Aircraft passenger oxygen mask with closed circuit concept

Abstract

The invention relates to an aircraft passenger emergency oxygen supply device comprising an oxygen mask having a mask body with a first opening for covering mouth and/or nose of the passenger, a second opening connecting said first opening with a source of oxygen, a passenger service unit, a connecting line fixed to the oxygen mask body at one end and having a coupling at the other end for coupling said line to the passenger service unit wherein a chemical reaction component is comprised in the oxygen mask.

Claims

1. Aircraft passenger emergency oxygen supply device, comprising: an oxygen mask having a mask body with an oxygen-delivery opening for covering a mouth and/or a nose of a passenger, a first opening connecting said oxygen-delivery opening with a source of oxygen, the first opening comprising a control unit with an inhaling valve, a passenger service unit, a connecting line fixed to the mask body at a first end of the connecting line and having a coupling at a second end for coupling said connecting line to the passenger service unit, the connecting line comprising a coupling element, a chemical reaction component connected to the mask body for receiving exhaled air out of said mask body via a second opening, converting said exhaled air into supply air by a chemical reaction between said exhaled air and a chemical reaction material comprised in said chemical reaction component to produce oxygen-enriched air and for supplying said oxygen-enriched air as the supply air to the mask body, a flexible buffer connected to the mask body via the chemical reaction component, an exhaling valve interconnected between the chemical reaction component and the flexible buffer a second inhaling valve interconnected between the mask body and the flexible buffer, and a third opening with an integrated check valve, wherein: the inhaling valve opens when pressure from a first exhaling cycle is applied to an inside of the mask body and is below a predetermined threshold, wherein opening of the inhaling valve provides oxygen from the source of oxygen through the oxygen delivery opening, the integrated check valve opens when a vacuum from a first inhaling cycle is applied to the inside of the mask body, wherein opening of the integrated check valve draws ambient air through the check valve into the inside of the mask body, the integrated check valve closes when pressure from a second exhaling cycle is applied to the inside of the mask body that is above the predetermined threshold, and wherein closing of the integrated check valve draws the exhaled air through the second opening into the chemical reaction component, the exhaling valve opens if a pressure in the chemical reaction component is higher than in the flexible buffer and closes if a pressure in the flexible buffer is higher than in the oxygen mask, the second inhaling valve opens if a pressure in the flexible buffer is higher than in the oxygen mask and closes if a pressure in the chemical reaction component is higher than in the flexible buffer, and the coupling element is adapted to maintain the connection provided by the connecting line and the coupling element between the oxygen mask and the passenger service unit if a predetermined pulling force along the connecting line is not exceeded, and to release the connection provided by the connecting line and the coupling element between the oxygen mask and the passenger service unit if the predetermined pulling force along the connecting line is exceeded.

2. Oxygen supply device according to claim 1, wherein said connecting line is an oxygen supply line for connecting said mask body with the source of oxygen in said passenger service unit, wherein said source of oxygen is a chemical oxygen generator or a pressurized oxygen tank.

3. Oxygen supply device according to claim 1, wherein said connecting line is a wire or rope for connecting said mask body with a fixing point in said passenger service unit, wherein said oxygen mask further comprises a source of oxygen, wherein said source of oxygen is a chemical oxygen generator or a pressurized oxygen tank.

4. Oxygen supply device according to claim 1, wherein said coupling element is connected to a starter unit integrated in said passenger service unit and adapted to start oxygen supply out of said source of oxygen, wherein said starter unit is adapted to start an oxygen supply out of said source of oxygen if a pulling force along the connecting line exceeds a lower pulling force start level, said lower pulling force start level being below the predetermined pulling force.

5. Oxygen supply device according to claim 1, wherein said coupling element is connected to a starter unit integrated in said oxygen mask and adapted to start oxygen supply out of said source of oxygen, wherein said starter unit is adapted to start oxygen supply out of said source of oxygen if a pulling force along the connecting line exceeds a lower pulling force start level, said lower pulling force start level being below the predetermined lower pulling force.

6. Oxygen supply device according to claim 1, wherein said chemical reaction component is integral with said oxygen mask.

7. Oxygen supply device according to claim 1, wherein the chemical reaction material is KO.sub.2.

8. Oxygen supply device according to claim 1, wherein the control unit further comprises a starting switch coupled to said connecting line and enabled by a pulling force along said connecting line, wherein said control unit is connected to the source of oxygen and adapted to initiate supply out of said source of oxygen if said starting switch is enabled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the invention are shown in the figures.

(2) FIG. 1 shows a simplified schematical set up of a first embodiment of an oxygen device according to the invention,

(3) FIG. 1a the embodiment shown in FIG. 1 in a released condition,

(4) FIG. 2 shows a simplified schematical set up of a second embodiment of an oxygen device according to the invention,

(5) FIG. 2a the embodiment shown in FIG. 2 in a released condition.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) FIGS. 1 and 1a show a first embodiment of the invention in an emergency situation. An oxygen mask 1 has dropped out of a passenger service unit 2 which is arranged as a sealing compartment inside an aircraft cabin. The passenger service unit 2 comprises a storing space 20 wherein the oxygen mask 1 can be stored in regular flight condition. A cover lid 11 on the bottom side of said storing space can be released and opened to the outside of the storing space thus opening the storing space in the direction of gravity thus effecting a falling out of the oxygen mask 1.

(7) The oxygen mask is connected to the passenger service unit 2 via a connecting line 20, 21. Said connecting line comprises a tether 21 and a flexible tube 20. The flexible tube is connected on the upper and to a chemical oxygen generator 30 and arranged in the passenger service unit. The downside end of the flexible tube is connected to a coupling element 40.

(8) The downside end of the tether 21 is connected to the coupling element, too. The upside end of the tether 21 is connected to a releasable pin 31 which is part of a starter unit 32 attached to the chemical oxygen generator 30.

(9) The coupling element 40 is integral with a control unit 50 which is attached to a mask body 60.

(10) The mask body 60 comprises a large opening 61 for covering mouth and nose of a passenger. Further, a first small opening 62 is provided in said mask body 60, said first opening 62 being in fluid connection with the flexible hose 20 via said control unit 50 and said coupling element 40. Further, a second small opening 63 is present in the mask body 60. Said second opening 63 connects the interior of the mask body 60 with a chemical reaction component 70. Said chemical reaction component 70 comprises a first opening in fluid connection with the mask body 60 and a second opening 72 in fluid connection with a flexible bladder 80.

(11) Finally, the mask body 60 comprises a third small opening 64 with integrated check valve 65.

(12) The function of the emergency oxygen device according to the first embodiment is explained in detail with reference to FIGS. 1, 1a now. In regular flight condition the oxygen mask is completely stored in the storing space 10 of the passenger service unit. In case of an emergency situation requiring supply of oxygen to the passenger the cover lid is released and opened and the oxygen mask 1 falls out of the storing space to be presented to the passenger. The tether 21 holds the oxygen mask 1 in a predetermined position wherein it is easy for the passenger to grasp the oxygen mask.

(13) The passenger will grasp the oxygen mask 1 and pull it downwards with a first pulling force. This first pulling force will affect release of the releasable pin 31 out of the starter unit 32. This pulling out of the pin 31 out of the starter unit 32 will effect a spark which activates the chemical oxygen generator to produce oxygen. The chemical oxygen generator 30 comprises oxygen in a chemically bound form selected from the groups of inorganic superoxides, chlorates, perchlorates and ozonides. Preferably, the chemical oxygen generator comprises sodium chlorate as a main ingredient. The oxygen produced in an exothermic reaction in the chemical oxygen generator is directed to the mask body via the flexible hose 20. The control unit 50 comprises an inhaling valve which opens if the passenger applies a low pressure to the inside of the mask body 60 and thus a partition of oxygen is provided to the mouth and nose of the passenger via the opening 61. This partition corresponds to an amount of oxygen produced by the chemical oxygen generator in the foregoing exhaling cycle. As soon as this amount of oxygen is exhausted the passenger may apply a larger vacuum to the inside of the mask body affecting an opening of the check valve 65. By this, ambient air is drawn into the mask body to allow the passenger to complete the inhaling cycle. This ambient air may have a low oxygen content but since the first partition of concentrated oxygen is delivered into the lung of the passenger this second partition of pure oxygen air only serves to fill the mouth and respiratory ducts of the passenger and does not require to be rich of oxygen herefor.

(14) After having inhaled this first and second partition through said first opening 62 and said third opening 64 the passenger will exhale the air. If the passenger applies a positive pressure to the inside of the mask body in this exhaling cycle the valve unit comprised in the control unit 50 will close and the check valve 65 will close. The exhaling air will thus flow through the second opening 63 into the chemical reaction component 70. The chemical reaction component 70 comprises potassium dioxide. This potassium dioxide reacts with the carbon dioxide of the exhaled air in an exothermic reaction as follows:
4KO.sub.2+2CO.sub.2=2K.sub.2CO.sub.3+3O.sub.2.

(15) Thus, carbon dioxide contained in the exhaled air is chemically bound in the chemical reaction component and oxygen is produces therein. It is an important aspect of the chemical reaction material comprised in the chemical reaction component to have the ability to bind carbon dioxide out of the exhaled air and to produce oxygen out of the exhaled air at the same time.

(16) It is to be understood that other materials might be used as a chemical reaction component as well. This may comprise lithiumhydroxide and/or breathing lime or calcium carbonate. In particular, the chemical reaction component may be adapted to extract carbondioxide out of the exhaled air only but to not produce additional oxygen. Such a chemical reaction component may be used in connection with a small oxygen source like e.g. a small oxygen pressure tank or a small chemical oxygen generator. Using such chemical reaction component will allow the passenger to participate in evacuation process of an aircraft without the risk of fainting due to carbon dioxide intoxication.

(17) After having passed through the chemical reaction component 70 from the first opening 71 to the second opening 72 the oxygen enriched and carbon dioxide depleted exhaled air flows into the flexible bladder 80 and is temporarily stored therein. The flexible bladder may be dimensioned in such a way to take up the whole exhaled air out of one breathing cycle of the passenger. Alternatively, the flexible bladder may be dimensioned in such a way to take up only a part of said exhaled air whereas a remaining part is exhaled through an exhale valve (not shown) into the ambient air inside the cabin. The check valve 65 may be adapted to open upon a high pressure inside the oxygen mask and thus allow the remaining second part of the exhaling air volume to pass into the ambient air.

(18) In the subsequent breathing cycle the passenger will take up first the oxygen produced by the chemical oxygen generator during the foregoing exhaling cycle. Hereafter the passenger will take up the exhaled air out of the flexible bladder 80. During this taking up of the exhaled air the exhaled air passes again through the chemical reaction component 70 thus being further enriched with oxygen and depleted from carbon dioxide.

(19) The chemical oxygen generator 30 is dimensioned to provide oxygen for less than one minute. It is to be understood, that the chemical oxygen generator may be adapted to supply oxygen for a shorter period of time like e.g. only 30 or 45 seconds and for a longer period of time like e.g. 1.5 minutes, 2 minutes or 5 minutes depending on the configuration of the system components. It is usually desired that after such time period the chemical reaction in the chemical reaction component 70 has fully started and the passenger will receive sufficient oxygen out of the chemical reaction in the chemical reaction component 70 to maintain his vital functions.

(20) Hereafter, the passenger may pull again the oxygen mask 1 to himself thus affecting a second pulling force on the coupling element 40. This second pulling force will affect a release of the coupling element and thus cut the last connection of the oxygen mask 1 to the passenger service unit 2 which was present by the flexible hose. The passenger may then move inside the cabin with the oxygen mask 1 being permanently supplied with oxygen enriched and carbon dioxide depleted air. In particular, the passenger may use his mask during evacuation of the passengers to the outside of the aircraft cabin after landing of the aircraft.

(21) FIGS. 2 and 2a show a second embodiment of the emergency oxygen device according to the invention. This second embodiment comprises an oxygen mask 101 having a mask body 160 with a large first opening 161 and small third opening 163 connecting the interior of said mask body 160 to a chemical reaction component 170 which is connected to a flexible bladder 180. These components correspond to the mask body 60 with the first opening 61, the third opening 63, the chemical reaction component 70 and the flexible bladder 80 of the first embodiment in design and function.

(22) Further, a force opening 164 with a check valve 165 is provided at the mask body 160 corresponding to the force opening 64 with check valve 65 of the first embodiment in design and function.

(23) As an important difference to the first embodiment the emergency oxygen device according to the second embodiment comprises a source of oxygen which is part of the oxygen mask 101. Said source of oxygen is a chemical oxygen generator 130 with integrated control unit 150 and a starter unit 132 attached thereto. The chemical oxygen generator 130 is directly attached to the mask body 160. The starter unit 132 is connected via releasable pin 131 to a tether 120 at one end of said tether. The other end of said tether 120 is connected to a fixing point inside the passenger service unit 102.

(24) The function of the second embodiment is explained with reference to FIGS. 2, 2a in detail now:

(25) In regular flight condition the oxygen mask 101 is completely stored in the passenger service unit 102. IN an emergency situation a cover lid 111 is opened and the oxygen mask falls out of the passenger service unit 102. The oxygen mask 101 is hold by the tether 120 and presented to the passenger to allow easy grasping of the oxygen mask. In this situation the passenger may decide or be instructed to start the oxygen flow at a certain time.

(26) If the passenger wishes to receive oxygen out of the oxygen mask 101 he will grasp the oxygen mask and pull it towards himself. In this case a pulling force is applied to the tether 120 affecting the releasable pin 131 to be pulled out of the coupling element 140 which is part of the starter unit 132. This pulling out action will ignite the chemical oxygen generator 130 and initiate a chemical reaction inside said chemical oxygen generator wherein oxygen is produced out of sodium chlorate.

(27) The passenger will inhale the so produces oxygen out of the chemical oxygen generator 130 through the control unit 150 as a first partition of the inhaled air volume. This first partition of oxygen is produced during the foregoing exhaling cycle.

(28) If no more generated gaseous oxygen is present in the chemical oxygen generator 130 the check valve 165 will open and allow the passenger to draw a second partition of the inhaling air volume into the mask body and to fill the respiratory ducts, the mouth and the nose with said second partition. This second partition may have a pure oxygen content which does not affect the supply of oxygen for vital functions to the passenger.

(29) The chemical oxygen generator 130 is dimensioned to provide oxygen to the passenger for approximately 10-30 breathing cycles i.e. approximately one minute. Hereafter, the chemical reaction in the chemical reaction component 170 comprising potassium dioxide as described beforehand will have started completely and the passenger is supplied with oxygen enriched and carbon dioxide depleted air in a closed circuit.

(30) In the second embodiment a singular pulling force is required to initiate the supply of oxygen to the passenger out of the chemical oxygen generator 130 and to release the oxygen mask 101 from the tether 120 and thus from the passenger service unit 102 at the same time. Thus, the passenger may immediately leave his seat after he applied said pulling force and started the oxygen supply when using the second embodiment of the invention.