MULTI-SHELL HELMET WITH PIVOTABLE OUTER SHELL
Helmet prevent or mitigate cervical spine fractures, including the type of injuries associated with axial compression of the spine and fracture of the spine which may otherwise result in deformation and/or injury to the spinal cord. Helmets convert an impact force with a component aligned with the axis of the spine (a “spinally axial component”) to rotational motion. In the event of a head-first impact, such helmets flexion of the neck so that the head and the cervical spine are not aligned (or less aligned) with the direction of an impact force, thereby mitigating the likelihood and/or severity of cervical spine fractures.
This application is a continuation of Patent Cooperation Treaty (PCT) application No. PCT/CA2021/051787 having an international filing date of 10 Dec. 2021 which in turn claims priority from, and for the purposes of the United States, claims the benefit under 35 U.S.C. § 119 of, U.S. application No. 63/124,678 filed 11 Dec. 2020 and entitled MULTI-SHELL HELMET WITH PIVOTABLE OUTER SHELL. All of the applications referred to in this paragraph are hereby incorporated herein by reference
TECHNICAL FIELDThe present invention relates to helmets and headwear. Particular non-limiting embodiments provide a multi-shell helmet with an inner member having a concavity for receiving at least a portion of the head of a user and an outer shell that is pivotable relative to the inner member and a method for using same to mitigate head and/or cervical spine injuries and/or fractures. Another embodiment provides a method for converting/retrofitting a single-shell helmet to a multi-shell helmet comprising an inner member having a concavity for receiving at least a portion of the head of a user and an outer shell that is pivotable relative to the inner member.
BACKGROUNDHelmets and other protective headgear are used in a variety of contexts and are designed to protect a wearer's head from physical impact. A typical helmet has an outer shell and an inner protective liner. The outer shell provides the structural rigidity of the helmet and is often made of a solid material, e.g. plastic, fiberglass, carbon fiber, polycarbonate or similar composites. The outer shell also protects against penetration of sharp objects and distributes an impact force across the inner protective liner. The inner protective liner typically provides deformable foam to absorb impact/crash energy so that the acceleration experienced by the head is reduced, relative to that which would be experienced by the head in the absence of a helmet. The inner protective liner may typically be made of expanded polystyrene (“EPS”), expanded polypropylene (“EPP”), vinyl nitrile (“VN”) or ethylene-vinyl acetate (“EVA”). Helmets with EPS liners are referred to as single-impact helmets because EPS permanently deforms upon impact. Helmets with EPP, VN or EVA liners are referred to as multiple-impact helmets because such liners can recover and return to their initial shapes after impact. Generally speaking, the thicker the inner protective liner is, the more impact/crash energy it will be able to absorb. However, if the inner protective liner is too thick, the outer circumference and weight of the helmet are correspondingly large, which may detract from the appearance of the helmet and may contribute to strain on the neck.
Most designs of helmets and protective headgear offer limited protection for the neck. The neck is the uppermost portion of the vertebral column and located between the head and thorax. It has seven cervical vertebrae C1-C7 separated by intervertebral discs except for the top two vertebrae where it joins to the head. Inadequate neck protection may lead to fracture of the vertebrae and the fractured vertebrae may compress or impart undesirable forces on the spinal cord resulting in spinal cord injuries which can be medically devastating events. Specifically, axial compressive type neck injuries can cause a particularly devastating type of spinal cord injury resulting in quadriplegia. Alternate terms for an axial compression injury include a vertebral compression fracture, fracture-dislocation of the cervical spine, axial compression fracture, axial compression burst fracture, or an axial load injury. Cervical spine fractures at the C1 or C2 vertebrae are frequently fatal, and fracture-dislocations at the C3-C7 vertebrae frequently result in quadriplegia.
Axial compressive type neck injuries are most likely when the head and the cervical spine are aligned with the direction of an impact force as shown in
There is a general desire for helmets and headwear that are comfortable to wear and can mitigate head and/or cervical spine fractures.
The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
SUMMARYThe following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
A pivot helmet is provided. The pivot helmet can be used to prevent or mitigate cervical spine fractures, including the type of injuries associated with spinal axial compression and fracture of the spine which may otherwise result in deformation and/or injury to the spinal cord. The pivot helmet is configured to convert an impact force with component aligned with the axis of the spine (an “axial component”) to rotational (or pivotal) motion. In the event of a head-first impact, the pivot helmet induces flexion of the neck so that the head and the cervical spine are not aligned with the direction of an impact force, thereby mitigating the likelihood and/or severity of cervical spine fractures.
One aspect relates to a multi-shell helmet. The helmet comprises an outer shell defining a concavity; an inner member, at least a portion of which is located within the concavity, the inner member pivotally coupled to the outer shell and permitted to move relative to the outer shell by rotation about a laterally oriented pivot axis. The helmet comprises a deployment device which, in the absence of sufficient external force, constrains rotational motion between the inner member and the outer shell about the pivot axis (e.g. to within a minimum rotational amount). That is, in the absence of sufficient external force, the deployment device constrains the initial relative angular orientations of the inner member and the outer shell about the pivot axis (e.g. to within minimum relative angular orientations). The deployment device may constrain the relative motion between the inner member and the outer shell by applying force between the inner member and the outer shell (or between any components of the pivotal coupling between the inner member and the outer shell) that tends to prevent relative rotation. When the helmet receives an impact having sufficient force (e.g. an external force greater than a threshold), the deployment device deploys to permit relative angular rotation between the outer shell and the inner member about the pivot axis. In some embodiments, the deployment device may be in an initial configuration in the absence of sufficient external force and a deployment configuration (different from the initial configuration) when the helmet receives an impact having sufficient force.
The location of the laterally oriented pivot axis can impact the motion path (kinematics) of a wearer's head and neck, and this motion can affect the mechanical loads (kinetics) acting on the head and neck. In some embodiments, the laterally oriented pivot axis is parallel to a coronal plane and orthogonal to a mid-sagittal plane of the helmet. The laterally oriented pivot axis passes a coupling zone bounded by three notional lines in the mid-sagittal plane of the helmet, the three lines being: a center of gravity line; a brow line running from a front portion to a back portion of the helmet and tangential to a lowermost point on a surface that defines a top edge of a face opening; and an anterior line parallel to the center of gravity line and intersecting the lowermost point of the top edge surface of the face opening.
In some embodiments, pivot joint and the deployment device may be separate from each other. In some other embodiments, the pivot joint and the deployment device may be integrated into one mechanism.
The pivot joint may comprise two pivot mechanisms located symmetrically on the helmet.
One or both of the two pivot mechanisms may be positioned between a center of gravity line of the helmet and a position where a maximal relative angular rotation range between the inner member and the outer shell after deployment of the deployment device is in a range of 10°-30°.
One or both of the two pivot mechanisms may be positioned such that a position that the laterally oriented pivot axis intersects the sagittal plane is at a midpoint between an arc center of the inner member and an arc center of the outer shell.
A first pivot mechanism may pivot around a first pivot axis and a second pivot mechanism may pivot around a second pivot axis.
The first pivot axis and the second pivot axis may and the laterally oriented pivot axis may be collinear.
One or both of the two pivot mechanisms may provide three degrees of rotational freedom.
The translational positions of the first and second axes may be fixed.
The orientation of at least one of the first and second pivot axes may be variable.
One or both of the pivot mechanisms may comprise a surface bearing pivot joint. Two complementary surfaces may bear against one another to provide the movement of the surface bearing pivot joint.
One or both of the pivot mechanisms may comprise one or more ball-socket pivot joints.
One or both of the pivot mechanisms may comprise one or more full-socket type pivot joints.
One or both of the pivot mechanisms may comprise one or more half-socket type pivot joints.
One or both of the pivot mechanisms may comprise one or more tapered components that are mounted to one of the inner member and the outer shell.
The outer shell may be shaped to induce torque on the outer shell (relative to the inner shell) by interaction between the outer shell and the ground (or other impact surface) to thereby cause the inner shell to rotate relative to the outer shell about the pivot axis. For example, helmets suitable for sports that involve low-friction impact surfaces such as ice and/or snow and/or for other applications involving pivotable helmets, the outer shell may be shaped to provide one or more extremities/apexes such that interaction between the outer shell and the ground (or other impact surface) induces torque on the outer shell. In some embodiments or applications, it may be desirable to provide a number (e.g. one or more) of extremities/apexes on the outer surface of the outer shell (e.g. at the intersection of the outer surface of the outer shell with the mid-sagittal plane).
Another aspect relates to a helmet that may comprise an outer shell defining a concavity, an inner member. At least a portion of the inner member may be located within the concavity. The helmet may further comprise first and second pivot joints located on opposing sides of the inner member which may facilitate relative pivotal movement between the inner member and the outer shell. The first pivot joints may permit rotation about corresponding first and second pivot axes. The first and second pivot joints may permit orientations of the first and second pivot axes to change while maintaining translational positions of the first and second pivot axes static.
Another aspect relates to a helmet that may comprise an outer shell defining a concavity and an inner member, at least a portion of which is located within the concavity. The helmet may further comprise first and second pivot joints located on opposing sides of the inner member which may facilitate relative pivotal movement between the inner member and the outer shell. The first pivot joints may permit rotation in three degrees of freedom and maintain static translation positions.
Another aspect relates to a method for mitigating cervical spine injuries and/or fractures. The method comprises providing a multi-shell helmet. The helmet comprises an outer shell defining a concavity; an inner member, at least a portion of which is located within the concavity, the inner member pivotally coupled to the outer shell and permitted to move relative to the outer shell by rotation about a laterally oriented pivot axis. The helmet comprises a deployment device which, in the absence of sufficient external force, constrains rotational motion between the inner member and the outer shell about the pivot axis (e.g. to within a minimum rotational amount). That is, in the absence of sufficient external force, the deployment device constrains the initial relative angular orientations of the inner member and the outer shell about the pivot axis (e.g. to within minimum relative angular orientations). The deployment device may constrain the relative motion between the inner member and the outer shell by applying force between the inner member and the outer shell (or between any components of the pivotal coupling between the inner member and the outer shell) that tends to prevent relative rotation. When the helmet receives an impact having sufficient force (e.g. an external force greater than a threshold), the deployment device deploys to permit relative angular rotation between the outer shell and the inner member about the pivot axis. In some embodiments, the deployment device may be in an initial configuration in the absence of sufficient external force and a deployment configuration (different from the initial configuration) when the helmet receives an impact having sufficient force.
Another aspect relates to a method for retrofitting a single-shell helmet to a multi-shell helmet. The method comprises determining a coupling zone, the coupling zone being bounded by three notional lines in a mid-sagittal plane of the single-shell helmet, the three lines being: a center of gravity line; a brow line running from a front portion to a back portion of the helmet and tangential to a lowermost point on a surface that defines a top edge of a face opening; and an anterior line parallel to the center of gravity line and intersecting the lowermost point of the top edge surface of the face opening. At least a portion of a second shell is positioned within a concavity of the first shell. The second shell and the first shell are pivotably coupled together by a pivot joint having a laterally oriented pivot axis that intersects the mid-sagittal plane in the coupling zone, so that the second shell and the first shell are movable relative to one another by rotation about the laterally oriented pivot axis, wherein the laterally oriented pivot axis is parallel to a coronal plane and orthogonal to a mid-sagittal plane of the helmet. The helmet comprises a deployment device which, in the absence of sufficient external force, constrains rotational motion between the inner member and the outer shell about the pivot axis (e.g. to within a minimum rotational amount). That is, in the absence of sufficient external force, the deployment device constrains the initial relative angular orientations of the inner member and the outer shell about the pivot axis (e.g. to within minimum relative angular orientations). The deployment device may constrain the relative motion between the inner member and the outer shell by applying force between the inner member and the outer shell (or between any components of the pivotal coupling between the inner member and the outer shell) that tends to prevent relative rotation. When the helmet receives an impact having sufficient force (e.g. an external force greater than a threshold), the deployment device deploys to permit relative angular rotation between the outer shell and the inner member about the pivot axis. In some embodiments, the deployment device may be in an initial configuration in the absence of sufficient external force and a deployment configuration (different from the initial configuration) when the helmet receives an impact having sufficient force.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.
Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
Aspects of the present invention can be used to prevent or mitigate cervical spine fractures, including the type of injuries associated with axial compression of the spine and fracture of the spine which may otherwise result in deformation and/or injury to the spinal cord. Aspects of the present invention convert an impact force with a component aligned with the axis of the spine (a “spinally axial component”) to rotational motion. In the event of a head-first impact, the present invention induces flexion of the neck so that the head and the cervical spine are not aligned (or less aligned) with the direction of an impact force, thereby mitigating the likelihood and/or severity of cervical spine fractures.
A number of aspects of the present invention will be described below and include:
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- a helmet comprising an inner member having a concavity for receiving at least a portion of the head of a user and an outer shell that is pivotable relative to the inner member;
- a method for using a multi-shell helmet with an inner member and outer shell that is pivotable relative to the inner member to reduce the severity of and/or mitigate head and/or cervical spine fractures; and
- a method for converting/retrofitting a single-shell helmet to a multi-shell helmet with an outer shell that is pivotable relative to an inner member.
For each aspect, one or more embodiments may be described.
First Aspect—Helmet with Outer Shell Pivotable Relative to Inner Member
A first aspect of the present invention provides a helmet comprising an inner member 106 having a concavity for receiving at least a portion of the head of a user and an outer shell 104 that is pivotable relative to inner member 104. As schematically shown in
The
The helmet comprises a deployment device which, in the absence of sufficient external force, constrains rotational motion between the inner member 106 and the outer shell 104 about the pivot axis 138 (e.g. to within a minimum rotational amount). That is, in the absence of sufficient external force, the deployment device constrains the initial relative angular orientations of the inner member 106 and the outer shell 104 about the pivot axis 138 (e.g. to within minimum relative angular orientations). In some embodiments, this minimum relative rotation is less than 5°. In some embodiments, this minimum relative rotation is less than 2.5°. In some embodiments, this minimum relative rotation is less than 1.25°. The deployment device may constrain the relative motion between the inner member 106 and the outer shell 104 by applying force between the inner member 106 and the outer shell 104 (or between any components of the pivotal coupling 108 between the inner member 106 and the outer shell 104) that tends to prevent relative rotation. When the helmet receives an impact having sufficient force (e.g. an external force greater than a threshold), the deployment device deploys to permit relative angular rotation between the outer shell 106 and the inner member 104 about the pivot axis 138. In some embodiments, the deployment device permits a larger range of motion (between outer shell 104 and inner member 106 about pivot axis 138) upon receiving an impact force (as compared to the absence of an impact force). In some embodiments, this larger range of permissible relative rotation is greater than 5°. In some embodiments, this larger range of permissible relative rotation is greater than 10°. In some embodiments, this larger range of permissible relative rotation is greater than 15°. In some embodiments, the deployment device may be in an initial configuration in the absence of sufficient external force and a deployment configuration (different from the initial configuration) when the helmet receives an impact having sufficient force.
The deployment device performs several functions. For example, the deployment device provides helmet stability by maintaining an initial relative angular relationship between the inner member 106 and the outer shell 104 about the pivot axis 138. A good helmet fit can be achieved because, in the absence of an impact, the outer shell 104 will not rotate relative to the inner member 106. Also, the deployment device may function to permit sufficient frictional force to build up when the helmet receives an impact. This frictional force may then help to induce rotation between the inner member 106 and the outer shell 104 and change the direction of the head's momentum. In response to an impact force (e.g. an axial force that may be (or may have a component) parallel to the spinal axis), the multi-shell helmet may induce flexion of the neck and thereby mitigate cervical spine fractures.
As used herein, unless the context dictates otherwise, the expressions “axial loading in the spine”, “spinally axial force”, and “spinally axial impact force” mean an impact force with a component aligned with the axis of the cervical portion of the spine, when such cervical portion is generally aligned. Similarly, unless the context dictates otherwise, a “spinally axial component” means a component of an impact force aligned with the axis of the cervical portion of the spine, when such cervical portion is generally aligned.
As used herein, unless the context dictates otherwise, the terms “rotation angle” and/or “angle of rotation” mean the angle that an inner member and an outer shell are able to rotate (or have rotated) relative to one another or relative to their initial angular position about a laterally oriented pivot axis.
(a) A First Helmet EmbodimentHead 10 comprises a frontal region 18, a left side region 20, a right side region 22, an occipital region 24, and a crown region 26. Frontal region 18 corresponds substantially to the frontal bone region of head 10. Left and right side regions 20, 22 are located above the left and right ears of the wearer. Occipital region 24 and crown region 26 correspond substantially to the back and top of head 10.
Referring to
COG line 102 is named as such because when helmet 100 is worn on head 10, the center of gravity of head 10 is located at least approximately on COG line 102. The center of gravity of helmet 100 may also be located on COG line 102, but this may not always be the case. The location of the center of gravity of helmet 100 depends on the specific design of a helmet.
Brow line 112 is located in mid-sagittal plane 120 of helmet 100. Brow line 112 runs from a front portion to a back portion of helmet 100 and is tangential to a surface 116 of helmet 100 that defines a top edge of a face opening 119 at the lowermost point of this surface 116. When helmet 100 is worn on head 10, brow line 112 runs from an anterior aspect of the frontal bone to the occipital region.
Anterior line 114 is located in mid-sagittal plane 120 of helmet 100. Anterior line 114 is parallel to COG line 102 and intersects the lowermost point of top edge surface 116 of face opening 119.
Structurally, helmet 100 comprises an outer shell 104 shaped to provide an outer concavity 105 and an inner member 106 which is at least partially located in outer concavity 105 and is shaped to receive an inner head-receiving concavity 115. Outer shell 104 and inner member 106 are pivotably connected and are permitted to pivot relative to one another by rotation about a laterally oriented pivot axis 138. In the illustrated embodiment, outer shell 104 and inner member 106 are connected by a pair of pivot joints 108 located and aligned to facilitate rotation about pivot axis 138. Helmet 100 also comprises a deployment device 124 (described in more detail below) which, in the absence of sufficient external force, constrains rotational motion between inner member 106 and outer shell 104 about pivot axis 138 (e.g. to within a minimum rotational amount). That is, in the absence of sufficient external force, deployment device 124 constrains the initial relative angular orientations of inner member 106 and outer shell 104 about pivot axis 138 (e.g. to within minimum relative angular orientations). In some embodiments, this minimum relative rotation is less than 5°. In some embodiments, this minimum relative rotation is less than 2.5°. In some embodiments, this minimum relative rotation is less than 1.25°. Deployment device 124 may constrain the relative motion between inner member 106 and outer shell 104 by applying force between inner member 106 and outer shell 104 (or between any components of the pivotal coupling between inner member 106 and outer shell 104) that tends to prevent relative rotation. When the helmet 100 receives an impact having sufficient force (e.g. an external force greater than a threshold), deployment device 124 deploys to permit relative angular rotation between outer shell 104 and inner member 106 about pivot axis 138 (see e.g.
Outer shell 104 is configured to provide the structural rigidity of helmet 100 and to protect against penetration of sharp objects. Outer shell 104 defines an outer concavity 105. When helmet 100 is worn on head 10, outer shell 104 is shaped to cover at least one of frontal region 18, crown region 26, and occipital region 24 of head 10. Outer shell 104 may be made of any suitable solid, rigid materials, including plastic (including fiber reinforced plastics), fiberglass, carbon fiber (including a variety of different carbon fibers such as carbon fiber pre-preg and/or carbon fibers with various fabrics, tows and/or weaves), bulk moulding compounds polycarbonate, similar composites and/or the like. In some embodiments, outer shell 104 may have a cross-sectional thickness on the order of 35 mm, 30 mm, 25 mm, 20 mm, 15 mm, 10 mm, 5 mm or less, for example.
Inner member 106 is located either entirely or partially within outer concavity 105 of outer shell 104. In some embodiments, inner member 106 comprises more than one component, and each component may be pivotably coupled to outer shell 104. Inner member 106 may be made of any suitable material, including plastic (including fiber reinforced plastics), fiberglass, carbon fiber (including a variety of different carbon fibers such as carbon fiber pre-preg and/or carbon fibers with various fabrics, tows and/or weaves), bulk moulding compounds, polycarbonate, EPS, EPP, EVA, VN, combinations of these materials and/or the like. In some embodiments, inner member 106 may comprise a partial or full coverage scaffold EPS layer, where scaffold EPS is positioned between one or more elements of inner member 106 and head 10 when helmet 100 is worn. In some embodiments, inner member 106 may comprise full coverage EPS. Inner member 106 may comprise one or more holes. Such holes may advantageously aid in the ventilation of helmet 100. In some embodiments, inner member 106 may comprise a plurality of layers. In some embodiments, inner member 106 may have a cross-sectional thickness on the order of 35 mm, 30 mm, 25 mm, 20 mm, 15 mm, 10 mm or less, for example. In some embodiments inner member 106 may have a cross-sectional thickness of 1 mm to 5 mm. In some embodiments inner member 106 may have a cross-sectional thickness of 2 mm to 3 mm. Inner member 106 and outer shell 104 may be made of the same material or different materials. Inner member 106 and outer shell 104 may have the same cross-sectional thickness or different cross-sectional thicknesses.
In some embodiments inner member 106 may comprise a shell made up of one or both of carbon fiber and fiberglass and an EPS layer. The EPS layer may be situated within a concavity of the shell. The EPS layer may be in contact with head 10 when worn by a wearer.
As shown in
Motion zone 142 (which may be defined by the outer surface 106A of inner member 106 and the inner surface 104A of outer shell 104) may have any suitable shapes and/or dimensions. In some embodiments, motion zone 142 has a uniform cross-sectional thickness over at least a portion of motion zone 142, i.e. inner surface 104A of outer shell 104 and outer surface 106A of inner member 106 are separated by a uniform motion distance 140 over at least a portion of motion zone 142. Motion distance 140 may be equal to 1 cm to 3 cm over at least a portion of motion zone 142. For example, motion distance 140 may be about 2.5 cm over at least a portion of motion zone 142. In other embodiments, motion zone 142 has varying thickness, i.e. motion distance 140 varies throughout motion zone 142.
The shape and dimension of motion zone 142 may depend on (i) the shapes of inner surface 104A of outer shell 104 and outer surface 106A of inner member 106 (ii) motion distance 140 (iii) the impact stiffness of one or both of outer shell 104 and inner member 106 and (iv) the deformation properties of one or both of outer shell 104 and inner member 106. Inner member 106 and outer shell 104 may experience the same or different deformation in the event of the application of force. The deformation of inner member 106 and/or outer shell 104 may be a result of one or more of the geometry, thickness and material properties of inner member 106 and/or outer shell 104. For example, varying one or both of the thickness and geometry of inner member 106 and/or outer shell 104 may vary the stiffness of inner member 106 and/or outer shell 104. Increasing the thickness of inner member 106 and/or outer shell 104 may increase the stiffness of inner member 106 and/or outer shell 104. Geometric smoothing of the surface topology of inner member 106 and/or outer shell 104 may increase the stiffness of inner member 106 and/or outer shell 104. An increase in stiffness may allow inner member 106 and/or outer shell 104 to resist more force. Different materials may have varying abilities to resist deformation in part due to how different materials perform when force is applied. A single material may have varying abilities to resist deformation when loads are applied in one or more differing directions. In some embodiments it may be desirable for the one or more materials that make up one or both of inner member 106 and outer shell 104 to have a sufficient stiffness to prevent one or both of outer shell 104 and inner member 106 from deforming so much that a collision between the outer and inner shell impedes rotation.
Motion zone 142 may impact the angular range of relative rotation between inner member 106 and outer shell 104 about pivot axis 138. For example, motion zone 142 may only permit inner member 106 to rotate in a first angular direction (relative to outer shell 104 about pivot axis 138) to a first angular range maximum and may only permit inner member 106 to rotate in a second angular direction (opposite the first angular direction) to a second angular range maximum. In some embodiments, motion zone 142 may permit unlimited relative rotational movement between inner member 106 and outer shell 104 about pivot axis 138 in one or both angular directions.
In some embodiments, a cushioning material (e.g. a crushable or plastically deformable material) and/or fluid material (e.g. one or more of air, oil, lubricant, gel, etc.) is located in motion zone 142. Such material may be used to dampen rotational acceleration and/or velocity and/or may reduce the energy imparted to the head of the wearer.
Inner member 106 and outer shell 104 are pivotably coupled together so that inner member 106 can rotate relative to outer shell 104 (or vice versa) about pivot axis 138. Pivot axis 138 is generally parallel to the lateral plane and orthogonal to mid-sagittal plane 120 of helmet 100.
The location of pivot axis 138 can impact both the motion path (kinematics) of head 10 and the neck of the wearer of helmet 100, and this motion can affect the mechanical loads (kinetics) acting on head 10 and the neck of the wearer of helmet 100. For example, the location of pivot axis 138 can impact the moment which is created by the relative pivotal movement of inner member 106 and outer shell 104 to change the direction of momentum of head 10 upon impact. The optimization strategy when selecting the location of pivot axis 138 to facilitate rotational motion of head 10 and the neck of the wearer may comprise (without limitation): (i) maximizing (or providing at or above an acceptable threshold level), the available space for relative pivotal movement between outer shell 104 and inner member 106 so that, for example, the relative angular rotation range is maximized; (ii) increasing applied torque on the head and neck; (iii) decreasing the mass moment of inertia of the head and neck that the applied torque needs to overcome; and (iv) minimizing or reducing the probability of traumatic brain injury (which may be achieved by reducing one or both of the rotational velocity and rotational acceleration) while having enough velocity to protect the neck of the wearer.
To maximize available space for rotation, the location of pivot axis 138 may be placed as close as possible to the centers of curvature of inner member 106 (e.g. outer surface 106A) and outer shell 104 (e.g. inner surface 104A) to prevent the two from colliding with one another prematurely.
To increase the applied torque between inner member 106 and outer shell 104 about pivot axis 138, one option is to increase the distance (w) between COG line 102 and a parallel line 145 that intersects pivot axis 138 on mid-sagittal plane 120.
To decrease the mass moment of inertia, one option is to reduce the distance (d) between a center of gravity 143 of head 10 and the location of pivot axis 138 on mid-sagittal plane 120.
Ipivot=ICOG+md2
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- ICOG=mass moment of inertia of head-and-neck about its COG 143
- Ipivot=mass moment of inertia of head-and-neck about pivot axis 138
- m=mass of head-and-neck
- d=distance between pivot axis 138 and COG 143
It may be desirable to have a large range of relative angular motion between inner member 106 and outer shell 104 and to create a small mass moment of inertia to resist changes to the magnitude of head rotational momentum. However, these two goals may be viewed as competing. The greatest range of rotational motion typically involves locating pivot axis 138 as close as possible to the intersection between brow line 112 and COG line 102. This would also minimize the mass moment of inertia. On the other hand, to create the largest moment possible that will change/offset the direction of head momentum, it may be desirable to locate pivot axis 138 as close as possible to the intersection between brow line 112 and anterior line 114.
The location of pivot axis 138 is an important consideration. In some embodiments (including the illustrated embodiment, as shown best in
In some embodiments, pivot axis 138 is located so that it intersects mid-sagittal plane 120 within a narrow area 122 near brow line 112. Without being bound by theory, locating pivot axis 138 in this narrow area 122 enables the creation of a reasonably large moment to offset the direction of head momentum. In some embodiments, it is preferred to locate pivot axis 138 so that it intersects mid-sagittal plane 120 as close to brow line 112 as possible, e.g. in some embodiments, within 6 cm from brow line 112; in some embodiments, within 5 cm from brow line 112; in some embodiments, within 4 cm from brow line 112; in some embodiments within 3 cm from brow line 112; in some embodiments, within 2.5 cm from brow line 112; in some embodiments, within 2 cm from brow line 112; in some embodiments, within 1.25 cm from brow line 112; and in some embodiments, within 1 cm from brow line 112.
Helmet 100 comprises a pair of pivot joints 108 to enable the rotational motion between inner member 106 and outer shell 104 about pivot axis 138. To determine a location for pivot joints 108 and their corresponding pivot axes, one may define an x-y coincident with mid-sagittal plane 120 of helmet 100, such that when helmet 100 is worn on head 10, the y-axis may be generally parallel with the superior/inferior direction of head 10 and the x-axis may be generally parallel with the posterior/anterior direction of head 10 (see x-y plane in
An x-coordinate of pivot joints 108 may be selected to (without limitation): (i) maximize (or provide at or above an acceptable threshold level) the available space for relative pivotal movement between outer shell 104 and inner member 106; (ii) increase the applied torque on the head and neck; and/or (iii) decrease the mass moment of inertia of the head and neck that the applied torque needs to overcome. As the distance between the x-coordinate of pivot joints 108 and the midpoint 101 between the arc centers 157, 159 of inner member 106 and outer shell 104 increases (e.g. the x-coordinate gets further from the midpoint) the range of pivotal movement between inner member 106 and outer shell 104 may decrease. Increasing the distance between the x-coordinate of pivot joints 108 and COG line 102 increases the torque applied to the head of the wearer when force is applied, facilitating flexion of the neck which may mitigate injury. Decreasing the distance between the x-coordinate and COG line 102 decreases the mass moment of inertia that torque must overcome.
In some embodiments, the x-coordinate of pivot joints 108 may be positioned at a location anterior to COG line 102 such that a maximal relative angular rotation range between inner member 106 and outer shell 104 (prior to contact therebetween) is in a range of 10°-30°. In some embodiments, the x-coordinate of pivot joints 108 is located anterior to COG line 102 and selected such that this maximal rotational range is 15°-25°. At pivot joint x-coordinates in this range, rotation time, torque on the head of the wearer, and/or angular acceleration and velocity may be within suitable ranges. In some embodiments, 10° may be the minimum acceptable rotational range between inner member 106 and outer shell 104 prior to contact therebetween. In some embodiments, this minimum acceptable rotational range is 15°. In some embodiments, this minimum acceptable rotational range is 20°. In some embodiments, the x-coordinate of the pivot joints 108 may be located between the COG line 102 and the x-coordinate that is associated with minimum desired relative angular rotation range between inner member 106 and outer shell 104.
Pivot joints 108 may be made of:
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- plastics (including reinforced plastics) (e.g. glass filled PEEK, UHMW-PE, PPS, PC, delrin/acetal, nylon, combinations thereof and/or the like);
- metal (e.g. stainless steel, aluminum, titanium, aluminum-bronze, combinations thereof and/or the like);
- combinations of metals and polymers;
- combinations thereof; and/or
- the like.
Some pivot joints 108 described herein (for example, the pin-style pivot joints 108 described above in connection with
The inventors have discovered, however, that it may be desirable to provide pivot joints 108 with additional degrees of rotational freedom. Such additional degrees of rotational freedom can facilitate the operation of helmet 100 (e.g. the relative movement between inner member 106 and outer shell 104) to mitigate spinal cord injury even where inner member 104, outer shell 106 and/or pivot joints 108 are deformed (e.g. due to impact). In some such embodiments, each of pivot joints 108 may be operative to provide three degrees of rotational freedom, but, in the absence of deformation of inner member 106, outer member 106 or pivot joints 108, do not provide any translation degrees of freedom. In some such embodiments, pivot joints 108 on each side of helmet 100 may have their own corresponding pivot axes 138 and pivot joints may allow these pivot axes 138 to change orientations. In some such embodiments, in the absence of deformation of inner member 106, outer member 106 or pivot joints 108, the translational locations of the respective pivot axes 138 of pivot joints 108 may be fixed (e.g. at an origin which may in a plane that coincides with, or is located between, inner member 106 and outer shell 104), while the orientations of the respect pivot axes 138 may be permitted to change provided that the translational locations of their respective origins are fixed (i.e. provided that pivot axes 138 still extend through their respective origins). Such functionality (multiple rotational degrees of freedom and/or rotational about an axis where the orientation of the axis is permitted to change) may be provided by surface-bearing pivot joints, for example. Such surface-bearing pivot joints may comprise a first component (e.g. a male component) comprising a first surface and a second component (e.g. a female component) comprising a second surface that is complementary to the first surface to permit slidable engagement between the first and second complementary surfaces. The first and second complementary surfaces may be curved.
One type of surface-bearing pivot joint that permits multiple rotational degrees of freedom and/or rotational about an axis where the orientation of the axis is permitted to change is known as a full-socket type pivot joint. One or both of pivot joints 108 may comprise a full-socket type pivot joint.
Another type of surface-bearing pivot joint that permits multiple rotational degrees of freedom and/or rotational about an axis where the orientation of the axis is permitted to change is known as a half-socket type ball joint. One or both of pivot joints 108 may comprise a half-socket type ball joint.
Pivot joints 108 may additionally or alternatively comprise one or more of disk locks, snap locks, t-joints (e.g.
Pivot joints 108 may be custom made or made using off the shelf parts. Multiple off the shelf parts may be combined to create a custom pivot joint 108. Off the shelf parts may include one or more of, bolts, washers, nuts, clip bearings, etc. Off the shelf parts may be made of plastics, reinforced plastics, metals, fiberglass, carbon fiber, combinations thereof and/or the like.
Pivot joints 108 facilitate the pivotal coupling of outer shell 104 and inner member 106 to facilitate rotational movement of outer shell 104 relative to inner member 106 about pivot axis 138. In some embodiments, such as full-socket type pivot joints (
Components of pivot joint 108 (e.g. male components or female components) may be coupled to inner member 106 by means of one or more of:
-
- integration with inner member 106 by inlaying the component of pivot joint 108 in inner member 106;
- mechanically coupling the component of pivot joint 108 to inner member 106 (e.g. using one or more of drilled holes, bolts, plastic melting bolts, etc.); and
- adhering the component of pivot joint 108 to inner member 106 using an adhesive (e.g. 3M glue, epoxy, etc.).
Components of pivot joints 108 may each be coupled to outer shell 104 by means of a recess in outer shell 104 and adhesive. Alternatively or additionally components of pivot joints 108 may each be coupled to outer shell 104 through mechanical means (e.g. drilled holes, bolts, plastic melting bolts, etc.) and/or adhesive (e.g. 3M glue, epoxy, etc.).
To reduce the likelihood that components of pivot joints 108 will peel or separate from outer shell 104 (or inner member 106) with the application of force, the coupling of components of pivot joint 108 to outer shell 104 (or inner member 104) may include one or more of:
-
- The component(s) 108A of pivot joints 108 may be tapered in one or more dimensions. It may be desirable to taper pivot joint components 108A so as to provide thinner in regions where a peeling stress is considered to be more likely. The thickness of pivot joint component 108A may be tapered as shown in
FIGS. 32, 33A and 33B . Tapers may or may not be linear. Additionally or alternatively, pivot joint component 108A may be aperture or provided with other surface profiles (as shown in the embodiment ofFIGS. 33A and 33B ) to provide for improved adhesive bonding (relative to flat or planar surfaces). - Pivot joint components 108A may be coupled to outer shell 104 such that outer shell 104 generally contacts two perpendicular ends of pivot joint component 108A and partially contacts a third end of pivot joint component 108A as shown in
FIG. 34 in a “hook” like attachment. - Pivot joint components 108A may be coupled to outer shell 104 using one or more bolts (see e.g.
FIG. 35 ), rivets and/or similar fasteners. - Pivot joint components 108A may be shaped to have an increased area in regions of higher stress which in turn may produce a larger bond area between pivot joint component 108A and outer shell 104 in high stress regions (see e.g.
FIG. 36 in which the larger areas of pivot joint component 108A have higher stress).
- The component(s) 108A of pivot joints 108 may be tapered in one or more dimensions. It may be desirable to taper pivot joint components 108A so as to provide thinner in regions where a peeling stress is considered to be more likely. The thickness of pivot joint component 108A may be tapered as shown in
Helmet 100 also comprises deployment device 124 (one embodiment of which is shown in
One function of deployment device 124 is to maintain an initial angular relationship between inner member 106 and outer shell 104 about pivot axis 138 until helmet 100 receives an external (e.g. impact) force greater than a configurable threshold. Deployment device 124 may be characterized as being in an initial configuration prior to receiving such an impact force. The maintaining of the initial angular relationship minimizes mechanical rattling and/or unwanted motions during activity (e.g. sporting activity). Another function of deployment device 124 may be to mitigate head 10 decoupling from inner member 106. The inventors have determined that if inner member 106 begins to rotate before the impact force on outer shell 104 builds to at least 300-500N, then head 10 does not ‘stick’ with inner member 106 and will likely slip and move independently of inner member 106.
Deployment device 124 may also enable sufficient frictional force to build up when helmet 100 receives an impact. When helmet 100 receives an impact having a force above the threshold of deployment device 124, the friction between outer shell 104 and ground may be large enough to change the momentum of head 10. In other words, outer shell 104 may be able to roll/rotate without slipping if the frictional force between outer shell 104 and the impact surface is sufficiently high to prevent slipping. In contrast, if the motion of outer shell 104 at the impact surface is slipping, then outer shell 104 could rotate but the head and neck could continue with the incoming momentum.
Deployment device 124 may be positioned at any suitable location within and/or on helmet 100. Deployment device 124 may be positioned within one or more pivot joints 108, 1 cm to 3 cm from one or more pivot joints 108 and/or at the back of helmet 100. The back of helmet 100 may be defined by the region of helmet 100 posterior to the coronal plane 12 (see
In some embodiments (in particular in the embodiment of
When shear pin 128 breaks, it frees inner member 106 and outer shell 104 from their initial relative angular relationship and outer shell 104 is able to rotate relative to inner member 106 about pivot axis 138 (by the action of pivot joints 108).
In some embodiments, deployment device 124 comprises a pair of polylactic acid (PLA) plastic shear pins installed on the left and right sides of helmet 100. Such pins having diameters of 2.85 mm can each resist up to 477N.
In other embodiments, deployment device 124 may comprise other frangible or breakable devices. For example, deployment device 124 may comprise one or more breakable seals. Frangible deployment devices 124 may behave in a manner generally similar to shear pin 128. For example, frangible deployment devices 124 may maintain an initial configuration between inner member 106 and outer shell 104, frangible deployment devices 124 may break when sufficient force is applied to them, where such a break allows inner member 106 to pivot in relation to outer shell 104 (by the action of pivot joints 108).
In another example embodiment, deployment device 124 comprises an elastic attachment member 128, 164 (e.g. an elastomeric tether, instead of a shear pin) to hold inner member 106 and outer shell 104 in their initial relative angular positions. A graphic representation of the elastic attachment member 128, 164 may be similar to that of a shear pin 128 as shown in
Deployment device 124 may comprise a snap-fit connector 154 as shown in
Deployment device 124 may comprise a mechanistic deployment device. For example, deployment device 124 may comprise one or more torsion springs. Upon deployment, the one or more torsion springs stretch or otherwise deform and allow rotation (or a larger range of relative rotation) of inner member 106 with respect to outer shell 104 about pivot axis 138. In some embodiments, this larger range of permissible relative rotation is greater than 5°. In some embodiments, this larger range of permissible relative rotation is greater than 10°. In some embodiments, this larger range of permissible relative rotation is greater than 15°. In some embodiments, the one or more torsion springs may be configured to break if the force applied to helmet 100 is greater than a configurable threshold.
In some other embodiments, pivot joints 108 and deployment devices 124 are incorporated together as one mechanism. For example,
With reference to
These example embodiments show that pivot joints 108 and deployment device 124 may be separate structural components or may be combined into a single mechanism.
Helmet 100 may comprise a protective liner (not shown) located on an interior surface of inner member 106. Protective liner may be similar to the protective liner provided on prior art helmets and may comprise foam materials of any variable density.
Helmet 100 may also comprise a retention strap (not shown), chin strap or other suitable means for securing helmet 100 to head 10.
Helmet 100 can be used for mitigating cervical spine injuries and/or fractures. Responsive to an impact force greater than a configurable threshold, deployment device 124 is deployed to free inner member 106 and outer shell 104 from their initial relative angular relationship and outer shell 104 is able to rotate relative to inner member 106 about pivot axis 138. In the event of a head-first impact, helmet 100 induces flexion of the neck and thereby mitigates cervical spine fractures.
Second Helmet EmbodimentWithout limitation, helmet 200 may be useful for sports that involve low-friction impact surfaces such as ice and/or snow. Upon impact, low-friction impact surfaces may permit a helmet to slide on such surfaces and, because of such sliding, may not (via friction alone) produce the desired torque between the inner member and outer shell to facilitate the relative pivotal motion. In these scenarios, the underlying mechanics desired to elicit relative pivotal motion between the inner member and the outer shell and the corresponding neck flexion may be different than those involving relatively higher friction impact surfaces. A back-up feature to combat slippery surfaces is to shape the sagittal-plane profile 204C of the outer surface 204B of the outer shell 204 such that there are one or more beveled regions 249 between corresponding pairs of apexes 251A, 251B.
For example, the sagittal-plane profile 204C of the outer surface 204B of outer shell 204 in the
The outer surface 204B of outer shell 204 (with its bevelled surfaces 249A and apexes 251A, 251B) help to create additional force between helmet 200 and an impact surface where such force is oriented to cause torque between outer shell 204 and inner member 206 that tends to cause relative pivotal movement therebetween and to induce neck flexion both in the case of a high-friction impact surface and a low-friction impact surface. This effect can be seen in
The location of contact force imparted on outer shell 204 is initially at the location of apex 251B. This force manifests itself as clockwise torque (on outer shell 204 about pivot axis 238) which tends to cause the outer shell to pivot relative to the inner member in a clockwise direction. This clockwise rotation is shown as the helmet transitions from the initial impact (
In other respects, helmet 200 may be similar to helmet 100 described and illustrated herein.
Use of Multi-Shell Helmet to Prevent Spinal InjuryFor brevity and without loss of generality, the description of this section focusses on helmet 100, but is also applicable to helmet 200 and other helmets described herein. As shown in
Table 1 shows changes to experimentally measured loads and accelerations as a result of the pivot motion between inner member 106 and outer shell 104 conducted on a commercial helmet (
Helmet 100 can be made by retrofitting a single-shell helmet. The single-shell helmet comprises a first shell and an inner protective liner. The inner protective liner may be a single-impact protective liner (e.g. EPS) or a multiple-impact protective liner (e.g. EVA). The single-shell helmet with a single-impact protective liner may be referred herein to as single-impact, single-shell helmet. The single-shell helmet with a multiple-impact protective liner may be referred herein to as multiple-impact, single shell helmet.
At step 302, the location of coupling zone 110 is determined. Coupling zone 110 is bounded by three lines embedded in mid-sagittal plane 120 of helmet 100: (i) COG line 102, (ii) brow line 112, and (iii) anterior line 114. As discussed above, the location of COG line 102 may be specified by a helmet manufacturer, especially if the manufacturer uses the standardized Anthropomorphic Test Devices (“ATDs”), commonly referred to as dummies, to design the dimensions and shapes of the helmets.
At step 304, a second shell is pivotably coupled to the first shell of the single-shell helmet to create a multi-shell structure. The first shell is movable relative to the second shell by rotation about a laterally oriented pivot axis 138. Pivot axis 138 is parallel to a lateral plane and orthogonal to a mid-sagittal plane of the multi-shell structure. The pivot axis also passes the coupling zone 110 (see above description of pivot axis 138 and coupling zone 110). The second shell may go within the single-shell helmet or outside of the single-shell helmet. The second shell may span the entirety or a portion of the single-shell helmet.
The second shell may be coupled to the first shell via a pivot mechanism. The second shell can be coupled to the first shell by pivot joint 108.
At step 306, deployment device 124 is added to detachably couple outer shell 104 and inner member 106 together. As discussed above, in the absence of sufficient external force, deployment device 124 constrains rotational motion between inner member 106 and outer shell 104 about pivot axis 138 (e.g. to within a minimum rotational amount). That is, in the absence of sufficient external force, deployment device 126 constrains the initial relative angular orientations of inner member 106 and outer shell 104 about pivot axis 138 (e.g. to within minimum relative angular orientations). Deployment device 124 may constrain the relative motion between inner member 106 and outer shell 104 by applying force between inner member 106 and outer shell 104 (or between any components of the pivotal coupling between inner member 106 and outer shell 104) that tends to prevent relative rotation. When the helmet receives an impact having sufficient force (e.g. an external force greater than a threshold), deployment device 124 deploys to permit relative angular rotation between outer shell 104 and inner member 106 about pivot axis 138. In some embodiments, deployment device 124 may be in an initial configuration in the absence of sufficient external force and a deployment configuration (different from the initial configuration) when the helmet receives an impact having sufficient force. Deployment device 124 may also permit sufficient frictional force to build up when the helmet 100 receives an impact. This frictional force may then change the direction of the head's momentum.
The invention has a number of aspects. Non-limiting aspects of the invention provide:
-
- 1. A helmet comprising:
- an outer shell defining a concavity;
- an inner member, at least a portion of which is located within the concavity, the inner member pivotally coupled to the outer shell and permitted to move relative to the outer shell by rotation about a laterally oriented pivot axis;
- one or more pivot joints which facilitate relative pivotal movement between the inner member and the outer shell about the laterally oriented pivot axis and constrain relative movement between the inner member and outer shell to movement about the laterally oriented pivot axis; and
- a deployment device which:
- in the absence of sufficient external force, constrains rotational motion between the inner member and the outer shell about the pivot axis; and
- when the helmet receives an impact having sufficient force, deploys to permit relative angular rotation between the outer shell and the inner member about the pivot axis.
- 2. The helmet as defined in aspect 1 wherein the deployment device constrains the relative rotational motion between the inner member and the outer shell, in the absence of sufficient external force, by applying force that tends to prevent relative rotation between the inner member and the outer shell or between any components of the pivotal coupling between the inner member and the outer shell.
- 3. The helmet as defined in any one of aspects 1 and 2 wherein, in the absence of sufficient external force, the deployment device constrains rotational motion between the inner member and the outer shell about the pivot axis to a minimum relative rotation.
- 4. The helmet as defined in aspect 3 wherein the minimum relative rotation is less than 50.
- 5. The helmet as defined in any one of aspects 3 to 4 wherein when the helmet receives an impact having sufficient force, the deployment device deploys to permit a larger range of relative angular rotation between the outer shell and the inner member about the pivot axis.
- 6. The helmet as defined in aspect 5 wherein the larger range of relative rotation is greater than 5°.
- 7. The helmet as defined in any one of aspects 1 to 6, wherein the laterally oriented pivot axis is parallel to a lateral plane and orthogonal to a mid-sagittal plane of the helmet.
- 8. The helmet as defined in aspect 7, wherein the laterally oriented pivot axis passes a coupling zone bounded by three notional lines in the mid-sagittal plane of the helmet, the three lines being:
- a center of gravity line;
- a brow line running from a front portion to a back portion of the helmet and tangential to a lowermost point on a surface that defines a top edge of a face opening; and
- an anterior line parallel to the center of gravity line and intersecting the lowermost point of the top edge surface of the face opening.
- 9. The helmet as defined in aspect 8, wherein the laterally oriented pivot axis intersects a narrow area within the coupling zone, the narrow area within 2.5 cm above the brow line.
- 10. The helmet as defined in any one of aspects 1 to 9, wherein the inner member and outer shell are coupled together by the one or more pivot joints.
- 11. The helmet as defined in any one of aspects 1 to 10, wherein the one or more pivot joints comprise two pivot mechanisms located symmetrically on the helmet.
- 12. The helmet as defined in aspect 11, wherein one or both of the two pivot mechanisms are positioned between a center of gravity line of the helmet and a position where a maximal relative angular rotation range between the inner member and the outer shell after deployment of the deployment device is in a range of 10°-30°.
- 13. The helmet as defined in any one of aspects 11 to 12, wherein one or both of the two pivot mechanisms are positioned such that a position that the laterally oriented pivot axis intersects the sagittal plane is at a midpoint between an arc center of the inner member and an arc center of the outer shell.
- 14. The helmet as defined in any one of aspects 11 to 13, wherein the one or both of the two pivot mechanisms comprise one or more tapered components that are mounted to one of the inner member and the outer shell.
- 15. The helmet as defined in any one of aspects 10 to 14, wherein the inner member and the outer shell are coupled together by engagement of a pin through a pair of aligned apertures in the inner member and the outer shell.
- 16. The helmet as defined in aspect 15, wherein the pin comprises a longitudinal axis aligned with the laterally oriented pivot axis.
- 17. The helmet as defined in any one of aspects 1 to 16, the deployment device comprising a shear pin, wherein the shear pin shears and breaks when the helmet receives the impact force greater than a configurable threshold.
- 18. The helmet as defined in aspect 17, wherein the shear pin is placed near a posterior-lateral region of the helmet.
- 19. The helmet as defined in any one of aspects 1 to 16, the deployment device comprising an elastic attachment member connected between the inner member and the outer shell, wherein when the helmet receives the impact, the elastic attachment member deforms to permit relative rotation of the inner member and the outer shell about the laterally oriented pivot axis.
- 20. The helmet as defined in any one of aspects 1 to 19, wherein the one or more pivot joints and the deployment device are separate from each other.
- 21. The helmet as defined in any one of aspects 1 to 19, wherein the deployment device is provided as part of at least one of the one or more pivot joints that permits relative rotational movement between the inner member and outer shell about the pivot axis.
- 22. The helmet as defined in any one of aspects 1 to 21, further comprising a cushioning layer positioned between the inner member and the outer shell, the cushioning layer configured to control rotational acceleration or deceleration of outer shell relative to inner member.
- 23. The helmet as defined in any one of aspects 1 to 22, wherein the outer shell comprises one or more beveled regions.
- 24. The helmet as defined in any one of aspects 1 to 22, wherein a mid-sagittal plane of the outer shell comprises one of more apexes.
- 25. The helmet as defined in any one of aspects 1 to 22, wherein:
- the outer shell comprises one or more beveled regions, each beveled region defined by a pair of corresponding apexes on a mid-sagittal plane of the outer shell; and
- the apexes interact with an impact surface to increase the torque (relative to a round surface) experienced by the outer shell as a result of the interaction between the outer shell and the impact surface.
- 26. The helmet as defined in aspect 25, wherein the laterally oriented pivot axis passes through a coupling zone bounded by three notional lines in the mid-sagittal plane of the helmet, the three lines being:
- a center of gravity line;
- a brow line running from a front portion to a back portion of the helmet and tangential to a lowermost point on a surface that defines a top edge of a face opening; and
- an anterior line parallel to the center of gravity line and intersecting the lowermost point of the top edge surface of the face opening; and
- the center of gravity line intersects one of the pair of apexes.
- 27. The helmet as defined in any one of aspects 1 to 26, further comprising a protective liner attached to an inner surface of the inner member.
- 28. The helmet as defined in any one of aspects 1 to 27, wherein the outer shell is shaped to cover at least one of a crown region, a front region and a back region of a wearer's head.
- 29. The helmet as defined in any one of aspects 1 to 28, wherein the inner member is shaped to cover at least one of a crown region, a front region and a back region of a wearer's head.
- 30. The helmet as defined in any one of aspects 1 to 29, wherein the deployment device is positioned at the back of the helmet.
- 31. A helmet comprising:
- an outer shell defining a concavity;
- an inner member, at least a portion of which is located within the concavity;
- first and second pivot joints located on opposing sides of the inner member which facilitate relative pivotal movement between the inner member and the outer shell;
- wherein the first and second pivot joints permit rotation about corresponding first and second pivot axes and wherein the first and second pivot joints permit orientations of the first and second pivot axes to change while constraining translational positions of the first and second pivot axes.
- 32. The helmet according to aspect 31 having any of the features, combinations of features and/or sub-combinations of features of any other aspects herein.
- 33. A helmet comprising:
- an outer shell defining a concavity;
- an inner member, at least a portion of which is located within the concavity;
- first and second pivot joints located on opposing sides of the inner member which facilitate relative pivotal movement between the inner member and the outer shell;
- wherein the first and second pivot joints permit rotation of their respective pivot axes in three rotational degrees of freedom and maintain the translational positions of their respective pivot axes.
- 34. The helmet according to aspect 33 having any of the features, combinations of features and/or sub-combinations of features of any other aspects herein.
- 35. A method for mitigating cervical spine injuries, the method comprising:
- providing a helmet as defined in any one of aspects 1 to 34; and
- when the helmet receives the impact force, the deployment device allows relative rotational motion between the outer shell and the inner member about the laterally oriented pivot axis.
- 36. A method for mitigating cervical spine injuries, the method comprising:
- providing a helmet as defined in any one of aspects 1 to 34; and
- when the helmet receives the impact force, the first and second pivot joints facilitating motion about corresponding first and second pivot axes and wherein the first and second pivot joints permit orientations of the first and second pivot axes to change while maintaining translational positions of the first and second pivot axes static.
- 37. A method for mitigating cervical spine injuries, the method comprising:
- providing a helmet as defined in any one of aspects 1 to 34; and
- when the helmet receives the impact force, the first and second pivot joints facilitating rotation in three degrees of freedom and maintain static translation positions.
- 38. The method as defined in any one of aspects 35 to 37, further comprising: converting a linear force with a spinally axial component into rotational motion.
- 39. A method for retrofitting a single-shell helmet to a multi-shell helmet, the method comprising:
- determining a coupling zone, the coupling zone being bounded by three lines in a mid-sagittal plane of the single-shell helmet, the three lines being:
- a center of gravity line;
- a brow line running from a front portion to a back portion of the helmet and tangential to a lowermost point on a surface that defines a top edge of a face opening; and
- an anterior line parallel to the center of gravity line and intersecting the lowermost point of the top edge surface of the face opening;
- positioning at least a portion of a second shell within a concavity of a first shell, the first shell comprising the single-shell helmet;
- pivotably coupling the second shell and the first shell by a pivot joint and the pivot joint having a laterally oriented pivot axis that intersects the mid-sagittal plane in the coupling zone so that the second shell and the first shell are movable relative to one another by rotation about the laterally oriented pivot axis, wherein the pivot joint constrains relative movement between the first shell and the second shell to movement about the laterally oriented pivot axis, wherein the laterally oriented pivot axis is parallel to a lateral plane and orthogonal to a mid-sagittal plane of the helmet; and
- coupling the first shell to the second shell by a deployment device, which:
- in the absence of sufficient external force, constrains rotational motion between the inner member and the outer shell about the pivot axis; and
- when the helmet receives an impact having sufficient force, deploys to permit relative angular rotation between the outer shell and the inner member about the pivot axis.
- coupling the first shell to the second shell by a deployment device, which:
- 40. A method for retrofitting a single-shell helmet to a multi-shell helmet, the method comprising:
- determining a coupling zone, the coupling zone being bounded by three lines in a mid-sagittal plane of the single-shell helmet, the three lines being:
- a center of gravity line;
- a brow line running from a front portion to a back portion of the helmet and tangential to a lowermost point on a surface that defines a top edge of a face opening; and
- an anterior line parallel to the center of gravity line and intersecting the lowermost point of the top edge surface of the face opening;
- positioning at least a portion of a second shell around at least a portion of a concavity of a first shell, the first shell comprising the single-shell helmet;
- pivotably coupling the second shell and the first shell by a pivot joint and the pivot joint having a laterally oriented pivot axis that intersects the mid-sagittal plane in the coupling zone so that the second shell and the first shell are movable relative to one another by rotation about the laterally oriented pivot axis, wherein the pivot joint constrains relative movement between the first shell and the second shell to movement about the laterally oriented pivot axis, wherein the laterally oriented pivot axis is parallel to a lateral plane and orthogonal to a mid-sagittal plane of the helmet; and
- coupling the first shell to the second shell by a deployment device, which:
- in the absence of sufficient external force, constrains rotational motion between the inner member and the outer shell about the pivot axis; and
- when the helmet receives an impact having sufficient force, deploys to permit relative angular rotation between the outer shell and the inner member about the pivot axis.
- coupling the first shell to the second shell by a deployment device, which:
- 1. A helmet comprising:
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are consistent with the broadest interpretation of the specification as a whole.
Claims
1.-20. (canceled)
21. A helmet comprising:
- an outer shell defining a concavity;
- an inner member, at least a portion of which is located within the concavity, the inner member pivotally coupled to the outer shell and permitted to move relative to the outer shell by rotation about a laterally oriented pivot axis;
- one or more pivot joints which facilitate relative pivotal movement between the inner member and the outer shell about the laterally oriented pivot axis and constrain relative movement between the inner member and outer shell to movement about the laterally oriented pivot axis; and
- a deployment device which:
- in the absence of sufficient external force, constrains rotational motion between the inner member and the outer shell about the pivot axis; and
- when the helmet receives an impact having sufficient force, deploys to permit relative angular rotation between the outer shell and the inner member about the pivot axis.
22. The helmet as defined in claim 21 wherein the deployment device constrains the relative rotational motion between the inner member and the outer shell, in the absence of sufficient external force, by applying force that tends to prevent relative rotation between the inner member and the outer shell or between any components of the pivotal coupling between the inner member and the outer shell.
23. The helmet as defined in claim 21 wherein, in the absence of sufficient external force, the deployment device constrains rotational motion between the inner member and the outer shell about the pivot axis to a minimum relative rotation.
24. The helmet as defined in claim 23, wherein when the helmet receives an impact having sufficient force, the deployment device deploys to permit a larger range of relative angular rotation between the outer shell and the inner member about the pivot axis.
25. The helmet as defined in claim 21, wherein the laterally oriented pivot axis is parallel to a lateral plane and orthogonal to a mid-sagittal plane of the helmet.
26. The helmet as defined in claim 25, wherein the laterally oriented pivot axis passes a coupling zone bounded by three notional lines in the mid-sagittal plane of the helmet, the three lines being:
- a center of gravity line;
- a brow line running from a front portion to a back portion of the helmet and tangential to a lowermost point on a surface that defines a top edge of a face opening; and
- an anterior line parallel to the center of gravity line and intersecting the lowermost point of the top edge surface of the face opening.
27. The helmet as defined in claim 21, wherein the inner member and outer shell are coupled together by the one or more pivot joints.
28. The helmet as defined in claim 21, wherein the one or more pivot joints comprise two pivot mechanisms located symmetrically on the helmet.
29. The helmet as defined in claim 28, wherein one or both of the two pivot mechanisms are positioned between a center of gravity line of the helmet and a position where a maximal relative angular rotation range between the inner member and the outer shell after deployment of the deployment device is in a range of 10°-30°.
30. The helmet as defined in claim 27, wherein the inner member and the outer shell are coupled together by engagement of a pin through a pair of aligned apertures in the inner member and the outer shell.
31. The helmet as defined in claim 21, the deployment device comprising a shear pin, wherein the shear pin shears and breaks when the helmet receives the impact force greater than a configurable threshold.
32. The helmet as defined in claim 21, the deployment device comprising an elastic attachment member connected between the inner member and the outer shell, wherein when the helmet receives the impact, the elastic attachment member deforms to permit relative rotation of the inner member and the outer shell about the laterally oriented pivot axis.
33. The helmet as defined in claim 21, wherein the one or more pivot joints and the deployment device are separate from each other.
34. The helmet as defined in claim 21, wherein the deployment device is provided as part of at least one of the one or more pivot joints that permits relative rotational movement between the inner member and outer shell about the pivot axis.
35. The helmet as defined in claim 21, further comprising a cushioning layer positioned between the inner member and the outer shell, the cushioning layer configured to control rotational acceleration or deceleration of outer shell relative to inner member.
36. The helmet as defined in claim 21, wherein the outer shell comprises one or more beveled regions.
37. The helmet as defined in claim 21, wherein a mid-sagittal plane of the outer shell comprises one of more apexes.
38. The helmet as defined in claim 21, wherein:
- the outer shell comprises one or more beveled regions, each beveled region defined by a pair of corresponding apexes on a mid-sagittal plane of the outer shell; and
- the apexes interact with an impact surface to increase the torque (relative to a round surface) experienced by the outer shell as a result of the interaction between the outer shell and the impact surface.
39. The helmet as defined in claim 21, further comprising a protective liner attached to an inner surface of the inner member.
40. The helmet as defined in claim 21, wherein at least one of the outer shell and the inner member is shaped to cover at least one of a crown region, a front region and a back region of a wearer's head.
41. The helmet as defined in claim 21, wherein the deployment device is positioned at the back of the helmet.
Type: Application
Filed: Jun 8, 2023
Publication Date: Dec 7, 2023
Inventors: Peter Alec CRIPTON (Vancouver), Vivian Woan Jien CHUNG (Vancouver), Thomas Christopher WHYTE (Chippendale), Gabrielle Rose BOOTH (Vancouver)
Application Number: 18/331,888