Patent Application
20240237777
Helmets and other protective headgear are used in many applications, including sports, construction, mining, industry, law enforcement, military and others, to reduce injury to a wearer. Potential injury to a wearer can occur by way of contact with hard and/or sharp objects, which can be reduced by a helmet that prevents such objects from directly contacting the wearer's head. In addition, non-contact injury to the wearer, such as results from linear and/or rotational accelerations of the wearer's head and can cause brain injury, can be reduced by helmets that absorb or dissipate the energy produced during impacts, including oblique impacts.
A helmet usually is adapted to fit to the head of the wearer. In many helmets, this is accomplished by attaching one or more fit pads (or comfort pads) formed of a compressible material to the interior of the helmet at desired locations to create a desired fit between the helmet and the wearer's head. Fit pads are typically removable so they can be laundered or replaced. Some fit pads are attached with hook and loop fasteners.
Some helmets are designed with shear action displacement devices that are designed to dissipate energy, especially in cases of oblique impacts, by undergoing shear.
Described below are implementations of a helmet fit pad connector that can be used with a helmet fit pad and a shear action displacement device providing protection from linear and/or rotational accelerations. The fit pad connector also reliably couples the fit pad and shear action displacement device to the helmet, but allows them to be removed as desired.
According to one implementation, a helmet comprises an outer shell with an energy absorbing layer positioned inwardly thereof, a connector receiver mounted in the energy absorbing layer, wherein the connector receiver has a body and a receiver opening defined in the body and facing inwardly, a helmet fit pad assembly positioned inwardly of the energy absorbing layer, the helmet fit pad assembly having a shear action displacement device and a fit pad positioned inwardly thereof, wherein the helmet fit pad assembly has a bore aligned with the receiver opening in the connector receiver, and a fit pad connector having a head, a body extending from the head and a distal end, wherein the distal end is insertable through the bore and into the receiver opening in the connector receiver to movably couple the helmet fit pad assembly to the energy absorbing layer.
A portion of the bore can extend through the fit pad and comprise a recess sized to receive the head of the fit pad connector. The receiver opening of the connector receiver can be recessed from a surrounding inner surface of the energy absorbing layer.
The distal end of the fit pad connector can comprise an enlarged distal end sized larger than the receiver opening, and wherein the connector receiver can be resiliently deformable to allow the distal end of the fit pad connector to be inserted into and removed from the receiver opening by application of positive force. The distal end of the fit pad connector is ball-shaped.
The head and the body of the fit pad connector can be hollow, and further comprising an axial opening in the body and a pad connector pin receivable in the body and having a projecting end positionable to extend through the axial opening in the body to define the distal end of the fit pad connector. The body of the fit pad connector can have a series of external ribs.
The fit pad connector can be dimensioned to permit the body to pivot or deform such that the helmet fit pad assembly can move within a plane defined at the connector receiver.
The connector receiver can be mounted within a recessed area providing space for the body of the fit pad connector to move without interference.
In some implementations, the body of the fit pad connector is formed of a substantially non-resilient material. In some implementations, the body of the fit pad connector is formed of a resilient material.
According to another implementation, a helmet comprises an outer shell with an energy absorbing layer, a connector receiver mounted in the energy absorbing layer, wherein the connector receiver has a body and a receiver opening defined in the body and facing inwardly, a shear action displacement device and a fit pad positioned inwardly of the energy absorbing layer and having respective openings aligned with the receiver opening in the connector receiver, and a fit pad connector assembly. The fit pad connector assembly can have a boss with a head, a body extending from the head and a bore extending through the head and the body, and a pad connector pin received in the bore of the boss and having a projecting end positionable to extend from the bore and define a distal end. The distal end can be insertable through the respective openings in the fit pad and the shear action displacement device and into the receiver opening in the connector receiver to movably couple the shear action displacement device and the fit pad to the energy absorbing layer.
Any of the shear action displacement devices can have inwardly protruding portions received in corresponding openings of the fit pad. The inwardly protruding portions can include securing portions that secure the shear action displacement device and the fit pad together.
The foregoing and other objects, features, and advantages will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
Described below are embodiments of a helmet having a helmet fit pad connector arrangement permitting desired movement of the helmet relative to the wearer's head in response to an oblique or rotational impact.
The helmet 100 has a front, which is indicated at 110, and a rear, which is indicated at 112. To adapt the helmet to fit the user's head, a fit pad assembly 118 with one or more fit pads 120 is positioned on or adjacent the inner surface 104 as shown. The fit pads 120, which are also known as comfort pads, typically have one or more components formed of a compressible material, as is described below in greater detail. The fit pad assembly 118 is typically used with a fit system and a chin strap, which are not shown in
The helmet 100 has air vent openings 115, some of which are labeled in
The fit pad assembly 118 can be mounted or coupled to the helmet 100 by one or more fit pad connectors 122, which are shown schematically in
As shown in
As best shown in
The pad connector 122′ of
The fit pad 120 can be formed of one, two or more than two layers or components, as is described in detail below. In the illustrated implementation, the fit pad 120 has an inner layer 242 and an outer layer 244.
For sake of illustration, the pad connector pin 220 is illustrated below the pad connector boss 200, but the pad connector pin 220 is inserted through the opening 214 in the boss 200 for installation into the helmet, as shown in
The connector receiver 252 is preferably recessed from the inner surface 104 as shown, such as within a pad connection recess 254 as shown. The pad connection recess 254 can be sufficiently large to accommodate the base 208 of the boss surrounding the pad connector pin 220 (see
In
Among other mechanisms, the outer layer 244 responds to the force F by exhibiting shear, as is described below in greater detail. Also, the outer layer 244 and/or the inner layer 242 can shift to the right as shown. In some implementations, the pad connector pin 200′/connector receiver 252 connection is designed to release or separate at a predetermined force to allow for greater relative movement.
As shown in
The outer layer 244 can be a shear action displacement device capable of causing shear to occur in response to forces or torques urging relative movement. The present assignee's U.S. Patent Application Publication 2021/0015195 A1 and pending application Ser. No. 17/836,939, which describe representative shear action displacement devices and their behavior in responding to an impact to the helmet, are incorporated herein by reference. The displacement devices can be formed of an elastomer or similar material, e.g., a silicone gel, polyurethane or similar material, including a TPU (Thermoplastic Polyurethane) or a TPE (Thermoplastic Elastomer). The displacement devices may be made of a shearable material such that relative movement causes shear to occur, with the shear being damped by progressively increasing resistance.
The displacement devices can be affixed to facing surfaces of the inner layer 242, or they can be held in position by the connectors as described herein. In some embodiments, the displacement devices comprise a silicone gel, TPU and/or TPE having predetermined properties selected for the application. For example, the displacement devices can be pieces of silicone gel, TPU and/or TPE sheet material having predetermined material properties, such as a Shore 00 durometer of 0 to 60 (measured using the Shore 00 scale suited for extra soft materials).
Suitable silicone gels include certain silicone gels used in medical treatment of scarred tissue. As one example, a suitable class of silicone gels is available from Wacker (SilGel family 612 and 613, https://www.wacker.com/cms/en/products/brands_3/wacker-silgel/wacker-silgel.jsp). For example, Wacker SilGel 613 is described to have a dynamic viscosity (at 25° C.) of 150 MPa·s (uncured) and a density of 0.97 g/cm3 (at 23° C., cured and uncured). The material is described as having very low viscosity, rapid curing at room temperature, very low hardness, inherent tack and excellent damping properties. The Wacker technical data sheet for Wacker SilGel 613, Version 1.1 (date of alteration 21, May 2010) is incorporated herein by reference.
Additionally, polyurethanes having similar properties to silicone gels are also suitable materials. For example, Sorbothane® material (https://www.sorbothane.com/) is another example of a suitable class of materials. See, e.g., “Data Sheet 101 Material Properties of Sorbothane® (effective Jun. 1, 2018),” specifying tensile strength, bulk modulus, density, resilience test rebound height, dynamic Young's modulus and other physical and chemical parameters of Sorbothane® materials, which is incorporated herein by reference.
The displacement devices can be dimensioned to have suitable thicknesses to maintain desired spacings adjacent components. In some implementations, the spacing is a 1.5 to 3 mm, so the displacement devices can be dimensioned to have a corresponding 1.5 to 3 mm thickness as appropriate.
The displacement devices may be affixed self-adhesively, and/or with an added adhesive, including, e.g., a suitable structural adhesive, pressure-sensitive adhesive or other affixing method, such as a tape (see, e.g., the products described at www.gergonne.com/en/standard-products/gergosil.htmi).
The silicone gel and polyurethane materials as described herein are primarily implemented for use in their elastic region, i.e., such that the materials will deform during loading and then return to their original shape when the load is removed. The stress-strain curve for elastic materials, which is a progressively steepening curve, indicates that elastic materials are initially compliant and then become stiffer as the load is increased.
In some implementations, the silicone gel and polyurethane materials may exhibit viscoelastic effects. When an elastic material containing fluid is deformed, the return of the material to its original shape is delayed in time and it is slower to return to its original position. A purely elastic material behaves like an ideal spring with a linear response, and no energy loss as it is loaded and unloaded. In contrast, a viscoelastic material exhibits a time delay in returning to its original shape, and some energy is lost (or absorbed) during deformation, such as by way of heat. The viscoelastic material exhibits both viscous damping and an elastic response during deformation. The viscoelastic material is modelled by a spring (which models the elastic behavior) in series with a dashpot (which models viscosity). To the extent that displacement devices absorb energy during deformation, then less energy is available to be transferred to the wearer's head, which is a benefit of such displacement devices over other types that may primarily rely on sliding surfaces.
The illustrated helmet is a sports helmet, i.e., a cycling helmet, but the same principles can be applied to protective helmets for ice hockey, lacrosse, football, baseball, rugby, cricket, climbing, motorcycling, car racing, skiing, snowboarding, skating, skateboarding, equestrian activities and other such activities. Further, the same principles can be applied to helmets or hard hats for mine workers, builders, industrial machine operators, soldiers, law enforcement personnel and others. The helmet fit pad connector can be made from any suitable material(s) that provides the required physical properties appropriate for the specific application. For example, the coupler may be constructed of nylon (polyamide), ABS (acetal butadiene styrene), acetal/polyoxymethylene (POM) (including, e.g., Delrin®), polycarbonate, polypropylene, HDPE (polyethylene), thermoplastic polyester (including, e.g., Hytrel®) and/or other similar materials. In general, the pad connector pin 220, 220′ and connector receiver 252 are made from materials that have greater strength, hardness and lower elasticity than the boss 200, the outer layer 244 (displacement devices), and the inner layer 242. The materials may be suited to injection molding.
As also described elsewhere herein, the energy absorbing layer or layers may be formed of any suitable materials. In some implementations, the energy absorbing layer is formed of an EPS (expanded polystyrene) material or a similar foamed polymer material. Other energy absorbing materials, such as expanded polypropylene (EPP), vinyl nitrile foam, thermoplastic urethane (TPU) foam and others, can also be used. In some implementations, polycarbonate can be used.
In some implementations, one or more energy absorbing layers are formed of a plastic material having a hollow geometry designed to produce reliable crush characteristics. One such material is sold under the name Koroyd® and has co-polymer extruded tubes that are thermally welded together into a core. Another such material is sold under the name Wavecel® and is described as dual-density cellular co-polymer material formed into collapsible cells. In some implementations, such a hollow plastic material is formed using a 3D printing or other similar process. The protective outer shell is preferably formed of a hard plastic, such as polycarbonate, ABS or other suitable plastic.
In view of the many possible embodiments to which the disclosed principles may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of protection. Rather, the scope of protection is defined by the following claims. We therefore claim all that comes within the scope and spirit of these claims.
