. In a preferred form the headwear is in the form of a protective helmet. In another preferred form the protective headwear includes a flexible skirt to overlap the wearer's shoulders, and even more preferably has a breathing mask therein.
Protective headwear is described which provides protection against radio-active contaminants, or chemically or bacteriologically polluted atmospheres, (i.e. A B C
environment) This headwear protects a user's head and respiratory system, and is fabricated of a material resistant to the A B C environment. An A B C proof visor is mounted sealably in a from t portion of the headwear, frequently in the form of a hood, with the lower edge of the visor being detachable from the hood material. The visor can thus be lifted. The hood also has provisions to prevent the atmosphere outside the hood from reaching the head via the neck region. This arrangement permits the wearer to breathe acceptable air and/or oxygen. In a preferred form the headwear is in the form of a protective helmet. In another preferred form the protective headwear includes a flexible skirt to overlap the wearer's shoulders, and even more preferably has a breathing mask therein.
Description
The present invention relates to ?rotective ileadwear, and particularly to headwear worn by military personnel for protection against radio-active contaminants, or chemically or bacteriologically polluted atmospheres. Such atmospheres are herelnafter termed A B C
(atomic, bacteriological, chemical) environment.
According to the present invention a hood for protection of a human head against an ABC environment i9 fabricated of A B C proof material with an A B C proof visor sealably mounted in a front portion thereof, the lower edge of the visor being detachable from the hood fabric 90 that the visor can be lifted, the hood having also provisions for preventing atmosphere outside the hood from reaching the head via the neck and for permitting the wearer to breathe acceptable air and/or oxygen.
Where hoods in accordance with the invention are to be used in conjunction with existing protective helmets such as those worn by ;
aircrew, which have in the ear region hinges or pivots for a helmet ~; ;
visor, the hood visor may be shaped and adapted to locate on these hinges or pivot points with the helmet visor removed. Preferably the ;~
visor attaches to the hinges or pivot points by detachable detent means.
The A B C proof material in the region of the hinges and the upper edge of the visor i8 advantageously readily flexible~
According to a feature of the invention the lower edge of the vi90r may be attached to the hood material by a gas-tight sliding ~ ~ -fastener, preferably sited and arranged to obtain support from the Visor edge so that it can be readily closed and opened. Another such fastener may be fitted down the back of the hood for the purposes of donning and removal.
The hodd would usually form part of an ABC protective sult ensemble, and may thus be provided with means in the neck region for sealing to such a su~t or with means for sealing it against the wearerls neck. Adequate sealing may be obtained in a skirt formed by excess ' ~; .
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fle~ible material which would overlap the wearer~s shoulders and protective body garment. Both provision may be usecl together. Suitable A B C proof materials include Eabrics such as butyl proofed nylon and neoprene nylon fabrics or material such as neoprene or nylon dippings. The visor may be made of a transparent plastics material such as rigid or semi-rigid methyl methacrylate, the more impact proof polycarbonate sheet or non rigid even extensible material such as polyurethane film or silicone rubber which would permit the wearer to use an optical instrument while wearing the hood.
The nature of the provision for permitting the wearer to breathe uncontaminated gas will depend upon the user situation. In a solely ground role the provision may merely comprise adaptor means in the material allowing the passage of the gas from a supply thereof to the interior of the hood.
For use in flying and like situations, the wearer may have an oro-nasal breathing mask worn inside the hood. The hood may further be adapted for use with emergency or routine oxygen supply in a rarified atmosphere situation, such as flight at high altitude.
According to another feature of the invention, therefore, a ;`
provision for emergency oxygen supply may comprise a direct supply through the hood wall for metered constant flow oxygen to the mask.
The filtered breathing air supply may remain connected to the mask, and an emergency switching arrangement is preferably provided~
According to yet another feature of the invention, a provision ~`
for routine oxygen supply msy include a regulator fitted to the hood wall, ~`
the regulator being of a type which will pass oxygen on demand. The ;
regulator may be associated with a separate supply means for breathable air, with an appropriate switch-over control, so that the supply duct from the hood wall to the mask need not be duplicated. Means provided for the contingency of oxygen supply failure or regulator failure may include respectively a manual control to the breathable air supply and a manual MR/
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or automatic regular bypass control adapted ~o provlde a metered constant flow oxygen supply to the mask.
In all circumstances it may be advantageous from the polnts of view of personal comfort and ABC protection ~or the hood interior as a whole to be maintained at a gas pressure above that of the exterior, 80 that the hood can be continuously purged. When an oro-nasal mask is to be employed this can be effected by allowing a separate bypass of suitable uncontaminated gas such as filtered blown air to the interior of the hood.
The hood may have means for separately ducting exhalant from the mask.
The hood may also have, a hood air outlet non-return valve for exhausting the hood purging gas. This may be spring loaded in order to ensure a slight positive pressure in the hood. ~;
The hood may be provided with intercommunication means such as microphone and earphone attachments, or if used with helmet and mask which already has these, it may have an intermediate intercommunication lead passing through the hood fabric with connection means (plug or socket) inside and outside. A microphone switch may also be provided outside the hood.
A preferred embodiment of the invention, therefore, is a hood ~ -for use in conïunction with a helmet of the type worn by aircrew, the helmet having a detachable visor, built-in earphones, and an associated attached or attachable breathing mask, the hood being fabricated of A B C proof material with a skirt extension for overlapping the wearer~s shoulders, and having a gas tight fastener enabling its fitting over the wearer~s helmet, means for sealing on the wearer~s neck or protecting body garment, a visor sealed to the fabric along its upper edge and ~
detachably attached to the fabric by a gas tight fastener along ltS ~ ~ -lower edge between hinge points, means for permitting uncontaminated ~-~
breathable gas to enter the interior of the hood and of the mask and means for permitting exhaled gas to leave the hood without entering the ;
hood space, intercommunication means, the visor having detents for engag-MR/
ing on visor hinges or hinge stucls on the wearer's helmet so that when the detents are so engaged the wearer can undo the gas tight fastener attaching the bottom edge of the visor and lift the visor.
Such a hood may be donned by a wearer already wearing helmet and mask but with the helmet visor removed, by first plugging the breathing pipe or pipes and the intercommunication leads from the mask into the hood provisions therefore, then attaching the hood visor to the helmet hinge points, and finally fastening the gas tight hood fitting fastener. Alternatively the mask may be permanently coupled to hood mounted breathing components and attached to the helmet during the donning procedure. The visor opening facility of the hood provides a ready means of removing the mask from the face in the event of an emergency involving water entry. At the same time it i9 particularly ~i useful during A B C warfare flight training, because it can be opened for an emergency purpose and then readily resealed.
According to another feature of the invention provision may be made in the hood for permitting access to the wearer~s face without opening the hood. Such access is often desired in order that the wearer may adjust his breathing apparatus or his comfort. It may comprise a pair of sealed finger stalls, for example, or a~gas-tight pouch or pocket or one or more sealed gussets or convolutions in the chin region of the fabric, and perhaps in the brow region also~ These pouches, pockets or convolutions may be stowable by means of fasteners such as sliding fasteners to minimise the bulk and encumbrance of their excess Eabric. If the wearer feels the need to adjust the position of his mask or manipulate his face for his personal comfort he can unstow the ~ -face manipulation means and insert his fingers to carry out the said manipulation via the hood fabric. ~-An A B C protective hood in accordance with the invention will now be described by way of example, with reference to the accompanying drawings which illustrate certain embodiments of the invention, and wherein:
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~. . . . - ., ~ . , - -FIGURE 1 is a 8kle elevfltlon of the hood whilst being worn, FIGUR~ 2 i9 a diagram of one hood breathing system, FIGUR~ 3 i9 a diagram of second hood breathing system, snd FIGUR~ 4 is a diflgram of a third hood breathing system, for routine oxygen supply.
: ' As shown in Figure ] the hood comprises an envelope 11 of butyl rubber proofed nylon fabric having a skirt 12 for overlapping the wearer's shoulders. The envelope has a primary gas tight sliding fastener 13 down the back. It is fitted with a perspex (TM) visor 14 10 which is sealed to the fabric along its upper edge but detachable from -the fabric along îts lower edge by means of an other gâgiitightdslide fastener 15 which runs approximately from visor hinge point to hinge point. A
suitable slide fastener has the teeth at each side protruding through the corresponding sheet of fabric to be joined, near -the edge of the fabric, so that when the fastener is closed and the teeth engage into each other the surfaces of the fabric sheets are pressed together. The visor is thus linked to one side of said other fastener 15 by a lip 16 of the fabric.
The hood is made to fit over a helmet 17 and the visor has ~
20 at each side a manually operable detent 18 by which it can be mounted ~ ;
on helmet hinges or hinge studs. The position of these hinges and the shape of the visor are such that the visor can be raised above the head, clearing the helmet sufficiently not to overstress the fabric and so that the visor profile presents no unacceptable limitation to the field of view when down or up.
In the chin region of the hood, below the fastener 15, there is formed a series of radial convolutions 19 normally closed and restrained by a further slide fastener 20. The convolutions provide sufficient excess fabric such that when they are unrestrained the visor can be raised, without affecting the integrity of the sealed hood, and the 'loose' fabric raised to allow the wearer to reach with his fingers '`
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to at leaYt the vicinity of the Nasion.
The helmet 17 has an associated breathing mask 21 which i8 fastened over the oro-nasal area of the face of the wearer. The hood is fitted with a valve chest 22 for passing filtered breathing gas to the interior of the hood and oE the mask. It i8 also fitted with an adaptor 23 (see Figure 2) for the exhaust of exhaled air from the mask and an adaptor 24 for connecting microphone and earphone leads. A
spring loaded exhaust non'return valve 25 i~ fitted to the neck region of the hood.
The layout of the breathing system indicated in Figure 1 i9 shown more clearly in Figure 2. The valve chest 22 which can be con- -nected to a filtered breathing ga9 i9 a forked duct which has on one , side a spring loaded non-return valve 30 for allowing gas into the ~`~
interior of the hood generally, and maintaining a mask positive safety pressure relative to hood space and on the other a connection for a flexible tube 31 to the mask 21, the mask having a non-return valve -21a permitting inboard flow. The other breathing component contains a non-return valve 32 for allowing exhaled mask gas to leave the hood, for which purpose the adaptor 23 ccnnects with a flexible tube 33 from the mask 21. The non-return valve 32 is backed up by a second mask mounted non-return valve (not shown) to ensure the non-en~y of toxic ag~ents. ~ ;
The hood described may be donned together with the helmet 17 `;
as an assembly, the visor 14 having already been attached at the hinges 18, the fasteners 12 and 15 being fully open and the visor 14 raised.
Once the helmet/hood i9 on the wearer~s head the fastener 12 is fully closed bringing the neck skirt to bear on the wearerls neck or body garment neckline. The mask 21 is then fastened into place with the tubes 31 and 33 connected to the adaptors 22 and 23 respectively. The microphone and earphone leads are connected to the adaptor 24. The visor may then be lowered and the fastener 15 closed.
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The ~earer's head will then be protected agalnst contact with B C substances ancl he will be able to breathe and communicate with the outside world. In breathlng, the facial atmosphere hetween the mask and the hood may tend to follow n simllar pattern of pressure fluctuation, and gas in excess of that inhaled will be allowed into the hood by the spring-loaded non-return valve 30. Due to the exhaust valve 25 being spring-loaded, however, a pressure slightly hi8her than that outside the hood may be maintained inside. This serves to prevent the ingress of contamina-ted atmosphere from outside the hood~
The wearer is at risk if his aircraft is ditched in water, of suffocating or sucking water into the mas~. Eor such an emergency, thP
facility of opening the fastener 15 and raising the visor 14 is provided. -The breathing mask 21 may then be removed. The facility is also useful during A B C~training flights.
In the second breathing sys-tem shown in Figure 3 the mask 40 has only one breathing tube 41. The hood is fitted with an adaptor 42 which would replace the adaptors 22 and 23 of Figures 1 and 2. The adaptor 42 has an inlet connector 43, a non-return valve 44 to the interior of the hood, and a breathing tube 41 to a connector 45 as before.
It has also a non-return valve 46 between the supply to the valve and the connector 43 for preventing exhaled gas from going back down the supply or into the hood interior. A spring loaded non-return ~ `
valve 47, a non-return valve 48 in series and an orifice 49 in the adaptor 42 permit the exhaust of inhaled air from the tube 41.
Figure 4 illustrates a preferred breathing system when the hood has to be used in a routine oxygen supply situation.
It shows aniadaptor-50 located in a hood wall 11, and an oxygen regulator 51 attached to the adaptor 50 inside the wall 11. The regulator 51 has an outlet communicating with an inner chamber 52 in the adaptor and an inlet communicating with an oxygen supply tube 53, - 7 - ;~
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to wllich an emergency oxygen s~lpply also ~eeds. The chamber 52 communicates also via a tube 5~ w~th tlle mask 21, and via an anti-suffocation valve 55 with an outer chamber 56. The vfllve 55 is a non-return valve preventing gas flow from the inner chamber 52 to the outer 56. The valve 55 has, however, a manual override 57 wlth detents (not shown) for the fully in and out position. The outer chamber 56 has an inlet tube 58 for connection ~ ~-to a supply of filtered air and a non-return valve 59 allowing ~as flow only from the chamber 56 to the interior of the hood wall 11.
The oxygen supply tube 53 has a regulator emergency by-pass 60 `~
10 which communicates via a hole 61 in the override 57 with the inner chamber ~-52. The override 57 is thus dual purpose, operating in push/pull mode ~ -for switching between oxygen and filtered air supplies and in rotary mode for opening/closing the regulator by-pass 60.
The mask 21 is exhausted via a compensated expiratory valve in the mask and (32 in Figure 2) via a tube 33 and a non-return valve (not shown) in the hood wall 11.
In the configuration shown in the drawing the hood is adapted to ~
supply demand oxygen to the mask 21 and filtered blown air via the tube ~ ~`
58, the chamber 56 and the valve 59 to the interior of ~he hood only.
Upon each inhalation by the wearer, the regulator senses the pressure drop in the chamber 52 and permits oxygen to pass therethrough from the supply 53. Exhalate passes out via the tube 33.
If in this configuration oxygen fails to be drawn up the tube 54 then upon inhalation the anti-suffocation valve 55 will open. This however is arranged to require a greater suction to operate than does the regulator and its operstion will be sensed by the wearer. If the ;;
wearer thinks that the 109s of oxygen supply may be due to failure of the regulator 51 he can turn the override 57 and thus open the oxygen by-pass 60. This will, if the fault is in the regulator 51, supply metered oxygen at a constant rate to the chamber 52. If the failure is in the oxygen supply upstream of the regulator 51 the wearer will sense this because of continuing inspiratory resistance of the anti-suffocation .
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valve 55. At ~his stage the limitecl eme-rgency oxygen supply would be utilised for immediflte descent to a safe altitude at wllich filtered air breathing is physiologically acceptable. Air breathing, after discharge of the emergency oxygen supply would be achieved by pushing the override 57. This closes off the by-pass 60 if open and lifts the valve 55, which by virtue of a deten-t will remain open, and the chamber 52 will be open to a supply of filtered air via the tube 58.
The above embodiment is particularly suitable for use by aircrew in high performance aircraft where oxygen and filtered air supplies may readily be installed. Insofar as the filtered air supply operates on environmental air without maintaining a store of same then clearly in the event of a failure of oxygen supply at high altitude, other than `~
failure of the regulator 51, the aircraft will have to be brought to an acceptable altitude for filtered air breathing.
If it is required that aircrew should be protected whilst proceed-ing to or from their aircraft portable filter blower units may be provided and these can, if separate aircraft installed units are not provided, be arranged for mounting and operation within the aircraft once the aircrew are inside.
It will be appreciated that the invention does not include the ~;~
oxygen mask, the breathing systems and the oxygen regulator per se or their use in contexts other than the ABC hoods hereindescribed and claimed.
Indeed the ambodiment of Figure 2 may employ a standard P or Q type oxygen ;~
maak currently in military service, while the embodiment of Figure 3 may ~ ~
employ a similar mask but with the mask mounted valves removed and one ~ -aperture blanked off. For the embodiment of Figure 4 there is a number of 100% oxygen miniature regulators which are available for the use described.
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(atomic, bacteriological, chemical) environment.
According to the present invention a hood for protection of a human head against an ABC environment i9 fabricated of A B C proof material with an A B C proof visor sealably mounted in a front portion thereof, the lower edge of the visor being detachable from the hood fabric 90 that the visor can be lifted, the hood having also provisions for preventing atmosphere outside the hood from reaching the head via the neck and for permitting the wearer to breathe acceptable air and/or oxygen.
Where hoods in accordance with the invention are to be used in conjunction with existing protective helmets such as those worn by ;
aircrew, which have in the ear region hinges or pivots for a helmet ~; ;
visor, the hood visor may be shaped and adapted to locate on these hinges or pivot points with the helmet visor removed. Preferably the ;~
visor attaches to the hinges or pivot points by detachable detent means.
The A B C proof material in the region of the hinges and the upper edge of the visor i8 advantageously readily flexible~
According to a feature of the invention the lower edge of the vi90r may be attached to the hood material by a gas-tight sliding ~ ~ -fastener, preferably sited and arranged to obtain support from the Visor edge so that it can be readily closed and opened. Another such fastener may be fitted down the back of the hood for the purposes of donning and removal.
The hodd would usually form part of an ABC protective sult ensemble, and may thus be provided with means in the neck region for sealing to such a su~t or with means for sealing it against the wearerls neck. Adequate sealing may be obtained in a skirt formed by excess ' ~; .
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fle~ible material which would overlap the wearer~s shoulders and protective body garment. Both provision may be usecl together. Suitable A B C proof materials include Eabrics such as butyl proofed nylon and neoprene nylon fabrics or material such as neoprene or nylon dippings. The visor may be made of a transparent plastics material such as rigid or semi-rigid methyl methacrylate, the more impact proof polycarbonate sheet or non rigid even extensible material such as polyurethane film or silicone rubber which would permit the wearer to use an optical instrument while wearing the hood.
The nature of the provision for permitting the wearer to breathe uncontaminated gas will depend upon the user situation. In a solely ground role the provision may merely comprise adaptor means in the material allowing the passage of the gas from a supply thereof to the interior of the hood.
For use in flying and like situations, the wearer may have an oro-nasal breathing mask worn inside the hood. The hood may further be adapted for use with emergency or routine oxygen supply in a rarified atmosphere situation, such as flight at high altitude.
According to another feature of the invention, therefore, a ;`
provision for emergency oxygen supply may comprise a direct supply through the hood wall for metered constant flow oxygen to the mask.
The filtered breathing air supply may remain connected to the mask, and an emergency switching arrangement is preferably provided~
According to yet another feature of the invention, a provision ~`
for routine oxygen supply msy include a regulator fitted to the hood wall, ~`
the regulator being of a type which will pass oxygen on demand. The ;
regulator may be associated with a separate supply means for breathable air, with an appropriate switch-over control, so that the supply duct from the hood wall to the mask need not be duplicated. Means provided for the contingency of oxygen supply failure or regulator failure may include respectively a manual control to the breathable air supply and a manual MR/
lS~
or automatic regular bypass control adapted ~o provlde a metered constant flow oxygen supply to the mask.
In all circumstances it may be advantageous from the polnts of view of personal comfort and ABC protection ~or the hood interior as a whole to be maintained at a gas pressure above that of the exterior, 80 that the hood can be continuously purged. When an oro-nasal mask is to be employed this can be effected by allowing a separate bypass of suitable uncontaminated gas such as filtered blown air to the interior of the hood.
The hood may have means for separately ducting exhalant from the mask.
The hood may also have, a hood air outlet non-return valve for exhausting the hood purging gas. This may be spring loaded in order to ensure a slight positive pressure in the hood. ~;
The hood may be provided with intercommunication means such as microphone and earphone attachments, or if used with helmet and mask which already has these, it may have an intermediate intercommunication lead passing through the hood fabric with connection means (plug or socket) inside and outside. A microphone switch may also be provided outside the hood.
A preferred embodiment of the invention, therefore, is a hood ~ -for use in conïunction with a helmet of the type worn by aircrew, the helmet having a detachable visor, built-in earphones, and an associated attached or attachable breathing mask, the hood being fabricated of A B C proof material with a skirt extension for overlapping the wearer~s shoulders, and having a gas tight fastener enabling its fitting over the wearer~s helmet, means for sealing on the wearer~s neck or protecting body garment, a visor sealed to the fabric along its upper edge and ~
detachably attached to the fabric by a gas tight fastener along ltS ~ ~ -lower edge between hinge points, means for permitting uncontaminated ~-~
breathable gas to enter the interior of the hood and of the mask and means for permitting exhaled gas to leave the hood without entering the ;
hood space, intercommunication means, the visor having detents for engag-MR/
ing on visor hinges or hinge stucls on the wearer's helmet so that when the detents are so engaged the wearer can undo the gas tight fastener attaching the bottom edge of the visor and lift the visor.
Such a hood may be donned by a wearer already wearing helmet and mask but with the helmet visor removed, by first plugging the breathing pipe or pipes and the intercommunication leads from the mask into the hood provisions therefore, then attaching the hood visor to the helmet hinge points, and finally fastening the gas tight hood fitting fastener. Alternatively the mask may be permanently coupled to hood mounted breathing components and attached to the helmet during the donning procedure. The visor opening facility of the hood provides a ready means of removing the mask from the face in the event of an emergency involving water entry. At the same time it i9 particularly ~i useful during A B C warfare flight training, because it can be opened for an emergency purpose and then readily resealed.
According to another feature of the invention provision may be made in the hood for permitting access to the wearer~s face without opening the hood. Such access is often desired in order that the wearer may adjust his breathing apparatus or his comfort. It may comprise a pair of sealed finger stalls, for example, or a~gas-tight pouch or pocket or one or more sealed gussets or convolutions in the chin region of the fabric, and perhaps in the brow region also~ These pouches, pockets or convolutions may be stowable by means of fasteners such as sliding fasteners to minimise the bulk and encumbrance of their excess Eabric. If the wearer feels the need to adjust the position of his mask or manipulate his face for his personal comfort he can unstow the ~ -face manipulation means and insert his fingers to carry out the said manipulation via the hood fabric. ~-An A B C protective hood in accordance with the invention will now be described by way of example, with reference to the accompanying drawings which illustrate certain embodiments of the invention, and wherein:
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~. . . . - ., ~ . , - -FIGURE 1 is a 8kle elevfltlon of the hood whilst being worn, FIGUR~ 2 i9 a diagram of one hood breathing system, FIGUR~ 3 i9 a diagram of second hood breathing system, snd FIGUR~ 4 is a diflgram of a third hood breathing system, for routine oxygen supply.
: ' As shown in Figure ] the hood comprises an envelope 11 of butyl rubber proofed nylon fabric having a skirt 12 for overlapping the wearer's shoulders. The envelope has a primary gas tight sliding fastener 13 down the back. It is fitted with a perspex (TM) visor 14 10 which is sealed to the fabric along its upper edge but detachable from -the fabric along îts lower edge by means of an other gâgiitightdslide fastener 15 which runs approximately from visor hinge point to hinge point. A
suitable slide fastener has the teeth at each side protruding through the corresponding sheet of fabric to be joined, near -the edge of the fabric, so that when the fastener is closed and the teeth engage into each other the surfaces of the fabric sheets are pressed together. The visor is thus linked to one side of said other fastener 15 by a lip 16 of the fabric.
The hood is made to fit over a helmet 17 and the visor has ~
20 at each side a manually operable detent 18 by which it can be mounted ~ ;
on helmet hinges or hinge studs. The position of these hinges and the shape of the visor are such that the visor can be raised above the head, clearing the helmet sufficiently not to overstress the fabric and so that the visor profile presents no unacceptable limitation to the field of view when down or up.
In the chin region of the hood, below the fastener 15, there is formed a series of radial convolutions 19 normally closed and restrained by a further slide fastener 20. The convolutions provide sufficient excess fabric such that when they are unrestrained the visor can be raised, without affecting the integrity of the sealed hood, and the 'loose' fabric raised to allow the wearer to reach with his fingers '`
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to at leaYt the vicinity of the Nasion.
The helmet 17 has an associated breathing mask 21 which i8 fastened over the oro-nasal area of the face of the wearer. The hood is fitted with a valve chest 22 for passing filtered breathing gas to the interior of the hood and oE the mask. It i8 also fitted with an adaptor 23 (see Figure 2) for the exhaust of exhaled air from the mask and an adaptor 24 for connecting microphone and earphone leads. A
spring loaded exhaust non'return valve 25 i~ fitted to the neck region of the hood.
The layout of the breathing system indicated in Figure 1 i9 shown more clearly in Figure 2. The valve chest 22 which can be con- -nected to a filtered breathing ga9 i9 a forked duct which has on one , side a spring loaded non-return valve 30 for allowing gas into the ~`~
interior of the hood generally, and maintaining a mask positive safety pressure relative to hood space and on the other a connection for a flexible tube 31 to the mask 21, the mask having a non-return valve -21a permitting inboard flow. The other breathing component contains a non-return valve 32 for allowing exhaled mask gas to leave the hood, for which purpose the adaptor 23 ccnnects with a flexible tube 33 from the mask 21. The non-return valve 32 is backed up by a second mask mounted non-return valve (not shown) to ensure the non-en~y of toxic ag~ents. ~ ;
The hood described may be donned together with the helmet 17 `;
as an assembly, the visor 14 having already been attached at the hinges 18, the fasteners 12 and 15 being fully open and the visor 14 raised.
Once the helmet/hood i9 on the wearer~s head the fastener 12 is fully closed bringing the neck skirt to bear on the wearerls neck or body garment neckline. The mask 21 is then fastened into place with the tubes 31 and 33 connected to the adaptors 22 and 23 respectively. The microphone and earphone leads are connected to the adaptor 24. The visor may then be lowered and the fastener 15 closed.
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The ~earer's head will then be protected agalnst contact with B C substances ancl he will be able to breathe and communicate with the outside world. In breathlng, the facial atmosphere hetween the mask and the hood may tend to follow n simllar pattern of pressure fluctuation, and gas in excess of that inhaled will be allowed into the hood by the spring-loaded non-return valve 30. Due to the exhaust valve 25 being spring-loaded, however, a pressure slightly hi8her than that outside the hood may be maintained inside. This serves to prevent the ingress of contamina-ted atmosphere from outside the hood~
The wearer is at risk if his aircraft is ditched in water, of suffocating or sucking water into the mas~. Eor such an emergency, thP
facility of opening the fastener 15 and raising the visor 14 is provided. -The breathing mask 21 may then be removed. The facility is also useful during A B C~training flights.
In the second breathing sys-tem shown in Figure 3 the mask 40 has only one breathing tube 41. The hood is fitted with an adaptor 42 which would replace the adaptors 22 and 23 of Figures 1 and 2. The adaptor 42 has an inlet connector 43, a non-return valve 44 to the interior of the hood, and a breathing tube 41 to a connector 45 as before.
It has also a non-return valve 46 between the supply to the valve and the connector 43 for preventing exhaled gas from going back down the supply or into the hood interior. A spring loaded non-return ~ `
valve 47, a non-return valve 48 in series and an orifice 49 in the adaptor 42 permit the exhaust of inhaled air from the tube 41.
Figure 4 illustrates a preferred breathing system when the hood has to be used in a routine oxygen supply situation.
It shows aniadaptor-50 located in a hood wall 11, and an oxygen regulator 51 attached to the adaptor 50 inside the wall 11. The regulator 51 has an outlet communicating with an inner chamber 52 in the adaptor and an inlet communicating with an oxygen supply tube 53, - 7 - ;~
MR/
4~
to wllich an emergency oxygen s~lpply also ~eeds. The chamber 52 communicates also via a tube 5~ w~th tlle mask 21, and via an anti-suffocation valve 55 with an outer chamber 56. The vfllve 55 is a non-return valve preventing gas flow from the inner chamber 52 to the outer 56. The valve 55 has, however, a manual override 57 wlth detents (not shown) for the fully in and out position. The outer chamber 56 has an inlet tube 58 for connection ~ ~-to a supply of filtered air and a non-return valve 59 allowing ~as flow only from the chamber 56 to the interior of the hood wall 11.
The oxygen supply tube 53 has a regulator emergency by-pass 60 `~
10 which communicates via a hole 61 in the override 57 with the inner chamber ~-52. The override 57 is thus dual purpose, operating in push/pull mode ~ -for switching between oxygen and filtered air supplies and in rotary mode for opening/closing the regulator by-pass 60.
The mask 21 is exhausted via a compensated expiratory valve in the mask and (32 in Figure 2) via a tube 33 and a non-return valve (not shown) in the hood wall 11.
In the configuration shown in the drawing the hood is adapted to ~
supply demand oxygen to the mask 21 and filtered blown air via the tube ~ ~`
58, the chamber 56 and the valve 59 to the interior of ~he hood only.
Upon each inhalation by the wearer, the regulator senses the pressure drop in the chamber 52 and permits oxygen to pass therethrough from the supply 53. Exhalate passes out via the tube 33.
If in this configuration oxygen fails to be drawn up the tube 54 then upon inhalation the anti-suffocation valve 55 will open. This however is arranged to require a greater suction to operate than does the regulator and its operstion will be sensed by the wearer. If the ;;
wearer thinks that the 109s of oxygen supply may be due to failure of the regulator 51 he can turn the override 57 and thus open the oxygen by-pass 60. This will, if the fault is in the regulator 51, supply metered oxygen at a constant rate to the chamber 52. If the failure is in the oxygen supply upstream of the regulator 51 the wearer will sense this because of continuing inspiratory resistance of the anti-suffocation .
M~/
i5 4;~
valve 55. At ~his stage the limitecl eme-rgency oxygen supply would be utilised for immediflte descent to a safe altitude at wllich filtered air breathing is physiologically acceptable. Air breathing, after discharge of the emergency oxygen supply would be achieved by pushing the override 57. This closes off the by-pass 60 if open and lifts the valve 55, which by virtue of a deten-t will remain open, and the chamber 52 will be open to a supply of filtered air via the tube 58.
The above embodiment is particularly suitable for use by aircrew in high performance aircraft where oxygen and filtered air supplies may readily be installed. Insofar as the filtered air supply operates on environmental air without maintaining a store of same then clearly in the event of a failure of oxygen supply at high altitude, other than `~
failure of the regulator 51, the aircraft will have to be brought to an acceptable altitude for filtered air breathing.
If it is required that aircrew should be protected whilst proceed-ing to or from their aircraft portable filter blower units may be provided and these can, if separate aircraft installed units are not provided, be arranged for mounting and operation within the aircraft once the aircrew are inside.
It will be appreciated that the invention does not include the ~;~
oxygen mask, the breathing systems and the oxygen regulator per se or their use in contexts other than the ABC hoods hereindescribed and claimed.
Indeed the ambodiment of Figure 2 may employ a standard P or Q type oxygen ;~
maak currently in military service, while the embodiment of Figure 3 may ~ ~
employ a similar mask but with the mask mounted valves removed and one ~ -aperture blanked off. For the embodiment of Figure 4 there is a number of 100% oxygen miniature regulators which are available for the use described.
:, .
_ 9 _ MR/
Claims (10)
IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A hood for providing protection of a human's respiratory system against a contaminated atmosphere, said hood being adapted to be worn over a wearer's head and neck, including a helmet; comprising a cowl made of a fabric impervious to the contaminated atmosphere, the cowl having a face opening therein;
a transparent visor overlying the face opening, and having upper first and lower second edges, each with sealing means thereon, said edges being permanently sealed to the cowl peripherally of the face opening;
primary sealable fastening means in the cowl opposite the face opening for enabling doffing and donning of the hood;
second sealable fastening means provided in the cowl adjacent the lower edges of the visor, such second fastening means being operative to enable detachment and lifting of said visor free of the face opening; and skirt-like extension means connected to the cowl to pre-vent the contaminated atmosphere from reaching the wearer's head via areas around the neck, said hood including a valve and connection assembly permitting the wearer to be supplied with breathable gases.
a transparent visor overlying the face opening, and having upper first and lower second edges, each with sealing means thereon, said edges being permanently sealed to the cowl peripherally of the face opening;
primary sealable fastening means in the cowl opposite the face opening for enabling doffing and donning of the hood;
second sealable fastening means provided in the cowl adjacent the lower edges of the visor, such second fastening means being operative to enable detachment and lifting of said visor free of the face opening; and skirt-like extension means connected to the cowl to pre-vent the contaminated atmosphere from reaching the wearer's head via areas around the neck, said hood including a valve and connection assembly permitting the wearer to be supplied with breathable gases.
2. The hood defined in claim 1, wherein said second fastening means includes a slide fastener extending coextensively of the lower edge of the transparent visor, and a third sealable slide fastener of shorter length is provided in a region of the hood generally covering an area of the wearer's chin and jaw and enveloping some excess fabric of the cowl, the second slide fastener accommodating detachment and lifting of said visor free of the face opening, while the third slide fastener is operable to accommodate limited raising of said visor without affecting the integrity of the sealed hood.
3. The hood defined in claim 1, wherein a breathing mask is associated with said helmet, the breathing mask including duct means connectible to the valve and connection assembly for carrying inhalent and exhalent gases.
4. The hood defined in claim 3, wherein said valve and connection assembly includes a separate duct for conducting the exhalent gases out of the hood.
5. The hood defined in claim 1, wherein said hood includes regulator means therein operable to supply oxygen on demand from a supply of the same.
6. A hood for providing protection of a human's respiratory system against a contaminated atmosphere, said hood adapted to be used in conjunction with a helmet of the type worn by aircrew, such helmet having a detachable visor, built-in earphones and an attachable breathing mask, said hood being adapted to be worn over a wearer's head and neck, includ-ing said helmet, said hood comprising;
a cowl made of a fabric impervious to the contaminated atmosphere, and having a face opening therein;
a transparent visor secured at two spaced apart pivot points to said cowl so as to overlie the face opening, the visor having sealing means peripherally thereof to effect a permanent seal to the fabric cowl peripherally of the face opening;
primary sealable fastening means in the cowl opposite the face opening to enable doffing and donning said hood;
second sealable fastening means provided in the cowl adjacent lower sealed edges of the visor, said second fastening means being operable to enable detachment and pivotally lifting of the visor free of the face opening; and skirt-like extension means connected to the cowl to prevent the contaminated atmosphere from reaching the wearer's head via areas around the neck, said hood including a valve and connection assembly adapted to supply breathable gases to said breathing mask.
a cowl made of a fabric impervious to the contaminated atmosphere, and having a face opening therein;
a transparent visor secured at two spaced apart pivot points to said cowl so as to overlie the face opening, the visor having sealing means peripherally thereof to effect a permanent seal to the fabric cowl peripherally of the face opening;
primary sealable fastening means in the cowl opposite the face opening to enable doffing and donning said hood;
second sealable fastening means provided in the cowl adjacent lower sealed edges of the visor, said second fastening means being operable to enable detachment and pivotally lifting of the visor free of the face opening; and skirt-like extension means connected to the cowl to prevent the contaminated atmosphere from reaching the wearer's head via areas around the neck, said hood including a valve and connection assembly adapted to supply breathable gases to said breathing mask.
7. The hood defined in claim 6 wherein third sealable fastening means are provided in said cowl, generally in regions thereof about the wearer's chin and jaw, said third fastening means enclosing excess quantities of fabric of the cowl when closed and enabling, when opened; limited raising of the visor without affecting the integrity of the sealed hood.
8. The hood defined in claim 1 or 6, wherein said valve and connection assembly includes separated ducts for inhalent and exhalent gases.
9. The hood defined in claim 1 or 6, wherein said trans-parent visor is made of one of a rigid and a semi-rigid plastics material.
10. The hood defined in claim 1 or 6, wherein said trans-parent visor is made of a film-like non-rigid plastics material.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB57941/73 | 1973-12-13 | ||
| GB5794173 | 1973-12-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1088841A true CA1088841A (en) | 1980-11-04 |
Family
ID=10480421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA215,913A Expired CA1088841A (en) | 1973-12-13 | 1974-12-13 | Protective clothing |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1088841A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7210477B2 (en) | 2002-05-29 | 2007-05-01 | Brookdale International Systems, Inc. | Respirator hood assembly |
| WO2017075382A1 (en) * | 2015-10-29 | 2017-05-04 | W. L. Gore & Associates, Inc. | Protective integrated hood for garment |
-
1974
- 1974-12-13 CA CA215,913A patent/CA1088841A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7210477B2 (en) | 2002-05-29 | 2007-05-01 | Brookdale International Systems, Inc. | Respirator hood assembly |
| WO2017075382A1 (en) * | 2015-10-29 | 2017-05-04 | W. L. Gore & Associates, Inc. | Protective integrated hood for garment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |