Chemical solid state breathing fluid supply system

BACKGROUND OF THE INVENTION

The present invention relates to a breathing fluid supply system, and in particular, to an auxiliary breathing fluid supply system having a plurality of breathing masks and independently actuated chemical, solid state, breathing fluid generators disposed adjacent passenger and crew stations in a vessel such as an aircraft for emergency use in the event of cabin depressurization or otherwise.

Known breathing fluid supply systems having face masks for use at individual passenger and crew stations have a centrally located auxiliary breathing fluid supply, usually in the form of a pressurized reservoir or bottle, which depends on a series of conduits passing through the aircraft structure to transmit the breathing fluid to the face masks at the various individual stations. This type of system requires a large number of valves and seals and constant maintenance if the system is to be reliable and operational at all times. Any leak or rupture in the reservoir or the conduits creates a potential hazard in the event of a fire whether the aircraft be in flight or merely stationary on the ground.

SUMMARY OF THE INVENTION

It is a primary object of the present invention to provide a breathing fluid supply system having a plurality of self-contained breathing fluid sources for providing breathing fluid to a plurality of associated individual crew and passenger stations in an aircraft or the like, wherein breathing fluid communication between stations is eliminated. This is accomplished by the present invention which provides a chemical, solid state, breathing fluid generator and one or more masks at each station, the breathing fluid generator at each station being operable independently of the generators at other stations.

It is another object of the present invention to provide a breathing fluid supply system having the foregoing characteristics wherein the breathing fluid generator at each station must be positively actuated by a user thereof at that station. To this end, the present invention provides a housing carrying the breathing fluid generator and one or more breathing masks, the breathing mask or masks being attached to the actuator of the breathing fluid generator whereby separating movement of one of the masks from the actuator actuates the generator to provide breathing fluid to the masks.

It is still another object of the present invention to provide the foregoing in a breathing fluid supply system which is highly reliable and requires little or no maintenance.

In one aspect thereof, the present invention is characterized by a housing, a chemical solid state breathing fluid generator mounted in the housing, a face mask carried by the housing and adapted to provide breathing fluid to a user thereof, a flexible conduit connecting between the face mask and breathing fluid generator, means providing for the removal of the face mask from the housing, actuating means for the breathing fluid generator, and means connecting the face mask with the actuating means and responsive to separating movement therebetween to actuate the generator and provide breathing fluid through the conduit to the face mask.

The foregoing and other objects, advantages and characterizing features of the breathing fluid supply system of the present invention are pointed out in the following detailed description of a typical embodiment thereof considered in conjunction with the accompanying drawings depicting the same wherein like numerals represent like parts throughout the various views.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 2 is a schematic illustration of a control circuit for use with the breathing fluid supply system of FIG. 1, one of the generator or mask housings being shown in cross section;

FIG. 3 is enlarged cross-sectional view of one of the 5 breathing fluid generators; and

FIG. 4 is a transverse cross-sectional view, on an enlarged scale, of a generator and mask housing.

DESCRIPTION OF THE PREFERRED EMBODIMENT

There is schematically illustrated in FIG. 1 one form of a breathing fluid supply system, generally indicated 10, arranged in accordance with the present invention and located in a vessel, in this instance, an aircraft indicated at 11. A plu15 rality of housings 12, each containing a chemical solid state breathing fluid generator 13 and a plurality of face masks 14 (FIGS. 2 and 4) are located in aircraft 11 above various passenger stations. The passenger stations can be the usual transverse rows of seats arranged on opposite sides of an aisle in a 20 passenger compartment 15 located behind the crew compartment 16 in the forward part of the aircraft, the aircraft structure comprising the seats and aisles not being shown. It is apparent that one or more similar housings 12 also can be provided in crew compartment 16, and elsewhere although these 25 are not shown for convenience in illustration. Each housing 12 can serve a plurality of passengers at each station, the illustrated form providing face masks for three individuals at a station although a greater or a lesser number of face masks obviously could be provided at each station, depending upon the number of persons to be served.

Referring to FIGS. 2 and 4, a generator 13 is s fixed within and at one side of each housing 12 by a suitable mounting bracket 18 and has a fluid outlet 19 communicating with a cylindrical manifold 20. Manifold 20 has a plurality of outlet nipples 21 connecting with the ends of a like number of flexible fluid supply conduits 22, the other ends of conduits 22 connecting with the several face masks 14. In the illustrated form, each mask 14 comprises a truncated hollow cone of 40 suitable material such as synthetic sponge rubber open through its larger end which is adapted to be held against the face. The smaller end of each mask 14 is closed, and is connected to the other end of an associated conduit 22 whereby breathing fluid is provided through conduit 22 into the mask. 45 Other face masks, including masks equipped with demand regulators, can be utilized in the present invention although the illustrated form is preferred in view of its low cost and the limited time during which it is intended to be used.

Each housing 12 has a door or shelf 24 suitably pivoted at 5° 25 for swinging movement between the closed position shown in FIG. 4 and an open position as illustrated in broken lines therein. Each door 24 forms a portion of the underside of its housing 12 in laterally offset relation to generator 13 and manifold 20 therein. In the normal, inoperative condition of ⁵⁵ the fluid supply system, masks 14 and their associated coiled flexible conduits 22 rest freely on shelf 24, in stored position within housing 12. Each shelf 24 is held in closed position by a solenoid operated latch generally indicated at 26 (Fig. 4) the operation of which will now be described.

” To release door or shelf 24 and thus drop the masks 14 supported thereby into position for use at each passenger station, latches 26 are automatically actuated in response to a drop in the pressure within the aircraft below a predetermined pres05 sure. The pressure is sensed by a pair of aneroids 27 and 28 housed at 29 and 30 in the crew and passenger compartments 16 and 15, respectively. Aneroids 27 and 28 can be conventional in design, and are arranged in controlling relation to a pair of switches 31 and 32, respectively which are arranged in 70 parallel controlling relation to an energizing circuit for solenoids 33 which operate the associated latches 26. A current

FIG. 1 is a fragmentary, schematic layout of a breathing fluid supply system arranged in accordance with the present invention within the fuselage of an aircraft shown in cross section and partly broken away;

source is provided at 34 and actuation of either switch 31 or 32 in response to the sensing of a predetermined pressure by its corresponding aneroid 27 and 28 completes an energizing 75 circuit with all of the solenoids 33 to release latches 26

3,536,070 whereby all of the doors 24 freely pivot downwardly. For example, should the pressure in passenger compartment 15 drop below the predetermined pressure, aneroid 28 operates to close switch 32 and complete a circuit including current source 34 and leads 35, 36, 37, 38 and 39 to energize solenoids 33 and thereby release door 24. Should the pressure in pilot compartment 16 drop below the predetermined pressure, aneroid 27 operates to close switch 31 and complete a circuit including current source 34 and leads 40, 41, 42, 37, 38 and 39 to likewise energize solenoids 33 and thereby release doors 24.

An indicator light 44 and a manually operated switch 45 are included in the control circuit and are located in pilot compartment 16. Thus the pilot can manually close switch 45 to energize a circuit including current source 34 and leads 40, 37, 38 and 39 to actuate solenoids 33 and release doors 24. Whenever the control circuit is energized, either manually or automatically by either aneroid, indicator light 44 is energized via lead 46 to give visual warning to the pilot that the pressure within the aircraft has dropped below the predetermined pressure and that auxiliary breathing masks have dropped into the passenger stations.

Upon release of its associated latch 26, shelf 24 pivots downwardly under the influence of gravity to an open position as indicated by broken lines in FIG. 4, and masks 14 will freely fall and drop down from housing 12 into positions within reach of individuals at associated passenger stations. The free fall of masks 14 is arrested by lanyards 47 which connect each of the masks 14 with an ignitor pin 48 on the generator 13 associated with those masks, the lanyards 47 threading through a common eyelet 49 fixed to housing 12 to provide substantially direct axial withdrawing force to pin 48. Lanyards 47 thus support masks 14 from housing 12 within reach of individuals at the passenger stations and, in this position, hang taut under the weight of masks 13 while conduits 22 remain slack. The force applied to ignitor pin 48 via lanyards 47 by the arrestment of the masks is insufficient to overcome the resistance offered by pin 48 and withdraw it from ignitor assembly 50. Further traction on lanyard 47, as by the positive force of an individual pulling downwardly on one of masks 14, is required to withdraw pin 48 and actuate generator 13.

Breathing fluid generator 13 (FIG. 3) comprises a metal or ceramic canister 51 having a suitable interior lining of filter and insulating material 52, such as fibreglass. Canister 51 contains an oxygen liberating composition, generally designated 53, such as a chlorate or a perchlorate which generates oxygen on combustion, a metal powder such as iron or carbon for burning and supplying part of the heat needed for combustion, a binder such as inorganic glass fibers for holding the mass together and aiding in the even decomposition of the chlorate or perchlorate, and a peroxide for chemically eliminating the traces of chlorine gas released during thermal breakdown of the chlorate or perchlorate. Such oxygen candle compositions are known per se and form no part of the present invention.

Composition 53 is pressed molded or cast to form a consolidated body having a substantially cylindrical shape, as illustrated, and has an ignition section 54 formed within a recess 55 on an end face thereof, ignition section 54 comprising the foregoing composition enriched with metal powder, such as iron, to provide a concentrated area of intense heat when ignited. A filter screen 56 separates composition 53, ignition section 54 and insulation and filter material 52 from an outlet nipple 57 having a lateral outlet orifice 58. Outlet nipple 57 houses ingitor assembly 50 which can be of the well known percussion fired squib type operable in response to the withdrawal of ignitor pin 48, this being conventional as typified by the bouchon of a hand grenade. The details of ignitor assembly 50 are known, form no part per se of the present invention and accordingly require no further description. Electrical or other conventional oxygen candle ignitors also can be used. Thus, by withdrawing pin 48, ignitor assembly 50 ignites ignition section 54 which in turn ignites oxygen generating composition 52.

The operation is believed to be apparent from the foregoing description. Latches 26 operate automatically in response to de-pressurization within the aircraft or manually to release doors 24 whereby masks 14 gravitate downwardly to positions 5 where they are suspended by lanyards 47 within reach of individuals in the crew and passenger stations. Pulling downwardly on any of the masks 14 and/or attached lanyards 47 withdraws pin 48 from ignition assembly 50, of the generator 13 associated with those masks. This ignites composition ¹⁰ 53 to thereby generate oxygen which passes through insulator and filter 52, screen 56, orifice 58 in outlet nipple 57, outlet conduit 19, into manifold 20 and out through nipples 21 into each of the masks via conduits 22.

It is seen that the individual generators 13 are indepen¹⁵ dently actuated by individuals at the various stations and that if one or more stations are unoccupied, the generator at that station or stations remains unactuated and ready for future use. Moreover, oxygen generators 13 at each station can be 20 actuated by simple traction on any one of masks 14 at that station whereby oxygen will flow to all of the masks 14 at that station. It is apparent that sequentially actuated generators or a single generator having sequentially actuated generating stages could also be utilized at each station whereby succes25 sive quantities of oxygen could be provided by successively pulling lanyards 47 to thereby provide for multiple emergency situations.

Thus, my invention fully accomplishes its intended objects. Oxygen is generated at each station independently of the 30 others, as it is needed. There is no piping of oxygen between stations, or to the stations from a remote source, and the problems inherent in the storage of oxygen under pressure are avoided.