1. Field of Invention

This invention relates to an emergency escape breathing apparatus particularly adapted for a single use and throw-away function and to provide a short term air supply to the wearer in a dangerous environment including a smoke-filled or burning building.

2. Brief statement of the Prior Art Heretofore, types of escape apparatus have been heavy, bulky, complicated in structure giving rise to difficulty in manipulation, application and making operation¬ al in times of emergency. Moreover, prior structures have been expensive to manufacture and subject to malfunction. This criticism of prior art includes typical structures shown in the following U.S. patents:

E. M. Spears et al. 3,043,302 July 10, 1962 G. W. Oetjen et al. 4,019,507 April 26, 1977 Max L. Kranz 4,221,216 Sept. 9, 1980

BRIEF DESCRIPTION OF INVENTION The invention comprises as one of the main com¬ ponents a relatively rigid, light-in-weight and transparent face mask structure easily attachable to the head of the wearer and serving as the sole support for and from which other parts of the apparatus freely hang to form a sub- stantially short and straight-line suspension. Said parts include a flexible hose connecting the chamber formed be¬ tween the mask and the wearer's face and a flow-control assembly for a pressurized bottle supply of air or oxygen- enriched and other types of air. The air is thus adapted to be fed in respirable condition to said mask chamber. The

-£- flow-control assembly is comprised of a light, stress-resist¬ ing and pressure-reducing chamber or reservoir for the pressurized bottle supply of gas and a suitable and con¬ ventional valve structure between and connecting said re- dueing chamber and bottle. The valve structure includes a rupturable seal or pressure-resisting disc element which normally closes the gas supply in the pressurized bottle and is further provided with an external valve element easily accessible and manipulable by the wearer to cause seal rup- ture for gas flow and continuous operational use of the apparatus. Under the invention the valve flow area is pre¬ ferably variable in view of loss of pressure in the gas bottle during gas flow to the mask to enable the feeding of respirable gas to the mask chamber under acceptable con- ditions of pressure and content for a preset and predeter¬ mined time period. Because of the novel features and im¬ provements in- the apparatus and parts thereof as will, herein- _* after be described, the apparatus is discardable after a single use, and prior to use, the apparatus is capable of being folded and stored for accessibility.

BRIEF DESCRIPTION OF DRAWINGS Accompanying ¹ this specification are drawings show¬ ing a preferred form of the invention wherein:

Fig. 1 is a view in perspective showing the apparatus of the invention secured to and depending from the head of a wearer;

Fig. 2 is an enlarged elevational and fragmentary view of Fig. 1 along plane 2 - 2 thereof and showing sub¬ stantially in block form the -valve structure in sealing relationship with respect to the gas bottle and the pressure- reducing chamber or reservoir;

Fig. 3 is a view similar to Fig. 2 but showing the valve structure open and operational; and

Fig. 4 is an enlarged sectional view of Fig. 1 across the plane 4 - 4 thereof showing functions of mask filters and flapper valves when the apparatus is operational.

UBSTITUTE E - OMPI

DESCRIPTION OF PREFERRED EMBODIMENT In accordance with the invention and the pre¬ ferred form shown in the drawings. Fig. 1 best illustrates the improved apparatus as a single and integrated unit 5 supported and freely suspended from the head of the wearer and generally indicated by reference numeral 10. Thus, the unit is comprised of a novel and improved component in the form of a chamber-forming mask 11 having an adjustable attachment 12 for the head of the wearer, a flexible hose 10 13 for gas feed to the mask chamber, a- pressurized bottle of gas 14 connected to a flow-control assembly comprising the valve structure 15 in association with a gas pressure- relieving or regulator chamber 16 for gas feed to hose 13 while the mask is in use. The disposition of the components 15 of the integrated unit 10 as best seen in Fig. 1, namely, a substantially straight and short gas flow-path to mask 11, enables the wearer to go through two simple steps for application of the apparatus. First, the mask 11 is easily and conventionally attached to the head of the wearer for 20 support and free suspension of the other components of the integrated unit. Then an external and accessible-by-feel valve fitting is manipulated for opening of the gas supply. Moreover, such disposition of the components of the inte¬ grated unit allows complete freedom of movement of both 25 body and limbs in all postures and reduces the chances of malfunctioning of the apparatus due to accidental fouling or entanglements of and with parts of the apparatus.

Mask 11, adapted to form a breathing chamber 11a with the face of the wearer, is formed of a transparent 30. and substantially rigid and inert plastic material as a preferred composition including the styrenes and acrylics, and capable of. resisting the stress imposed thereon by the weight of the other components of the apparatus suspended from said mask. As best shown in Figs. 1 and 4, mask 11 35 is provided with one or more conventional flapper or one-way valves 17 interposed along the face shape-conforming rim 18. Valves 17 function to exhaust to the ambient atmosphere the

SUBSTITUTE SHEET

mixture of gas contents within chamber 11a due to gas feed and the wearer's exhalations thereby providing a sub¬ stantially constant flow of breathable atmosphere over a predetermined time period such as from 3 - 7 minutes and preferably 5 minutes as will hereinafter be discussed. The mask rim 18 is preferably formed of any suitable elastomeric sealing material which is face shape-conforming and sub¬ stantially nonflammable such as a synthetic sponge or the like. Mask 11 is further and optionally provided with one or more conventional and available filters 19 mounted in the face of the mask and adapted to eliminate inhalation of toxic elements in the ambient air, and/or aid or substitute for said exhalation valves 17 when the ambient ^" atmosphere is depleted as through complete combustion of respiratory oxygen content.

Flexible hose 13 of suitable and substantially nonflammable material is suitably connected at the upper end : of 13a to the body of mask 11 preferably at the lower end of the mask vertical"axis for communication with chamber 11a, while _, the lower end of said hose 13 as at 13b is suitably connected to the upper opening 16a of the pressure-reducing or regulator chamber 16 of the gas flow-control assembly for communication therewith. Hose 13 as shown is preferably ring-reinforced to prevent gas-flow cutoff if and when flexed, and is relatively short in length. Both of these con¬ siderations are hose features which minimize drop in gas- flow pressure therethrough when the apparatus is operational in the period of emergency.

The lower opening 16b of the ^" regulator chamber is connected to and for communication with the outlet of valve structure 15 while the inlet of said valve structure is con¬ nected to and is adapted to communicate with the gas con¬ tents of bottle 14 at bottle mouth 14a. Bag or pressure- reducing chamber 16 is adapted to function so as to reduce gas pressure of and accumulate gas from pressurized bottle 14 for conveyance to mask chamber 11a through hose 13 while the mask is in use. Chamber 16 as shown is in the form of

SUBSTITUTE SHEET _f

a pressure-resisting plastic container such as formed from a styrene or acrylic material and of a capacity to enable proper volumetric flow and pressure of gas from bottle 14. For the sake of safety and economy of production of the bottle component of the instant throw-away apparatus, said bottle as shown is preferably of a low pressure-rated aluminum or spun filament plastic container with an initial working pressure of about 1800 psi and of about a 20 cubic inch volumetric capacity to provide a supply of breathable oxygen for about a five minute period. For such bottle pressure and capacity, chamber 16 should preferably be of 15 inch volumetric capacity.

Gas supply valve structure 15 is necessarily of conventional and simplified type economical to manufacture and adapted to conform with feed requirements for mask chamber 11a. Said structure may be formed from a block of metal such as aluminum and the body suitably bored, drilled, recessed, tapped and equipped to afford functions for suit¬ able and proper performance. And although progressive di- minution of gas supply pressure within bottle 14 is com¬ pensated by the pressure-reducing or regulating chamber 16 leading to chamber 11a to maintain a pressure therewithin which is as safe and constant as possible, valve structure 15 in order to augment or serve said purpose may be pro- vided with conventional or other structures for increasing the valve flow area. Said means add to the expense of valve production and are not shown and described herein.

Gas supply valve body 20 as shown substantially in diagrammatic form serves as a closure cap for bottle 14 and as a connector for the chamber 16, engagement of the valve body with mouth of bottle or container 14 and lower end of chamber 16 being conventional as by screw attachment or the like. A rupturable element such as a frangible disc 21 adapted normally to serve as the valve closure is dis- posed across an internal valve body bore connecting valve inlet and outlet channels, said bore and channels not being shown and described herein. Disc 21 is adapted to be

T ϊΪE

-£ - pierced for gas flow through the valve structure as by an externally operated screw 22 adapted to puncture or eliminate disc 21 at the screw shank end 23 by finger manipulation of external screw knob 24. Fig. 3 shows disc 21 in process of being pierced or destroyed for valve opening.

Apparatus as above described is designed for throw- away purposes after a single use and to provide a constant flow of breathable atmosphere over a predetermined time period as hereinbefore stated from about 3 to about 7 minutes, preferably about 5 minutes. The gas supply source as above specified within a container of 20 cubic inch capacity and under an initial working pressure of about 1800 psi and with utilization of the chamber 16 having about a 15 cubic inch capacity will supply adequate air to maintain a breathable atmosphere for a wearer under normal or extended exertion for a 5 minute period. It is submitted that a- pressurized steel container of higher psi internal pressure and of smaller cubic capacity of employed would require a more complex and expensive valve and pressure-regulator assembly and as described in prior art cited herein under O\S. Pat. NO. 4,221,216.

As hereinbefore described, the apparatus functions by supplying and maintaining a breathable atmosphere within mask chamber 11a. A sufficient supply of air is available from gas bottle 14 to permit the wearer when rebreathing the air contained within the chamber 11a, to maintain a level of at least about 16-17% oxygen within said chamber over a period of 5 minutes. As air is introduced into chamber 11a, exhalation valves 17 in concert with filters 19 pro- vides a constant exhausting of air from the chamber 11a thereby maintaining a constant, slightly super-atmospheric pressure within said chamber. When use of pressurized gas is unnecessary and the apparatus is used solely for filter¬ ing toxic elements out of oxygenated ambient atmosphere, valves 17 alone function as exhausts for mask chamber 11a.

As is typical in devices adapted to perform similar functions as in the instant apparatus, chamber 11a may be

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maintained at a pressure of from 0=018 to about 0.036 psi above the surrounding atmosphere. Thus, gas supply valve structure 15 is designed to provide in conjunction with chamber 16 a conventional flow rate of about 10 liters per minute, and which has been deemed sufficient to equal the consumption of oxygen at a moderate exertion level such as ascending stairs or inclines of about 1.6 liters per minute. Pressurized gas bottle 14 is adapted to contain a •suitable source of breathable atmosphere and may comprise air or oxygen-enriched air having an elemental oxygen con¬ tent less than about 28% so as to be under oxygen levels which could readily ignite combustible materials. Or, in some applications it may be desirable to extend the usable period of the apparatus by providing a breathable atmosphere containing higher elemental oxygen contents. Thus, the invention contemplates the use of pure oxygen or oxygen con¬ tent within the bottle 14 at any level from 20.9 to 100%.

The preferred form of the invention as above described has been designed for functionality over a pre- determined time period as heretofore specified in emergency situations, for economy in cost of production to sustain its throw-away characte isitics after a single use, for its simple, convenient and easy application and safe use as by merely applying the mask 11 to the head of the wearer and puncturing the valve closure element 21 by screw 22. A further feature of the invention resides in the easy folding of the apparatus, easy accessibility and exposure in a room as on a wall or shelf and simple definition of directions for applying and activating the- apparatus. It is understood that minor changes and variations in the materials, assembly, integration, size, location of parts and pressures of gas utilized may all be resorted to without departing from the spirit of the invention and the scope of the appended claims.