Patent Grant
10799726
This application claims the benefit of priority under 35 U.S.C. § 119 (a) and (b) to French patent application No. 1457491, filed Aug. 1, 2014, the entire contents of which are incorporated herein by reference.
Field of the Invention
The present invention relates to respiratory equipment. The invention relates more particularly to a full-hood respirator, notably for an aircraft.
Related Art
Full hood respirators are conventionally used onboard aeroplanes when the cabin atmosphere is vitiated (depressurised, smoke, chemical agents, etc).
This equipment must also notably allow the flight crew to tackle the problem, provide emergency assistance to the passengers and manage a potential evacuation of the aircraft.
The technical specifications for such devices are defined according to class of use (in-flight damage, protection against high-altitude hypoxia, emergency evacuation on the ground, etc).
Known respiratory equipment chiefly employs two types of oxygen source:
Hoods using the second type (pressurized oxygen reservoir associated with a calibrated orifice) thus generally contain a source of oxygen that allows an individual to be supplied with oxygen for fifteen minutes at a determined gas flow rate profile. This equipment may also in certain cases have a means of limiting the pressure inside the hood (for example an overpressure relief valve).
This technology using compressed oxygen in a sealed container associated with a calibrated orifice is safer. Nevertheless, certain users may have problems keeping the hood in place, particularly in stressful situations.
Known respiratory equipment generally uses either a fully transparent outer bag or systems that include buckles, straps or elastics for adjustment and holding in place.
Even if the transparent outer bags do not follow the rotations of the head, the user can nevertheless still see out. These transparent bags (of the Kapton® type) are, however, generally less fire resistant than opaque bags (of the coated Nomex® type). In addition, the ergonomics of these solutions is mediocre because the transparent bag “floats” on the user's head.
In the other known solution, buckles, straps or elastics are provided around the face and possibly the torso or bust of the user. In that case, the visor or viewing window follows the movements of the user's head but the straps and buckles take time to fit. Aside from the effort and loss of time spent fitting, this solution exhibits risks of oversight and incorrect adjustment. Ultimately, there is the risk that the device may not follow the movements of the head and/or the risk that it may hamper the user. It is an object of the present invention to alleviate all or some of the abovementioned disadvantages of the prior art.
To this end, the invention is directed to a hood comprising a fluidtight flexible bag intended to be slipped over the head of a user, the flexible bag being equipped with a transparent window and comprising, in its lower part, a source of oxygen-enriched gas and connected to an outlet orifice opening into the internal volume of the flexible bag. The hood further comprises a flexible suspension member arranged inside the flexible bag, the suspension member forming a hat or cap having a surface area smaller than the surface area of the outer flexible bag. At least part of the border of the suspension member is rigidly connected to the flexible bag. The suspension member is adapted and configured, when the hood is in the position of use, to rest on the top of the head of the user at a height somewhere between the base and the top of the hood. Moreover, some embodiments of the invention may comprise one or more of the following features:
The invention may also relate to any alternative device or method comprising any combination of the features hereinabove or hereinbelow.
Other specifics and advantages will become apparent from reading the following description given with reference to the figures in which:
The fluidtight flexible bag 2 is made for example of a fire retardant textile that is fluidtight or made to be fluidtight, for example of the type marketed under the Nomex® brand and coated with a fluidtight and fire retardant coating.
This bag 2 is intended to be slipped over the head of the user to isolate the head of the user from the external surroundings and incorporate the functionalities described hereinafter. In order to seal around the neck of the user and as described in
The flexible bag 2 preferably delimits a volume of around twenty litres (plus or minus five litres) around the head of the user and this may form a buffer volume of breathable gas that is sufficient to absorb spikes in the user's breathing. This inflated volume also makes it possible to absorb any mismatch between the decreasing output of an oxygen source 3 which delivers gas into the flexible bag 2 and the relatively constant oxygen requirements of the user.
For preference, the flexible bag 2 is equipped on its front face with a curved visor with an anti-fog treatment on its interior face and an anti-scratch treatment on its exterior face and forming a viewing window 20 for the user.
As may be seen in
The hood 1 comprises a source 3 of oxygen-enriched gas comprising an outlet orifice 7 opening into the internal volume of the bag 2, preferably in the rear part of the hood 1.
The oxygen reservoir or reservoirs 3 for example have a volume of between 0.20 and 0.4 litres and store gas at a pressure of between for example 150 and 200 bar. The calibrated outlet orifice 7 for example has a diameter of between 0.04 and 0.15 mm to release for example between twenty and sixty litres of oxygen over fifteen minutes. Each reservoir 3 may be made of a tube made of stainless steel or some other material having a diameter of, for example, between 30 and 50 mm.
For example, the oxygen-enriched gas source 3 is connected to the lower part (base) of the flexible bag 2 and is positioned around the user's neck.
The gas source 3 may comprise one or more pressurized-oxygen reservoirs, for example one or more curved tubular reservoirs associated where applicable with a filter cartridge intended to absorb the carbon dioxide exhaled by the user. The filter cartridge for example comprises an inlet communicating with the interior volume of the flexible bag 2 (preferably at the front of the hood 1) and a filtered-air outlet opening into the interior volume of the flexible bag 2 (preferably at the rear part of the hood).
For preference, the filter cartridge uses soda lime in granular form to capture the carbon dioxide. Of course any other suitable filtration system may be contemplated. For example, the filter cartridge may also use lithium hydroxide. The filtration product may be stored in the cartridge in the form of granules, sheets with canals or porous mats for example.
In general, the system that captures the carbon dioxide may be of the passive type (the interior of the breathable volume being lined with a compound that absorbs CO2) or active (where the gas that is to be purified is captured and channelled through the filter element).
The reaction for fixing the carbon dioxide is generally an exothermic reaction. That allows the relatively warm gases coming from the filter cartridge to mix with the relatively cooler oxygen leaving the reservoir 3. That means that a gas temperature that is very acceptable to the user can be maintained.
For preference also, the outlet orifice of the tubular oxygen reservoir and the filtered-air outlet 6 of the filter cartridge may be arranged relative to one another (particularly concentrically and coaxially) so as to form a venturi device.
This venturi device thus makes it possible to use the energy of expansion of the gas supplied by the pressurized reservoir 3 to create a recirculation stream through the filter cartridge (soda lime or lithium hydroxide). The oxygen is supplied by the oxygen reservoir 3 to the venturi which then generates a suction through the filter cartridge. The oxygen-enriched breathable mixture is delivered to the flexible bag 2.
For preference, the venturi has an entrainment ratio (aspirated flow rate/injected flow rate) of between 10 and 20 over the range of injected flow rates of 1 to 5 litres per minute for example.
This carbon dioxide capture system is thus independent of the breathing of the user. In addition, during the first fifteen minutes of use, the venturi blows for example between thirty and seventy litres of gas per minute. That makes a noise (blowing) audible to the user. That informs him that the equipment is working correctly.
This solution of the active filtration of the carbon dioxide produced by the user may be supplemented (or even replaced) by a passive filtration solution such as: lining the inside of the breathable volume with a compound which absorbs carbon dioxide or positioning one or more composite panels that absorb carbon dioxide at the key points (for example near the user's mouth).
According to one advantageous feature, the hood 1 comprises an internal structure as described hereinbelow.
Thus, the hood 1 may comprise, inside the flexible bag 2, a flexible suspension member 16 such as a cap or hat. This suspension member 16 is fixed to the flexible bag 2 and forms an internal hat or cap having a surface area smaller than the surface area of the outer bag 2. At least part of the border of the suspension member 16 is connected (bonded, stitched or the like) to the flexible bag 2, preferably a set distance from the upper end of the flexible bag 2. In this way, when the user slips the hood 1 on, this suspension member 16 rests on the top of the head of the user at a height somewhere between the base and the top of the hood 1 (cf.
That allows the weight of the hood 1 to be distributed over the head of the user and also means that the gas source 3, 4 (reservoir(s) filter cartridge, etc.) is not made to rest on the user's shoulders.
In this way, the hood 1 may move with the head of the user, the window 20 notably always remaining positioned in front of the user's eyes.
In addition, this structure keeps the viewing window 20 vertical with respect to the top of the user's head. The hood 1 thus does not need to have a tightening buckle and/or a strap that has to be adjusted in order to maintain a good fit, because there is very little spread in the morphology of the top of the head of potential users. The structure of the hood 1 is thus universal and does indeed fit a large number of different users.
In addition, this structure allows the outer bag 2 to inflate in order to form enough of a buffer volume without “floating” and moving around excessively around the user's head.
The suspension member 16 preferably comprises at least one portion 17 comprising at least one of the following: a flexible mesh, a cloth, a fabric, an elastic zone, a rigid zone, a semi-rigid zone.
In the example of
The rear portion 17 is connected to the rear part of the flexible bag, preferably at the lower base thereof. The lower rear end of the flexible member 16 may notably be connected to a gas source 3.
For preference, the gas source is distributed around the neck of the user predominantly in the rear part of the head and neck (because for example the front end of the hood or front half does not receive a gas source portion).
For example, the gas source has the overall shape of a U or a C and the opening of the U or of the C is situated in the front part of the hood (for example under the user's chin or lower jaw) while the base of the U or C is situated in the rear part of the hood (for example behind the nape of the neck of the user). The end of the second front portion 19 (helmet visor) is itself connected to the front end of the flexible bag, preferably above the viewing window 20.
This allows the transparent window 20 to be held a set distance away from the user's face (cf.
For preference, and as described hereinafter with reference to
Of course, the suspension member 16 could be formed of a single flexible or semi-rigid portion.
Of course, as an alternative, the suspension member 16 could be fixed (stitched, bonded or the like) around its entire circumference to the flexible bag 2.
The suspension member 16 allows the hood 1 to be suspended and allows the centre of gravity of the hood to be re-centred with respect to the head of the user by fitting any type of hair style. This suspension system allows the function of holding the hood in place to be disassociated from the function of forming a buffer volume. In this way, the hood 1 may constitute an adequate buffer volume while the at the same time being correctly positioned and following head movements.
Thus, while being of simple and inexpensive structure, the hood 1 according to the invention offers numerous advantages over the prior art.
In particular, the hood 1 offers better ergonomics, displaying the possibility of having a large volume of gas around the user's head. Its structure, donning and wearing limit the risks of error, discomfort and the feeling of confinement. The hood has a universal structure which fits a broad spread of morphologies (sizes, spectacles, hair styles, etc.).
In addition, the relative arrangement of the gas source and of the suspension member allows an advantageous distribution of the weight of the hood on the head of the user and prevents the gas source from resting on the user's shoulders.
The gas source has a tendency to pull the flexible bag backwards toward the nape of the user's neck. The suspension member balances and compensates for this effect. The cap may thus press essentially on the forehead or the top of the forehead of the user.
The size needed is not increased and is even reduced in the case of the folding structure.
In the above example, the internal suspension structure has been described in a hood equipped with a gas source comprising a pressurised oxygen reservoir. Of course, this internal structure (suspension member 16) can be used for any other type of hood, notably one using a gas source that comprises a chemical oxygen generator.
While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.
The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.
“Comprising” in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of “comprising.” “Comprising” is defined herein as necessarily encompassing the more limited transitional terms “consisting essentially of” and “consisting of”; “comprising” may therefore be replaced by “consisting essentially of” or “consisting of” and remain within the expressly defined scope of “comprising”. “Providing” in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.
Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.
Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.
All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.
| Number | Date | Country | Kind |
|---|---|---|---|
| 14 57491 | Aug 2014 | FR | national |
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| 2 621 744 | Jun 2004 | CN |
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| Entry |
|---|
| Rolland, et al., “Full Hood Respirator,” U.S. Appl. No. 14/814,886, filed Jul. 31, 2015. |
| French Search Report and Written Opinion for FR 1457491, dated Mar. 18, 2015. |
| French Search Report and Written Opinion for FR 1 457 490, dated Mar. 18, 2015. |
| Number | Date | Country | |
|---|---|---|---|
| 20160030774 A1 | Feb 2016 | US |
