GB2191950A - Emergency escape breathing apparatus - Google Patents

Emergency escape breathing apparatus Download PDF

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Publication number
GB2191950A
GB2191950A GB8615744A GB8615744A GB2191950A GB 2191950 A GB2191950 A GB 2191950A GB 8615744 A GB8615744 A GB 8615744A GB 8615744 A GB8615744 A GB 8615744A GB 2191950 A GB2191950 A GB 2191950A
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GB
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Application
Patent type
Prior art keywords
breathing
gas
hood
valve
half
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.)
Granted
Application number
GB8615744A
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GB2191950B (en )
GB8615744D0 (en )
Inventor
Michael Harvey Glynn
Simon Kugler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sabre Safety Ltd
Original Assignee
Sabre Safety Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date

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Classifications

    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62BDEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B7/00Respiratory apparatus
    • A62B7/02Respiratory apparatus with compressed oxygen or air
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62BDEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B17/00Protective clothing affording protection against heat or harmful chemical agents or for use at high altitudes
    • A62B17/04Hoods

Abstract

Emergency escape breathing apparatus includes a hood 1 enveloping the head of a wearer and a source such as an oxygen cylinder 3 or (25) (Fig. 4, not shown) for supplying breathing gas to the wearer of the hood 1. A reservoir of breathing gas is provided from which the wearer draws his gas on each breath. This reservoir may be either the interior of the hood 1 or a breathing bag 24 (Figure 4, not shown) which communicates with the interior of a half mask (22) worn by the wearer. Instead of gas being supplied continuously to the reservoir by the oxygen cylinder 3 or (25) gas is drawn from the oxygen cylinder 3 or (25) only when the fall in pressure in the reservoir is sufficient to open a demand valve 9 or (30) controlling flow of gas from the source or cylinder 3 or (25) to the reservoir. Several alternative embodiments of emergency escape breathing apparatus are described and illustrated. <IMAGE>

Description

SPECIFICATION Emergency escape breathing apparatus This invention relates to emergency escape breathing apparatus.

Emergency escape breathing apparatus for escaping from dangerous situations are well known and are used,for example, for areas which may be liable to an outbreak of fire or an escape of toxic gas. These known emergency escape breathing apparatus rely on a hood for protecting the head, and in particular the breathing passages, eyes and hairofthewearer.

The hood is generally a flexible hood oftransparent plastics material.

Breathing gas is stored under pressure in a high pressure gas cylinder and may be either air, or oxygen, or oxygen enriched air depending on the design and use of the emergency escape breathing apparatus. The gas cylinder is connected to the hood by means of a flexibletube and when a manual or automaticon/offvalve is operated, a continuousflow of breathing gas isfed to the hood.

It has further been proposed that the hood of such an emergency escape breathing apparatus may incorporate an inner mask, i.e. a half mask, with suitable valves to control the build-up of carbon dioxide within the hood. It has also been proposed that a chemical carbon dioxide absorbent may be included if required within the hood in orderto economisethe use of breathing gas. In the present Applicants' copending PatentApplication No. 86.09387, a chemical carbon dioxide absorbent is provided either in the walls of a half mask, or in a container outside the half mask ensuring that all gases both inhaled and exhaled are passed through the carbon dioxide absorbent.

In the present Applicants' co-pending Patent Application No. 86.09389 it is further proposed that the emergency escape breathing apparatus may further incorporate a separate breathing bag providing a re servoir of the breathing gas which is supplied forthe use of the wearerthrough a half mask entirely inde pendentlyofthe remainder of the interior of the hood outside the half mask. The breathing gas does not thereforepassthroughthatpartofthe interiorofthe hood which is outside the half mask, any part ofthe breathing bag which may be within the hood, and the direct connections of the breathing bag to the half mask. One particular use of such an emergency escape breathing apparatus is in the event offire in the cabin of a passenger aircraft.

It is well known that oxygen, and hence the breathing gas, consumed by a wearer of breathing appar atus,andthecarbondioxideproduced bythe wearer, depends on his or her metabolic rate. In otherwords, the harder the person works the more oxygen is consumed and the more carbon dioxide produced. The rate of oxygen consumption and carbon dioxide production is also affected by the bodyweightofthewearer, and bythewearer's mental state, for example, the rateisgreaterwhen the wearer is in a state of alarm or panic.

Emergency escape breathing apparatus must therefore be designed to cater for all these conditions, which depend on the type of use and on the user, who may be a trained person or a civilian, young or old, and of either sex, and will further de- pend on the assumed duration of each type of use.

As an example the escape apparatus may be designed for trained service personnel escaping from a fire on a ship or for climbing in an emergency up a leg of an oil rig. On the other hand it may be intended for civilians caught by a fire in a hotel, who may sit in their bedrooms for a period of low activity, followed by a rapid walk to a fire exit when the route is clear.

Blockages on the route may also necessitate climbing over obstacles. It is therefore evident that, depending on all these factors, many different designs of emergency escape breathing apparatus are necessary, with different breathing gas flow rates and dif ferent cylinder gas contents.

Also, because the flow rate must be designed to meetthe worst conditions, much of the breathing gas will be wasted during periods when the wearer requires less gas than is being provided bythe apparatus, and therefore more gas has to be carried than is strictly necessary to meet the required conditions and duration. Whilstthe weight of the additional gas in itself is negligible,thecylindercontaining the gas will need to increase in size to hold the additional gas and this increases the weight and bulk, as well as the cost, all of which are undesirable.

According to the present invention there is provided emergency escape breathing apparatus comprising a flexible hood, at least part of which is transparent, for enveloping the head of a wearer, a source of breathing gas under pressure, and means for supplying breathing gas from the said source to a reservoir of breathing gas from which the wearer of the hood draws gas on inhalation, said means including a demand valve responsive to a fall in pressure ofthe gas in the reservoir to cause breathing gas to be supplied to the reservoir.

The use of a demand valve in the emergency escape breathing apparatus of the present invention results in breathing gas being supplied to the breathing reservoir from the source only when there is a significant fall in the pressure of gas in the breathing reservoir. The breathing reservoir may be the interior ofthe hood which is effectively sealed at its open lower end by a neck seal when the hood is enveloping the head of the wearer. Alternativelythe breathing reservoir may be a breathing bag provided between the source and a half mask provided within the hood. The breathing bag will supply all inhaled gas, but the half mask may either pass exhaled gas to the interior of the hood or effect a total seal so that all breathed gases are isolated from the interior of the hood outside the half mask.As a further possibility, the breathing reservoir may be the interior of an impermeable half maskto which breathing gas is supplied direct.

The present invention will be described as applied, inter alia, to emergency escape breathing apparatus embodying the inventive features of our co-pending PatentApplications Nos. 86.09387,86.09388 and 86.09389. Preferably, a neck seal is provided near the open lower end of the hood in all embodiments of the invention to prevent the ingress of toxic gases, fumes or particles from the surrounding atmosphere and consequent discomfort, for example, to the eyes ofthewearerofthe hood when the whole breathing system is isolated from the interior ofthe hood outside the half mask.

The demand valve employed may be of any known type which maintains a positive or safety pressure within the reservoir of breathing gas at all times. The demand valve thus operates between two small positive pressures in the reservoir of breathing gas, for example between 10 mms and 50 mmswatergauge.

The demand valve in this example is therefore shut when the pressure in the reservoir has reached 50 mmswater gauge and isfullyopen when the pressure has dropped to 10 mms water gauge.

The demand valve may be mounted on the inlet connection to the hood, breathing bag or half mask, or it may be mounted on the gas cylinder or other source of breathing gas.

Preferably, in orderto keep the bulk and weight of the demand valve to a minimum a servo valve is used incorporating a small pilot valve reacting to the selected pressures to open and shut the servo valve.

When a servo valve is used this is conveniently mounted on the source of breathing gas with a pressure sensing line connecting the pilot valve to the reservoir of breathing gas in addition to the gas supply line from the servo or main gas valve to the reservoir of breathing gas.

The present invention will be further understood from the following detailed description of preferred embodiments thereof which is made, by way of ex ample,with reference to the accompanying dia grammaticdrawings in which Figures la and ib are representations of alternative embodiments of emergency escape breathing apparatus in accordance with the present invention in which the reservoir of breathing gas is an airfed hood, Figure2 shows a further embodiment of emergency escape breathing apparatus in accordance with the present invention in which the reservoir of breathing gas is an oxygen fed hood, Figure3 is an enlarged view of partofthe hood of Figure 2 showing in detail the construction of the half mask, Figure 4 is a representation in part section of a still further embodiment of emergency escape breathing apparatus in accordance with the present invention in which the reservoir of breathing gas is provided by a breathing bag, Figure 5is a detail of a modification oftheemer- gencyescape breathing apparatus of Figure4, FiguresGand 7are representations ofyetfurther embodiments of emergency escape breathing apparatus incorporating the present invention in which the reservoir of breathing gas is an airfed hood.

In the drawings the same or similar parts are designated by like reference numerals.

Referring to Figures 1a and lboftheaccompany- ing drawings, there is shown emergency escape breathing apparatus according to the present invention which includes a flexible hood 1 made ofthe heat resistant transparent plastics material obtainable underthe name Kapton in position on the head of a wearer. The interior ofthe hood 1 is arranged to be fed with airthrough a flexible pipe 2 from a source of compressed air such as the cylinder 3, the air supply being initiated by opening a valve 4, which may be a simple on/offvalve as illustrated, or a valve automatically operated by taking the apparatus from its packaging, or by donning the hood 1.

A simple half mask 5 is secured to the inside ofthe hood 1 in a position such that the half mask engages the face ofthe wearer over his nose and mouth. The half maskS is retained in position against the face of the wearer by any conventional means such as elastic 6 incorporated in the hood 1. At the lower open end ofthe hood 1 there is provided a neck seal 7 which is conveniently an elastic polyurethane sealing flap which has a central hole small enough to provide a good seal around the smallest neck and yet elastic enough to be pulled over the largest head.

The neck seal 7 prevents the ingress of toxic gases, fumes or particles from the surrounding atmosphere, and in these embodiments ofthe invention also ensures that pressure changes in the reservoir of breathing gas, which is the interior of the hood 1, as a result of use of the breathing gas are not lost and are effective to open a demand valve 9 or 10 as will be described belowwhen a further supply of breathing gas is required.

In both the embodiments of Figures 1a and 1 b a low resistance exhale valve 8 is mounted in the hood within the half mask to allow exhaled gases to excape from within the half mask 5. The exhale valve 8 is designed to open at a pressure a little above the closing pressure of the demand valve, for example the exhale valve 8 may open at 60 mms water gauge when the demand valve is shut at 50 mmswater gauge.

In accordance with the present invention air is supplied by the air cylinder3 through the pipe2 only when the demand valve 9 or 10 is opened in consequence of a predetermined fall in the pressure of gas in the interior of the hood 1. As indicated in Figure lathe demand valve 9 can be mounted on the outside of the hood 1 at the inlet connection to the hood 1 from the flexible pipe so that the demand valve 9 senses the pressure within the hood 1 in comparison with the atmospheric pressure.Alternatively, as shown in Figure 1 b the demand valve 10, which is conveniently a pilot-operated servo valve, may be mounted on the air cylinder 3 in which case the demand valve 10 has a pressure sensing line 11 connecting the pilot valve to the reservoir of breathing gas which is the interior of the hood 1.

In Figure 2 ofthe accompanying drawings there is shown another embodiment of the present invention which has basic similarities with the embodiment of the invention described above with reference to Figure 1 b. However, in Figure 2 an oxygen cylinder 13 is the source of gas, the half mask 15 is of a special construction, and the exhale valve 8 is omitted.

Referring to Figure3 the walls of the half mask 15 are of a sandwich construction in which a carbon dioxide absorbent material 18 is retained between layers 19 of a porous material such as an open seal foamed plastics material, for example foamed poly vinyl chloride orfoamed polyurethane.

In the embodiment of the invention illustrated in Figures 2 and 3, the gases breathed by the wearer of the hood 1 in both inhalation and exhalation are caused to pass through the walls of the half mask 15 in a pendulum breathing operation so that carbon dioxide present in the gases is absorbed in the walls of the half mask 15 on each pass. When the oxygen consumption as a resultofthe breathing of the wearer has caused a significant fall in the pressure in the interiorofthe hood 1 this is sensed by the pilot valve through the sensing line 11 and the servo valve of the demand valve 10 is opened to allow oxygen to pass through the pipe 2 to the interior of the hood 1.

As an alternative to the embodiment ofthe invention described with reference to Figures 2 and 3,the demand valve may be located in the inlet connection ofthe flexible pipe 2 to the head 1 similarly to the embodiment of Figure la.

A modification of the embodiment described with reference to Figures 2 and 3 but operating in similar manner to that embodiment, may be achieved by using a half mask of impermeable material and placing a container holding carbon dioxide absorbent material on the outside of the hood 1 in such a way that inhaled and exhaled gases will pass through the carbon dioxide absorbent material from and to the interior of the hood 1 outside the half mask.

In Figure 4 of the accompanying drawings there is shown emergency escape breathing apparatus in which a half mask 22 of impermeable material, such as rubber, is supplied with breathing gas from a re servoirconstituted buy a ring-shaped breathing bag 24 through a flexible connecting means 27, an inhale valve 28 and an annular carbon dioxide absorbent filter 29. The breathing bag 24 is supplied with oxygen from an oxygen cylinder 25 through a demand valve 30, the oxygen cylinder and the demand valve 30 being both mounted on the outside ofthe breathing bag 24. The breathing bag 24 may include an exhale valve 26 to safeguard against an undue pressure rise in the breathing bag.The reservoir of breathing gas and its supply to and from the half mask 22 is isolated from the remainder of the interior of the hood 1 so that there is no necessity to provide a neck seal for effective operation of the demand valve 30 which responds to a fall in pressure in the breathing bag 24. However, a neck seal 31 is conveniently provided on the inside edge of the ring-shaped breathing bag 24so asto provide protection against toxic fumes entering the interior of the hood 1 outside the half mask 22 and the associated breathing system.

Figure 5shows a modification of the emergency escape breathing apparatus of Figure 4 in which the oxygen cylinder 25 and the demand valve 30 are located inside the breathing bag 24 so that oxygen passes directly to the reservoirwithin the breathing bag 24 and leakage from the oxygen cylinder is not loss of oxygen to the emergency escape breathing apparatus as a whole. In the embodiment of Figure 5 the demand valve 30 must have aventthroughthe wall of the breathing bag 24 which it is mounted to enablethe demand valve 30 to respond to a selected difference between the atmospheric pressure and the higher pressure within the breathing bag 24.

In addition to the oxygen cylinder 25 and the demand valve 30 being located within the breathing bag 24 in the embodiment of Figure 5, the inhale valve 28 and the annular carbon dioxide absorbent filter 29 are also located within the breathing bag 24.

Other shapes of breathing bag may be employed, for example the alternative shapes described and illustrated in the Applicants' co-pending Application No.86.09389.

Figure 6 shows an embodiment of the invention similarto that of Figures 1 a and 1 b butwithoutthe half mask. In Figure 6 alternative positions for the demand valve are denoted by numerals 9' and 10', the latter requiring the presence ofthe sensing line 11.

In Figure 7 there is shown a modification ofthe arrangement according to Figure 6 utilising the demand valve 9' mounted on the outside of the hood 1 at the inlet connection from the pipe 2 to the hood 1.

In the embodiment of Figure 7 the demand valve 9' is mounted on the outside of the hood 1 opposite the mouth and nose of the wearer of the hood 1 and the outlet of the demand valve 9' is arranged to provide a flow of air directionally towards the nose and mouth and with minimal mixing ofthe newly supplied air with the air already inside the hood 1 and containing exhaled carbon dioxide. In this embodiment the demand valve 9' will be fitted with directional ventilation louvers, such as are conventionally provided for passengers, for example, on aircraft.

In addition to the embodiments of the invention described above, the flexible hood may contain an impermeable half mask to which breathing gas is supplied either viva an inhale valve from the interior of the hood or direct from the gas cylinder. In the first ofthese cases the breathing reservoir is the interior of the hood, and in the second case the breathing reservoir is the interior of the half mask.

Claims (19)

1. Emergency escape breathing apparatus comprising a flexible hood, at least part of which is trans- parent, for enveloping the head of a wearer, a source of breathing gas, and meansforsupplying breathing gas from the said source to a reservoir of breathing gas from which the wearer of the hood draws gas on inhalation, said means including a demand valve re sponsivetoafall in pressure ofthe gas in the re servo to cause breathing gas to be supplied to the reservoir.
2. Emergency escape breathing apparatus according to Claim 1, wherein a neck seal is provided nearthe open lower end ofthe hood for inhibiting ingress of gas into the hood when the hood is enveloping the head of the wearer, and wherein the reservoir of breathing gas is constituted by the interior of the hood above the neck seal.
3. Emergency escape breathing apparatus according to Claim 2, wherein the hood further includes a half mask in the interior of the hood, the half mask being engageablewiththewearer'sfaceto cause all gas breathed by the wearer to be inhaled from or exhaled to, the space within the half mask.
4. Emergency escape breathing apparatus ac cording to Claim 3, wherein an exhale valve is mounted in the hood within the halfmaskfor allowing exhaled gas to escape from the half mask to the surrounding atmosphere when the pressure of exhaled gas within the half mask reaches a predetermined level in excess ofthe closing pressure of the demand valve.
5. Emergency escape breathing apparatus according to Claim 3 or Claim 4, wherein the half mask is constructed of an open cell foamed plastics material.
6. Emergency escape breathing apparatus according to Claim 3, wherein the walls of the half mask include layers of porous material retaining therebetween a material capable of absorbing carbon dioxide.
7. Emergency escape breathing apparatus according to Claim 1 ,which further includes a breathing bag which constitutes the reservoir of breathing gas, a half mask in the interior ofthe hood, the half mask being engageable with the wearer's face to cause all the gas breathed by the wearer to be inhaled from or exhaled to, the space within the half mask, and connecting means connecting the interior ofthe half mask to the breathing bag such that gas is supplied to the interior of the half mask from the breathing bag upon inhalation by the wearer.
8. Emergency escape breathing apparatus according to Claim 7, wherein the interior of the half mask is isolated from the remainder of the interior of the hood.
9. Emergency escape breathing apparatus according to Claim 8, wherein the connecting means includes a carbon dioxide absorbentfilter.
10. Emergencyescape breathing apparatusaccording to Claim 9, wherein the connecting means includes an inhale valve permitting breathing gasto pass directly from the breathing bag to the half mask during inhalation and causing exhaled gas to pass through the carbon dioxide absorbentfilter.
11. Emergency escape breathing apparatus according to any one of Claims 7 to 1 0,wherein the demand valve is located between the breathing bag and the source of breathing gas.
12. Emergency escape breathing apparatus according to any one of Claims 7 to 10, wherein the source of breathing gas and the demand valve are located within the breathing bag.
13. Emergency escape breathing apparatus according to any one of Claims 1 to 6, wherein the demand valve is located on an outside surface of the hood.
14. Emergency escape breathing apparatus according to Claim 1 or Claim 2, wherein the demand valve is located in a position on the outside surface of the hood opposite to the mouth and nose ofthe wearer of the hood.
15. Emergency escape breathing apparatus according to Claim 14, whereinthe demand valve has an outlet providing directionai flow of breathing gas from the demand valve towards the nose and mouth ofthe wearer ofthe hood.
16. Emergency escape breathing apparatus according to any one of Claims 1 to 6, wherein the de mand valve is located at the source of breathing gas.
17. Emergency escape breathing apparatus according to any one ofthe preceding claims, wherein the demand valve comprises a pilot-operated servo valve.
18. Emergency escape breathing apparatus substantially as hereinbefore described with reference to any one of the accompanying drawings.
19. Emergency escape breathing apparatus according to Claim 1 and substantially as hereinbefore described.
GB8615744A 1986-06-27 1986-06-27 Emergency escape breathing apparatus Expired - Fee Related GB2191950B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8615744A GB2191950B (en) 1986-06-27 1986-06-27 Emergency escape breathing apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8615744A GB2191950B (en) 1986-06-27 1986-06-27 Emergency escape breathing apparatus

Publications (3)

Publication Number Publication Date
GB8615744D0 GB8615744D0 (en) 1986-08-06
GB2191950A true true GB2191950A (en) 1987-12-31
GB2191950B GB2191950B (en) 1990-03-21

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB8615744A Expired - Fee Related GB2191950B (en) 1986-06-27 1986-06-27 Emergency escape breathing apparatus

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2233905A (en) * 1989-07-19 1991-01-23 Sabre Safety Ltd Emergency escape breathing apparatus
EP0470791A2 (en) * 1990-08-10 1992-02-12 Sabre Safety Limited Emergency escape breathing apparatus
GB2247396A (en) * 1990-08-10 1992-03-04 Sabre Safety Ltd Emergency escape breathing apparatus
FR2673380A1 (en) * 1991-02-28 1992-09-04 Intertechnique Sa personal respiratory protective equipment.
GB2257346A (en) * 1991-07-12 1993-01-13 S M Alexander Protective hood
US5690095A (en) * 1995-05-24 1997-11-25 Protector Technologies Limited Emergency escape breathing apparatus
WO2002036206A1 (en) * 2000-11-02 2002-05-10 Nicholas John Foss Breathing apparatus
US7210477B2 (en) 2002-05-29 2007-05-01 Brookdale International Systems, Inc. Respirator hood assembly

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2044110A (en) * 1979-03-05 1980-10-15 Draegerwerk Ag Respiratory mask
GB2074456A (en) * 1980-04-23 1981-11-04 Draegerwerk Ag Protective suit
GB2164570A (en) * 1984-09-21 1986-03-26 Interspiro Ab Respirator

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2044110A (en) * 1979-03-05 1980-10-15 Draegerwerk Ag Respiratory mask
GB2074456A (en) * 1980-04-23 1981-11-04 Draegerwerk Ag Protective suit
GB2164570A (en) * 1984-09-21 1986-03-26 Interspiro Ab Respirator

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2233905A (en) * 1989-07-19 1991-01-23 Sabre Safety Ltd Emergency escape breathing apparatus
EP0470791A2 (en) * 1990-08-10 1992-02-12 Sabre Safety Limited Emergency escape breathing apparatus
GB2247396A (en) * 1990-08-10 1992-03-04 Sabre Safety Ltd Emergency escape breathing apparatus
EP0470791A3 (en) * 1990-08-10 1992-04-22 Sabre Safety Limited Emergency escape breathing apparatus
FR2673380A1 (en) * 1991-02-28 1992-09-04 Intertechnique Sa personal respiratory protective equipment.
US5265592A (en) * 1991-02-28 1993-11-30 Intertechnique Individual protective breathing equipment
GB2257346A (en) * 1991-07-12 1993-01-13 S M Alexander Protective hood
GB2257346B (en) * 1991-07-12 1995-05-10 S M Alexander Protective hood
US5690095A (en) * 1995-05-24 1997-11-25 Protector Technologies Limited Emergency escape breathing apparatus
WO2002036206A1 (en) * 2000-11-02 2002-05-10 Nicholas John Foss Breathing apparatus
US7210477B2 (en) 2002-05-29 2007-05-01 Brookdale International Systems, Inc. Respirator hood assembly

Also Published As

Publication number Publication date Type
GB2191950B (en) 1990-03-21 grant
GB8615744D0 (en) 1986-08-06 grant

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Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19980627