WO1982002665A1

WO1982002665A1 - Heat and smoke protective hood

Info

Publication number: WO1982002665A1
Application number: PCT/GB1982/000021
Authority: WO
Inventors: La Pena Michael De; Charles Wocker Small
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-02-05
Filing date: 1982-01-26
Publication date: 1982-08-19
Anticipated expiration: 1983-08-05
Also published as: JPS58500350A; EP0070839A1

Abstract

Capuchon (10) compose d'un materiau de polyimide non-thermoplastique pourvu d'un tampon (24) permeable a l'air mais empechant la penetration a l'interieur du capuchon de la fumee ou des gaz nocifs.Cap (10) composed of a non-thermoplastic polyimide material provided with a plug (24) permeable to air but preventing penetration inside the cap of smoke or harmful gases.

Description

HEAT AND SMOKE PROTECTIVE HOOD

FIELD OF THE INVENTION

This invention relates to a hood for wearing on the head for use in fire protection situations or when a person is to be evacuated from an area or a room where there is a fire or where there is smoke or noxious fumes.

PRIOR ART

There have been many proposals for protective hoods and respiratory devices, often intended to enable the wearer to breathe, when the surrounding atmosphere is noxious or toxic.

British Patent No. 1 569 088 (MORRIS) discloses a welder's hood with an air filter. British Patent No. 1 587 121 discloses headgear and a respirator for aircrew.

British Patent No. 1 593 360 discloses a hood of plastics material having welded seams in a special arrangement.

British Patent No. 1 395 099 discloses clothing to wear in an operating theatre. British Patent No. 1 352 982 discloses a stretchable hood, and British Patent No. 1 302 670 discloses a stretchable suit. British Patent No. 1 103 380 discloses a filter arrangement for use to improve the ventilation of motor vehicles. British Patent 1 173 143 discloses a hood or a glove which is oleophobic and has a lining which includes activated charcoal. Other proposals have been made in British Patents Nos. 1 587 121, 1 376369,

1 088 293, 896 345, 842 766, 482137, 357 773 and U.K. Published

Application No. 2 024 6 1A. British Patent No. 1529 558 shows a respirator hood tightly fitting the head with a filter container rigidly connected to a mouthpiece.

British Patent No. 1 526134 shows a protective hood for use with an air-exhausting device also worn on the head.

None of the numerous suggestions mentioned above are in any way suitable to be worn by members of the general public seeking to escape from a burning building e.g. a hotel or a burning vehicle, e.g. an aeroplane, train, or bus.

It is an aim of this invention to provide a hood of simple construction which can be. folded flat, which is comfortable to wear, and which when worn provides good protection against heat and against breathing smoke and noxious gases such as the products of combustion.

SUMMARY OF THE IN7EHTI0N

According to the present invention in its broadest aspect, there is provided a hood of non-thermoplastics polyimide material having an open end wherein the head of the wearer may be inserted and having, located in its front wall, a pad which is air permeable but which prevents the passage to the interior of the hood of smoke and noxious gases. PREFERRED EMBODIMENTS

In a preferred embodiment of the invention, the hood is made from two superposed substantially rectangular sheets or of one sheet folded down one of its longer sides of KAPTON plastics material, of approximately 1000th of an inch (25 micrometres) in thickness .

In a specially preferred embodiment of the invention a pair of tapes are provided on the hood whereby it may be securely fastened to the head, and according to an advantageous feature of the invention the tapes are located in such a manner as to minimise the dead space within the hood when the tapes are fastened in a prescribed manner. For this purpose the tapes may be fastened one to each upper corner of the rectangular hood, and then each led down to pass through a loop which is secured to the face of the hood, there being one loop at each side inset about 6 or 7 centimetres from the nearer edge of the hood and disposed about 15 - 18 centimetres, preferably 16 - 17 centimetres, from the bottom or open end of the hood. KAPTON is a Trade Mark of Du Pont de Nemours International S.A., and KAPTON film may be obtained from this company, PP and R Films Division, CH1211 Geneva, Switzerland.

Alternatively, the hood may be constructed including an elastic or rubber strap having two ends each of which is secured to an upper region of the front wall of the hood in such a way that the strap extends substantially horizontal when the hood is worn normally by an erect person, and also including a pair of neck tapes, each of which has two ends one of which is secured to the hood and the other of which is free, these tapes being led around the hood and passed through one or more loops attached to the hood, the arrangement being such that the tapes can be pulled in opposite directions to tighten a lower region of the hood snugly around the neck of the wearer.

In a particularly preferred arrangement according to the invention, a filter pad is provided over a "window", i.e. an aperture made in one of the superposed sheets of "KAPTON" film. The filter pad may be a 4-layer pad which includes the following layers laminated to one another:-

1. (Outer) a layer of spark-resistant and flame-resistant charcoal cloth.

2. A layer of microfine fibre for example polycarbonate fibre, as another example a microfine polypropylene fibre layer may be used.

3. A layer of charcoal cloth in which the carcoal is in activated form and which in addition is impregnated with a copper salt and with organic compounds to render this layer adsorbtive to hydrogen cyanide and to nitrogen oxides.

4. A porous open cell plastics foam layer which is preferably loaded with a suitable amount for example 60 grammes per square metres of activated charcoal powder.

As an alternative to using "KAPTON" film, one may use any polyimide film having adequate heat radiation resistance and chemical resistance at elevated temperatures and, which preferably is not a thermosplastic material. SHORT DESCRIPTION OF THE DRAWINGS

The invention will be better understood from the following illustrative description of one non-limiting example thereof, given with reference to the accompanying drawings in which:- Figure 1 is a front view of one example of protective hood according to the invention; Figure 2 is a vertical cross-section on the line II-II of Figure

1; Figure 3 is a cross section through a four-layer filter pad used in a hood as shown in Figures 1 and 2; and

Figure 4 shows diagrammatically an alternative example of hood according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The illustrated hood includes front and rear walls 10, 12 made of a polyimide film which is flame-resistant, infusible, non-peimeable to gases, resistant to heat radiation and not thermoplastic. The front and rear walls are substantially rectangular and are joined around two or three of their edges to form a bag or hood which can be worn on the head. The hood may be made from a single rectangular sheet of film which is folded over and then secured together along two edges so producing a rectangular bag shape with one end constituting an open mouth into which the wearer inserts his head. Alternatively it may be made from two superposed sheets joined along three edges. The open edges indicated at 14 in Figure 1. The front wall 10 has a window cut therein, and over this window is placed a filter pad layer which in the preferred embodiment of the invention is as shown in Figure 3 and comprises a four-layer laminate. This filter pad layer is secured to th wall 10 by adhesive, by heat sealing, or by other convenient means.

Also attached to the front wall 10 are two tape loops 16, 18 each of these being joined to the wall 10 by their end portions and having a central portion separated from the wall 10 so that a tape 20 or 22 as the case may be, can be passed through the resulting loops so formed. In wearing the hood, these tapes 20 and 22 are then tied by the user around his neck, so in substance closing off the lower opening 14 and also flattening the hood to conform quite closely to the head of the wearer in order to reduce the free space within the hood within which dead air can accumulate. It has been found that this particular arrangement of tapes and loops is particularly successful from this point of view as v/ell as making the hood very easy to put on and take off.

Referring now to Figure 3, one example of a filter pad 24 is shown in Figure 3. Alternative filters may be used. The outer layer 26 (Figure 3) is preferably commercially available

charcoal cloth prior to activation of the charcoal. The next layer

28 is a layer of microfine fibres for this purpose polycarbonate or polypropylene fibres may be used. A particularly suitable layer is randomized polycarbonate fibre sold by the company Carl Freudenberg of West Germany. This layer forms a good filter for particulate material in smoke. The third layer is preferably a charcoal cloth which has been subjected to a double impregnation in order to render it such that it will absorb hydrogen cyanide gas and nitrogen oxides. The fourth layer is a porous open cell plastics foam which is loaded with a suitable amount of activated charcoal powder. Polyurethane foam having substantially 60 grammes per square metre of such powder may for example be used.

Filter including these layers in combination is believed to give good protection against the products of combustion and so will provide good protection to a person who wears such a hood during, for example, escape from a burning building.

Figure 4 illustrates in front view an alternative design of hood according to the invention, which is similar to that shown in Figures 1-3, except as regards the arrangement of tapes.

The hood 30 illustrated in Figure 4 has an elastic or rubber strap 31 extending across the top of its front surface, secured to the hood at each end. When the hood is worn, this strap 31 is pulled down (indicated dotted at 31a) and hooked below the chin of the wearer (or in a retainer as described later) so diminishing the internal volume of the hood. Alternatively, the strap 31 may be held down by a retainer 34 fixed to the front surface of the hood. The retainer 34 may be such that the strap 31 must be stretched to reduce its diameter in order that it can be hooked or clipped or otherwise retained in a suitable recess or formation (not shown) in the retainer 34. The hood also includes a neck tape encircling the lower part of the hood and held by retaining loops 32, 33 and 38. The two ends 36 and 37 of the tape are free and when the hood is donned, are pulled one by each hand of the wearer in order to fit the lower part of the hood snugly around the neck of the wearer. It will be seen that there has been particularly described and illustrated a protective hood, particularly intended for use by members of the general public unexpectedly involved in an emergency, which can easily be manufactured, which can be folded flat, and therefore easily transported, which is easy to apply and comfortable to wear, which is easy to remove, and which will provide good protection in an emergency situation.

Claims

1. A protective hood of polyimide plastics material having an open end wherein the head of the wearer may be inserted and having, located in its front wall, a pad which is air permeable but which prevents the passage to the interior of the hood of smoke and noxious gases.

2. A hood according to claim 1 wherein the hood is made from two superposed substantially rectangular sheets of polyimide plastics material, each of approximately 1000th of an inch (25 micrometres) in thickness, said sheets being secured together around three of their four edges .

3- A hood according to claim 1 and made from one substantially rectangular sheet folded over to provide two superposed sheets which are then secured together along two of their edges, the rectangular sheet being substantially 1000th of an inch (25 micrometres) in thickness.

4. A hood according to claim 1 including a pair of tapes, each of which is fastened at one end to a respective upper corner of the hood and is then led down to pass through a respective loop, said loops being fastened approximately 2/3 down the height of the hood when the hood is flat and each being spaced from the adjacent vertical edge of the hood by a distance of substantially 18 to 20 percent of the width of the hood when flat.

5. A hood according to claim 1 including an elastic or rubber strap having two ends each, of which is secured to an upper region of the front wall of the hood in such a way that the strap extends substantially horizontal when the hood is worn normally by an erect person, and also including a pair of neck tapes, each of which has two ends one of which is secured to the hood and the other of which is free, these tapes being led around the hood and passed through one or more loops attached to the hood, the arrangement being such that the tapes can be pulled in opposite directions to tighten a lower region of the hood snugly around the neck of the wearer.

6. A hood according to claim 1 wherein the pad is a laminated pad having at least the following 4 layers laminated together: (i) as an outer layer a layer of spark-resistant and flameresistant charcoal cloth; (ii) a layer of microfine fibre; (iii) a layer of charcoal cloth the charcoal being in activated form the cloth being impregnated with a copper salt and organic compounds whereby this layer Is absorptive to hydrogen cyanide and nitrogen oxides; and (iv) a porous open cell synthetic plastics foam layer.

7. A protective hood comprising an open-ended envelope of polyimide material which is flame-resistant, infusible, non-permeable to gases, resistant to heat radiation and non-thermoplastic, the envelope being made up of front and rear walls of said material and the open end being of dimensions such that a wearer can insert his head therein, one of the walls having a window aperture therein covered by an air-permeable laminate capable of filtering out the gases hydrogen cyanide and nitrogen oxides thereby preventing ingress of such gases to the hood while allowing the wearer to breathe, the hood also having neck tapes so arranged that upon tightening the tapes minimise the volume of dead air within the hood and cause the lower region of the hood to fit snugly around the neck of the wearer.