A negative stiffness shell has a convex first position, but can transition or snap to a concave second position under a force applied to the exterior surface of the shell in the convex first position. During the transition, the shell exhibits negative stiffness that permits a large amount of energy to be absorbed. The negative stiffness shell can withstand a high initial force threshold prior to transitioning. In the second, concave position the shell can still resist force. Moreover, it is possible for the shell to revert back to the first, convex position with minimal plastic deformation for subsequent use. The negative stiffness shells can be used collectively and/or in layers to increase the efficiency of the overall negative stiffness shell unit.

The present technology relates generally to protective helmets with non-linearly deforming members. Helmets configured in accordance with embodiments of the present technology can comprise, for example, an inner layer, an outer layer, a space between the inner layer and the outer layer, and an interface layer disposed in the space. The interface layer comprises a plurality of filaments, each having a height, a longitudinal axis along the height, a first end proximal to the inner layer, and a second end proximal to the outer layer. The filaments are sized and shaped to span the space between the inner layer and the outer layer. The filaments are configured to deform non-linearly in response to an external incident force on the helmet.

The invention relates to a multi-step method with a number of processes and sub-processes that interact to allow for the selection, design and/or manufacture of a recreational sports helmet for a specific person wearing the helmet. Once the desired recreational sports helmet is selected, information is collected from the individual wearer regarding the shape of his/her head and information about the impacts he/she has received while participating in the activity. The collected information is processed to develop a bespoke energy attenuation assembly for use in the recreational sports helmet. The energy attenuation assembly includes at least one energy attenuation member with a unique structural makeup and/or chemical composition. The energy attenuation assembly is purposely engineered to improve comfort and fit, as well as how the helmet responds when an impact or series of impacts are received by the recreational sports helmet.

A microlattice structure may be used for a variety of different applications with a protective helmet assembly. The three-dimensional microlattice layer comprising a plurality of interconnected filaments extending along at least three different directions from a plurality of nodes. The microlattice layer may further comprise at least one material layer extending laterally between and interconnecting at least two or more nodes. The at least one material layer may be configured to transversely and rotationally constrain the nodes to increase the overall compressive strength and stiffness of the microlattice structure. The at least one material layer may comprise a single, continuous layer and/or a plurality of material layer segments. The microlattice layer may comprise a single, continuous layer or a plurality of microlattice layer segments. The microlattice layer may be stacked, the stacked microlattice layers may further comprise one or more material layers and/or one or more impact mitigation layers.

The present technology relates generally to protective helmets with non-linearly deforming members. Helmets configured in accordance with embodiments of the present technology can comprise, for example, an inner layer, an outer layer, a space between the inner layer and the outer layer, and an interface layer disposed in the space. The interface layer comprises a plurality of filaments, each having a height, a longitudinal axis along the height, a first end proximal to the inner layer, and a second end proximal to the outer layer. The filaments are sized and shaped to span the space between the inner layer and the outer layer. The filaments are configured to deform non-linearly in response to an external incident force on the helmet.

A garment worn by a wearer has an impact absorbing material comprising arrays of various hexagonal or other deformable polygonal-shaped structures positioned between an exterior surface and an interior surface. When force is applied to the exterior surface, the structures of the impact absorbing materials deform (e.g., buckle) in a desired manner, reducing the force received by the interior surface.

A helmet harness (5000) has an outer frame (5015), an inner frame (5020), and a coupler (5010). The outer frame has a central portion with a plurality of notches (5510). The inner frame has a central portion with an approximately circular hole (5610). The coupler has a first section (5025), a second section (5035), an upper core (5030) between the first section and the second section, the upper core having a hollow central column (5110) and a plurality of supports (5030) surrounding the hollow central column, a third section (5045), and a lower core (5050) between the second section and the third section. The lower core is a sprocket having a plurality of splines (5060) for engaging the plurality of notches of the outer frame. The central portion of the outer frame and the central portion of the inner frame are between the second section and the third section.

A bicycle helmet that fits over a surface of a head of a user generally includes at least one segment of flexible cell structures that form a radial honeycomb matrix movable between a folded condition where each side of the at least one segment is disposed generally parallel and an expanded condition where the radial honeycomb matrix of the at least one segment is configured to be expanded at least partially over the head of the user and arranged radially relative to the surface of the head of the user.

A helmet has inner and outer shells separated by a plurality of interconnected relatively soft columns or posts. The columns each have a middle post or pillar section, a capital that is of larger diameter than the post, and a base also of larger transverse dimension than the post. When an impact above a design threshold occurs on the outer shell, the columns, particularly the post sections thereof, near the impact location compress and buckle, dissipating impact kinetic energy, while columns spaced from the impact zone stretch and support more of the impact force. The applied force is therefore reduced and spread out over a relatively large area, and a resultant wave created within the column manifold disperses additional heat, further reducing the force and torque applied on the outer shell and transmitted to the inner shell and onto the skull of a helmet user. A method and mold for fabricating the column manifold are also disclosed.

A bicycle helmet that fits over a surface of a head of a user generally includes at least one segment of flexible cell structures that form a radial honeycomb matrix movable between a folded condition where each side of the at least one segment is disposed generally parallel and an expanded condition where the radial honeycomb matrix of the at least one segment is configured to be expanded at least partially over the head of the user and arranged radially relative to the surface of the head of the user.