Classifications

• • A—HUMAN NECESSITIES
  • A42—HEADWEAR
  • A42B—HATS; HEAD COVERINGS
  • A42B3/00—Helmets; Helmet covers ; Other protective head coverings
  • A42B3/04—Parts, details or accessories of helmets
  • A42B3/06—Impact-absorbing shells, e.g. of crash helmets
• • A—HUMAN NECESSITIES
  • A42—HEADWEAR
  • A42B—HATS; HEAD COVERINGS
  • A42B3/00—Helmets; Helmet covers ; Other protective head coverings
  • A42B3/04—Parts, details or accessories of helmets
  • A42B3/06—Impact-absorbing shells, e.g. of crash helmets
  • A42B3/062—Impact-absorbing shells, e.g. of crash helmets with reinforcing means
  • A42B3/063—Impact-absorbing shells, e.g. of crash helmets with reinforcing means using layered structures
  • A42B3/064—Impact-absorbing shells, e.g. of crash helmets with reinforcing means using layered structures with relative movement between layers
• • A—HUMAN NECESSITIES
  • A42—HEADWEAR
  • A42C—MANUFACTURING OR TRIMMING HEAD COVERINGS, e.g. HATS
  • A42C2/00—Manufacturing helmets by processes not otherwise provided for

Definitions

• the invention relates to the field of health protection, specifically to a helmet for protecting the head from injury capable of absorbing also rotational forces generated during a fall, such as helmets for motorists, cyclists, and others.
• One variant may be a helmet according to the application US20200022443 A1 .
• the inner part is suspended on strips on the outer part, which however allows movement of the parts only at a certain angle and range and does not guarantee effective dissipation of forces during impact.
• EP2854584 A1 describes a helmet with a central layer of honeycomb material which, in the event of an impact, is capable of absorbing both linear and rotational forces, but only through deformation of the material, or destruction of the helmet, and not through the relative movement of the inner and outer layers of the helmet.
• Another variant may be a helmet according to US20140208486 A1 or US9439469 B2 that comprises shock absorbers between the inner and outer layers formed of elastic materials such as rubber parts or springs. All these connections between the inner and outer layers absorb the impact force by means of connectors based on soft elastic absorbers by deforming the material. The connector thus transmits the shear stress itself, although it absorbs it to a certain extent.
• US 2018/000186 discloses a helmet with a multi-directional suspension system, according to the preamble of claim 1, and which comprises an array of polymeric springs.
• the EPS layer cannot deform properly due to its high density. This problem has already been solved by implementing multiple EPS layers, but this still does not solve the angular impacts that cause the rotational movement.
• a helmet with a multi-directional suspension system comprising an outer helmet shell and an inner helmet shell and at least three suspension connectors, where each suspension connector comprises two opposite parts, wherein a first part of the suspension connector is connected to the first one of the inner helmet shell or the outer helmet shell and a second part of the suspension connector is connected to the second one of the inner helmet shell or the outer helmet shell, wherein each part of the suspension connector comprises a base and at least one bracket extending therefrom in a direction towards the base of the opposite part, where the bases are connected by at least three flexible suspensions and the tops of the brackets are connected by at least one flexible suspension, wherein the top of the bracket of the first part is closer to the base of the second part than the top of the bracket of the second part, wherein the length of the flexible suspensions is adapted such that the flexible suspensions are in a tensioned state. From a physical point of view, it is clear that all the flexible suspensions must be in a tensioned state for the suspension connector to function.
• Prestressing of the tensile elements by force ensures tractive forces in all loaded states while the structure remains elastic.
• the forces are absorbed by the flexibility and/or elasticity of the suspension and, if the limit force is exceeded, by the destruction of the entire connector.
• the tensegrity connector allows for wider movement between the outer and inner shell, while at the same time it can dissipate linear impacts to a certain extent by stretching the flexible suspensions in the suspension connectors.
• a tensegrity-based helmet is the solution for the new helmet standards, where the helmet should induce an angular acceleration of less than 5000 rad/s 2 at an angular impact of 5 m/s with BrIC (brain injury criterion; a parameter indicating the probability of a severe brain injury based on the angular velocity and acceleration applied in the accident) of less than 0,6, but at the same time, for linear impacts of 5,2 m/s, the HIC (head injury criterion; a parameter indicating the probability of a severe head injury based on the time and forces applied in the accident) it should not exceed 2400.
• the indirect connection between the inner and outer shell allows the outer shell to rotate independently before the movement is transferred to the inner shell and subsequently to the head and brain in the event of a tangential impact.
• the indirect connection is realized by a special helmet structure where the inner and outer shells are connected only by tensegrity connectors and at least one of the rigid parts of the helmet is not attached to the soft central part. This feature allows relative rotation between the outer and inner layers of the helmet, provided that the individual parts of the helmet are at least similar in shape. At the same time, the connectors hold the structural integrity of the helmet. This connection reduces the rotational acceleration of the head when it hits an obstacle.
• One of the advantages of the present invention is the possibility of using the system in virtually any type of helmet, since the use of the suspension system by means of tensegrity connectors does not require the exact spherical shape of the individual parts of the helmet as is the case with prior art variants.
• a central part of soft material adapted to absorb the impact forces comprising pockets for the suspension connectors, wherein the central part is rigidly connected to the inner shell of the helmet or to the outer shell of the helmet.
• This layer has the potential to improve the dissipation of the linear force components acting on the user's head in the event of an accident.
• the central part is most often made of a layer of expanded polystyrene with pockets for the suspension connectors, wherein the pockets are wider compared to the suspension connectors to allow movement between the inner and outer shell of the helmet.
• the flexible suspensions connecting the bases of the suspension connector are anchored at the edge of the bases, wherein by the edge of the base is meant any point on the base surface the distance of which from the connector axis is greater than 70 % of the shortest distance from the connector axis to the edge of the base surface, thus achieving the balancing of the tensile forces within the connector and thus maximum stability of the connector.
• the second shell of the helmet is then positioned and the second bases of the suspension connectors are rigidly connected to the second one of the inner shell of the helmet or outer shell of the helmet, again by means of a glue, fusion, or other suitable fasteners.
• the glue can be applied either to the bases of the connectors or to the appropriate areas of the shell of the helmet. From a functional point of view, it is irrelevant whether the connector is first connected to the inner or outer shell. However, the shape of the helmet can be a limiting factor, where, for example, in the case of integral helmets it is possible that the inner shell with the connectors applied could not be inserted into the outer shell due to the dimensions of the individual parts.
• the manufacturing procedure includes the steps of applying the central part of the helmet before the step of connecting the first bases of the suspension connectors to the first one of the inner shell of the helmet or the outer shell of the helmet, where models simulating the shape of the suspension connectors adapted to define the space for the suspension connectors at the areas where the real connectors will subsequently be located are placed on the inner shell of the helmet or the outer shell of the helmet, and, for example, EPS or other material of the central part of the helmet is applied.
• the application is done by spraying or applying a fluid material, which is then cured or hardened with appropriate agents.
• the models have the same shape as the connector with adequate clearance to allow the real connector to move as desired.
• the central part of the helmet is connected to the inner shell of the helmet or the outer shell of the helmet using gluing, fusion, or fasteners before the step of connecting the first bases of the suspension connectors to the first one of the inner shell of the helmet or the outer shell of the helmet.
• the stiffness of the connector 8 can be adjusted by the stress of the suspension 7 .
• the connection between the rigid parts and the suspension 7 can be made by drilling an opening in the rigid part, threading the suspension 7 through the opening and securing it with a knot and/or glue on the other side, or by securing it with a screw or plug or other stop.
• the base 5 and the element of the connected brackets 6 are manufactured separately and subsequently connected, e.g., by gluing, fusion, or fasteners.
• the parts are further connected by suspensions 7 at the place of the connection of the three brackets 6 and at the edge parts of the bases 5 .
• Other variants of the tensegrity suspensions are also possible.
• the procedure for assembling the connection between the inner shell 4 and the outer shell 1 of the helmet comprises, first of all, the manufacture of the suspension connector 8 .
• a first and a second part of the suspension connector 8 is manufactured, for example by 3D printing.
• Each part of the connector 8 comprises a base 5 and a bracket 6 extending therefrom.
• the first and second parts of the suspension connector 8 are connected by means of flexible suspensions 7 , wherein the tension of the suspensions 7 is adjusted at the same time. This completes the suspension connector 8 .
• the steps of manufacturing the suspension connector 8 are repeated depending on the number of the suspension connectors 8 needed to manufacture the helmet.
• the steps of applying the central part 2 of the helmet are included in the manufacturing procedure before the step of connecting the first bases 5 of the suspension connectors 8 to the inner shell 4 of the helmet.
• Models of the suspension connectors 8 adapted to define the space for the suspension connectors 8 at the locations where the real connectors 8 will subsequently be located are placed on the inner shell 4 of the helmet, and e.g., EPS or other material of the central part 2 of the helmet is applied.
• the application is done by spraying or applying a fluid material, which is then cured or hardened with appropriate agents.
• the models have the same shape as the connector 8 with adequate clearance to allow the real connector 8 to move as desired.
• the size of the difference between the width of the model of the connector 8 and the width of the real connector 8 depends on the set stiffness of the suspension 7 , the length of the suspension 7 , and the stiffness of the individual parts of the connector 8 . After application or curing of the central part 2 the models of the connectors 8 are removed and the procedure as described above continues.
• the central part 2 of the helmet is connected to the inner shell 4 of the helmet (alternatively the outer shell 1 of the helmet) by gluing, fusion, or fasteners before the step of connecting the first bases 5 of the suspension connectors 8 to the inner shell 4 of the helmet.
• Helmet with multi-directional suspension is characterized by the ability to absorb rotational and linear forces at the same time.
• the absorption of rotational forces is particularly desirable in the case of motorcyclist injuries.
• the absorption properties of the suspension connector can be changed by the choice of the suspension, its elasticity, and length. This makes the principle also applicable in applications for helmets designed for other sports such as equestrianism, cycling, etc. Different sports are characterized by different injury mechanisms and therefore require different helmet parameters.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Helmets And Other Head Coverings (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=83004671

Family Applications (1)

Country Status (3)

Families Citing this family (1)

Family Cites Families (7)

• 2021
  • 2021-11-01 CZ CZ2021-499A patent/CZ309734B6/cs unknown
• 2022
  • 2022-07-28 WO PCT/CZ2022/050066 patent/WO2023072321A1/en not_active Ceased
  • 2022-07-28 EP EP22757480.3A patent/EP4426154B1/en active Active

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