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
  • 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
  • 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
  • A42B3/065—Corrugated or ribbed shells
• • 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
  • A42B3/10—Linings
  • A42B3/12—Cushioning devices
  • A42B3/124—Cushioning devices with at least one corrugated or ribbed layer
• • 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
  • A42B3/10—Linings
  • A42B3/12—Cushioning devices
  • A42B3/125—Cushioning devices with a padded structure, e.g. foam

Definitions

• Embodiments herein relate to the field of protective helmets and, more specifically, to helmets designed to protect the head from linear and rotational acceleration
• Helmets protect the head from injury during a direct impact.
• An impact to the head can cause skull fracture and/or traumatic brain injury (TBI), and TBI is the leading cause of death and long-term disability in the US among people under 45.
• TBI traumatic brain injury
• 90% of traumatic brain injuries occur without the presence of a skull fracture, and TBI can be induced by rotational acceleration alone.
• contemporary bicycle helmets are primarily designed and tested to mitigate linear acceleration.
• Most contemporary helmets have two principal shortcomings: first, they have limited means to absorb rotational acceleration, and second, elastic helmet liners may store energy during impact, and release of the stored energy may induce a rebound after impact that may contribute to the severity and duration of rotational head acceleration.
• Figure 1 illustrates a cross-sectional mid-sagittal view of an example of a helmet, shown in an unloaded, non-deformed configuration, in accordance with various embodiments;
• Figure 2 illustrates a cross-sectional mid-sagittal view of a helmet shown during impact in a loaded, partially deformed configuration, and depicting relative translation between the outer and inner layers, accommodated by in-plane compression and tension of the intermediate layer, in accordance with various embodiments;
• Figures 3A and 3B illustrate non-elastic, plastic deformation of an example of a honeycomb membrane, shown in non-deformed ( Figure 3A) and deformed ( Figure 3B, with cut-away) states, in accordance with various
• Figures 4A and 4B illustrate schematic drawings of a planar segment (Figure 4A) and a spherically shaped segment (Figure 4B) of an exemplary honeycomb configuration that enables spherical, three-dimensional shaping, in accordance with various embodiments;
• Figures 5A, 5B, and 5C depict a schematic drawing of a honeycomb layer segment with alternate fixation points, shown in unloaded (Figure 5A) and loaded, deformed conditions (Figure 5B), and a perspective view of the honeycomb layer in a loaded, deformed condition ( Figure 5C), in accordance with various embodiments;
• Figure 6 illustrates a cross-sectional mid-sagittal view of an exemplary helmet shown in conjunction with additional layer segments adjacent to the intermediate layer to facilitate sliding of the intermediate layer relative to the inner and outer layers, in accordance with various embodiments;
• Figure 7 illustrates a cross-sectional mid-sagittal view of one embodiment of a helmet, shown during impact in a loaded, partially deformed configuration, in accordance with various embodiments; and [0012]
• Figure 8 illustrates a cross-sectional view of a section of another embodiment, wherein the outer layer and inner layer are perforated with a multitude of holes, which may allow for ventilation through the honeycomb cells, in accordance with various embodiments.
• Coupled may mean that two or more elements are in direct physical or electrical contact.
• Coupled may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.
• a phrase in the form "A/B” or in the form “A and/or B” means (A), (B), or (A and B).
• a phrase in the form "at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).
• a phrase in the form "(A)B” means (B) or (AB) that is, A is an optional element.
• Embodiments herein provide protective helmets designed to lessen the amount of harmful acceleration (both straight linear and rotational) that reaches the brain of a wearer during an impact to the head.
• the helmets may include a multilayer construction for both cushioning and absorbing impact and rotational energy, thus reducing peak acceleration or deceleration of a wearer's head in an impact.
• this reduction in head acceleration and deceleration may result in a corresponding reduction in the magnitude of acceleration or deceleration experienced by the brain, reducing the risk and/or severity of traumatic brain injury (TBI).
• TBI traumatic brain injury
• the helmets disclosed herein may include a suspension of a compressible intermediate layer suspended between generally non- compressible inner and outer layers.
• the suspension of the compressible intermediate layer may mitigate transfer of rotational acceleration from the outer layer to the inner layer.
• the suspension may be created by coupling the compressible intermediate layer, such as a honeycomb layer, through discrete, alternate (e.g., non-opposing) fixation sites, to the outer and inner helmet layers in a manner that allows substantially tangential translation of the outer layer relative to the inner layer.
• the compressible intermediate layer such as a honeycomb layer
• alternate fixation sites to the outer and inner helmet layers in a manner that allows substantially tangential translation of the outer layer relative to the inner layer.
• translation of the outer layer relative to the inner layer may induce in-plane compression and tension in the intermediate layer, rather than shearing.
• the intermediate layer in addition to providing a suspension between the inner and outer layers, the intermediate layer also may crumple and/or compress in an essentially non-elastic manner to mitigate linear acceleration by depleting impact energy and minimizing elastic rebound, which can otherwise contribute to linear and rotational head acceleration.
• the disclosed helmets may allow tangential impact components to be absorbed by in- plane compressive or tensile deformation of the intermediate layer, and
• the intermediate layer may include a honeycomb, such as a honeycomb formed from any material having little or no elastic rebound.
• the honeycomb may be formed from compressible aluminum elements.
• aluminum honeycombs one of skill in the art will appreciate that other lightweight, compressible materials may be employed that have little or no elastic rebound, such as cardboard or paper pulp, various natural or synthetic foams (such as aluminum foam), plastic, non-elastic polymers, and the like.
• the layered construction of the helmets disclosed herein may be used to construct any type of protective headgear, such as safety helmets, motorcycle helmets, bicycle helmets, ski helmets, lacrosse helmets, hockey helmets, football helmets, batting helmets for baseball and softball, headgear for rock and mountain climbers, headgear for boxers, construction helmets, helmets for defense and military applications, and headgear for underground activities.
• the layered technologies disclosed herein may be adapted for use in other types of protective gear, such as elbow pads, knee pads, shoulder pads, shin guards, and the like.
• FIG. 1 illustrates a cross-sectional mid-sagittal view of an example of a helmet, shown in an unloaded, non-deformed configuration, in accordance with various embodiments.
• the helmet 101 has an aerodynamic shape designed for use by bicyclists.
• helmet 101 may include an outer layer 104, an inner layer 105, and an intermediate layer 102.
• intermediate layer 102 may be made from a honeycomb material, such as an aluminum honeycomb material, and may be coupled to the outer and inner layers 104, 105 at alternate fixation sites 103a, 103b, 103c.
• alteration fixation sites refers to attachment points between the outer and intermediate layers, or the intermediate and inner layers, that are spaced apart such that the outer and intermediate layers are not coupled together at a point directly above (e.g., across a thickness dimension of the helmet) a fixation site between the intermediate and inner layers.
• the term “alternate fixation sites” does not require that each fixation site alternates with respect to adjacent sites along a length of a layer. In embodiments, there may be, for example, two fixation sites adjacent to each other between the intermediate layer 102 and the outer layer 104 and one or more fixation sites between the intermediate layer 102 and the inner layer 105 further in one direction along the layers.
• these alternate fixation sites 103a, 103b, 103c may be positioned such that intermediate layer 102 is not coupled to both the outer and inner layers 104, 105 at opposing locations of intermediate layer 102, so that, for example, a fixation site 103b between intermediate layer 102 and outer layer 104 is not directly opposed to a fixation site 103a, 103c between intermediate layer 102 and inner layer 105, and vice versa.
• this alternate fixation may leave portions of intermediate layer 102 that are coupled to neither outer layer 104 nor inner layer 105, enabling stretching and/or compression of intermediate layer 102 between alternate fixation sites 103a, 103b, 103c, thus enabling translation of outer layer 104 relative to inner layer 105, as described in greater detail below.
• outer helmet layer 104 may be sufficiently stable, rigid, and/or non-compressible to distribute impact forces over an extended area.
• helmets in accordance with the present disclosure may include additional features, such as a cage for a hockey helmet, a face mask for a football helmet, a visor for a motorcycle helmet, and/or retention straps, chin straps, and the like.
• inner, intermediate, and/or outer layers 105, 102, 104 may include one or more ventilation openings to permit air flow for cooling the wearer's head.
• intermediate layer 102 may include an aluminum honeycomb, arranged with its cells oriented generally perpendicular to the outer layer 104 of the helmet.
• inner layer 105 may be applied to at least a portion of the intermediate layer 102 interior surface.
• the inner layer covers most if not all of the intermediate layer.
• the inner layer may be comprised of a singular component, of multiple, partially overlapping components, or of multiple components that are joined together in a flexible manner (e.g., like the sewn patches of a soccer ball).
• intermediate layer 102 may be coupled to outer layer 104 and inner layer 105 at discrete and alternate fixation sites 103a, 103b, 103c so as to provide a suspension between outer layer 104 and inner layer 105.
• outer layer 104 may be coupled to intermediate layer 102 at the helmet crown 103b
• inner layer 105 may be coupled to intermediate layer 102 at the helmet periphery 103a, 103c.
• this configuration may reduce the rotational head acceleration caused by the impact component acting tangential to the helmet surface, and it also may reduce linear head acceleration caused by the impact component acting perpendicular to the helmet surface, as described in greater detail below.
• Other configurations/arrangements may be used in other embodiments.
• Figure 2 illustrates a cross-sectional mid-sagittal view of a helmet 201 shown during impact in a loaded, partially deformed configuration, and depicting relative translation between the outer and inner layers 204, 205, accommodated by in-plane compression and tension of the intermediate layer 202, in accordance with various embodiments.
• intermediate layer 202 may be suspended between inner layer 205 and outer layer 204 via coupling to both layers 204, 205 at alternate fixation sites 203a, 203b, 203c.
• this impact induces relative translation between outer layer 204 and inner layer 205,
• in-plane compression 206 and tension 207 (e.g., expansion) of intermediate layer 202 are accommodated by in-plane compression 206 and tension 207 (e.g., expansion) of intermediate layer 202.
• the suspension of intermediate layer 202 between inner layer 205 and outer layer 204 also may allow for small amounts of translation of inner layer 205 perpendicular to and away from outer layer 204. In various embodiments, this increase in separation between outer layer 204 and inner layer 205 may accommodate tangential translation between outer and inner layers 204, 205 in an ovoid, non-spherical shape of helmet 201.
• a primary benefit of translation between the outer and inner layers 204, 205 during impact may be mitigation of rotational head acceleration.
• an additional benefit may be that translation distributes the impact over a larger segment of intermediate layer 202, which may increase absorption of the impact force component perpendicular to the outer layer 204 by controlled crumpling of the honeycomb of the intermediate layer 202 in a direction perpendicular to the honeycomb elements.
• a surface of inner layer 205, outer layer 204, or intermediate layer 202 may include one or more indicators that show the amount of translation 208 between the outer and inner layers 204, 205 in response to an impact to estimate impact severity.
• such indicators may be comprised of graded color bands 209, 210 that circumscribe the periphery of the inside of outer layer 204, whereby increased exposure of color bands 209, 210 indicates an increased impact force.
• the intermediate layer may include two or more layers of honeycomb materials having different stiffness, such that the less stiff layers protect the brain during mild impacts, and the stiffer layers protect the brain during severe impacts.
• the honeycomb cells may be entirely or partially filled with an additional energy absorbing material, such as an expanded foam.
• the additional energy absorbing material may be of non-uniform thickness, and may be configured, for example, such that the
• the additional energy absorbing material also may form a solid layer on the inner and/or outer surface of the honeycomb.
• Figures 3A and 3B illustrate non-elastic, plastic deformation of an example of a honeycomb layer, shown in non-deformed ( Figure 3A) and deformed, partially cut-away ( Figure 3B) states, in accordance with various embodiments.
• an impact force acting perpendicular to the outer helmet surface in excess of the compressive strength of the honeycomb layer may induce plastic, permanent compression of the honeycomb layer by means of crumpling of honeycomb cells.
• the plastic, non-recoverable crumpling of honeycomb cells may absorb an impact by depleting a portion of the impact force. Thus, this crumpling may reduce or eliminate rebound after impact, which may otherwise induce rotational head acceleration subsequent to a primary impact.
• the honeycomb layer in order to minimize an initial peak force required to initiate crumpling, the honeycomb layer may be pre-crushed to a certain degree, such as about 1 -20% of its thickness, or about 5-15% in various embodiments.
• FIGS 4A and 4B illustrate schematic drawings of a planar portion ( Figure 4A) and a spherically shaped portion (Figure 4B) of an example honeycomb configuration that enables spherical, three-dimensional shaping, in accordance with various embodiments.
• this honeycomb configuration 404 enables conforming of an aluminum honeycomb into the spherical, three- dimensional shape of a helmet, while retaining a substantially symmetric shape of honeycomb elements without buckling of honeycomb elements.
• FIGS 5A, 5B, and 5C depict a schematic drawing of a honeycomb layer segment with alternate fixation points, shown in unloaded (Figure 5A) and loaded, deformed conditions (Figure 5B), and a perspective view of the honeycomb layer in loaded, deformed condition (Figure 5C), in accordance with various embodiments.
• Figure 5A illustrates an example of a non-deformed honeycomb 502, with some fixation sites 510 attached to an inner helmet layer, and other fixation sites 511 attached to an outer helmet layer.
• honeycomb 502 may include void sections 512 for ventilation, which may correspond to similar void sections in the inner and outer helmet layers.
• Figure 5B illustrates honeycomb 502 under tangential loading, whereby honeycomb segments between alternate fixation points 510 and 511 are deformed to accommodate suspension and translation between the inner and outer helmet layers.
• Figure 5C illustrates again the deformed shape of honeycomb 502 due to tangential force introduction through fixation point 511 .
• the alternate fixation sites between the respective layers may include non-permanent connections, such as hook-and-loop connections, and may allow for replacement of the inner, outer, or intermediate layer if damaged.
• the inner layer may be attached to the outer layer with an elastic material, and wherein the elastic material holds the inner layer in place during normal wearing, but allows relative displacement between the inner layer and outer layer in an impact.
• FIG. 6 illustrates an example of a helmet 601 having an intermediate layer 602 in suspension between outer layer 604 and inner layer 605, wherein intermediate layer 602 is coupled to the inner and outer layers via alternate fixation sites 603.
• helmet 601 also includes a padding layer 608 on the inside of inner layer 605 to improve comfort and help attenuate impacts.
• padding layer 608 may include a single layer or may be comprised of multiple sections.
• one or more glidable interface layers 607 may be added between at least a part of intermediate layer 602 and outer layer 604.
• one or more glidable interface layers 606 may be added between at least a part of intermediate layer 602 and inner layer 605.
• these interface layers 606 and 607 may reduce friction to enhance tangential displacement between the inner and outer layers during an oblique impact.
• inner layer 605 may be configured with perforations or alternative means to reduce its in-plane stiffness in order to enhance tangential displacement between the inner and outer layer during an oblique impact.
• intermediate layer 602, and/or inner 605 layer or outer 607 layer may be provided with a colorimetric indicator that indicates the severity of impact when the helmet sustains an impact force.
• the severity of impact may be shown as the degree of displacement of the outer layer 607 relative to the inner 605 and/or intermediate 602 layers.
• Figure 7 illustrates a cross-sectional mid-sagittal view of another embodiment of a helmet 701 shown during impact in a loaded, partially deformed configuration.
• fixation points 703a, 703b, 703c are not rigid connections (703b), but rather are unidirectional couplings 703a, 703c that locally couple the layers together upon tangential forces in one direction, while allowing free relative displacement upon tangential forces in another direction.
• relative translation between the outer layer 704 and inner layer 705 is accompanied by in-plane compression of the intermediate layer 702 on one side 706, but the other side 707 remains undeformed in the in-plane direction.
• the inner layer 705 is held in place in the undeformed configuration by elastic connections 708, and in various embodiments, these elastic connections may allow for relative displacement between the outer layer 704 and inner layer 705 in an impact. In practice, this embodiment may allow for greater control of the in-plane stiffness of the intermediate layer 701.
• Figure 8 illustrates a cross-sectional view of a section of another embodiment, wherein the outer layer 801 and inner layer 802 are perforated with a multitude of holes 803, which may allow for ventilation through the honeycomb cells in intermediate layer 804.
• a particular hole size is illustrated, one of skill in the art will appreciate that a range of hole sizes is contemplated, for example, from about 1 mm to about 3 cm, such as about 0.5-2 cm, or about 1 cm, depending on the application.
• the holes may be ordered in an array or random in placement, and different portions of the helmet may have holes of different sizes and/or placement, depending on the ventilation needs of the particular application. It will be
• the helmet may be advantageous to supply the helmet with a multitude of small ventilation holes in order to prevent the gaps in protection that may result from the larger ventilation holes used in most conventional helmets. Additionally, providing a multitude of small holes may enable the helmet to have a more streamlined, smooth shape, which in turn may reduce the chance that a helmet contour may "catch" on an obstacle or obstruction during a fall or other head impact, which could increase rotational impact forces.

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Publications (1)

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• 2013
  • 2013-03-14 US US13/803,962 patent/US20140013492A1/en not_active Abandoned
  • 2013-07-10 CA CA2878613A patent/CA2878613A1/fr not_active Abandoned
  • 2013-07-10 CN CN201380036845.XA patent/CN104427896A/zh active Pending
  • 2013-07-10 EP EP13816787.9A patent/EP2854584A4/fr not_active Withdrawn
  • 2013-07-10 AU AU2013290156A patent/AU2013290156A1/en not_active Abandoned
  • 2013-07-10 WO PCT/US2013/049968 patent/WO2014011802A1/fr not_active Ceased

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