[1 ] The present application relates to a personal protective gear for impact absorption, involving a cranial component and a cervical component. More particularly, the present application is designed to optimise impact absorption (linear, rotational or both) and prevent excessive head and neck motion during a traumatic impact, thereby minimising the seventy and extent of the head and neck injury sustained by the user.

[2] Traumatic head and neck injuries amass 1.7 million cases per year in the US. and are the primary cause of major trauma-related deaths. (ATLS manual, 10th edition, 2008). The seventy and extent of the head and neck injury sustained is dependent on the mechanism of injury and the energy transmitted to the victim.

[3] Head injuries are associated with more than 90% of pre-hospital trauma-related deaths. Cervical spine injuries are associated with 5% of head injuries, and are a major cause of long-term morbidity following trauma. Approximately 55% of spinal trauma is sustained in the cervical spine. The pattern and severity of injuries sustained depend on the mechanism of injury and the energy imparted to the head and cervical spine. Intrinsic brain injuries are caused by both direct physical trauma and accelerationdeceleration processes shifting the brain within the skull, resulting in brain contusions, haemorrhage and shearing injuries to the brain (diffuse axonal injury). Injuries to the cervical spine broadly entail spinal fractures with or without dislocations and soft tissue injuries including disc disruptions, ligamentous injuries, facet joint injuries and muscular injuries. In particular, a cervical spine injury incurred may render a spine unstable which further poses a risk of neurological injury, i.e. , spinal cord or nerve root injury. The neurological injury incurred can manifest as limb pain, weakness, sensory disturbance, paralysis or bladder/bowel dysfunction. High cervical spinal cord injuries might also cause severe cardiorespiratory complications.

[4] Current shock absorption technology focuses predom inantly on optim ising the design and safety of helmets. However, cervical spine motion during a traumatic injury also plays a critical role in determining these particular injuries: by minimising the excessive and rapid motions incurred by the cervical spine, not only is the severity of the cervical spine injury reduced but also the magnitude of the accelerationdeceleration injury to the brain is also diminished.

[5] Therefore, the subject application proposes a personal protective gear for impact absorption that is capable of substantially absorbing the energy from an impact by improving the efficiency of shock absorption. The present application is applicable to many applications, such as cyclists, motorcyclists, e-scooter riders, contact sports (such as rugby, American football, etc.), robotics, high-speed activity prone to traumatic injury (such as skiing, water sport activities, winter sports, and motor racing), and workers in construction, mining etc. where there is a possibility of impact on head/neck or essentially require a helmet.

[6] The personal protective gear of the present application enables the wearer to move the head freely under normal circumstances but when a traumatic force is imparted to the victim, the present application functions to maximise force absorption and substantially limit the velocity and range of head and neck motion which would otherwise contribute to a significant head and neck injury.

[7] In accordance with their structures, the personal protective gear also has many advantages such as being lightweight, flexible, durable, reusable, non-biodegradable, washable, inert, inflammable, and waterproof. In particular, the personal protective gear of the present application is provided to be variable in fitting size for suiting to a specific wearer’s head and neck structure. The wearer may select an appropriate size (such as S, M, L, 15 XL, etc.) or even customize to his/her size.

[8] The present application is described hereinafter by various embodiments. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein.

[9] According to an aspect of the present application, the personal protective gear comprises a cranial component adapted to be worn on a head of a wearer for shock attenuation; and a cervical component (optionally detachable) connected with the cranial component and adapted to be worn on a neck of the wearer. Herein, the cervical component comprises a plurality of energy absorption units adapted to absorb or attenuate linear impact, rotational impact or a combination thereof. The linear impact is meant to include impact to tensile and compressive forces, while rotational impact is meant to include impact due to rotation or twist of head/neck (with or without collision).

[10] In accordance with an embodiment of the present application, the cranial component has a multi-layer design and a shock absorption mechanism for shock absorption in the cranial component.

[11] In accordance with an embodiment of the present application, the shock absorption mechanism of the multi-layered cranial component comprises a compressible ball disposed within an intermediate layer.

[12] In accordance with an embodiment of the present application, the compressible ball is configured to provide additional shock absorption during a compressive phase as well as a smooth transmission surface between the inner and outer layers which tend to slide during the rotational impact. The compressible ball may be disposed within an intermediate layer of the multi-layered cranial component and is held in-situ by one or more tension cables traversing between inner and outer layers of the cranial component.

[13] The array of tension cables/cords selected from, but not limited to, band, wire, rope, cable, cord form a tension cable system, for absorbing the external shock. The tension cable system is designed to maximize force absorption and works in conjunction with the other parts of the personal protective gear, including the cranial part and the cervical part. The tension cable system works in conjunction with the other parts of the personal protective gear for limiting excessive motions in all directions (such as forward flexion, extension, lateral flexion, rotation).

[14] In accordance with an embodiment of the present application, the cranial component further comprises one or more head plates and a ventral facial ring contained within the intermediate layer and the one or more head plates and the ventral facial ring are hinged at their base to the craniocervical ring of the cervical component.

[15] In accordance with an embodiment of the present application, the cervical component includes a plurality of rings concentrically arranged, and a set of polyarticular columns spanning a circumference of the plurality of rings.

[16] In accordance with an embodiment of the present application, the plurality of rings include three primary rings selected from a craniocervical ring, a mid-cervical ring and a cervicothoracic ring.

[17] In accordance with an embodiment of the present application, the plurality of rings further include two intermediate rings interposed equidistant to the three primary rings.

[18] In accordance with an embodiment of the present application, each polyarticular column includes a plurality of energy absorption units and is configured to provide flexibility during normal cervical motions and absorb the impact of a traumatic force when stressed.

[19] In accordance with an embodiment of the present application, the cervical component is provided with a double lining of a neck collar, having an inner lining and an outer lining.

[20] In accordance with an embodiment of the present application, the plurality of energy absorption units are welded together to form the polyarticular column or manually connected via locks or pins.

[21 ] In accordance with an embodiment of the present application, the set of polyarticular columns in the cranial component are arranged in a longitudinal, diagonal, or criss-cross manner throughout the circumference of the plurality of rings.

[22] In accordance with an embodiment of the present application, each polyarticular column further comprises a cord running along a central axis of each polyarticular column to provide stability and cohesion to each polyarticular column. This enables to connect the set of polyarticular columns and the adjacent plurality of rings to be connected via a single winding cord.

[23] In accordance with an embodiment of the present application, ends of the cords of each polyarticular column merge at a front of the neck of the wearer, where the wearer is enabled to pull and tie both ends of the cord to tighten the cervical component worn around the neck.

[24] In accordance with an embodiment of the present application, a dial is disposed at an anterior or posterior base of the cervical component to provide additional finetuned control to modulate the tension on the cord. [25] In accordance with an embodiment of the present application, the dial is configured to tighten or loosen the cord upon anti-clockwise or clockwise rotation, respectively.

[26] In accordance with an embodiment of the present application, each energy absorption unit comprises an assembly made of one or more of a poly-axial ball and socket joint, mono-axial cylindrical compressible chambers, connecting arms, perforated circular plates, springs, and ball connectors.

[27] In accordance with an embodiment of the present application, upon application of a unidirectional force to individual energy absorption unit, the rate of flexion is modulated by an elastic modulus of the spring and limited by the configuration of the poly-axial ball and socket joint.

[28] In accordance with an embodiment of the present application, upon application of a unidirectional force to the plurality of energy absorption units, collectively, within the individual polyarticular column, the set of polyarticular columns work synergistically to maximise force absorption and limit the degree of flexion or extension of the neck of the wearer.

[29] In accordance with an embodiment of the present application, the energy absorption unit comprises a poly-axial ball and socket joint is connected to one mono- axial cylindrical compressible chamber with the help of a flexible spring and connecting arms.

[30] In accordance with an embodiment of the present application, the energy absorption unit comprises a mono-axial cylindrical compressible chambers on either side of a poly-axial ball and socket joint, connected to with the help of a flexible spring and connecting arms. [31 ] In accordance with an embodiment of the present application, the poly-axial ball and socket joint is configured to flex while the mono-axial chambers are configured to compress under the influence of axial loading force on each energy absorption unit, to cushion the applied force.

[32] In accordance with an embodiment of the present application, the poly-axial ball and socket joint is configured to flex and/or rotate while the mono-axial chambers are configured to expand under the influence of rotary force on each energy absorption unit, to cushion the applied force.

[33] In accordance with an embodiment of the present application, the energy absorption unit further comprises a plurality of circumferential tension fibres emanating from a cord and passing through a perforated circular plate, which itself is fused to a cup of the poly-axial ball and socket joint.

[34] In accordance with an embodiment of the present application, upon application of a force to the individual energy absorption unit, the plurality of circumferential tension fibres are pulled into tension and become tented against a rim of the perforations of the perforated circular plate, thereby amplifying the tension applied to the winding cord running through the polyarticular column

[35] In accordance with an embodiment of the present application, each energy absorption unit is encased in a concertina spring with valve inlets and outlets of different dimensions to regulate the flow into and out of a chamber, and hence modulate the rate of compression or expansion of the energy absorption unit.

[36] In accordance with an embodiment of the present application, the cervical component comprises a locking mechanisms are incorporated at multiple points along a length of the entire cord. [37] In accordance with an embodiment of the present application, the locking mechanism comprises a pressure-differential chamber communicating either side with two flexible concertina-spring compartments and a set of valves located within the pressure-differential chamber to regulate airflow between the outer atmosphere and concertina-spring compartments. A variant of this fundamental design includes a headspring system encased in a flexible sheath, which functions in an identical manner.

[38] In accordance with an embodiment of the present application, the locking mechanism is adapted to transmit the tension to a distal end of each concertina compartments via the cord and cause expansion, upon application of force on the neck of the wearer and/or the cervical component; entrain air into each concertina compartments via the pressure-differential chamber due to the negative pressure created by the expansion, thereby further increasing rate of expansion and the tension on the cord; and halt the expansion using a tertiary valve and thereby restricting the further neck motion when the tension on the cord exceeds a predetermined threshold and/or a predetermined pressure differential is generated.

[39] The accompanying Figures (Figs.) illustrate embodiments and serve to explain principles of the disclosed embodiments. It is to be understood, however, that these Figures are presented for purposes of illustration only, and not for defining limits of relevant applications. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this application and are therefore not to be considered limiting of its scope, for the application may admit to other equally effective embodiments.

[40] These and other features, benefits, and advantages of the present application will become apparent by reference to the following text Figure, with like reference numbers referring to like structures across the views, wherein: Figure 1 illustrates a side view of a personal protective gear for impact absorption, in accordance with an embodiment of the present application;

Figures 2-6 illustrate a shock absorption mechanism of the cranial component under the influence of different kind of forces/impact, in accordance with an embodiment of the present application;

Figures 7-8 illustrate sectional and detailed views of the cranial component, in accordance with an embodiment of the present application;

Figures 9-10 illustrate a functioning of the occipital plate of the cranial component under the influence of force, in accordance with an embodiment of the present application;

Figures 11-12 illustrate a tension cable system of the personal protective gear, in accordance with an embodiment of the present application;

Figure 13 illustrates a cervical component of the personal protective gear, in accordance with an embodiment of the present application;

Figure 14 illustrates a detailed view of an internal structure of the cervical component, in accordance with an embodiment of the present application;

Figure 15 illustrates various arrangements of a plurality of energy absorption units in polyarticular column of the cervical component, in accordance with an embodiment of the present application;

Figure 16 illustrates an individual energy absorption unit, in accordance with an embodiment of the present application;

Figure 17 illustrates multiple embodiments of the individual energy absorption units;

Figure 18 illustrates various states of the individual energy absorption unit under the influence of compressive and tensile forces, in accordance with an embodiment of the present application; Figures 19-20 illustrate states of the individual energy absorption units under the influence of rotational forces, in accordance with an embodiment of the present application;

Figure 21 (i) and (ii) illustrates a poly-axial compartment of the energy absorption unit and a rate-sensitive flexion thereof, in accordance with an embodiment of the present application;

Figure 22 illustrates a mono-axial compartment of the energy absorption unit and a rate-sensitive compression thereof, in accordance with an embodiment of the present application;

Figures 23-24 illustrate another embodiment of the energy absorption unit including a perforated circular plate and circumferential tension fibres;

Figures 25-27 illustrate arrangement and states of the set of polyarticular columns of the cervical component, in accordance with an embodiment of the present application; Figures 28-29 illustrate a longitudinal and criss-cross arrangement of the set of polyarticular columns in between primary rings of the cervical component, in accordance with an embodiment of the present application.

Figure 30 illustrates multiple embodiments of the cervical component with different arrangement of the set of polyarticular columns in the upper and lower part of the cervical component;

Figures 31 -32 illustrate a dial of the cervical component for tightening and loosening the winding cord(s) within the neck collar, in accordance with an embodiment of the present application;

Figure 33 illustrates the cervical component with a winding cord running through the polyarticular columns, as worn by a wearer, in accordance with an embodiment of the present application; Figures 34-35 illustrate cross-sectional views (top) of cervical component, in accordance with an embodiment of the present application;

Figures 36 and 37 illustrates a locking mechanism in the cervical component, in accordance with an embodiment of the present application;

Figures 38 illustrates another embodiment of the locking mechanism in the cervical component; and

Figures 39-41 illustrate working of the locking mechanism, in accordance with an embodiment of the present application.

[41] The present application is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description.

[42] While the present application is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the application is not limited to the embodiments of drawing or drawings described and are not intended to represent the scale of the various components. Further, some components that may form a part of the application may not be illustrated in certain Figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the application to the particular form disclosed, but on the contrary, the application is to cover all modifications, equivalents, and alternatives falling within the scope of the present application as defined by the appended claim. As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes.

[43] Figure 1 illustrates a side view of a personal protective gear 100 for impact absorption, in accordance with an embodiment of the present application. As shown in Figure 1 , the personal protective gear 100 comprises a cranial component 110 adapted to be worn on a head of a wearer 101 for shock attenuation; and a cervical component 120 adapted to be worn on a neck of the wearer 101 . The cervical component 120 may be detachably connected with the cranial component 110 or may be provide as integral protective gear. The personal protective gear 100 may be provided in a form of balaclava, that covers most part of the head and neck, leaving only the face uncovered (refer fig. 1 ). In that sense, the personal protective gear 100 of the present application is provided to be variable in fitting size for suiting to a specific wearer’s head and neck structure. The wearer 101 may select an appropriate size (such as S, M, L, 15 XL, etc.) or even customize to his/her size. This enables the wearer 101 to move the head freely under normal circumstances but when a traumatic force is imparted to the victim, the device functions to maximise force absorption and substantially limit the velocity and range of head and neck motion which would otherwise contribute to a significant head and neck injury.

[44] Returning to Figure 1 , the cranial component 110 may have a multi-layer design including a plurality of layers, such as, but not limited to, an outer layer 102, an intermediate layer 104 and an inner layer 106. The multi-layer design employs a shock absorption mechanism that is capable of absorbing linear (tensile, compressive) and rotational impacts. The cervical component is adapted to have a multi- layered structure having double lining i.e., an inner lining 134 and an outer lining 132 and a central cavity for wearer’s 101 neck. The outer lining 132 is located away from the central cavity; while the inner lining 134 is located towards the central cavity of the cervical component 120. In one embodiment, the cranial component may have outer and inner linings. The outer lining may be made of a thin, flexible, and expansive material such as, but not limited to, nylon. In some embodiments, the outer lining may have multiple layers: in the event that one of the multiple layers’ ruptures, the other layers can still maintain the normal function of the outer lining. In contrast, the inner lining may be made of a flexible, soft, light and inert material, including, but not limited to, nylon, polyether-polyurea copolymer (such as Spandex) or nomex (an example of flame-retardant material). The inner lining is in direct contact with the scalp or cutaneous surface of neck and upper thorax. The inner lining is configured to fit the shape of the head of the wearer 101 .

[45] Figures 2-6 illustrate a shock absorption mechanism of the cranial component 110 under the influence of different kind of forces/impact, in accordance with an embodiment of the present application. Figure 2 illustrates a detailed section view of the cranial component 110 that includes the shock absorption mechanism in a normal (unstressed/neutral) condition. It can be seen that the inner layer 106 and outer layer 102 have a respective (& independently movable) peg-dome construct 118 that enables to absorb compressive stress on the cranial component 110. The peg-dome construct 118 may involve one or more lobes and grooves. Both the peg-dome constructs 118 of the inner layer 106 and outer layer 102 are separated by the intermediate layer 104 (gap in between). Additionally, a compressible ball 116 is disposed within the intermediate layer 104 and is held in situ by the tension cords/cables 114 (hereinafter referred to as “tension cable(s)”) traversing between the inner and outer layers 102. The peg-dome constructs 118 have one or more respective passages to allow the tension cable 114 to pass through. The compressible ball 116 assists in providing additional shock absorption during a compressive phase as well as a smooth transmission surface between the sliding inner layer 106 and outer layer 102 from a rotational impact. The tension cable(s) 114 ensure absorption of impact due to tensile force. The tension cable(s) 114 may be understood as a continuous stream of string such as band, wire, rope, cable, cord etc. The continuous stream of string is anchored along its course for holding the multiple layers of the cranial component 110 and the compressible ball 116 therein together and aids its ability to withstand an external force.

[46] The tension cable(s) 114 may be made of a material having a high tensile strength, meanwhile not penetrating through the inner lining 134 of the cranial component 110 under tension to avoid direct injuries to the wearer 101. Also, the tension cable(s) 114 comprise a material having a high elastic modulus (or also known as modulus of elasticity). The higher the elastic modulus is, the more elastic potential energy the tension cables could store; and thus, the more kinetic energy the tension cable(s) 114 could absorb. The elastic modulus is measured as a slope of a stressstrain curve in the elastic deformation region where permanent deformation does not occur yet. According to direction of the stress, the elastic modulus may be categorized as Young’s modulus, shear modulus and bulk modulus. In particular, the Young’s modulus determines elastic deformation (measured as tensile strain) along an axis of the material when opposing forces (measured as tensile stress) are applied along the axis. Thus, the Young’s modulus is defined as a ratio of the tensile stress to the tensile strain along the axis. The tension cable(s) 114 are configured to be under moderate tension in a resting state in order to minimize any motion between the inner shell and the outer shell during non-significant natural movements of the head. The tension cable(s) 114 may also have a high hysteresis. In a force-extension plot of a material, an area of a hysteresis loop represents energy dissipated due to internal friction of the material. The larger the hysteresis is, the more energy could be dissipated in a cycle of loading and unloading; and the more kinetic energy the tension cable(s) 114 could absorb. The tension cable(s) 114 may be made of a natural material, a synthetic material or a combination thereof. The natural materials include collagen, and natural rubber or the alike. While the synthetic materials include viscoelastic polymers - e.g., Sorbothane, synthetic rubbers (e.g. Silicon rubber, neoprene, butyl rubber, polyurethane), Akton polymer; and equivalent materials.

[47] Besides, both the inner layer 106 and outer layer 102 are composed of rigid materials (e.g. mesh fabrics etc.) in order to prevent the tension cables from being compromised if either or both of the inner layer 106 and outer layer 102 collapse. In addition, the compressible ball 116 may be made of or filled with a resilient compressible foam rubber, polyurethane foam, or gel material or the like of predetermined hardness to promote shock absorption and smooth rolling operation over hard continuous or uneven surfaces.

[48] The basic principle of operation of the shock absorption mechanism in the cranial component 110 involves absorbing the external shock (kinetic energy) from a colliding object, and then converting it into elastic potential energy (elastic deformation), in order to minimize the traumatic injury imparted to the victim. The external shock transmits kinetic energy from a colliding object to the wearer 101 upon impact. Herein, the kinetic energy may be converted into elastic potential energy due to elastic deformation of the inner layer 106, outer layer 102 and the compressible ball 116 there between. Alternately or additionally, the kinetic energy may be converted into thermal energy due to the friction generated between different components and sliding layers of the cranial component 110.

[49] More specific embodiments showing the shock absorption mechanism in operation under the influence of different forces, will now be described using figures 3- 6.

[50] Figures 3 and 4 show the working of shock absorption mechanism in different parts of the cranial component 110 under an influence of unidirectional/unilateral force 19. As can be seen from Figures 3 and 4, upon application of unilateral force 19, a site of contralateral expansion and a site of ipsilateral compression are formed on the cross of the cranial component 110. Figure 3 shows a detailed view of the site of contralateral expansion 20 on one side of the cranial component 110, where tensile force is absorbed by the shock absorption mechanism. The tensile force stretches the inner layer 106, the outer layer 102 and compressible ball 116 therein. The compressible ball 116 can be seen to be an expanded state, and the tension cable(s) 114 can be seen holding the outer layer 102 and the inner layer 106 together by absorbing the tensile force. The kinetic energy imparted due to application of tensile force is converted into elastic potential energy due to elastic deformation of the inner layer 106, outer layer 102 and the compressible ball 116 there between. The tension cable(s) 114 having a high elastic modulus, are able to store more elastic potential energy, and absorb more kinetic energy.

[51] Whereas Figure 4 shows a detailed view of the site of ipsilateral compression 24 on the other side of the cranial component 110, where compressive force is absorbed by the shock absorption mechanism. Herein, during compressive shock, the compressible ball 116 is trapped between the grooves and lobes of the respective pegdome constructs 118 of the inner layer 106 and outer layer 102 to reach a compressed state. Then, the compressible ball 116 in the maximum compressed state, prevents any further compression (or coming closer) of the inner layer 106 and outer layer 102. In other words, the kinetic energy imparted due to the compressive force is converted into elastic potential energy due to elastic deformation of the inner layer 106, outer layer 102 and the compressible ball 116 there between. In this manner, any external impact due to compressive or tensile force is absorbed by the cranial component 110 before transmitting to the head of the wearer 101 .

[52] Figures 5 and 6 show detailed views of two sites of rotation 30 and 37 under the influence of oppositely directed rotational forces 29 and 36 respectively. In Figure 5, it can be seen that under the influence of rotational force 29, the outer layer 102 is moving towards left and the inner layer 106 is moving towards right. The compressible ball 116 helps in smooth transmission of force between the sliding inner layer 106 and outer layer 102, while the tension cable(s) 114 hold the outer layer 102 and the inner layer 106 together and absorb the kinetic energy generated due to impact by the rotational force. Whereas in Figure 6, it can be seen that under the influence of rotational force 36, the outer layer 102 is moving towards right and the inner layer 106 is moving towards left. Again, the compressible ball 116 in the intermediate layer 104 helps in smooth transmission of force between the sliding inner layer 106 and outer layer 106, while the tension cable(s) 114 hold the outer layer 102 and the inner layer 106 together and absorb the kinetic energy generated due to impact by the rotational force. Additionally, in both the Figures 5 and 6, the kinetic energy may also be converted into thermal energy due to the friction generated between different moving/sliding components.

[53] Figures 7-8 illustrate sectional and detailed top views of the cranial component 110, in accordance with an embodiment of the present application. Apart from the multi-layer design, the cranial component 110 may include one or more head plates 1042 and a ventral facial ring 108. As can be seen from Figure 7 and 8, a series of three head plates (occipital 1042; left lateral 1044; right lateral 1046) and the ventral facial ring 108 are contained within the intermediate layer 104 between the inner layer 106 and outer layer 102. Furthermore, can be seen in figures 9 and 10, the above- mentioned components are hinged at their base to the cervical component 120. The rooves of each plate and the ventral facial ring 108 are connected by a series of solid rings over the vertex/crown 112 of the head. Figures 9 and 10 also illustrate a functioning of the occipital plate 1042 of the cranial component 110 under the influence of force. In figure 9 (a) and (b), the occipital plate 1042 is seen to be hinged 57 at a top of the cervical component 120. As the unidirectional force 54 is applied in figure 10 (a) and (b), the occipital plate 1042 is flexed and a proximal end of occipital plate 1042 is abutting cervical component 120 showing maximal extension. This enables to restrict the movement of the head and neck during the impact on the personal protective gear 100 to keep the wearer 101 safe.

[54] Figures 11 -12 illustrate a tension cable system 156 of the personal protective gear 100, in accordance with an embodiment of the present application. As shown in Figures 11 and 12, an array of tension cables/cords 63 selected from, but not limited to, band, wire, rope, cable, cord etc., originate from the perimeter of each ring of the cervical component 120 or plates of the cranial component 110 to form a tension cable system 156, for absorbing the external shock. The tension cable system 156 is anchored to the cervical component 120 and cranial component 110 via multiple points along its course using fixtures such as hinges, loops, latches etc. In addition, the tension exerted on the tension cable system 156 can be adjusted to achieve a desired limit of the motions in a particular direction for a specific user. The cervical component 120 may be provided with a plurality of fixing devices (hooks) for holding the array of tension cables 63.

[55] In that sense, the tension cables 63 may be made of a material having a high tensile strength meanwhile not penetrating through the inner lining 134 under tension to avoid direct head/neck injuries to the wearer 101. The tension cable system 156 is designed to maximize force absorption and works in conjunction with the other parts of the personal protective gear 100, including the cranial component 110 and the cervical component 120, for limiting excessive motions in all directions (such as forward flexion, extension, lateral flexion, rotation). For example (refer Figure 12), if a force is applied to the head in an anteroposterior direction, the head is forced to rock back - this causes the occipital plate 1042 to extend posteriorly, thereby placing tension on the cords running from its periphery to the anterior aspect of the craniocervical ring 1262.

[56] Figure 13 illustrates a cervical component 120 of the personal protective gear 100, in accordance with an embodiment of the present application. As shown in Figure 13, the cervical component 120 is worn as a neck collar by the wearer 101 . The cervical component 120 includes a plurality of rings concentrically arranged. The plurality of rings may be categorized into primary rings 126 and intermediate rings 128. The primary rings 126 may be, but not limited to, a craniocervical ring 1262, a mid-cervical ring 1264 and a cervicothoracic ring 1266. Optionally, the intermediate rings 128 may also be provided. The primary rings 126 and the intermediate rings 128 provide a shape and structure to the cervical component.

[57] Figure 14 illustrates a detailed view of an internal structure of the cervical component 120, in accordance with an embodiment of the present application. As can be seen from Figure 14, the cervical component 120 is envisaged to be a neck collar to wrapped around or worn on the neck of the wearer 101 . The cervical component is adapted to have a multi- layered structure having double lining i.e. , an inner lining 134 and an outer lining 132 and a central cavity for wearer’s 101 neck. The outer lining 132 is located away from the central cavity; while the inner lining 134 is located towards the central cavity of the cervical component 120. The outer lining 132 may be made of a thin, flexible, and expansive material such as, but not limited to, nylon. In one embodiment, the outer lining 132 may have two layers: in the event that one of the two layer ruptures, the other layer can still maintain the normal function of the outer lining 132. In contrast, the inner lining 134 is made of a flexible, soft, light and inert material, including, but not limited to, nylon, polyether-polyurea copolymer (such as Spandex) or Nomex® (an example of flame-retardant material). The inner lining 134 is in direct contact with the scalp or cutaneous surface of neck and upper thorax. The inner lining 134 is configured to fit the contour of the neck of the wearer 101 .

[58] Further, the cervical component 120 comprises a set of polyarticular columns 130 placed between the outer lining 132 and the inner lining 134 and spanning the circumference of the plurality of rings (i.e., the primary rings 126 and the intermediate rings 128). The centrum and distal ends of each polyarticular column 130 are anchored to the rim of the intermediate rings 128 and the primary rings 126, respectively. Further, each polyarticular column 130 includes a plurality of energy absorption units 136 connected in series and is configured to provide flexibility during normal cervical motions and absorb the impact of a traumatic force when stressed. The set of polyarticular columns 130 embed within the inner and outer lining 132, form the walls of the neck collar/cervical component 120.

[59] In accordance with an embodiment of the present application, the set of polyarticular columns 130 having plurality of energy absorption units 136 may be arranged in, but not limited to, longitudinal arrangement, diagonal arrangement, crisscross arrangement or a combination thereof, throughout the circumference of the plurality of rings. Figure 15(a) illustrates a plurality of energy absorption units 136 in the vertical/longitudinal polyarticular column 137 of the cervical component 120, in accordance with an embodiment of the present application. As can be seen from the example of figure 15(a), the plurality of energy absorption units 136, comprising three individual energy units 140, connected in a series. It will be appreciated by a skilled addressee that number of energy absorption units 140 can be increased or decreased as per the requirements of the application, without departing from the scope of the present application, Further, Figure 15(b) shows the plurality of energy absorption units 136 involve two series of energy absorption units 136 arranged in the criss- cross/diagonal manner, to form a single functioning unit. Selection of arrangement depends on the type of application for which the protective gear is required. Herein, the plurality of energy absorption units 136 may be, but not limited to, welded together or manually connected via locks or pins, to form the polyarticular column 130.

[60] Figure 16 illustrates an individual energy absorption unit 140, in accordance with an embodiment of the present application. As can be seen from Figure 16, each energy absorption unit 140 comprises an assembly made of one or more of, but not limited to, a poly-axial ball and socket joint 88, mono-axial cylindrical compressible chambers 81 (or simply referred as “mono-axial compartment”), connecting arms 85, perforated circular plate 202, flexible spring 87, and ball connectors 84. It will be appreciated by a person skilled in the art that multiple embodiments are possible by using different arrangements of the above-mentioned components. So, primarily the energy absorption unit 140 includes the poly-axial compartment 82 and the monoaxial compartment 81 encased in a single flexible spring 87 and connected via connecting arms 85. The distal end of this compartment is joined to a separate ball connector 84. Also, a cord 83 running along a central axis of each energy absorption unit 140. Herein, the mono-axial compartment 81 includes a compressive chamber 86, that permits expansion or contraction along one axis, and the polyaxial compartment 82 includes the poly-axial ball and socket joint 88, that enables lateral rotation and circumduction.

[61] The components of the energy absorption unit 140 such as the poly-axial ball and socket joint 88, mono-axial cylindrical compressible chambers 81 , connecting arms 85, perforated circular plates 202, ball connectors 84, may be made of a material selected from, rigid or semi-rigid plastic, polymer, metal, alloy or any combination thereof. In one embodiment, all the above mentioned components are made of same material. In another embodiment, the above mentioned components may be made of different materials. Apart from this, the flexible spring 87 may be made of, but not limited to, stainless steel, high carbon steel or any alloys, having a high modulus of elasticity.

[62] Figure 17 illustrates multiple embodiments of the individual energy absorption units 140. As can been, Figure 17(a) shows the energy absorption unit 140 comprises a poly-axial ball and socket joint 88 connected to one mono-axial cylindrical compressible chamber 81 with the help of a flexible spring 87 and connecting arms 85. The poly-axial ball and socket joint 88 together with the adjacent connecting arm 85 form the poly-axial compartment 82, which will be referred throughout the specification. Then, Figure 17(b) shows the energy absorption unit 140 comprises a mono-axial cylindrical compressible chambers 81 on either side of a poly-axial ball and socket joint 88, connected with the help of a flexible spring 87 and connecting arms 85. Additionally, Figure 17(c) shows a third embodiment, that can include either of the embodiment (a) or (b) encased in a concertina spring 93 with valve inlets and outlets of different dimensions to regulate the flow into and out of this chamber, and hence modulate the rate of compression or expansion of the energy absorption unit 140.

[63] Figure 18 illustrates various states of the individual energy absorption unit 140 under the influence of compressive and tensile forces, in accordance with an embodiment of the present application. Figure 18(a) shows a neutral position of the mono-axial compartment 81 of the energy absorption unit 140. Then, Figure 18(b) shows the mono-axial compartment 81 of the energy absorption unit 140 and the flexible spring 87, in compressed state under the influence of a unilateral compressive force. Additionally, Figure 18(c) shows the mono-axial compartment 81 of the energy absorption unit 140 as well as the flexible spring 87, in an expanded state as a unilateral/unidirectional tensile force is applied on the energy absorption unit 140. Upon application of the unilateral tensile force to individual energy absorption unit 140, the rate of flexion is modulated by an elastic modulus of the flexible spring 87 and limited by the configuration of the poly-axial ball and socket joint 88. It can be observed that, when the unidirectional force is applied, irrespective of whether it is compressive or tensile, the energy absorption unit 140 maintains a straight or substantially straight profile. In such states, only compression or extension of components (flexible/movable) takes place.

[64] Figure 19-20 illustrate working of the individual energy absorption unit 140 under the influence of rotational forces, in accordance with an embodiment of the present application. Herein, Figures 19(a) and (b) illustrate that when an axial loading force is applied on the energy absorption unit 140, then apart from compression and extension of components, the energy absorption unit 140 also undergoes a lateral flexion (bend) . As can be seen from the drawings, the poly-axial ball and socket joint 88 flexes (left or right depending upon the direction of force) while the mono-axial chamber/compartment 81 is compressed under the influence of axial loading force on the energy absorption unit 140, to cushion the applied forces. Furthermore, Figure 20 illustrates of circumduction of the energy absorption unit 140 upon application of a rotational/rotary force. As can be seen from the drawings, the poly-axial ball and socket joint 88 is configured to flex and/or rotate while the mono-axial chamber 81 is configured to expand under the influence of rotary force on each energy absorption unit 140, to cushion the applied force.

[65] Figure 21 (i) and (ii) illustrates a poly-axial compartment 82 of the energy absorption unit 140 and a rate-sensitive flexion thereof, in accordance with an embodiment of the present application. The rate sensitive flexion of the poly-axial compartment 82 is determined by the elastic or concertina spring. Figures 21 (i)(a)-(d) show the states of poly-axial compartment 82 from a normal/neutral state in (a) to a state of maximum flexion in (d), in increasing order of flexion due to force applied. The observations of the figures 21 (i)(b)-21 (i)(d) have been plotted as graph in figure 21 (ii) showing the degree of flexion (Y-axis) with respect to the magnitude of force applied on the poly-axial compartment 82 (X-axis). It is clearly observed from the figures and the graph that the rate of flexion increases with the increasing magnitude of axial loading force.

[66] Figure 22 illustrates a mono-axial chamber/compartment 81 of the energy absorption unit 140 and a rate-sensitive compression thereof, in accordance with an embodiment of the present application The rate sensitive flexion of the mono-axial compartment 81 is determined by the elastic or concertina spring. Figures 22(a)-(c) show the states of mono-axial compartment 81 from a normal/neutral state in (a) to a state of maximum compression in (c), in increasing order of compression due to force applied. The observations of the figures 22(b)-(c) have been plotted as graph showing the degree of compression (Y-axis) with respect to the magnitude of force applied on the mono-axial compartment 81 (X-axis). It is clearly observed from the figures and the graph that the rate of compression increases with the increasing magnitude of axial loading force.

[67] Figure 23-24 illustrates another embodiment of the energy absorption unit 140 including a perforated circular plate 202 and circumferential tension fibres 206. As can be seen from the Figure 23, in this embodiment, instead of flexible spring 87, the energy absorption unit 140 comprises a plurality of circumferential tension fibres 206 emanating from the cord 83 (which is a central tension cord) and passing through the perforated circular plate 202. The perforated circular plate 202 is fused to a cup of the poly-axial ball and socket joint 88. A top of the perforated circular plate 202 is shown on the right, where the ball of the poly-axial ball and socket joint 88 is seen in the center, and the circular perforations 204 can be seen on the periphery of the perforated circular plate 202. Solid black dots shown in the perforations 204 represent the circumferential tension fibre 206 passing through them. Herein, the rate-sensitive flexion of the poly-axial compartment 82 is determined by circumferential tension fibres 206. In that sense, the plurality of circumferential tension fibres 206 may be, but not limited to, band, wire, rope, cable, cord etc., In that sense, the plurality of circumferential tension fibres 206 may be made of a material having a high tensile strength, for limiting excessive motions in all directions (such as forward flexion, extension, lateral flexion, rotation).

[68] Figure 24 shows flexion and tension of the plurality of circumferential tension fibres 206 when a force is applied on the energy absorption unit 140 of Figure 23. As can be seen from Figure 24, as the axial loading force is applied towards the right, the plurality of circumferential tension fibres 206 are pulled into tension and become tented against a rim of the perforations 204 of the perforated circular plate 202. It can be seen that the plurality of circumferential tension fibres 206 on the right side (in the direction of force) are in a relaxed state whereas the plurality of circumferential tension fibres 206 on the left side are under tension. This limits the amount of flexion that can be achieved. In this manner, the usage of plurality of circumferential tension fibres 206 provide stability and greater shock absorption capability to the energy absorption unit 140.

[69] Figures 25-27 illustrate arrangement and states of the set of polyarticular columns 130 of the cervical component 120, in accordance with an embodiment of the present application. Figure 25 shows the wearer 101 wearing a cervical component 121 (may also be referred to as the “neck collar” during explanation) in a relaxed state (neutral position). The set of polyarticular columns 130 are arranged in a longitudinal array 137 on the sides and as a diagonal/criss-cross array 138 in the middle. Figure 26 shows the wearer’s head is bent towards right when an ipsilateral force applied to head, and therefore the vertical/longitudinal array of polyarticular column 137 on the right is flexed, while the same on the left is extended. At the same time, the diagonal array of polyarticular column 138, on the right is compressed, while the same on the left is expanded. This has been shown in Figure 27. In this manner, upon application of an ipsilateral force to the head, the set of polyarticular columns 130 work synergistically to maximise force absorption and limit the degree of flexion or extension of the neck of the wearer 101 .

[70] Figures 28-29 illustrate a longitudinal and criss-cross arrangement of the set of polyarticular columns 130 in between primary rings 126 of the cervical component 120, in accordance with an embodiment of the present application. Figure 28 shows a single cord 402 running through the central axis of a parallel series of polyarticular columns 137, whereas the Figure 29 shows two separate cords 402, 404 running through a diagonal configuration of polyarticular columns 138. Herein, the ends of the cords 402, 404 of each polyarticular column 130 merge at a front of the neck of the wearer 101 , where the wearer 101 is enabled to pull and tie both ends of the cord 402 to tighten the cervical component 120 worn around the neck. Although, the above arrangements of the set of polyarticular columns 130 are shown to be between craniocervical ring 1262 and mid cervical ring 1264, however, different arrangements can be made between upper and lower part of the cervical component 120.

[71] Figure 30 illustrates multiple embodiments of the cervical component 120 with different arrangement of the set of polyarticular columns 130 in the upper and lower part of the cervical component 120. Figure 30 (a), (b) and (c) shows various arrangements of the set of polyarticular column 130 that are possible in the cervical component 120. Figure 30(a) shows the diagonal arrangement 138 in the upper part 122 and the vertical arrangement 137 in the lower part 124 of the cervical component 120. Further, Figure 30(b) shows the vertical arrangement 137 in both the upper part 122 and the lower part 124 of the cervical component 120. While Figure 30(c) shows the diagonal arrangement 138 in both the upper part 122 and the lower part 124 of the cervical component 120. Apart from this, the diagonal arrangement 138 in the lower part 124 and the vertical arrangement 137 in the upper part 122 of the cervical component 120, is also possible. It is to be noted that the set of polyarticular columns 130 is shown as a series of energy of absorption units 136 that together form a polyarticular column.

[72] Figure 31 -32 illustrate a dial 602 of the cervical component 120 for tightening and loosening the neck collar (cervical component 120), in accordance with an embodiment of the present application. As can be seen from Figure 31 , the dial 602 may be disposed at an anterior or posterior base of the cervical component 120 to provide additional fine-tuned control to modulate the tension on the cord 402. The dial 602 connected to the cord(s) coming from the set of polyarticular columns 130 arranged on the circumference of the cervical component 120. The dial 602 may have an external part 604 and an internal part 606, where the cord 402 is wound, as shown in the Figure 31 .

[73] In that sense, the dial 602 may made of a material selected from, but not limited to, metal, alloy, polymer, rigid plastic etc. Additionally, the internal part 606 of the dial 602 may include one or more of gears, pulley etc. on which the cord(s) 402 is wound. Apart from the construction, it is also seen that the dial 602 is in a neutral position in figure 31 and therefore the cervical component 120 (or the neck collar) is in a normal/neutral state. Then, in Figure 14B, the dial 602 is rotated anti-clockwise, which in turn causes tension in the cord 402 and the cervical component 120 is apparently tightened. Similarly (although not shown), the dial 602 may be rotated clockwise to loosen the cord 402 and the cervical component 120.

[74] Figure 33 illustrates the cervical component 120 as worn by a wearer 101 , in accordance with an embodiment of the present application. This Figure 33 shows the plurality of energy absorption units 136 in the set of polyarticular columns 130 spanning the circumference of the cervical component 120. All already mentioned, the set of polyarticular columns 130 form the wall of the cervical component 120.

[75] Figures 34-35 illustrate cross-sectional views (top) of cervical component 120, in accordance with an embodiment of the present application. These figures are meant show how the set of polyarticular columns 130 are held together in the cervical component 120. Figure 34 illustrates a sectional top view of the craniocervical ring 1262 of the cervical component 120, and figure 35 shows a mid-section top view between the primary rings 126. It can be seen that a cord 167 traverses through craniocervical ring 1262 connecting different polyarticular columns 130 and holding them together, in figure 34. Additionally, in both the figures 34 and 35, it can be observed that one or more springs 165, bridges 164, zip and cord tighteners 163 have been provided to incorporate flexibility and stretchability in the cervical component 120. The one or more springs 165 and bridges 164 enable the cervical component 120 (neck collar) to be stretched while keeping the polyarticular columns 130 in place. The cord tighteners 163 further enable to adjust the tension of the cord 167 so that the cervical component 120 can easily conform to the neck of the wearer 101 .

[76] In some embodiments, for further security, a fail-safe locking mechanism 180 is incorporated into the cervical component 120, to buffer the sudden linear or rotatory accelerations to head. Figures 36-37 illustrates the locking mechanism 180 in the cervical component 120, in accordance with an embodiment of the present application. Herein, Figure 17 shows basic components of the locking mechanism 180. The locking mechanism 180 comprises a pressure-differential chamber 177 communicating either side with two flexible concertina-spring compartments 174 and a set of valves located within the pressure-differential chamber 177 to regulate airflow between the outer atmosphere and concertina-spring compartments 174. [77] The locking mechanism 180 may be incorporated in the cervical component 120 at multiple points along a length of the entire cord 179. Figure 17 shows the preferable position of the locking mechanism 180 in the cervical component 120. As can be seen in the Figure 17, the locking mechanism 180 may be disposed in a horizontal orientation (craniocervical ring 1262), in a vertical orientation (crossing bridge) and also, in a horizontal orientation (cervicothoracic ring 1266). In some embodiments, the locking mechanism 180 can be orientated in any orientation, be it, vertical, horizontal, diagonal or any other angle therebetween.

[78] The locking mechanism 180 and its components are illustrated in figure 37. As can be seen from the drawing, the locking mechanism 180 provided between the crossing bridge is shown in figure 18, where 172 and 173 represent a superior border 172 and an inferior border 173 of the bridge respectively. The locking mechanism 180 primarily comprises a pressure-differential chamber 177 communicating either side with two flexible concertina-spring compartments 174. A coil spring 176 is also disposed therein to facilitate expansion and recoil of the locking mechanism 180 as well as the tension cord 179 passing through the locking mechanism 180, during normal motion. Further, the pressure-differential chamber 177 is set of valves located to regulate airflow between the outer atmosphere and concertina-spring compartments 174. Referring to figure 37, it can be seen that an inlet valve 184 is provided at a bottom of the pressure-differential chamber 177 that for allowing air into pressure-differential chamber 177. Additionally, a tertiary valve 186 is provided to stop the air intake inside the pressure-differential chamber 177. Also, a flexible membrane 191 is disposed inside the pressure-differential chamber 177 in between the inlet valve 184 and the tertiary valve 186. Apart from this, one or more sub-compartments 185, 189 may also be provided. [79] Another embodiment of the locking mechanism 180 with a slight variation has been illustrated in Figure 38. This variant includes a bead-spring system encased in a flexible sheath 183, which functions in an identical manner. Herein, instead of concertina-spring compartments 174, a plurality of beads 182 connected via springs 176 and encased in the flexible sheath 183 are provided on either side of the pressuredifferential chamber 177.

[80] Figure 39-41 illustrate a working of the locking mechanism 180, in accordance with an embodiment of the present application. As shown in figure 39, when a force is applied on the neck of the wearer 101 and/or the cervical component 120, the locking mechanism 180 is adapted to transmit the tension to a distal end of each concertina compartments 174 via the tension cord 179 and cause expansion. Consequently, air is entrained into each concertina-spring compartments 174 via the inlet valve 184 of the pressure-differential chamber 177 due to the negative pressure (P. _x ) created by the expansion. As the magnitude of the force applied to the wearer - and hence the tension applied to the cord - increases, the concertina compartments expand at a slow rate.

[81] The same has been illustrated in figure 40 with more details. As can be seen from figure 40 that due to the negative pressure (P. _x ) created by the expansion, the air flows in from the inlet valve 184 at atmospheric pressure P _a into the pressuredifferential chamber 177 and flexes the flexible membrane 191 towards tertiary valve 186. Herein, it will be understood that (P. _x ) is less than P _a . Then, as the air continues to enter inside the pressure-differential chamber 177, and the flexible membrane 191 fully flexes to occlude/block the tertiary valve 186. The negative pressure P. _x inside the pressure-differential chamber 177 further reduces to P. _y . Due to this the expansion is halted using a tertiary valve 186 and accordingly further neck motion is restricted. The above operation is achieved when the tension on the cord 179 exceeds a predetermined threshold and/or a predetermined pressure differential is generated.

[82] Figure 40(d) is a graph showing pressure differential (6P) with respect to change in volume per unit time (6V/6T), inside the pressure-differential chamber 177. It is to be noted that:

P-y P-x Pa

Pa " Pa ⁼ 5P[a]

Pa " P-x ⁼ 5P[a-x]

Pa " P-y =6 P[a-y]

The graph clearly illustrates the threshold tension for no airflow would be when 5V/5T = 0.

[83] Furthermore, figure 41 (a)-(c) illustrate the working of the pressure-differential chamber 177 explained in figure 40(a)-(c), being implemented inside the locking mechanism 180. In this embodiment, the change in volume per unit time (5V/5T) is observed with respect to the cord tension in the locking mechanism 180. Accordingly, a graph plotted to represent same as observed in Figure 41 (a), (b) & (c). It has been shown in figure 41 (d). Again, the threshold tension for airflow turned out be when 6V/6T = 0, which is in figure 41 (c), where the tertiary valve 186 is completely occluded by the flexible membrane 191 .

[84] The present application offers a number of advantages. The present application provides a lightweight, durable and comfortable personal protective gear to protect the wearer from head and neck injuries. The personal protective gear of the present application enables the wearer to move the head freely under normal circumstances but when a traumatic force is imparted to the victim, the device functions to maximise force absorption and substantially limit the velocity and range of head and neck motion which would otherwise contribute to a significant head and neck injury. It has high compressive and tensile strength and is non-flammable as well as heat resistant.

[85] In the application, unless specified otherwise, the terms "comprising", "comprise", and grammatical variants thereof, intended to represent "open" or "inclusive" language such that they include recited elements but also permit inclusion of additional, non-explicitly recited elements.

[86] Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the application is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present application and the appended claims.

Reference Numerals

100 - Personal protective gear

101 - Wearer/wearer’s face

110 - Cranial component

102 - Outer layer

104 - Intermediate layer

1042 - Occipital plate

106 - Inner layer

108 - Ventral facial ring

112 - Vertex

114 - Tension cord

116 - Compressible ball

118 - Peg-dome construct

120 - Cervical Component

122 - Upper part of Cervical Component

124 - Lower part of Cervical Component

126 - Primary Rings

1262 - craniocervical ring

1264 - mid-cervical ring

1266 - cervicothoracic ring

128 - Intermediate rings

130 - Polyarticular column(s)

132 - outer layer of neck collar

134 - Inner layer of neck collar 136 - plurality of energy absorption units

137 - longitudinal polyarticular column (array/arrangement)

138 - diagonal/criss-cross polyarticular column (array/arrangement)

140 - Individual energy absorption unit

81 - Mono-axial compartment/chamber

82 - poly-axial compartment

83 - cord (of energy absorption unit with circumferential tension fibres)

88 - poly-axial ball and socket joint

87 - Flexible spring (energy absorption unit)

93 - Concertina spring

200 - Embodiment of energy absorption unit with circumferential fibres

202 - perforated circular plate

204 - perforations

206 - tension fibres

208 - ball (ball and socket joint)

402 - cord of polyarticular column

404 - second cord

602 - dial

180 - Locking Mechanism

174 - Concertina-spring compartments

177 - Pressure-differential chamber

182 - bead

183 - flexible sheath - Inlet valve - tertiary valve - Flexible membrane