US2444029A - Emergency oxygen supply - Google Patents

Description

June 29, 1948. w. J. BOWEN EME RGENCY OXYGEN SUPPLY Filed July 10, 1946 Patented June 29, 1948 uNiTso STATES PATENT orrica EMERGENCY OXYGEN SUPPLY William J. Bowen, Chevy Chase, Md.

Application July 10, 1946, Serial No. 682,523

(Granted under the act of March a, 1883, as amended April so, 192s; 310 o. a. 757) 3 Claims.

This invention relates to a method and apparatus for supplying oxygen. More specifically, this invention relates to a method and apparatus for quickly supplying oxygen for respiratory purposes during emergencies when the surrounding atmosphere either contains non-respirable gases or is lacking an adequate supply of oxygen.-

Although of obvious use in many other types of rescue work, such as mine rescue or fire fighting rescue work, my invention is of particular value in emergencies connected with the operation of aircraft exhaustion or failure of the airplanes .l" 'uiar oxygen supply may occur, or where the pilot may be required to bail out of the airplane at high altitudes. In such emergencies, a substantially instantaneous supply of oxygen is required. Other requirements are that the apparatus be foolproof and simple t operate, be substantially independent of variations in the pressure and temperature characteristics of the surrounding atmosphere, and be light and compact. Maintenance and recharging of the equipment should be simple and should not require extensive facilities.

Accordingly it is among the objects of my invention to provide a method and apparatus which will assure an instantaneous supply of oxygen in an emergency.

A further object of my invention is to devise an apparatus which will be foolproof and simple to operate, requiring not more than two operations.

Still another object is to make my method and apparatus operable under the extremes of temperatures and pressures encountered in the operation of aircraft.

A further object of my invention is to make my apparatus light and compact, and in part accomplishing this by utilizing equipment which the aircraft pilot must normally carry for other purposes.

Still another object of my invention is to provide a device which can be readily maintained and recharged by service personnel without the use of special and extensive equipment. These and other objects of my invention will be apparent from my specification.

In practicing my method, I add a small amount of water to a metallic peroxide, preferably a potassium peroxide commonly known to the art as KOX, in a closed rebreather system. The closed rebreather system may consist of but is not necessarily limited to a breathing mask, a canister containing the metallic peroxide and a breathing bag, connected in series in that sequence. The water may be either pure, or used as a. solvent. The

water will react with the peroxide and result in an immediate release of aburst of oxygen for breathing. The heating of the metallic peroxide by the reaction will also insure the immediate removal of CO2 and water vapor from the exhaled air regardless of the extremes of temperatureapt to be encountered in service. This water vapor and CO2 will react in turn with the metallic peroxide to continue a production of oxygen at the rate suflicient for physiological needs.

In a preferred modification of my invention, I employ anaqueous salt solution such as Caclz, in lieu of pure water. Theaddition of 02.012 to the water improves the reaction with KOX by producing a smoother and more prolonged release of the oxygen; decreasing the danger of the solution freezing either during storage or while in service, since the freezing point of the water is lowered by the salt; diminishing thealkali vapors which are given ofi by the more explosive action of pure water-and the KOX. These alkali vapors when inhaled in large quantities may cause coughing which, with inexperienced persons, might result in abandonment of the breathing apparatus.

For use with my emergency aircraft oxygen supply apparatus, I preferably employ grams of KOX to which I add 4 cc. of aqueous CaClz solution (30% concentration). The reaction produces almost immediately from 1.0 to 2.3 liters (S. T. P.) of oxygen. This volume is sufflcient for the immediate needs of the user at the altitude for which my apparatus is designed. The water vapor and'COz of the exhaled air, reacting in turn with the KOX, would in this case ordinaril continue to produce oxygen for approximately 20 minutes, and at a rate sufficient both to meet the users physiological needs and to compensate for the compression of the gas during descent, where the pilot or airplane passenger has had to bail out of his plane.

My apparatus is uniquely designed to make use of my method to meet the requirements noted previously for an emergency aircraft oxy en supply system, as will be made clear hereinafter and with reference to the drawings in which Fig. 1 is a partially sectioned view showing my apparatus hookup; l V

Fig. 2 is a. cross-sectional detail view ofthe plunger and glass capsule assembly enclosed within my oxygen canister; and

Fig. 3 is a cross-sectional detail view of my oxygen breather mask converter. ,1

Referring to Fig. 1, my apparatus comprises a closed rebreather system in which an oxygen I supply canister i is connected to a breather mask 2 by flexible tube 3, and to a breathing bag I by connection 6. The breathing bag is preferably constituted by the front compartment of a standard Navy pneumatic life-vest, partially shown in my drawing. The use of the life-vest for this purpose saves the weight and bulk entailed in the use of a separate breathing bag. The oxygen breather mask 2 is preferably a standard oxygen mask converted into a rebreather mask by a manually operable device for closing the exhaled air outlet port from the mask leaving the inlet port open. The canister connection 5 is a fixed connection, making the canister in effect a life-vest accessory and eliminating the necessity for connecting the canister'to the life-vest when use of the emergency oxygen supply apparatus is desired. The canister connection 8 to the breather mask is the flexible connection conventionally employed to connect the breather mask to the main aircraft oxygen supply system, and is provided with a quick-disconnect fitting at the end remote from the breather mask. This quick-disconnect fitting permits the occupant of the aircraft to quickly disconnect the flexible tube from the main aircraft oxygen supply system and connect the tube to the canister I, when use of the emergency equipment is desired.

As hereinafter described, the emergency apparatus is set into operation when the user disconnects flexible tube 3 from the main oxygen supply system, connects it to canister i, and manual- 1y closes the outlet port from the breather mask. on inhalation, oxygen is supplied to the inlet port of the mask from canister i through tube 3. On exhalation, C: and water vapor are discharged from the mask to the inlet port of the canister I through tube 8. The breathing bag 4 serves as an expansion chamber for the apparatus.

Referring to Figs. 1 and 2 for the details of my canister construction, the canister i comprises an outer cylindrical shell 6 approximately 5 inches long and 2 inches in diameter. The shape of the shell is a matter of choice and the approximate dimensions noted above are described herein only to indicate the compactness attainable. The shell 6 is partially filled with KOX denoted by I. The CaCh solution is retained in a frangible glass capsule 8 which is held in place in chamber9 by a capsule retainer. This retainer consists of a female portion ill open at its lower end, and a male portion Ii threadedly engaging portion ill for ease of assembly around the glass capsule. The male portion ii of the capsule retainer is provided with a longitudinal bore l2 opening into the capsule chamber 9. The walls of the bore I! serve as a guide to pointed plunger I3. The capsule retainer is threadediy engaged in an opening in the bottom of tubular shield M. This tubular shield is perforated by two circumferential rows of holes I5 drilled into the shield. Slidably mounted within shield I4 is valve ii to the lower side of which is attached the downwardly extending plunger Hi.

The upper face of gasket il seats against the lower surface of fitting i8. Fitting I8 is a conventional female member of a quick-disconnect fitting, which is engaged by a male member I! attached to flexible tube 3 connecting the breather mask 2 to the canister member I, and is supported within an opening in the upper surface of shell 6 by a cover plate and screws 2|. The lower surface of cover plate 20 supports an annular c01- lar 22 threadedly engaging shield ll. Aflixed to the upper surface of valve i6 is a wire basket 23 which extends upwardly within member i8 to a point just below the top of the member. Valve I. is retained in seated position by spring 24 bearing against the lower surface of valve II and the upper surface of capsule retainer member i I. I

The opening 25 in the lower portion of shell 8 is provided with a threaded female coupling 28, gasket 21. and removable screen 28. The male member for insertion into coupling 26 comprises a bored and threaded element 28 to which is affixed a collar 30. A second collar II is adapted to be slipped over element 29 and be advanced toward collar 30 by nut 32. The element protrudes through a hole in the breathing bag with collar 30 located inside the bag. Collar 8| is located on the outside of the bag, so that rotation of nut 32 will clamp the peripheral edges 33 of the hole in the breathing bag between collars iii and Ii, providing a sealed connection. Spreader I4 is afilxed to the a when the capsule is broken at altitude, since the bubble explosively shatters the glass when the capsule is broken, permitting rapid dissipation of the CaClz solution through the KOX. The capacity of the glass capsule, as noted previously is 4 cc. of CaCls solution. The canister contains 75 grams of KOX. Greater or lesser amounts of each may be used, depending on the desired capacity for the equipment.

Referring to Figs. 1 and 3, the-conventional oxygen breather mask 2 preferably employed in my'apparatus incorporates an oxygen inlet port 35 in circuit with flexible tube 3, and an exhaust port 36 opening to the atmosphere. Inserted in the exhaust port is a conventional check valve 31 having a flexible rubber flap valve 38 which opens on exhalation. My breather mask converter device is manually operable to retain the flap valve closed at all times when the emergency oxygen supply apparatus is in use, thus convertin the mask into a rebreather mask. The converter device consists Of a cap 39, preferably plastic, which is mounted on shaft 40 and is slidably supported in the base I. The base is provided with a splined lower portion 4!. Attached to the end of the shaft, remote from the plastic cap. is a knurled knob 43 for manually operating the shaft. A detent pin 44 is fixed in the shaft. The plastic cap is spring biased away from the base Si by spring 45, which is seated within a cylindrical bore located in the upper portion of the base.

The converter device is fitted into a hole in the mask, the peripheral edges of the hole fitting into an annular slot 86 cut into the exterior surface of base ii.

In operationlthe plastic cap 39 is retained away from flap valve 38 by pin 46 hearing against the lower surface of base ll. When operation of the emergency oxygen supply is desired, and the flexible tube 3 has been connected to the canister i, knurled knob 43 is rotated until detent pin 46 is aligned with spline 42. Spring 45 is now free to force plastic cap 39 against the flap valve 88, the spring force being sufflcient to retain the flap valve closed against the pressure within the mask.

As described above, my apparatus provides an instantaneous supply of oxygen, requiring only two simple manual operations to set it into operation. These operations comprise the attachment of flexible tube 3 to the canister I, and rotation of knurled knob 43 to release plastic cap 39 for closing flap valve 38. Extremes of temperatures and pressures do not afiect the operation of my device. The entire apparatus is light and compact, so that there will be a minimum of interference with pilot's or passenger's other functions during an emergency. Elaborate facilities for recharging the canister are not required, as would be the case if bottles of compressed oxygen were employed, since replacement of the KOX and the insertion of a fresh glass capsule can be performed with ease by simple tools.

Although I have described an apparatus specifically designed for aircraft flight operation, my

,method for generating instantaneous and continuous quantities of oxygen can be employed for other purposes such as fire-fiighting rescue work, mine rescue work, underwater escape from ditched planes and other types of rescue work. Suitable modifications to my apparatus, to fit the particular service requirements of my apparatus can be made within the scope of my invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is: l. A rebreather system for supplying oxygen during emergencies comprising: a breather mask; 1

a breathing bag; a container means connected to and interposed between said breather mask and breathing bag, said means enclosing a quantity of potassium peroxide; and means associated with said container means for introducing aquantity of an aqueous solution of CaCl: to said potassium peroxide whereby an instantaneous supply of oxygen will be generated and CO: and water vapors will be absorbed readily and result in continued generation of oxygen.

2. For use in an emergency rebreather system having a breather mask and a breathing bag, an oxygen canister for supplying oxygen for inhalation and for absorbing exhaled CO: and water vapor comprising: a container member having an upper port and a lower port; a female quick-disconnect fitting in the upper port adapted to acoommodate a male disconnect fitting for connection to the breathing mask; a fitting in the lower port adapted for connection to the breathing bag; a quantity of alkaline metal peroxide gible glass capsule containing a quantity of water;

means securing said glass capsule within the container member and adapted to permit ready replacement of said capsule; plunger means slidably supported within said capsule and adapted to break said capsule when brought in contact therewith; and plunger actuating means extending into said quick-disconnect fitting and connected to said plunger means whereby insertion of said male disconnect fitting into said female disconnect fitting will result in breaking of the glass capsule to provide an instantaneous supply of oxygen and ready absorption of CO: and water vapors for continued generation of oxygen.

3. For use in an oxygen rebreather system, a rebreather mask converter for an oxygen mask having an unrestricted oxygen inlet port and a C02 and water vapor outlet port controlled by an outwardly opening flap valve, comprising: a base portion adapted to be afiixed to said oxygen mask opposite said outlet port and having a longitudinal bore, a portion of which is cut to form a spline; a shaft extending through said bore, one end of said shaft being attached to a manually operable knob and the other end attached to a cap; a spring element around said shaft and interposed between said cap and said base;

a pin extending through said shaft and perpendicular to the longitudinal axis thereof, said pin cooperating with the spline in said supporting base to form a detent means whereby manipulation of the manually operable knob to render the detent means inoperable will result in engagement of the cap and flap valve to retain the latter closed, and manipulation of the knob to render the detent means operable will result in disengagement of the cap from the flap valve permitting normal operation of the valve.

' J. BOWEN.

REFERENCES CITED The following references are of record in the file of this patent:

Images