INFLATABLE CELLULAR STRUCTURE AND OBJECT WITH IT

Description

GENERAL TECHNICAL FIELD

[0001] The present invention lies in the field of devices for the protection of individuals when they fall or are the target of an impact.

[0002] It relates in particular to an inflatable cellular shock-absorbing structure. STATE OF THE ART

[0003] The term "back effect" commonly refers to the significant bending mechanism due to the dynamic indentation cone generated by the impact of a projectile or resulting from a fall.

[0004] It results from a transfer of kinetic energy to the body.

[0005] Examples of the consequences of the rearward effect caused by a fall or projectile on a human body are given below: Almost systematic parietal injuries include: Skin erosions and wounds; Cutaneous vasomotor reaction; Bone fractures; Perforation of the parietal pleura generally associated with rib fractures.

[0006] Lung lesions including: Pulmonary contusions and hemorrhages; Pneumothorax, gas embolisms and hemothorax; Abdominal injuries.

[0007] Abdominal injuries, particularly those affecting solid organs in contact with the abdominal wall (liver, spleen, kidneys).

[0008] Heart damage.

[0009] Bone lesions, fractures, are often limited to the area in contact with the cone of deformity, but may be associated with fractures or dislocations elsewhere. Spinal injuries and, occasionally, back injuries are also observed.

[0010] One solution for measuring the back effect is to use the "viscous criterion" ("VCmax"), which corresponds to the maximum product of the strain rate and the compression ratio, divided by the maximum strain over time. This "VCmax" has the advantage of using only readily available data and can serve as a basis for comparisons between different protection solutions.

[0011] In any case, the rearward effect can cause serious or disabling injuries. For the same level of protection and the same projectile (or identical fall characteristics), the severity of the injuries, as well as the significance of the physical parameters at the time of impact, are linked to the impact energy of the projectile or the fall and its speed of transmission to the body.

[0012] This problem is all the more important given the recent development of flexible bulletproof vests, so that under the effect of an impact, the vest deforms backwards, thus transmitting a significant energy wave.

[0013] However, the kinetic energy at the moment of impact does not correspond to the energy transmitted to the chest. It depends on the protective layer between the chest and the chest. This layer must be able to deform sufficiently, but not excessively, to absorb the energy without hindering the wearer.

[0014] In some cases, a "tension shield" can be used. This shield is placed between the individual's chest and the body armor, and its function is to disperse and absorb all or part of the impact energy. More specifically, the objective of such a shield in very high-speed impacts is to distribute the forces to reduce their impact. In practice, such a shield does not perfectly fulfill this function. In any case, in order to compare different types of protection, it is necessary to establish a link between the injuries and the deformation dynamics of the rear face of the body, that is, the side in contact with the body.

[0015] Thus, there are inflatable protections which are either compartmentalized, or in one piece, or have partition welds, and whose main disadvantage is a bulk (thickness) greater than 30mm, and a rigidity dependent on their inflation pressure.

[0016] Their individual compartments become weakened if the inflation pressure is too high, due to their excessive air volume. It then behaves like an inflatable balloon.

[0017] For example, US 876,237 describes an inflatable protective device for baseball players, designed to divide its inflatable components so that if one of them is punctured, the remaining sections stay inflated to continue providing protection. There is no logic to pressure management between the sections, but simply a desire to isolate them in case of a puncture.

[0018] US 3,550,159 describes a cellular structure designed to be worn by a person to protect them against impacts. This structure is formed of several layers of contiguous cells. Each cell comprises two large parallel faces and four partitions fused to these faces, giving it the general shape of a rectangular parallelepiped. Holes in some of the partitions allow air to pass through the thickness and laterally.

[0019] The layering of multiple cells is a significant drawback that hinders ergonomic use. Furthermore, if the cells are overinflated, they take on a balloon-like shape.

[0020] US patent 3,995,320 proposes to address the drawbacks of the aforementioned design. This design involves a welded assembly of two plastic panels, forming a series of longitudinal tubes connected to each other by numerous air vents. The main disadvantage of this type of structure is that, in the event of an impact, the entire impacted tube deforms, with the significant deformation resulting from the large number of air vents.

[0021] Additional prior art is constituted by documents US 5,771,490 (which describes the features of the preamble to attached claim 1), US 5,030,501 and US 5,238,231.

[0022] The objective of the present invention is to propose a thin structure which, when heavily inflated, effectively combats the "back effect", can deform in all directions, while being comfortable to wear and allowing great freedom of movement for its user. PRESENTATION OF THE INVENTION

[0023] Thus, the invention relates to an inflatable shock-absorbing cellular structure having the characteristics of claim 1. In such a structure, it is particularly provided that the structure consists of two sealed sheets welded to each other along weld lines which delimit inflatable cells, said inflatable cells are arranged according to at least a two-dimensional matrix of n rows and m columns of cells, n and m being equal or different integers, each greater than or equal to 2, a peripheral cell of said matrix is ​​connected to an inflation nozzle; which is characterized by the fact that: said cells are not contiguous;the cells of the row and / or column to which said peripheral cell connected to said inflation nozzle belongs communicate from one to the next by a constriction-forming channel, this channel being a small conduit which extends between two cells, without being part of them, while each remaining cell of said matrix is ​​also connected to at least one of the neighboring cells of the same row and / or column by a constriction-forming communication channel, each of said channels is shaped to slow the flow of an inflation fluid which runs through it, or this structure incorporates means shaped to slow the flow of an inflation fluid of the cells through each of said constriction-forming channels;and that, in the swollen state, the ratio between the largest dimension of the cross-section of a cell (2)) and the largest dimension of the cross-section of a channel (3) (D / d) is at least equal to 10, preferably at least equal to 14. ;

[0024] Thanks to these features of the invention, we are dealing with a structure of reduced thickness, which can be deformed, i.e. bent because the cells are not joined, and which has excellent shock absorption qualities, thus limiting the aforementioned phenomenon of back effect.

[0025] In other words, such a structure is thin, flexible, and lightweight. As it is an inflatable structure, it requires precise inflation control to ensure proper inflation, and the dissipation of air movement during impact must be carefully managed and slowed progressively so that the structure remains inflated while absorbing the shock.

[0026] According to other advantageous and non-limiting features of the invention, taken alone or in any combination of at least two of them: Each cell of said matrix communicates with each of the neighboring cells of the same row and the same column by means of a channel forming a constriction; with the exception of the cells of the peripheral row and / or column connected to said inflation nozzle, the remaining cells communicate only with two of the neighboring cells of the same row and / or the same column by means of a channel forming a constriction; it is provided with an overpressure exhaust valve; said sealing sheets are made of / based on thermoplastic polyurethane.said channels have a sinuous shape; at least some cells contain, at one end of said channel, a hinged flap which retracts, i.e., slides away when said inflation fluid passes in one direction of flow, or presses against said end of said channel in the opposite direction, thus obstructing the passage of the fluid in said channel; a porous intermediate layer is interposed between said two sealing sheets; said intermediate layer is made of / based on thermoplastic polyurethane.

[0027] The invention also relates to an article, in particular clothing, for protection against impacts, characterized by the fact that it is provided with at least one structure according to one of the preceding characteristics.

[0028] Advantageously, the clothing item is chosen from the following group: bulletproof vest, chest protector, jacket, vest, bomber jacket, body protection item. DESCRIPTION OF THE FIGURES

[0029] Other features and advantages of the invention will become apparent from the description which will now be given, with reference to the attached drawings, which represent, by way of example but not limitation, different possible embodiments.

[0030] In these drawings: [ Fig. 1 ] is a simplified top view of a first embodiment of an inflatable cellular structure according to the invention; [ Fig. 2 ] is also a simplified top-down view of another form of this structure, which here comprises two cell matrices; [ Fig. 3 ] is yet another top view of a third embodiment of said structure; [ Fig. 4 ] is a partial vertical cross-sectional view of a structure according to the invention, intended to show how the two sheets that constitute it are joined; [ Fig. 5 ] is a diagram showing, in cross-section, two neighboring cells communicating through a channel forming a constriction; [ Fig. 6 ] is a scheme analogous to that of the figure 5 , one of the cells exhibiting four constricting channels; [ Fig. 7 ] is yet another scheme analogous to that of the figure 5 , in which the channel connecting the two cells has a sinuous shape; [ Fig. 8 ] is a partial cross-sectional view of a structure according to the invention, in which a porous intermediate layer is intercalated between the two sheets that constitute it; [ Fig. 9 ] is a partial cross-sectional view of a structure according to the invention in which two adjacent cells contain a hinged flap at one end of the channel, strangely forming, showing more specifically the behavior of this flap in a first direction of circulation of an inflation fluid; [ Fig. 10 ] is a view analogous to the previous one, the direction of fluid flow being opposite to the previous one; [ Fig. 11 ] is a diagram intended to illustrate a possible application of the structure according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] To the figure 1 Attached is a representation of an inflatable cellular shock-absorbing structure 1 according to the invention.

[0032] This figure, like all the others, is intended solely to illustrate the invention. This means that it does not reflect reality, particularly in terms of dimensions, shapes, and proportions.

[0033] The aforementioned structure 1 essentially consists of two waterproof sheets 10 and 11. Advantageously, these sheets are made of high-strength plastic. Thus, a preferred material within the scope of the invention is "TPU", that is to say, thermoplastic polyurethane.

[0034] In addition to its strength qualities even at reduced thickness, such a material is particularly well suited to welding, especially high-frequency welding, which is a technique well known for its high strength.

[0035] In the embodiment presented here, structure 1 is roughly square. However, this is not a limiting shape, so the structure's outline can have a different shape, for example, a rectangle. In practice, this shape is adapted to the area of ​​the body that the structure is intended to protect. The two sheets 10 and 11 are welded together along weld lines 100, which define individual inflatable cells 2. The manufacturing process of this structure will be discussed later in the description.

[0036] According to the invention, the cells 2 are arranged within the structure 1 according to a two-dimensional matrix MA which consists of n rows and m columns of cells 2.

[0037] In the example presented here, n and m are equal to 6. However, this is just an example, so these values ​​may be different from six. In any case, according to the invention, these n and m are integers greater than or equal to 2. It is of course possible for the number of cells in at least one row and / or column to be different from the rest of the rows and columns.

[0038] In the figures 1 à 3 In the attached table, the rows are referenced L1 to L6, while the columns are referenced C1 to C6. In this way, cell 2 (L2 / C4) identifies the cell at the intersection of row L2 and column C4.

[0039] To the figure 1 The cells have an approximate square outline with rounded corners. However, any other shape (for example, circular) can be considered. Preferably, angular shapes should be avoided to prevent weakening the weld lines.

[0040] According to the invention, a peripheral cell 2 of the MA matrix is ​​connected to an inflation nozzle 4. This nozzle 4 is integrated within an appendage 40 which is one piece with the structure 1. In other words, this appendage 40 is formed by welding sheets 10 and 11 together. The nozzle 4 is, for example, of the type that can be connected to a hand pump.

[0041] The term "peripheral cell" refers to one of the cells closest to one of the edges of structure 1. In this case, it is cell 2(L1 / C1), but in another embodiment, it could be cell 2(L1 / C3), for example. According to the invention, the cells of line L1, to which cell 2, connected to the inflation nozzle 4, belongs, communicate progressively, that is, from one cell 2 to the neighboring cell 2, via a channel 3 forming a constriction. Throughout this text, the term "channel" refers to a small conduit extending between two cells, without being part of them. Due to the presence of these channels, the cells are not contiguous, as they are separated by channels, so that the weld lines delimiting a given cell are different from those delimiting a neighboring cell.

[0042] In practice, channel 3 is delimited, like cells 2, by the aforementioned weld lines 100. The term "constriction" refers to the fact that the width of this channel is significantly smaller than that of the cells 2 with which it communicates.

[0043] We can refer to the figure 4 on which is visible not only a cell 2 (its shape has been deliberately stylized), but also three channels 3 to which it is connected, as well as one of the weld lines 100 which delimit it.

[0044] Depending on the method of implementation of the figure 1 Each cell 2 in row L1 communicates with the cells 2 in row L2 via channels 3, and so on for the other rows. The same applies to the columns, so that each cell 2 communicates with its neighbors in adjacent rows and columns via a channel 3.

[0045] Under these conditions, as soon as an inflation fluid such as air is introduced into structure 1, the latter can diffuse into all cells along random paths.

[0046] If we now refer to the figure 6 We observe that the capacity of cell 2 on the right to expel air is greater than that of the cell on the left due to the larger number of channels to which it is connected.

[0047] Due to the shape of the cells 2 and their non-contiguous arrangement (in fact, they are spaced apart due to the presence of the channels 3), there are generally cross-shaped "plots" 6 at the intersections of the non-peripheral cells, in which the sheets 10 and 11 are not joined. It should be noted here, at the center of these plots 6, the existence of openings 60 which act as ventilation holes (the "breathable" nature of the structure) and some of which allow the structure 1 to be fixed to a support.

[0048] The presence of these studs 6 at the intersection of the rows and columns of cells 2 also allows for a certain deformation of the structure 1 along perpendicular directions, for example for fixing it to a non-planar support. Finally, is also represented at the figure 1 a pressure relief valve 5 connected to cell 2 (L1 / C6) which, although not essential, allows air to escape in case of overpressure (for example, due to overinflation, temperature rise, movement at increasing altitude, etc.). In the example of the figure 2 , we are dealing with a structure 1 which is provided with two matrices MA1 and MA2 arranged side by side.

[0049] These exhibit essentially the same "architecture" as the M matrix of the figure 1 However, they differ from them in the number and arrangement of the channels 3 connecting the cells.

[0050] Thus, considering matrix M1 and assuming that the inflation nozzle (not shown) is connected to cell 2(L6 / C6), the cells communicate step by step along line L6. However, only cell 2(L6, C1) communicates with the neighboring cell in line L5, and it can be observed that channels 3 are present only to ensure communication between cells 2 in a spiral or near-spiral arrangement. Under these conditions, and considering, for example, that cell 2(L4 / C5) undergoes an impact sufficient to deform, the air stored within it can only flow through channel 3, which connects it to cell 2(L3 / C5). It is easy to understand that its capacity to deform is less compared to the same cell 2(L4 / C5) in structure 1 of the figure 1 which communicates with all its neighbors via four canals.

[0051] Under these conditions, it is preferable to use an M1 matrix in situations where the structure undergoes rapid and violent shocks, such as military contexts, for example, war, riots, etc. Conversely, structure 1 of the figure 1 will be used more for less violent impacts such as those encountered during sports activities.

[0052] Within the M2 matrix of the figure 2 The cells communicate step by step in row L6. However, communication with the remaining cells occurs exclusively according to the orientation of columns C1 to C6. In this configuration, the ability of cells 2 to deform is essentially the same as in the structure of matrix M1.

[0053] In the implementation of the figure 3 (where the inflation nozzle has not been shown), we are dealing with an arrangement of cells 2 and channels 3 analogous to that of the matrix of the figure 1 .

[0054] However, it is observed that the size of cells 2 in columns C3 and C4 is greater than that of the other cells.

[0055] This can be explained, for example, by the morphology or the region of the body that such a structure is intended to protect. Thus, for example, this structure is designed to cover an individual's back, so that the larger cells of columns C3 and C4 will cover the vertebral region.

[0056] The situation depicted in the figure 5 is a theoretical construct. More precisely, it depicts two adjacent cells 2 connected by a channel 3, and assumes that the structure in which they are embedded has been inflated to its maximum. In such a situation, both the cells 2 and the channels 3 are considered to occupy a maximum volume.

[0057] Artificially, we consider here that the cross-sections of cells 2 and channels 3 are circular, and we have referenced their diameters D and d. In reality, these cross-sections are not perfectly circular. To use a visual analogy, these cross-sections are more like a rugby ball. Under these conditions, the values ​​D and d correspond to the largest dimension of their cross-section.

[0058] According to the invention, the D / d ratio is at least 10, preferably at least 14. Thus, the dimensions of the channels 3 are large enough to allow the structure 1 to inflate, but small enough to counteract, that is, limit, the escape of air towards neighboring cells in case of impacts. Other means of limiting / countering this air escape can also be considered.

[0059] Thus, in accordance with the method of implementation of the figure 7 We are dealing with channels 3 whose path is sinuous. Under these conditions, it is understandable that during inflation of the structure, as well as during an impact, air is forced to circulate through the channels 3 to reach the cells. However, this circulation is impeded by the various bends resulting from the sinuosity. In practice, during an impact, the cells 2 deform, but relatively little, so that the shock wave is only very partially transmitted. In other words, the structure 1 is neither completely rigid nor excessively deflated.

[0060] In the case of the implementation method of the figure 8 We are dealing with a porous intermediate layer 7 that is sandwiched between leaves 10 and 11. In practice, the nature and thickness of this layer must be chosen so that it is sandwiched and bonded together with the leaves. Advantageously, this layer will be of the same nature as leaves 10 and 11 and will have an open-cell structure so as to be porous and allow air to pass through. However, as in the previous embodiment, this air circulation is somewhat restricted.

[0061] Thanks to the invention, the fact that the cells are not contiguous allows for excellent deformability of the structure. Furthermore, due to the presence of channels between these cells and in accordance with all the described embodiments, it is possible to effectively slow the movement of fluid between the cells, so that the shock wave transmitted by the targeted cells is only partially transmitted into the surrounding region.

[0062] In the variant implementation of the figures 9 et 10 , cells 2 have the particularity of having a hinged flap 8 which is fixed to the wall of one of the sheets 10 and 11 and which extends to the end of one of the channels 3. Thus, when the air flows from right to left as shown in the figure 9 The airflow is sufficient for each flap 8 to retract and not obstruct the flow. Conversely, if the airflow is in the opposite direction, each flap presses against the end of channel 3, at least partially blocking it. In practice, this could be a tab, for example oval-shaped, welded to a wall of cell 2 opposite channel 3, which obstructs the channel as soon as pressure is applied to the cell.

[0063] Finally, it is represented in a very simplified way at the figure 11 an individual P that we propose to equip with a clothing item AR. The latter consists (from right to left in the figure) of a bulletproof vest G, a tension shield 9 and a structure 1 conforming to the present invention.

[0064] Of course, in an unrepresented variant, the structure according to the invention can simply be slipped inside a garment.

[0065] It should be noted that the organization of cells 2 according to a two-dimensional matrix allows the design of this matrix to be adapted according to the clothing item that one wishes to equip.

[0066] As a guide, such a structure, depending on the intended use, is suitable for inflation between 10 and 30 PSI, i.e., approximately 0.7 to 2 bar, which allows the use of a hand pump (or even a mini-compressor or an inflation bulb).

[0067] This structure adapts to a light weight impact at very high speed (ballistic) but also to a heavy weight impact at very low speed (fall during extreme sports) thanks to the wide possibility of pressure adjustment due to its resistance.

[0068] The various stages of an example of manufacturing a structure according to the invention can be summarized as follows: 1 / Define the airflow resistance at the cell outlet according to the intended impact. For example, consider a 200-joule impact resulting in a transmitted force of 12,000 newtons, or a 50-joule impact resulting in a transmitted force of 4,000 newtons. In practice, for example, a 200-joule shot is performed, and a performance "X" is observed with a simple channel 3 geometry. Then, the same test is performed with a different channel design, and the performance "Y" is assumed to be acceptable. The best configuration for the intended application is then deduced.2 / Calibration of the overpressure valve 5; 3 / Drawings of the channel shape 3; 4 / Creation of the mold for HF welding; 5 / Welding of the TPU sheets according to their thickness; 6 / Inflation using the hand pump; 7 / Validation by shock and measurement using a sensor / modeling clay known as "plastiline" / by the "pig test" (measurement of the cardiac back effect on a living subject).

[0069] This last test consists of putting the animal in a state of brain death, probing it and then measuring the change in heart rate following the shot during the shot its heart rate can be measured, and other reactions.

[0070] Throughout the preceding description, it has been assumed that the fluid used to inflate the cells is air. However, a liquid such as water can also be used.

Claims

1. An inflatable shock-absorbing cellular structure (1) which consists of two sealed sheets (10, 11) welded to each other along weld lines (100) which delimit inflatable cells (2), - said inflatable cells (2) being arranged in at least one two-dimensional matrix (MA, MA1, MA2) of n rows (L1-L6) and m columns (C1-C6) of cells (2), n and m being equal or different integers, each greater than or equal to 2; - a peripheral cell (2) of said matrix (MA, MA1, MA2) is connected to an inflation nozzle (4); designed so that: - said cells (2) are not contiguous; - the cells (2) of the row and / or of the column to which said peripheral cell (2) connected to said inflation nozzle (4) belongs, communicate step by step via a channel (3) forming a constriction this channel (3) being a small passage that extends between two cells without being part of them, while each remaining cell (2) from said matrix (MA, MA1, MA2) is also connected to at least one of the neighboring cells (2) of the same row and / or of the same column by a communication channel (3) forming a constriction, - each of said channels (3) is shaped to slow down the flow of an inflation fluid passing therethrough, or said structure incorporates means shaped to slow down the flow of a fluid for inflating the cells (2) through said channels (3) forming a constriction; - and that in the inflated state, the ratio (D / d) between the largest dimension of the cross section of a cell (2) and the largest dimension of the cross section of a channel (3) is at least equal to 10, preferably at least equal to 14.

2. The structure (1) according to claim 1, characterized in that each cell (2) of said matrix (MA, MA1, MA2) communicates with each of the neighboring cells (2) of the same row and of the same column by a channel (3) forming a constriction.

3. The structure (1) according to claim 1, characterized in that, with the exception of the cells (2) of the peripheral row and / or column connected to said inflation nozzle (4), the remaining cells (2) communicate only with two of the neighboring cells (2) of the same row and / or of the same column by a channel (3) forming a constriction.

4. The structure (1) according to one of the preceding claims, characterized in that it is provided with an overpressure exhaust valve (5).

5. The structure (1) according to one of the preceding claims, characterized in that said sealed sheets (10, 11) are made of / based on thermoplastic polyurethane.

6. The structure (1) according to one of claims 1 to 5, characterized in that said channels (3) have a sinuous shape.

7. The structure (1) according to one of claims 1 to 6, characterized in that at least some cells (2) contain, at one end of said channel (3), a tilting flap (8) which disappears that is to say retracts during the passage of said inflation fluid in a flow direction, respectively presses against said end of said channel (3) in the opposite direction, thus impeding the passage of the fluid in said channel.

8. The structure (1) according to one of claims 1 to 7, characterized in that a porous intermediate layer (7) is interposed between said two sealed sheets (10, 11).

9. The structure (1) according to claim 8, characterized in that said intermediate layer (7) is made of / based on thermoplastic polyurethane.

10. An item (AR), in particular a protective clothing item, for protection against shocks, characterized in that it is provided with at least one structure (1) according to one of the preceding claims.

11. The clothing item (AR) according to claim 10, characterized in that it is chosen from the following group: bulletproof vest, breastplate, jacket, waistcoat, coat, body protective element.