Abstract
The present invention provides an apparatus to disperse and attenuate mechanical waves which travel through a human brain upon direct and indirect blunt head trauma. The apparatus comprises a pressurizable and ventable outer balloon shell encasing an inner hard shell. The pressurizable and ventable outer balloon shell releases a pressurized gas to atmosphere upon an impact to said pressurizable and ventable outer balloon shell. The pressurizable and ventable outer balloon shell is configured to compartmentalize an impact region, to reduce amplitudes of incident, reflected and transmitted mechanical waves and to dampen resonance of the mechanical waves delivered to both the apparatus and a human head.
Claims
1. A mechanical-waves dispersing protective headgear apparatus, comprising: a pressurizable and ventable outer balloon shell enclosing a plurality of inner layers, and an inner hard shell; the pressurizable and ventable outer balloon shell, provided as an airtight shell reversibly pressurizable by a gas, which is configured to be reversibly and depressibly deformable by an impact of a blunt trauma at an angle to a planar surface of said pressurizable and ventable outer balloon shell, which is configured to release the gas upon said impact of said blunt trauma, which comprises a dome configured in a substantially hemispherical bowl shape conforming to a human head and a ballooned rim adjoining a circumferential margin of the dome, which provides a pressurizable space that encloses a plurality of the inner layers concentrically stacked up, which has a pressurized-gas intake valve and a plurality of pressure-triggerable gas release valves on a lower surface of a circumference of the ballooned rim, which has a pressure sensor device disposed on an outer surface of the ballooned rim having an alarm function for a gas pressure above or below an expected range of the gas pressure inside said pressurizable and ventable outer balloon shell and which slidably encases the inner hard shell; and the inner hard shell, provided in a single-piece dome configuration, which comprises at least three tight-bonded layers with an outer layer and an inner layer made of an impact resistant polymer and a mid layer made of a plurality of non-polymeric porous materials, which is undeformable upon the impact of the blunt trauma, which covers an area of the human head, which is configured to prevent fracture of a skull upon the impact of the blunt trauma to the skull and which is configured to reduce transmission of mechanical waves of the impact across said inner hard shell.
2. The mechanical-waves dispersing protective headgear apparatus according to claim 1, wherein the inner layer comprises: the inner layer, provided as a reversibly deformable thin sheet in a dome configuration covering a majority of an inner surface of an outer wall of the pressurizable and ventable outer balloon shell, which is enclosed detachably inside the pressurizable and ventable outer balloon shell, which comprises a plurality of ventable gas cells fixedly attached to an inner surface of said inner layer arranged in a mosaic pattern and a plurality of penetrating holes through an entire thickness of said inner layer in between the ventable gas cells, which comprises a ruffled free end extending from a circumferential edge of said inner layer, which serves as a boundary to the mechanical waves and which is configured to reduce amplification of an amplitude of the mechanical waves across said inner layer; the ventable gas cell, provided in a configuration of a broad base fixedly glued to a two-ply deformable semi-elliptical dome to produce a reversibly closable gas space, which is configured to maintain an equal pressure of the gas inside said ventable gas cell to a pressure of said gas in the pressurizable and ventable outer balloon shell outside said ventable gas cell and which is configured to retain a pressurized gas inside said ventable gas cell by and to release said gas through a two-ply offset gas vent slit of said semi-elliptical dome; and the ruffled free end, provided in a configuration of a plurality of thin linear strips for a length with one end of said ruffled free end being an extension from the circumferential edge of said inner layer and the other end being free and unattached, which is detachably housed inside the ballooned rim, which detachably anchors said inner layer inside said ballooned rim and which is configured to reduce resonant vibration of said inner layer upon a delivery of the mechanical waves of the impact of the blunt trauma to said inner layer.
3. The mechanical-waves dispersing protective headgear apparatus according to claim 1, wherein the pressurizable and ventable outer balloon shell is made of a semi-rigid thermoplastic elastomer which withstands a range of the gas pressure inside said pressurizable and ventable outer balloon shell above atmospheric pressure over a range of temperature from 0° F. to 175° F. and the mechanical waves from the impact of the blunt trauma.
4. The mechanical-waves dispersing protective headgear apparatus according to claim 1, wherein the pressurizable and ventable outer balloon shell is configured to be inflatably pressurized above atmospheric pressure by insufflation of the gas into said pressurizable and ventable outer balloon shell through the pressurized-gas intake valve and which is configured to release the pressurized gas to atmosphere through the pressure-triggerable gas release valves by reversibly depressive deformation of the outer wall of said pressurizable and ventable outer balloon shell squeezing out said pressurized gas at the site of the impact of the blunt trauma through said pressure-triggerable gas release valves upon said impact of said blunt trauma that increases the gas pressure in said pressurizable and ventable outer balloon shell above a predetermined limit of pressurization of said gas pressure, thereby reducing an amplitude of the mechanical waves of the impact of the blunt trauma.
5. The mechanical-waves dispersing protective headgear apparatus according to claim 1, wherein the gas pressure inside the pressurizable and ventable outer balloon shell is variably adjustable in proportion to a sum of a maximum anticipated weight of a source of the blunt trauma and a known weight of a victim of said blunt trauma, an anticipated velocity of the blunt trauma and an anticipated type of the blunt trauma.
6. The mechanical-waves dispersing protective headgear apparatus according to claim 1, wherein at least one pressure-triggerable gas release valve is assigned to each anatomic region of the human head, including frontal, parietal, temporal and occipital regions to facilitate release of the gas upon the impact on a particular region of the head through a nearest regional pressure-triggerable gas release valve.
7. The mechanical-waves dispersing protective headgear apparatus according to claim 2, wherein the inner layer comprises at least three tightly bonded plies with an outer ply and an inner ply made of a thermoplastic elastomer and a mid ply made of a plurality of non-polymeric porous materials, which is configured to dampen a fundamental frequency of vibration of said outer and inner plies by a lower fundamental frequency of vibration of the mid ply.
8. The mechanical-waves dispersing protective headgear apparatus according to claim 2, wherein the ventable gas cell comprises an opening on one side of the semi-elliptical dome of said gas cell through which the gas inside the pressurizable and ventable outer balloon shell moves into an inner space of said ventable gas cell and gets trapped by an one-way flap valve attached to an inner surface of said semi-elliptical dome until the gas pressure inside said pressurizable and ventable outer balloon shell is equalized with the gas pressure inside said inner space of said ventable gas cell.
9. The mechanical-waves dispersing protective headgear apparatus according to claim 2, wherein the semi-elliptical dome comprises: an outer ply made of a thermoplastic elastomer having a higher hardness on the Shore scale than an inner ply made of a different thermoplastic elastomer that is fixedly bonded with the outer ply; a gas vent slit on a relatively mid line of said semi-elliptical dome along a longitudinal axis of said semi-elliptical dome is provided in an offset configuration with an outer slit in the outer ply separated by a distance from and running in parallel with an inner slit in the inner ply, with the outer ply configured to cover the inner slit for said distance; the gas vent slit is in a closed configuration with the outer ply covering the inner slit preventing said inner slit from opening when the gas from the pressurizable space of the pressurizable and ventable outer balloon shell moves inside said ventable gas cell and the semi-elliptical dome is distended with the gas but not pressed down; and the gas vent slit is in an open configuration when both convex sides of the semi-elliptical dome across the gas vent slit are pressed down to a point both the outer slit and inner slit are concurrently open, through which the gas inside said ventable gas cell is released to the pressurizable space of the pressurizable and ventable outer balloon shell.
10. The mechanical-waves dispersing protective headgear apparatus according to claim 2, wherein a plurality of the inner layers are concentrically stacked up in the pressurizable and ventable outer balloon shell in an interlaced configuration that each convex side of the semi-elliptical dome across the gas vent slit of said semi-elliptical dome of a ventable gas cell of the first inner layer is aligned with an edge of each broad base of another ventable gas cell of the second inner layer disposed under said first inner layer.
11. The mechanical-waves dispersing protective headgear apparatus according to claim 2, wherein a plurality of the inner layers are configured to compartmentalize a region of the impact of the blunt trauma for, releasing the pressurized gas from said region of said impact of said blunt trauma to preferentially reduce the amplitude of the impact of the blunt trauma at the region of the impact by venting a plurality of the ventable gas cells of the inner layers clustered around the region of the impact of the blunt trauma as a primary release of the pressurized gas to the pressurizable space of the pressurizable and ventable outer balloon shell outside said plurality of said ventable gas cells.
12. The mechanical-waves dispersing protective headgear apparatus according to claim 2, wherein the ruffled free end is provided in a corrugated configuration in two out-of-phase sine waves along a longitudinal axis of said ruffled free end, with the first strip of said ruffled free end having one sine wave configuration and the second strip of said ruffled free end having an out-of-phase sine wave configuration with the sine wave configuration of the first strip.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1A-1B show a schematic presentation of a pressurizable and ventable outer balloon shell and an inner hard shell, respectively.
[0023] FIG. 2A˜2H show a schematic profile view of individual components of the pressurizable and ventable outer balloon shell and the inner hard shell: FIG. 2A represents an outline view of the pressurizable and ventable outer balloon shell without independent inner layers inside the pressurizable and ventable outer balloon shell; FIG. 2B shows a posterior-to-anterior outline view of the pressurizable and ventable outer balloon shell without the independent inner layers; FIG. 2C˜2F show a schematic profile outline view of the independent inner layers and FIG. 2G shows the inner hard shell; FIG. 2H shows a schematic profile outline view of the pressurizable and ventable outer balloon shell with the independent inner layers encased inside the pressurizable and ventable outer balloon shell and of the inner hard shell.
[0024] FIG. 3A˜3G illustrate a schematic configuration of ventable gas cells attached on an inner surface of an independent inner layer: FIG. 3A represents a schematic profile outline view of the ventable gas cells arranged in tandem along the inner surface of the independent inner layer; FIG. 3B˜3D show a schematic outline view of a hexagonal ventable gas cell; FIG. 3E˜3G show a schematic outline view of a pentagonal ventable gas cell.
[0025] FIG. 4A˜4D depict a schematic layout of a plurality of the independent inner layers stacked up in a concentric configuration inside the pressurizable outer balloon shell: FIG. 4A shows a schematic profile outline view of the independent inner layers in an interlaced configuration; FIG. 4B-4C show two different layouts of the ventable gas cells on each independent inner layer; FIG. 4D shows a see-through outline view of both independent inner layers stacked up together in the interlaced configuration.
[0026] FIG. 5A˜5F show a schematic illustration of an offset configuration of a gas vent slit on a semi-elliptical dome of the ventable gas cell: FIG. 5A shows a three-dimensional view of the hexagonal ventable gas cell; FIG. 5B shows a profile outline view of the semi-elliptical dome; FIG. 5C shows the semi-elliptical dome in a closed configuration; FIG. 5D shows a magnified profile outline view of the offset slit in the closed configuration; FIG. 5E shows semi-elliptical domes in an open configuration upon an impact; FIG. 5F shows a magnified profile outline view of the offset slit in the open configuration upon the impact.
[0027] FIG. 6A˜6D show a schematic drawing of components of the independent inner layer: FIG. 6A shows a profile outline view of a three-ply structure of the independent inner layer; FIG. 6B shows a three-dimensional view of an inner ply of the independent inner layer; FIG. 6C shows a three-dimensional view of a mid ply and an outer ply of the independent inner layer; FIG. 6D shows a schematic profile outline view of a section of the pressurizable and ventable outer balloon shell comprising an outer and an inner wall of the pressurizable and ventable outer balloon shell enclosing a plurality of stacked-up independent inner layers.
[0028] FIG. 7A-7B show a schematic profile outline view of an example of an operation of a section of the pressurizable and ventable outer balloon shell enclosing a plurality of stacked-up independent inner layers upon an impact: FIG. 7A depicts the pressurizable and ventable outer balloon shell enclosing a plurality of stacked-up independent inner layers before the impact; FIG. 7B illustrates the pressurizable and ventable outer balloon shell and the ventable gas cells attached to the independent inner layers venting a gas upon the impact.
[0029] FIG. 8A˜8G illustrate schematic outline views of examples of a collision between two oppositely placed human heads and mechanisms of the boundary effects of mechanical waves from the collision; FIG. 8A-8B show a collision between two unprotected human heads; FIG. 8C-8D show a collision between two protected human heads with each head wearing a headgear having the pressurizable and ventable outer balloon shell; FIG. 8E illustrates mechanical waves resulting from the collision between the unprotected human heads; FIG. 8F shows mechanical waves resulting from a protective headgear having a single layered pressurizable and ventable outer balloon shell; FIG. 8G shows mechanical waves resulting from a protective headgear having a pressurizable and ventable outer balloon shell with three inner layers inside the pressurizable and ventable outer balloon shell.
[0030] FIG. 9A-9B show a schematic detailed view of the pressurizable and ventable outer balloon shell; FIG. 9A shows a schematic profile outline view of the pressurizable and ventable outer balloon shell having a pressurized-gas intake valve, pressure-triggerable gas release valves and a pressure sensor device; FIG. 9B shows a schematic three-dimensional view of a ballooned rim portion of the pressurizable and ventable outer balloon shell.
[0031] FIG. 10A˜10F illustrate a ruffled free end of the independent inner layer and surface waves across a human head upon an impact; FIG. 10A shows a schematic view of the ruffled free end of the independent inner layer; FIG. 10B depicts a schematic profile outline view of sine-wave configurations of the ruffled free end; FIG. 10C-10D show the surface waves causing resonant amplification of mechanical waves upon the impact on an unprotected human head; FIG. 10E-10F show the surface waves with resonant amplification of mechanical waves upon the impact on a protected human head wearing the protective headgear having a pressurizable and ventable outer balloon shell.
[0032] FIG. 11A-11B show a schematic view of the inner hard shell: FIG. 11A shows a schematic three-dimensional view of the inner hard shell; FIG. 11B shows a schematic profile outline view of a three-layered structure of the inner hard shell.
DETAILED DESCRIPTION OF THE DRAWINGS
[0033] As described below, the present invention provides a mechanical-waves dispersing protective headgear apparatus and methods of use. It is to be understood that the descriptions are solely for the purposes of illustrating the present invention, and should not be understood in any way as restrictive or limited. Embodiments of the present invention are preferably depicted with reference to FIGS. 1 to 11, however, such reference is not intended to limit the present invention in any manner. The drawings do not represent actual dimension of devices, but illustrate the principles of the present invention.
[0034] FIG. 1A-1B show a schematic example of a pressurizable and ventable outer balloon shell and an inner hard shell, which would be useful for football in this particular example. FIG. 1A shows a three-dimensional view of the pressurizable and ventable outer balloon shell which comprises a dome portion 1, a lower ballooned rim 2, a frontal ballooned rim 3, a face guard harness attachment 4 and a face guard 5. FIG. 1B shows an inner hard shell 5 which is to be encased by the pressurizable and ventable outer balloon shell shown in FIG. 1A.
[0035] FIG. 2A˜2H show a schematic profile view of individual components of the pressurizable and ventable outer balloon shell and the inner hard shell. FIG. 2A shows an outline view of the pressurizable and ventable outer balloon shell without independent inner layers inside the pressurizable and ventable outer balloon shell, which comprises the dome portion 1 adjoining the lower ballooned rim 2, the frontal ballooned rim 3 and a temporal ballooned rim 7. An inner wall 8 of the pressurizable and ventable outer balloon shell borders a balloonable internal space 9 of the dome portion 1, a balloonable internal space 11 of the temporal ballooned rim 7 and balloonable internal space 10 of the lower ballooned rim 2. A concave space 12 underneath the inner wall 8 of the pressurizable and ventable outer balloon shell encases the inner hard shell 5 shown in FIG. 1B. FIG. 2B of the posterior-to-anterior outline view of the pressurizable and ventable outer balloon shell without the independent inner layers shows both the temporal ballooned rims 7 and 13 with the corresponding balloonable internal space 11 and 14, respectively. FIG. 2C˜2F show a schematic profile outline view of four independent inner layers 15 of FIG. 2C, 20 of FIG. 2D, 21 of FIG. 2E and 22 of FIG. 2F. FIG. 2G shows a schematic profile outline view of the inner hard shell 6. An outermost independent inner layer 15 shows a profile outline view of one ventable gas cell 17 arranged in a mosaic pattern with an intervening space 16 and a profile outline view of a temporal portion 19 and a lower portion 18 of a ruffled free end of the independent inner layer. The profile outline view of the inner hard shell 6 is shown with dotted dome shaped lines inside, indicating that the inner hard shell is multi-layered. FIG. 2H shows a schematic profile outline view of the pressurizable and ventable outer balloon shell with the independent inner layers and the inner hard encased inside the pressurizable and ventable outer balloon shell and of the inner hard shell.
[0036] FIG. 3A illustrates a schematic profile outline view of ventable gas cells 17 attached on an inner surface of an independent inner layer arranged in tandem along the inner surface of the independent inner layer, which bulges toward a center of a dome configuration of the independent inner layer. FIG. 3B shows a schematic top-down outline view of the hexagonal ventable gas cell 17 which comprises a broad base 23 and a semi-elliptical dome 24 which is fixedly glued to the broad base 23. In a mid-line of the semi-elliptical dome, there is provided a gas vent slit 25 along a longitudinal axis of the semi-elliptical dome 24 and a gas intake opening 27 on one side of the semi-elliptical dome. The gas intake opening 27 is closed and opened by an one-way valve 26 which is disposed on an undersurface of the semi-elliptical dome. FIG. 3C shows a schematic profile outline view of the ventable gas cell with an inner space 28 formed by the broad base 23 and the semi-elliptical dome 24. The gas vent slit 25 is located on a top portion of the semi-elliptical dome 24. FIG. 3D shows a schematic three-dimensional view of the ventable gas cell. FIG. 3E shows a schematic top-down outline view of a pentagonal ventable gas cell 29 which is configured similarly. FIG. 3F shows a schematic profile outline view of the pentagonal ventable gas cell with the gas vent slit 30 located on a top portion of the semi-elliptical dome. FIG. 3G shows a schematic three-dimensional view of the pentagonal ventable gas cell.
[0037] FIG. 4A˜4D depict a schematic layout of a plurality of the independent inner layers stacked up in a concentric configuration inside the pressurizable outer balloon shell. FIG. 4A shows a schematic profile outline view of the independent inner layers in an interlaced configuration. FIG. 4B represents a layout of the hexagonal ventable gas cell 17 and the pentagonal ventable gas cell 29 arranged in a mosaic pattern on an independent inner layer 31 in a configuration having a central pentagon pointing toward a lower portion of the independent inner layer 31. In between the ventable gas cells, there is provided a plurality of perforated holes that go through an entire thickness of the independent inner layer. FIG. 4C illustrates a different configuration of the layout of the ventable gas cells in a configuration having a central pentagon pointing toward a upper portion of another independent inner layer 33. FIG. 4D shows a see-through outline view of both independent inner layers stacked up together in the interlaced configuration which allows one ventable gas cell to overlie one side of the other ventable gas cell across the slit of the other ventable gas cell shown in FIG. 3B and FIG. 3C resulting in two ventable gas cells to overlap one ventable gas cell.
[0038] FIG. 5A˜5F shows a schematic illustration of an offset configuration of a gas vent slit on a semi-elliptical dome of the ventable gas cell. FIG. 5A shows a three-dimensional view of the ventable hexagonal gas cell having the slit 25 on the semi-elliptical dome 24 and the gas intake opening 27. FIG. 5B-5C show a schematic profile outline view of the semi-elliptical dome 24 which is made as a two-ply structure having an outer ply 35 bonded with an inner ply 37 under heat to form an inseparable sheet. In FIG. 5D, a magnified profile outline view of the slit 25 in a closed configuration shows an offset configuration of the slit, with an outer slit 34 separate by a distance from the inner slit 36 in a way that the outer ply 35 covers the inner slit 36 of the inner ply 37 for the offset distance between the outer slit 34 and the inner slit 36. The outer ply 35 is made of one thermoplastic elastomer and has a higher hardness on the Shore scale than the inner ply 37 made of a different thermoplastic elastomer having a softer hardness. On insufflation of a gas into the ventable gas cell, the inner ply 37 could be stretched but the outer ply 35 may not be stretchable by a pressurized gas inside the ventable gas cell, based on their difference in the hardness. The offset configuration of the two slits 34 and 36 is to let the semi-elliptical dome 24 distended by the pressurized gas which cannot escape through the inner slit 36 until the outer slit 34 is cracked open together with opening of the inner slit 36. FIG. 5E shows a schematic profile outline view of two independent inner layers having a layout of three ventable gas cells, with two ventable gas cells 38 and 40 on top of one ventable gas cell 42 below. One edge 39 of a broad base of the ventable gas cell 38 is vertically aligned with one side of a semi-elliptical dome of the ventable gas cell 42 across a slit 43 and the other edge 41 of a broad base of the ventable gas cell 40 is vertically aligned with the opposite side of the semi-elliptical dome of the ventable gas cell 42 across the slit 43. Upon an impact 44 at an angle to the ventable gas cells, both the edges 39 and 41 of the broad bases of the ventable gas cells 38 and 40, respectively, press down each side of the semi-elliptical dome of the ventable gas cell 42 along an opposite direction to a direction of the impact 44, opening the slit 43 thereby releasing a gas trapped inside the ventable gas cell 42. In FIG. 5F, a magnified profile outline view of the slit of the semi-elliptical dome illustrates an opening 45 of the outer ply 35 and an opening 46 of the inner ply 37. Until both plies 35 and 37 are open through the openings 45 and 46, the gas inside the ventable gas cell 42 will not be released.
[0039] FIG. 6A˜6D show a schematic drawing of the components of the independent inner layer. FIG. 6A shows a profile outline view of a three-ply structure of the independent inner layer which comprises an inner ply 47, a mid ply 48 and an outer ply 49. A plurality of ventable gas cell 17 are fixedly glued to an inner surface of the inner ply 47, arranged in tandem separated by a space. Both the inner ply 47 and outer ply 49 are made of a thermoplastic elastomer and the mid ply 48 is made of a woven cloth fabric. The three plies are bonded together under pressure and heat to impart enough hardness to maintain the dome configuration shown in FIG. 2C with reversible deformability over a range of temperature and enough tear strength to withstand repetitive deformative impacts from the blunt trauma without material failure, while reducing a natural vibration frequency of the thermoplastic elastomer by a natural vibration frequency of the woven cloth fabric. FIG. 6B shows a three-dimensional view of the inner ply 47 of the independent inner layer having a plurality of ventable gas cells 17 and a plurality of small holes 32 located in between ventable gas cells. FIG. 6C shows a three-dimensional view of the mid ply 48 and the outer ply 49 of the independent inner layer, with both of which showing a plurality of the small holes. FIG. 6D shows a schematic profile outline view of a section of the pressurizable and ventable outer balloon shell comprising an outer wall 50 and an inner wall 51 of the pressurizable and veritable outer balloon shell enclosing a plurality of stacked-up independent inner layers. A direction of convexity of each semi-elliptical dome of the ventable gas cell is toward the inner wall 51.
[0040] FIG. 7A-7B show a schematic profile outline view of an example of an operation of a section of the outer wall 52 and the inner wall 53 of the pressurizable and ventable outer balloon shell enclosing five stacked-up independent inner layers 54˜58 and a section of the inner hard shell 59 upon an impact. FIG. 7A depicts a pressurized pressurizable and ventable outer balloon shell with a gas enclosing the stacked-up independent inner layers 54˜58 having distended ventable gas cells with the gas before the impact. In FIG. 7B, upon an impact 60 of a blunt trauma toward a victim's head which generates a counter force 61 from the victim's head, both the pressurized pressurizable and ventable outer balloon shell and ventable gas cells attached to the independent inner layers are squeezed to increase a gas pressure inside the pressurized pressurizable and ventable outer balloon shell beyond a limit both the pressurizable and veritable outer balloon shell and ventable gas cells are configured to withstand. The pressurized gas inside both the pressurizable and ventable outer balloon shell and ventable gas cells is simultaneously released in directions 62 and 63 away from the impact through vents located around the ballooned rim, thereby decreasing an amplitude (kinetic energy) of the impact of the blunt trauma before the amplitude reaches the inner hard shell 59.
[0041] FIG. 8A˜8G illustrate schematic outline views of examples of a collision between two oppositely placed human heads and mechanisms of the boundary effects of mechanical waves from the collision. FIG. 8A shows a diagonal frontal collision between two unprotected human heads 64 and 65, respectively. Following the collision, illustrated in FIG. 8B, both the heads 66 and 67 bounce back after having received and retaining full mechanical waves of the collision inside the head. FIG. 8C shows a diagonal frontal collision between two protected human heads 68 and 69, respectively, with each head wearing a headgear with the pressurizable and ventable outer balloon shell. Following the collision, illustrated in FIG. 8D, both the heads 70 and 71 wearing the headgear with the pressurizable and ventable outer balloon shell bounce back after having received and retaining reduced mechanical waves of the collision inside the head. FIG. 8E illustrates mechanical waves from the collision between the unprotected human heads, showing incident mechanical waves 72 from the head 64 of FIG. 8A coming to a boundary 73 established between a contact point of the collision between both the heads 64 and 65. The incident mechanical waves 72 are both reflected at the boundary 73 as 74 and transmitted as 75 across the. boundary 73. Similarly, incident mechanical waves 79 from the head 65 of FIG. 8A are both reflected at the boundary 73 as 80 and transmitted as 81 across the boundary 73. Colliding mechanical waves toward and passing each other at a boundary of a matter produce zero displacement of the matter but stress (amplitude) delivered to the matter momentarily is doubled. Furthermore, polarity of the reflected waves at a fixed end of the matter is the same as that of the incident waves generating zero displacement but stress at the fixed end of the matter is doubled momentarily. Therefore, a sum of stress (amplitude) of the mechanical waves of 72+(74+81) becomes a total amplitude of the mechanical waves at the frontal part of the head 64 of FIG. 8A and a sum of stress (amplitude) of the mechanical waves of 79+(75 +80) becomes a total amplitude of the mechanical waves at the frontal part of the head 65 of FIG. 8A. A sum of stress (amplitude) of the mechanical waves of 74+81 becomes an amplitude of mechanical waves 82 coming to a posterior boundary 83 of the head 64 of FIG. 8A. Similarly, a sum of stress (amplitude) of the mechanical waves of 75+80 becomes an amplitude of mechanical waves 76 coming to a posterior boundary 77 of the head 65 of FIG. 8A. At both the posterior boundaries 83 and 77, these mechanical waves 82 and 76 are reflected as 84 and 78, respectively. A sum of stress (amplitude) of 82+84 for the head 64 of FIG. 8A becomes an amplitude of the mechanical waves delivered to an occipital region of the head 64, causing an injury occurring in an opposite site of the original collision at 73. Similarly, a sum of stress (amplitude) of 76+78 for the head 65 of FIG. 8A becomes an amplitude of the mechanical waves delivered to an occipital region of the head 65. [0042] FIG. 8F shows mechanical waves delivered to the head wearing a protective headgear which has a pressurizable and ventable outer balloon shell having a single inner layer insufflated with a pressurized gas. Incident mechanical waves 85 from the head 68 of FIG. 8C come to a boundary 86 established between a contact point of the collision between the pressurizable and ventable outer balloon shells for each head 68 and 69. The incident mechanical waves 85 are reflected as 87 and released as 88 at the boundary 86 through the vents of the pressurizable and ventable outer balloon shell, and then transmitted as 89. Similarly, incident mechanical waves 93 from the head 69 of FIG. 8C are reflected as 96 at the boundary 86 and released as 94 at the boundary 86 through the vents of the pressurizable and ventable outer balloon shell, and then transmitted as 95 across the boundary 86. A sum of stress (amplitude) of the mechanical waves of 85+(87+95) becomes a total amplitude of the mechanical waves at the frontal part of the head 68 of FIG. 8C and a sum of stress (amplitude) of the mechanical waves of 93+(89+96) becomes a total amplitude of the mechanical waves at the frontal part of the head 69 of FIG. 8C. Similar to a mechanism of an increase in stress (amplitude) of the mechanical waves illustrated in FIG. 8E, a sum of stress (amplitude) of the mechanical waves of 87+95 becomes an amplitude of mechanical waves 97 coming to a posterior boundary 98 of the head 68 of FIG. 8C. For the head 69 of FIG. 8C, a sum of stress (amplitude) of the mechanical waves of 89+96 becomes an amplitude of mechanical waves 90 coming to a posterior boundary 91 of the head 69. At both the posterior boundaries 98 of the head 68 and 91 of the head 69 of FIG. 8C, these mechanical waves 97 and 90 are reflected as 99 and 92, respectively. A sum of stress (amplitude) of 97+99 for the head 68 of FIG. 8C becomes an amplitude of the mechanical waves delivered to an occipital region of the head 68. A sum of stress (amplitude) of 90+92 for the head 69 of FIG. 8C becomes an amplitude of the mechanical waves delivered to an occipital region of the head 69. The diagram of FIG. 8F illustrates a reduction in the amplitude of the mechanical waves to both the heads by releasing the pressurized gas from the the pressurizable and ventable outer balloon shell having a single inner layer.
[0043] FIG. 8G shows mechanical waves on the head 68 of FIG. 8C wearing protective headgear having a pressurizable and ventable outer balloon shell with three inner layers inside the pressurizable and ventable outer balloon shell insufflated with a pressurized gas. Incident mechanical waves 100 from the head 68 of FIG. 8C come to a boundary 103 established between a contact point of the collision between the pressurizable and ventable outer balloon shells for each head 68 and 69. The incident mechanical waves 100 in this case needs to go through two additional boundaries of 101 and 102 undergoing a process of being reflected, transmitted and re-reflected at each boundary, while releasing the pressurized gas thereby reducing amplitudes of the mechanical waves at each boundary before being transmitted to the frontal region of the head 69 of FIG. 8C wearing a pressurizable and ventable outer balloon shell with three inner layers inside the pressurizable and ventable outer balloon shell insufflated with a pressurized gas. The same process of being reflected, transmitted and re-reflected while releasing the pressurized gas as on the boundaries of 103, 101 and 102 of the head 68 occurs upon each boundary of 103, 104 and 105 for the head 69 of FIG. 8C. Incident mechanical waves 107 from the head 69 of FIG. 8C undergo a similar process to what is described for the head 68 upon each boundary of 108, 109, 103, 110 and 111 before reaching the frontal region of the head 68. Amplitude of mechanical waves 112 and 106 reaching the occipital region of each head 68 and 69 therefore are substantially reduced by the release of the pressurized gas from the pressurizable and ventable outer balloon shell worn by each head 68 and 69. The diagram of FIG. 8G illustrates a significant reduction in the amplitude of the mechanical waves to both the heads by releasing the pressurized gas from the the pressurizable and ventable outer balloon shell having multiple inner layers serving as boundary for the mechanical waves.
[0044] FIG. 9A 9B show a schematic view of the pressurizable and ventable outer balloon shell. FIG. 9A shows a schematic profile outline view of the pressurizable and ventable outer balloon shell having a Schrader-type gas intake valve 114 embedded in a lower wall of the lower ballooned rim 2 below an occipital portion 113 of the dome 1 into the balloonable internal space 10, spring-operated pressure release gas valves 115˜117 disposed in the lower wall of the lower ballooned rim 2, and a pressure sensor device 118 located above an anterior portion 119 of the lower ballooned rim. Additional spring-operated pressure release gas valves 120˜121 and 122 are disposed in the temporal ballooned rim 7 and the frontal ballooned rim 3, respectively. FIG. 9B shows a schematic three-dimensional view of the ballooned rim with the Schrader-type gas valve, the spring-operated pressure release gas valves and the pressure sensor device, with an upper portion of the lower ballooned rim exposed. One frontal spring-operated pressure release gas valve 122 is shown magnified, having a cylindrical configuration with an outer cylinder 123 and a valve 124 which is pushable by a spring and quick-release.
[0045] FIG. 10A˜10F illustrate a ruffled free end 125 of an independent inner layer 47 and propagation of surface waves across a human head upon an impact. FIG. 10A shows a schematic view of the ruffled free end 125 of the independent inner layer 47. The ruffled free end 125 is configured in a plurality of thin linear strips for a length with one end coming out as an extension from an edge of the independent inner layer and the other end being free and unattached. Schematically illustrated in FIG. 10B, the ruffled free end 125 is press-made in a configuration of two out-of-phase sine waves 126 and 127 along a longitudinal axis of the ruffled free end, which is to reduce a resonant vibration 129 of the independent inner layer and the ruffled free end by their fundamental frequency resonating with a frequency 128 of a mechanical wave from an impact. FIG. 10C˜10D show the surface waves 131 and 133 originating from an impact site 130 and an opposite site 132 causing resonant amplification of mechanical waves disseminating from distant sites 134 and 135 away from the sites 130 and 132 upon the impact on an unprotected human head. FIG. 10E-10F show the surface waves 138 and 140 originating from an impact site 136 on a pressurizable and ventable outer balloon shell 137 and an opposite site 139 with resonant amplification of mechanical waves disseminating from distant sites 141 and 142 away from the sites 136 and 139 upon the impact on a protected human head wearing the protective headgear having the pressurizable and ventable outer balloon shell 137. Referring to FIG. 6, the woven cloth fabric of the mid ply 48 also contributes to dampening the resonant amplification of the mechanical waves by the independent inner layer based on a lower fundamental frequency of the woven cloth fabric compared to that of the outer and inner plies 47 and 49 made of the thermoplastic elastomer.
[0046] FIG. 11A-11B show a schematic view of a configuration of the inner hard shell 6 which is undeformable and resistant to material failure upon impact of a blunt trauma. FIG. 11A shows a schematic three-dimensional view of the inner hard shell, comprising at least three layers with both the outer 143 and inner layer 144 made of an impact resistant polymer and the mid layer 145 made of a plurality of non-polymeric porous materials. FIG. 11B shows a schematic profile outline view of a three-layered structure of the inner hard shell. Main role of the three layers is to protect the skull against fracture upon an impact of a blunt trauma to the head. The mid layer 145 of the non-polymeric porous materials serves to reduce transmission of an amplitude of the blunt trauma through the inner hard shell.
[0047] It is to be understood that the aforementioned description of the apparatus and methods is simple illustrative embodiments of the principles of the present invention. Various modifications and variations of the description of the present invention are expected to occur to those skilled in the art without departing from the spirit and scope of the present invention. Therefore the present invention is to be defined not by the aforementioned description but instead by the spirit and scope of the following claims.
