阅读说明：本技术 无面部接触的飞行员的呼吸设备 (Breathing apparatus for pilots without face contact ) 是由 金-巴普蒂斯泰·代尔普拉特 奥利维厄·波泰特 罗曼·费内里 于 2018-07-05 设计创作，主要内容包括：用于飞行器的呼吸设备(90),由飞行员作为呼吸设备的使用者(U),呼吸设备(90)包括肩部支撑件(1)、具有可变形膜(3)的基架(2)、刚性面甲(4)和具有拱部(50)和挠性壁的可伸缩罩篷(5),其中,所述可变形膜(3)包括具有自适应尺寸的中心孔(OC),所述中心孔(OC)被配置为能够以基本气密方式选择性地围绕使用者(U)的颈部,刚性面甲(4)在内缩位置和使用位置之间可移动地安装在基架上,其中刚性面甲(4)以气密方式接触基架,具可伸缩罩篷(5)通过气密方式与刚性面甲的上边界耦合,从而当刚性面甲(4)处于封闭/使用位置且可变形膜通过基本气密方式围绕使用者颈部时,提供基本封闭的空间,其中所述封闭空间由可变形膜、基架、可伸缩罩篷和刚性面甲所界定,并且仅能够通过一个或两个气体导管进行气体交换。(Breathing apparatus (90) for an aircraft, a user (U) of the breathing apparatus being a pilot, the breathing apparatus (90) comprising a shoulder support (1), a base frame (2) with a deformable membrane (3), a rigid visor (4) and a retractable canopy (5) with an arch (50) and flexible walls, wherein the deformable membrane (3) comprises a central aperture (OC) of adaptive size configured to be able to selectively surround the neck of the user (U) in a substantially airtight manner, the rigid visor (4) being movably mounted on the base frame between a retracted position and a use position, wherein the rigid visor (4) contacts the base frame in an airtight manner, the retractable canopy (5) being coupled with an upper boundary of the rigid visor in an airtight manner, such that when the rigid visor (4) is in a closed/use position and the deformable membrane surrounds the neck of the user in a substantially airtight manner, providing a substantially enclosed space, wherein the enclosed space is bounded by the deformable membrane, the base frame, the retractable canopy and the rigid visor and is capable of gas exchange only through one or two gas conduits.)

1. Breathing apparatus (90) for an aircraft, by a pilot or copilot of the aircraft as a breathing apparatus user (U), the breathing apparatus comprising:

a shoulder support (1),

-a base frame (2) having a deformable membrane (3), the deformable membrane (3) comprising a central hole (OC) of adaptive size configured to selectively surround the neck of a user (U) in a substantially airtight manner, the base frame (2) being mounted on the shoulder support (1),

-a rigid visor (4) movably mounted on the base frame between a retracted position (P2) and a use position (P1), wherein the rigid visor (4) contacts the base frame in an airtight manner,

-a retractable canopy (5) having one or more arches and a flexible wall (50) coupled in an airtight manner with an upper border of the rigid visor,

so as to provide, when said rigid visor (4) is in the closed/use position and the deformable membrane surrounds the neck of the user in a substantially airtight manner, a substantially closed space (CV) delimited by the deformable membrane, the base frame, the retractable canopy and the rigid visor, so that the head (UH) of the user is not in contact with said rigid visor and no element is worn on the face.

2. Breathing apparatus according to claim 1, wherein the aperture control means (6) are arranged to change the central aperture (OC) of the deformable membrane from a large aperture state to a small aperture state, wherein the deformable membrane surrounds the neck of the user (U) in a substantially airtight manner.

3. The respiratory apparatus of claim 2 wherein a surface ratio, L/S, defined by the area of the large aperture state divided by the area of the small aperture state is defined, wherein L/S is at least 4, preferably at least 5, and preferably about 6.

4. The respiratory apparatus of claim 2 or 3 wherein the aperture control device is driven in accordance with movement of the rigid visor.

5. The breathing apparatus according to claim 4, wherein the aperture control means is driven by a cable link (96) driven by the rigid visor.

6. The respiratory apparatus of any one of claims 2 to 5, wherein the aperture control device comprises a manual adjustment assist device.

7. The breathing apparatus according to any of the claims 2 to 5, wherein the aperture control means comprises a fixed ring (61), a movable ring (62) and a retractable cord (63), wherein the deformable membrane is formed as a sleeve, wherein the first edge (31) and the second edge (32) of the deformable membrane are attached to the fixed ring (61), and for each retractable cord the first end is attached to the fixed ring (61) and the second end is attached to the movable ring (62).

8. The breathing apparatus according to any one of claims 1 to 7, wherein the deformable membrane (3) comprises an elastic polymer having a large elastic elongation coefficient.

9. The breathing apparatus according to any of the claims 2-8, wherein the central aperture (OC) of the membrane is large enough to allow the passage of an adult head in a large aperture state, in practice an open cross section of at least 300cm²Preferably the cross-section of the opening is at least 400cm²And more preferably the opening cross section is at least 500cm²。

10. Breathing apparatus according to any of claims 1-9, further comprising a locking system (7) and an unlocking actuator/button (42), said locking system (7) being adapted to hold said rigid visor in at least one position, wherein the locking system (7) is adapted to lock the rigid visor in a retracted position (P2) and in a position of use (P1).

11. The respiratory apparatus of any one of claims 1 to 10 wherein the upper boundary of the rigid visor is arcuate on both side regions (left and right) providing good side visibility.

12. Breathing apparatus according to any of claims 1 to 11, wherein the arches (50) of the retractable canopy are arranged so as to be mutually inclusive when the retractable canopy is fully retracted.

13. The breathing apparatus according to any one of claims 1 to 12 wherein the rigid visor is rotatably mounted on the base frame with the articulation axis Y being disposed in the lower pinna region relative to the position of the user's head.

14. The breathing apparatus according to any of the claims 1-13, wherein one or more injectors (83) are provided for providing fresh air containing oxygen in the enclosed space, which injectors are provided in a front area (21) of the base frame.

15. Breathing apparatus according to any of claims 1-14, further comprising a re-breathing system connected to the enclosed space (CV) by one or more gas conduits (81,82), wherein gas exchange into and out of the enclosed space (CV) can only be performed through the gas conduits (81, 82).

16. A breathing apparatus according to any of the claims 1-15, further comprising a microphone (86) and one or two speakers (87).

17. Breathing apparatus according to claim 16, further comprising a position sensor (26) configured to detect a rigid visor in the use position, whereupon the avionics system automatically switches the audio channel to a microphone and speaker provided in the breathing apparatus.

Technical Field

The present disclosure relates to a breathing apparatus for a pilot.

Background

There is a trend to force and/or enforce the pilot and/or copilot of an aircraft to wear breathing equipment in a preventive mode, which is intended to avoid the hypoxic phenomenon at certain cruising altitude decompression.

More specifically, the pilots in the cockpit should be preventive wear of the breathing apparatus when the cruising altitude exceeds 41 kilo-feet and/or if only one pilot in the cockpit is at a cruising altitude exceeding 25 kilo-feet. Such preventative wear may also be required for certain flight regime conditions and/or certain geographical areas (e.g., mountainous areas).

In this view, it is necessary to propose new solutions that are advantageous for the practicality and comfort of the breathing apparatus.

Disclosure of Invention

According to one aspect of the invention, a breathing apparatus for an aircraft is disclosed, as a breathing apparatus user by a pilot or copilot of the aircraft, the breathing apparatus comprising:

-a shoulder support;

a base frame with a deformable membrane comprising a central hole of adaptive size configured to be able to selectively surround the neck of a user in a substantially airtight manner, the base frame being mounted on a shoulder support,

a rigid visor movably mounted on the base frame between a retracted position and a use position, wherein the rigid visor contacts the base frame in an airtight manner,

a retractable canopy having one or more arches and flexible walls, coupled in an airtight manner with the upper boundary of the rigid visor,

thereby providing a substantially enclosed space bounded by the deformable membrane, the base frame, the retractable canopy and the rigid visor when the rigid visor is in the use position and the deformable membrane surrounds the neck of the user in a substantially airtight manner.

Due to these configurations, the pilot's head is not in contact with the rigid visor, and the face does not wear any elements, which makes the pilot and/or copilot very comfortable, thereby increasing their safety and usability to perform other critical tasks.

Advantageously, the proposed solution is fully compatible with any type of beard and/or moustache (also including the big ear ring), since it avoids any contact between the user's face and the breathing apparatus.

Advantageously, the proposed solution allows the user to put down the rigid visor quickly and conveniently to reach the position of use, and makes the position of use safe and effective in using the breathing apparatus.

The enclosed space is sealed from the outside environment and is provided with breathable air therein, possibly in gas exchange with one or both gas conduits connected to the gas production/rebreathing system.

The term "rigid visor" herein denotes a self-supporting transparent wall. Such a rigid visor does not substantially impair or obstruct vision of the person.

The term "deformable membrane" means a flexible layer of material that is continuous and blocks the passage of air unless otherwise specified. The flexibility and extensibility of such films are great.

The term "use position" for a rigid visor means that the rigid visor is closed against the base frame. In this configuration, the user actually breathes the breathable air using the breathing apparatus.

In various embodiments of the present invention, one or more of the following arrangements may be used alone or in combination.

According to one solution, aperture control means are provided to change the central aperture of the deformable membrane from a large aperture state to a small aperture state, wherein the deformable membrane surrounds the neck of the user in a substantially airtight manner. Thus, in the event of a sudden need to use the breathing apparatus, the central aperture of the deformable membrane can be rapidly reduced for application to the neck of the user. Conversely, when effective use of the breathing apparatus is not required, the deformable membrane may be removed from the user's neck, wherein the deformable membrane may provide comfort to the user/pilot. The large aperture state also allows the head of the user to pass through.

According to one solution, a surface ratio L/S defined by the area of the large aperture state divided by the area of the small aperture state is defined, wherein L/S is at least 4, preferably at least 5, and preferably about 6.

According to one approach, rigid visor motion is relied upon to actuate the aperture control. Thus, the pilot need only move the rigid visor downward to automatically trigger the reduction of the central aperture of the deformable membrane. The pilot/user does not have to bother to adjust the deformable membrane around the neck, as the lowering of the rigid visor changes the central aperture from a large aperture to a small aperture, and does not require additional pilot control.

According to one approach, the aperture control device is driven by a rigid visor-driven cable link. This is a simple and reliable solution, which may improve safety.

According to one aspect, the aperture control device includes a manual adjustment assist. Advantageously, the pilot/user can adjust the neck tightening force to suit individual needs after the central aperture size is automatically reduced.

According to one solution, the aperture control device comprises a fixed ring, a movable ring and a retractable cord, wherein the deformable membrane is formed as a sleeve, wherein a first and a second edge of the deformable membrane are attached to the fixed ring, wherein for each cord a first end thereof is attached to the fixed ring and a second end is attached to the movable ring. Thus, upon rotation of the movable ring, the cords extend and pull the deformable membrane radially inward.

According to one solution, the retractable cord is elastic and provides elastic return to a large aperture state, and the movable ring comprises a lever that can be actuated manually and/or by a cable link.

According to one aspect, the movable ring is elastically restored by the elastic member. This is a supplementary measure, in addition to the elasticity of the cord itself.

According to one version, the deformable membrane comprises an elastic polymer having a relatively large elastic elongation coefficient. The linear elongation coefficient can be as large as 2, or even 2.5. The ratio of large pore size to small pore size may be 4 depending on the area of the central pore.

According to one aspect, a fabric collar, which may be configured to contact the neck of the user, may be additionally provided, thereby improving comfort. The fabric collar can be replaced, thereby improving sanitary conditions.

According to one solution, the collar of the fabric can be removably associated with the radially intermediate portion of the deformable membrane.

According to one solution, the central hole of the membrane is large enough to allow the head of an adult to pass through in the large-aperture state, and in practice, the opening section is at least 300cm²Preferably the cross-section of the opening is at least 400cm²And more preferably the opening cross section is at least 500cm². This enables the pilot toThe user can easily wear the helmet type breathing apparatus without damaging the hairstyle. The central aperture may exhibit a substantially circular or elliptical shape.

According to one version, the breathing apparatus may further comprise a locking system for holding the rigid visor in at least one position locking system and an unlocking actuator/button, wherein the locking system may lock the rigid visor in a retracted position (P2) and in a use position (P1). Advantageously, the retracted position is fixed so that the rigid visor does not accidentally fall off even if the aircraft is shaken. The use position is also fixed, even if the airplane shakes, the breathing enclosed space can not be damaged because the rigid visor is accidentally lifted.

According to one solution, the upper boundary of the rigid visor is curved on both side regions (left and right sides) to provide good side visibility. Even when viewed from the side, the wide field of view of the pilot is not significantly impaired by the rigid visor.

According to one solution, the arches of the retractable canopy are arranged so as to be mutually inclusive when the retractable canopy is fully retracted. Otherwise, when the arch is retracted, it is stacked up like Russian dolls. The arch also provides an advantageous structure for the canopy when it is deployed, avoiding contact with the top of the user's head.

According to one solution, the arch of the retractable canopy has substantially the same shape as the upper boundary of the rigid visor. Advantageously, in the retracted position, the rigid visor upper boundary and the arch occupy a small space. The seat headrest also leaves room for comfort to the user/pilot.

According to one solution, the rigid visor is rotatably mounted on the base frame, the hinging axis Y being arranged in the region of the lower auricle with respect to the position of the user's head. Simple and reliable kinematics.

According to one solution, one or more injectors for supplying fresh air containing oxygen to the enclosed space are provided, which injectors are arranged in the front area of the base frame. Fresh air is dispensed at the appropriate location.

According to one aspect, the breathing apparatus may further comprise a rebreathing system connected to the enclosed space by one or more gas conduits. Thus reducing the total oxygen consumption.

According to one solution, the retractable canopy comprises a rear wall and a flexible top wall arranged in an arch.

According to one solution, the rear wall of the canopy is connected to the base frame in a substantially air-tight manner.

According to one approach, the breathing apparatus may further comprise a microphone and one or two speakers. Thus, the pilot/user can communicate audibly with the local equipment and does not need to listen to the cockpit speakers or speak into the cabin microphones.

According to one solution, the breathing apparatus may further comprise a position sensor, wherein said position sensor is configured to detect a rigid visor in the use position and, as a result, the avionics system will automatically switch the audio channel to the microphone and speaker provided in the breathing apparatus.

Drawings

Further characteristics and advantages of the invention will become apparent from the detailed description of one of the embodiments, given by way of non-limiting example, and with reference to the accompanying drawings, in which:

FIG.1 shows a schematic perspective view of a breathing apparatus according to the present disclosure, with the rigid visor in the position of use, the closed space containing the pilot's head, so that breathing is achieved and a wider field of view is available,

FIG.2 is a view similar to FIG.1, showing the breathing apparatus with the rigid visor in a retracted position, with the cabin ambient air being used for breathing,

figures 3A, 3B and 3C show the deployment of the retractable canopy and the rigid visor from the retracted position to the use position,

figure 4 shows a top view of the base frame, with the deformable membrane in a large aperture configuration, corresponding to the retracted position of the rigid visor,

figure 5 is a cross-sectional view of the pedestal assembly taken along line V-V in figure 4,

FIG.6 is similar to FIG.4, showing the deformable membrane during conversion to a small aperture configuration,

FIG.7 is similar to FIG.4, showing the deformable membrane in the position of use, in which it surrounds the neck of the pilot in a substantially airtight manner in a small aperture configuration,

FIGS. 8A and 8B show a linkage that drives the membrane aperture control system upon a closing movement of the rigid visor,

figure 9 shows the locking mechanism for securing the rigid visor in the retracted or use position.

Figure 10 shows a re-breathing system,

figure 11 shows a cross-section of the base member and the deformable membrane around the neck of the user.

Detailed Description

In the drawings, like numbering represents the same or similar elements. It should be noted that for clarity, some of the elements are not shown to scale.

As shown in fig.1, a pilot, labeled U, wears a breathing apparatus 90. In addition to the pilot, the user of the breathing apparatus 90 may be a co-pilot of the aircraft.

The user U of the breathing apparatus may be male or female; the anthropometry varies from subject to subject, particularly in terms of head size, neck height, and generally all anthropometric measures.

Hairstyles vary from subject to subject. Some people have short hair and some people have long hair. The number of female pilots/co-drivers is increasing and the proposed breathing apparatus should be compatible with various anthropometric measures. Advantageously, this solution is also compatible with various ponytail/ponytail styles.

Still other male pilots prefer to leave beard or moustache. Also, many beard patterns are contemplated, as well as hair length or coverage area. The proposed breathing apparatus should be compatible with most popular beard species. Advantageously, the proposed solution is fully compatible with any type of beard or moustache (including the big ear ring), since it avoids any contact between the user's face and the breathing apparatus.

In the breathing apparatus, a shoulder support 1 is provided. The shoulder support includes a left side member 1G and a right side member 1D. A linking member 12 may be provided connecting the left and right support elements, said linking member 12 being arranged in the rear area, as shown in fig. 3C. It is noted that the linking function may be provided by a base frame, as will be discussed below.

As seen in fig. 1-2, the shoulder support is compatible with a variety of pilot harnesses 10. In one embodiment, the pilot's harness 10 may be secured atop a portion of the left and right shoulder support members. In another embodiment, the pilot may pre-install his harness 10 and then install the breathing apparatus such that the left and right shoulder support members are on top of the pilot harness 10.

The shoulder support 1 is adjustable in size: the span between the left and right support members may be adjusted, for example, by incremental adjustment.

The shoulder support may comprise a comfort pad in a downwardly concave region intended to be in contact with the top of the user's shoulders, wherein the weight of the breathing apparatus is primarily transferred to the user.

The shoulder support 1 may be made of a hard synthetic material or reinforced plastic or the like.

Base frame

A base frame 2 is provided which is mounted on the shoulder support 1. In the example shown, the base frame is fixedly secured to the shoulder support, which from another perspective is fixedly secured to the base frame. According to another possible option, a height adjustment system may be provided to take into account the variety of human necks; for example, the height of the pedestal relative to the shoulder support may be incrementally adjusted by rotating a latch system that controls the rack and pinion.

The base frame comprises an arcuate front portion 21 and a rear portion 20 fixed to each other forming an armature/strength member. The rear portion may be straight or may have a slightly arcuate shape with the recess facing the neck shaft region, e.g. towards the arcuate front portion 21 (fig. 4).

The base frame 2 defines a central channel which is large enough to allow the head of a user to pass through. The structure and features contained within the pedestal will be described in detail below.

The base frame 2 may be made of a hard synthetic material, reinforced plastic, PET, PP, etc. A metal armature may be provided.

Rigid visor

A rigid visor 4 is movably mounted to the base frame 2 between a retracted position (P2 of fig.2 and 3A) and an in-use position (P1 of fig.1 and 3C). In the use position P1, the rigid visor 4 is in contact with the base frame 2 in an airtight manner.

In the example shown, the rigid visor 4 is rotatably mounted on a base frame, the hinge of which has an axis denoted Y. The hinge unit 8L is provided on the left side and the hinge unit 8R is provided on the right side, both of which may have functions other than swivel mounting, as will be described in detail below.

In the example shown, the rigid visor 4 is made of a transparent material such as polycarbonate. The rigid visor 4 has an overall arc shape. The rigid visor lower boundary 47 has a shape similar to the base frame arcuate front portion 21. A seal (not shown) may be provided to tightly connect the lower pedestal boundary to the curved front portion 21 of the pedestal.

The upper boundary 44 extends upward in front of the hinge axis Y, and a downward bent portion 43 is provided. In this configuration, the pilot/user U can directly view the frontal and lateral environment; therefore, even if the rigid visor 4 is put down, good visibility can be ensured.

A locking system assembly 7 is provided, as will be described in detail below.

Awning

A retractable canopy 5 having one or more arches 50 and flexible walls is provided, coupled in an airtight manner to the upper boundary of the rigid visor 4.

The retractable canopy 5 comprises a rear wall 51 and a flexible top wall 52 arranged at the arch 50. The top wall of the retractable canopy 5 may be made of coated fabric or may be made of a flexible polymer material. The rear wall may be made of the same material. According to one solution, the rear wall and the canopy material are integrally formed, which contributes to the air tightness. The canopy material may be translucent or even transparent.

The telescoping canopy arches 50 are arranged to mutually contain when the telescoping canopy is fully retracted (fig. 3A). More precisely, the arches are stacked like Russian dolls when retracted. Advantageously, the arch also provides an advantageous structure to the canopy when it is deployed, so that contact with the top of the user's head is avoided (fig. 3C). In this configuration, the flexible top wall is tensioned. The flexible top is not loose, there is enough space to accommodate many hairstyles and hair does not hit the canopy. The invention is thus very comfortable compared to known hoods.

A space for hairstyle of horse tail is also left at the rear wall 51.

Advantageously, in the retracted position, the rigid visor upper boundary and the arch occupy a small space. Behind the rear wall 51, a seat headrest space is left for the comfort of the user/pilot. Thus, freedom of shoulder movement or slight rotation of the shoulders is provided without obstruction of the rear of the breathing apparatus (shoulder support and canopy back wall).

2 or 3 arches may be provided. Each arch may be formed as a flexible rod having a circular or rectangular cross-section, for example, at 3mm²To 5mm²In the meantime. Each arch may be made of a flexible reinforced plastics material.

The perimeter of the rear wall 51 can be considered the last arch.

According to another possibility, all the arches 50 of the retractable canopy have substantially the same shape as the upper boundary of the rigid visor.

When the rigid visor 4 is in the closed/use position, there is an interior space bounded by the base frame, the retractable canopy and the rigid visor. The breathing apparatus may be considered a wide hood or a non-contact helmet.

The breathing apparatus can bear a weight of between 1 kg and 3 kg. The weight is supported by the user's U-shoulders and the head itself does not support any weight.

The breathing apparatus 90 may comprise two gas conduits 81,82 for providing breathable air to a user, the rebreathing system being described below in connection with fig. 10.

In one configuration, not shown, there may be a single gas conduit rather than two.

The breathing apparatus 90 may further include a microphone 86 and one or two speakers 87 to enable audio communication between the user and others (in the aircraft or remotely). In the example shown, the microphone 86 is located in the front of the mouth of the pilot/user U in the use configuration (fig. 4), and the two speakers 87 are located behind the hinge axis of the visor.

Additionally, a cable 88 is provided for linking/coupling the microphone and speaker with the car audio equipment and the remote communication.

In the example shown, the gas conduits 81,82 and the cable 88 enter the inner space through the right-hand hinge 8R.

As is evident from fig.3A to 3C, movement of the rigid visor drives movement of the retractable canopy. More precisely, fig.3A shows the fully retracted position P2 in which the flexible canopy is folded on itself, with the arches adjacent to one another or with the arches contained within one another (russian dolls). In this configuration, the pilot can directly view the environment in front and to the side. When the user U pulls down on the rigid visor by grasping the handle 48 (optionally unlocked in advance, as described below), the visor upper boundary 43 correspondingly pulls on the foremost arch 50 and, when moved, the other arches (fig. 3B shows an intermediate state).

The visor rotates about an axis Y. The arch 50 also rotates about the axis Y. The rear wall 51 of the retractable canopy remains fixed.

When the rigid visor reaches the lowermost position, i.e., contacts the base arcuate section 21, the flexible wall 52 of the canopy is substantially tensioned, as shown in fig. 3C. At this point, the interior space of the breathing apparatus is defined by the base frame, the retractable canopy, and the rigid visor.

Conversely, when the user wants to release the device, the user pushes up on the rigid visor and reverses the operation as the visor rotates and the retractable canopy collapses.

It is important to note that the user's head UH does not contact the rigid visor and that the face does not wear any elements, which applies to the retracted position P2 and the use position P1. Thereby increasing the comfort of use.

As is evident from fig.1 to 9, the key feature is the airtightness of the neck of the user, for which purpose a deformable membrane is provided.

Deformable membrane

A deformable membrane 3 is provided in connection with the base frame 2. A bottom connecting wall 22 is provided linking the base member and the deformable membrane 3 in a gastight manner. The bottom connecting wall 22 is arranged outside the deformable membrane 3, attached to the base frame 2 in a gastight manner.

The deformable membrane 3 defines a central aperture OC of the head channel and neck interface, as discussed below.

The deformable membrane 3 comprises an elastic polymer having a large elastic elongation coefficient (at least 2, even 2.5) providing a large to small aperture ratio of at least 4, depending on the central aperture OC area.

A deformable aperture control means 6 is provided. The aperture control means 6 allow to change the central aperture (OC) of the deformable membrane from a large aperture state to a small aperture state, wherein the deformable membrane surrounds the neck of the user U in a substantially airtight manner.

The aperture control means 6 may be referred to as an "iris" or "diaphragm".

More precisely, according to one illustrative example, the aperture control device comprises a fixed ring 61, a movable ring 62 and a retractable cord 63.

The deformable membrane is formed as a sleeve having a first edge 31 and a second edge 32.

Both the first edge 31 and the second edge 32 are attached to the fixed ring 61.

For each cord 63, a first end is attached to the fixed ring 61 and a second end is attached to the movable ring 62.

Upon rotation of the movable ring 62, the cords 63 extend inwardly in a radial direction (toward the center, i.e., toward the user's neck) and pull the deformable membrane. More precisely, each cord pushes the radially intermediate portion 30 of the deformable membrane towards the centre.

Four cords may be provided. However, the number of cords may be any number between 3 and 24. Each cord is between 5 and 25 centimeters in length. The cords are made of an extensible elastomeric material. The cords may be made of natural or synthetic rubber.

Advantageously, the outer layer of the cord may be a slip coating, so that the elastic extension of the cord does not pull the radially intermediate portion 30 of the deformable membrane in a tangential direction.

According to another example, the shape of the entity to which the deformable membrane is attached may be different. Any fixed and movable members, regardless of their shape, are contemplated in place of the rings.

When the central hole OC of the membrane is in a large-aperture state, the central hole is large enough to allow the head of an adult to pass through, and in practice, the opening cross section is at least 300cm²Preferably at least 400cm²And more preferably at least 500cm²。

When closed, the minimum dimension of the membrane central bore OC may be as small as 100cm²Even as small as 80cm²。

Also, a surface ratio L/S (large/small) defined by an area in a large aperture state divided by an area in a small aperture state is defined.

Advantageously, the ratio L/S is at least 4, preferably at least 5, and preferably about 6.

According to a particular aspect, a fabric collar 37 is additionally provided that can be configured to contact the neck of the user, thereby improving comfort. The fabric collar can be replaced, thereby improving sanitary conditions. The collar may be removably attached to the radially intermediate portion 30 of the deformable membrane (see fig. 11).

The movable ring 62 includes a lever 65 that is actuated by a pull cable 96. In a variant, it may also be actuated manually to move the movable ring 62.

Because the retractable cord 63 is elastic and provides elastic recovery to a large aperture state. However, additional biasing means may be provided to resiliently return the movable ring to a position corresponding to the large aperture condition. In the example shown, a bungee cord 67 (or tension spring) is provided, one end of which is anchored to an appendage 66 rigidly fixed to the base frame, the other end of which is fixed to the control rod 65, or another point rigidly fixed to the movable ring 62.

It should be noted that both the fixed ring 61 and the movable ring 62 may be slightly deformed so as to become oval in shape to allow the head of the user to pass through when mounting/dismounting the breathing apparatus.

In addition to the above-mentioned membrane, such as the deformable membrane, a closure member operated using a manual zipper 31 is not excluded, as a further example of a deformable membrane, as schematically illustrated in fig. 2.

In the example shown, the left articulation unit 8L comprises a locking system 7 and a link mechanism 9 to drive the movable ring according to the visor position.

Visor/membrane linking mechanism

In the example shown, visor/membrane linking mechanism 9 includes a pull cable 96 for rotating movable ring 62.

One end of the traction cable 96 is attached to the control lever 65. The other end of the traction cable 96 is attached to the pulley 91 inside the left hinge unit 8L. The attachment point is indicated at 97. The traction cable 96 and the pulley 91 basically function as a winch. The pulley 91 is rotatably mounted on the hinge shaft Y. According to an advantageous solution, a multiplier gear is provided to convert the visor rotation into a cable traction with a suitable range to pull the movable ring out by a quarter turn (see fig. 4-7).

Planetary gears are provided for this purpose. According to one possible configuration, the centre of the visor is attached to the planet carrier 94 of the planet gear, the sun gear 92 is fixed, and the outer gear 93 is rigidly fixed by the pulley 91. This essentially doubles the range/stroke. It is known from planetary gear technology that high ratios may also alter the action of the planet carrier, sun gear and outer gear. The planet is marked 95.

Locking mechanism

The locking mechanism is mainly illustrated in fig. 9.

A lever 74 is provided extending from the region of the handle 48 to the central region.

A button 42 is provided which acts to pull the control rod 74 outwardly. At the centre of the visor there are provided recesses 72, one recess corresponding to the closed position of the visor and one or more additional recesses 71 corresponding to one or more open positions of the visor. A spring 77 is provided to bias the control lever 74 toward the locked state.

The control rod may be any control member, not necessarily rod-shaped. For example, the user may push the button forward with his thumb 49. Other variations of providing an unlock security operation are also contemplated.

The skilled person will appreciate that locking may be achieved passively by means of a return spring 77.

Advantageously, a breathing circuit as shown in fig.10 is provided. This is a substantially closed air circuit with a fan for circulating the air/gas and ensuring its regeneration. The oxygen supply device is provided with an oxygen tank for compensating the oxygen used by the user and adjusting the oxygen content in a closed loop. A carbon dioxide capture cartridge (e.g., sealed with soda lime or lithium hydroxide) is provided. Furthermore, a gas cooling unit for reducing the temperature of the air in the enclosed space and for condensing the water vapour and exhausting it from the circuit may be provided.

Inside the breathing apparatus there are one or more injectors 83 for admitting air from the fan, and vents 84 for exhausting air from the interior space to the fan.

A plurality of sensors (pressure, flow, CO) may be provided, not shown₂…) to control the system.

The air-tightness properties of the proposed solution allow a pressure difference of 1 bar between the interior enclosed space and the environment outside the aircraft cabin without significant leakage.

For tightness around the user's neck, a third ring 69 may be provided that moves relative to the second double ring 62. This additional control loop allows the user to manually control to fine-tune the tightness.

A sensor 26 is provided which is capable of detecting the closed position of the rigid visor. This enables the avionics system to automatically switch the audio communication to the microphone and speaker provided in the breathing apparatus.