Patent Application
20160030776
This application claims the benefit of priority under 35 U.S.C. §119 (a) and (b) to French patent application No. 1457490, filed Aug. 1, 2014, the entire contents of which are incorporated herein by reference.
1. 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.
2. Related Art
Full-hood respirators are conventionally used onboard aeroplanes when the cabin atmosphere is vitiated (depressurized, 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:
The technology using compressed oxygen in a sealed container associated with a calibrated orifice is generally safer. Nevertheless, this type of device may be relatively bulky for being stored in an aeroplane.
In addition, certain users may have problems putting the hood on and keeping it in place under certain circumstances, particularly in a stressful situation.
Known solutions use half-masks or full-face masks. These solutions present problems of sealing because sealing is difficult to achieve with an item of equipment that is intended for universal use. In order to avoid a lack of sealing, the known systems are relatively uncomfortable and take a relatively long time to fit (positioning using straps, buckles or elastics). In addition, the breathing resistance is relatively high (the half-mask channels the fluids in pipes fitted with filter cartridges at its ends).
One object of the present invention is to alleviate all or some of the abovementioned disadvantages of the prior art.
To this end, the invention is directed a hood comprising a fluidtight flexible bag intended to be slipped over the head of a user, the flexible bag being provided with a transparent window and comprising, in its lower part, a rigid base element of annular overall shape intended to be positioned around the neck of the user, the base element comprising a tubular oxygen reservoir of pressurized oxygen provided with a calibrated outlet orifice opening into the internal volume of the flexible bag. The base element comprises at least two rigid parts connected by an articulation, the two parts being movable relative to one another between a furled first position that prevents a head from entering the hood through the base element and an unfurled second position of use that allows a head to enter the hood through the base element.
Moreover, embodiments of the invention may comprise one or more of the following features:
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 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 ten 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 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 lower part of the bag 2 comprises a rigid base element 3, 4 of annular overall shape intended to be fitted around the neck of the user. The base element 3, 4 comprises a tubular oxygen reservoir 3 of pressurized oxygen. This base element forms a mass which holds the hood 1 in place.
The hood 1 also comprises a calibrated outlet orifice 7 connected to the oxygen reservoir 3 and opening into the internal volume of the bag 2, preferably in the rear part of the hood 1.
The oxygen reservoir 3 for example has a volume of between 0.20 and 0.4 litres and stores gas at a pressure of for example between 150 and 200 bar. The calibrated outlet orifice 7 has for example a diameter of between 0.04 and 0.15 mm in order to release for example between twenty and sixty litres of oxygen over fifteen minutes. The reservoir 3 may consist of a tube made of stainless steel or some other material, with a diameter of, for example, between 30 and 50 mm.
According to one advantageous feature, the base element comprises at least two rigid parts 3, 4 connected together by an articulation 5. The two parts 3, 4 can be moved relative to one another between a furled first position that prevents a head from entering the hood 1 through the base element 3, 4 (cf.
The base element is preferably secured to the base of the flexible bag 2, for example incorporated into a sleeve formed by the flexible bag 2.
In the example depicted in the figures, the two articulated parts 3, 4 of the base element consist of two curved tubular portions connected at an articulation 5. The two parts 3, 4 in the unfurled position form an open ring (for example a C-shape as visible in
For example, in the furled position, the longest transverse dimension (in a direction perpendicular to the top/bottom axis of the hood) of the central opening delimited by the base element 3, 4 is between five and ten cm. That is not enough to pass a head through. In the unfurled position, this longest transverse dimension of the central opening delimited by the base element is, for example, between twenty and forty cm, which is large enough for the vast majority of heads.
For example, the two parts 3, 4 of the base component pivot relative to one another at the articulation 5 between the furled and unfurled position in an angular range of between thirty and one hundred and eighty degrees (the angle between the two parts 3, 4 may vary for example between thirty degrees in the furled position and one hundred and eighty degrees in the unfurled position).
In the example depicted, the base element is made up of two articulated rigid parts 3, 4. Of course, it is possible to conceive of a structure having more than two articulated parts (3, 4, etc). likewise, as an alternative, the base element 3, 4 may have the shape of a closed ring (articulated chain for example) or any other appropriate form.
Likewise, in the above example, the two parts are made up respectively of a pressurized-oxygen reservoir 3 and of a filter cartridge 4. As an alternative, the two articulated parts 3, 4 could be made up respectively of two distinct articulated oxygen reservoirs. In that case, the carbon dioxide filtration could be of the passive or active type and incorporated into another (third) articulated (furlable) or otherwise element. As illustrated schematically in
As illustrated in
Likewise, the hood 1 may comprise one or more mechanical stops 14, 15 respectively defining the furled and unfurled positions. These stops may constitute regions of contact between the two parts 3, 4, notably at the articulation 5 (cf.
The hood 1 may where appropriate also comprise a mechanism for keeping the relative position of the two rigid parts 3, 4 stable. For example, an elastic deformation system (snap-fastening or the like) may be provided in order to form a “hard point” in at least one of the following positions: the furled position, the unfurled position.
For preference, the opening of the ring formed by the unfurled position of the two parts 3, 4 is situated at the front face of the hood 1. That means to say that the open part of the ring is positioned on that side of hood 1 that comprises the transparent window 20. That makes it easier to fit the hood 1 over the head. This positioning of the opening makes it easier to accommodate the user's face, and notably any spectacles, the nose, the chin, etc.
This structure balances the distribution of weight around the head of the user. In addition, the centre of gravity of the system may thus be offset slightly towards the rear (with respect to the centre of the user's head).
For preference, the hood 1 comprises a cartridge 4 for filtering the air in the flexible bag 2 in order to remove the carbon dioxide generated when the user exhales. The filter cartridge 4 comprising an inlet 22 communicating with the interior volume of the flexible bag 2 (preferably at the front of the hood) and a filtered-air outlet 6 opening into the interior volume of the bag 2 (preferably at the rear part of the bag).
In that case, and as illustrated in the figures, the two parts 3, 4 of the base piece are made up respectively of a tubular oxygen reservoir 3 and of a carbon dioxide filter cartridge 4. These two devices preferably have similar mass and volume, making the whole nicely balanced.
For preference, the filter cartridge 4 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 4 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 4 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 and as illustrated in
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 twenty and forty-five 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).
As illustrated in
For preference, activation of the gas (release of oxygen into the hood 1) is initiated (preferably automatically) when the hood 1 is unfurled. Thus, for example, in its furled position, the pressurized gas from the oxygen reservoir 3 is not placed in communication with a fluid circuit supplying the outlet orifice 7 whereas in its unfurled position the pressurized gas from the oxygen reservoir 3 is placed in communication with a fluidic circuit supplying the outlet orifice 7. This initiation is preferably generated as soon as the pivoting movement of the articulation exceeds a set threshold of a few degrees, for example of between three and ten degrees.
For example, and as illustrated in the example of
For example, the removable plug 8 is moved and/or broken mechanically through collaboration with a stop 9 of the hood 1 when the base element 3, 4 is moved from its furled position into its unfurled position.
As illustrated in the example of
As illustrated in
Of course, as an alternative to a permanently broken plug 8, the plug 8 could simply be mobile and able to return elastically to its closed position when the hood 1 is furled again.
Irrespective of the articulated structure thereof and of the potential automatic release of oxygen upon unfurling, the hood 1 may potentially have an internal structure as described hereinbelow with reference to the embodiment of
Thus, the hood 1 may comprise, inside the flexible bag 2, a flexible suspension member 16. 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.
For example, the suspension member 16 is attached to the bag 2 at the front rear and side (for example at one attachment at the front, one attachment at the rear and two attachments at the sides which are situated respectively one on each side of the bag 2). This allows the weight of the hood to be distributed across the head of the user and also means that the base element 3, 4 (reservoir, filter cartridge, etc) does not 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 end of the front second portion 19 (helmet visor) is itself connected to the front end of the flexible bag, preferably above the viewing window 20.
That allows the transparent window 20 to be held a set distance away from the user's face (cf.
The rear portion 17, preferably made of a flexible or even elastic mesh, essentially rests on the rear half of the user's head and allows an easy fit for female users wearing their hair in a bun or wearing hair slides (female cabin crew for example). That allows the hood to fit and be positioned correctly on any type of user by distributing the centre of gravity of the hood 1 for greatest user comfort.
Of course, the suspension member 16 could be formed of a single flexible or semi-rigid portion.
The suspension member 16 allows the base element 3, 4 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 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.).
The size needed is not increased and is even reduced in the case of the folding structure.
Thus the invention may have the following advantages:
Purification of carbon dioxide in the hood 1 can be independent of the way in which the user breathes. What that means to say is that there is no risk of poor purification even if the user breaths in small puffs (is short of breath/exhibiting the panting typical of a state of panic).
By contrast, solutions employing passive filtration are generally less effective and entail oversizing the amount of filter agent.
Unlike other known devices, the breathing resistance is zero or very low, making it very comfortable for the user to use.
Unlike the known solutions that use half-masks, the hood is not subject to a risk of poor sealing.
The active carbon dioxide filtration system means that the quantity of filter substance carried can be optimized.
The hood uses no moving parts to supply the gas. That makes the whole system more reliable.
The venturi device can be produced by injection moulding of plastic. This allows its cost to be reduced.
The ergonomics of the hood are improved because of the balanced distribution of its mass and its non-inhibiting positioning. The hood can be put on easily and comfortably even if the user wears spectacles.
The folding structure is reliable and robust via its rigid articulation and its sealing for any angular opening.
In comparison with the known solutions (venturi system placed behind the head of the user, down his back or on his chest), the above solution is better balanced and more ergonomic around the user's head.
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 |
|---|---|---|---|
| FR 1457490 | Aug 2014 | FR | national |
