The present invention relates to a safety helmet fitting and impact attenuation system and a safety helmet fitting and impact attenuation system that may be retrofitted to existing helmet shells.
Modern safety helmets must fulfill a number of functions for the helmet wearer. The helmet must provide protection from any one or combination of blast, debris, projectile or impact as a result of striking an object or being struck by an object; support the mounting and use of additional devices worn on or near the head or helmet, such as various types of glasses, goggles, communications devices, microphones and other devices; and provide a comfortable fit and ventilation for the wearer without comprising the other functions.
To illustrate an embodiment of the invention, a military helmet shall be used in the description. For military applications, helmet design is further limited in the choice of materials, fasteners and space that can be used to meet these design goals and create a helmet that functions in harsh environments.
A safety helmet typically is comprised of layers of components to provide comfort, fit and impact protection. A hard helmet shell at the outside layer provides protection from blasts, impact, ballistics and debris. Interior to the shell, a crown webbing layer, a headband and straps comprise the helmet suspension and retention systems which must provide for proper retention, fit and placement of the helmet on the wearer. An impact attenuation liner or material also may be present to further protect the wearer against impact.
Within traditional helmet suspension systems, an interior crown webbing layer provides for outward displacement of the helmet shell relative to the wearer's head.
An example of a previous helmet design, which is shown in
A further headband layer provides fit and support of the helmet and is adjustable, for example via Velcro™, to adapt to different head circumferences. The headband is affixed to the annular band through multiple loops of crown webbing which allow for adjustment of the headband or removal and replacement of a headband. The crown webbing layer also may be adjusted to the wearer's head via a drawstring. Although existing helmet designs provide for some adjustment of the crown webbing layer, the webbing loops and drawstring are known to create pressure points and cause discomfort for the wearer.
Adjustable retention straps typically extend from the permanent mounting points on the helmet shell to affix the helmet to the wearer. Straps extending between the back and respective front side mounting points further provide stability for the helmet. The straps typically are joined under the wearer's chin, which is supported by a chin cup, to securely retain the helmet against the wearer's head. In some helmets, a further nape strap is provided at the back mounting point to separate the attachment of the straps at the back and increase the stability of the helmet. Although the nape strap may increase stability of the helmet on the wearer's head, it also may provide a further source of discomfort, pressure and fit problems for the helmet wearer.
Impact attenuation liners come in many different form factors utilizing many different materials. Current safety helmets use a combination of a webbing system offset from the helmet shell, an expanded polystyrene (EPS) foam liner and a series of foam pucks around the headband to attenuate impacts. However, other safety helmet designs use all EPS construction, some have individual pads which can be removed and repositioned for fitting purposes. The material makeup of impact attenuation liners also vary from one safety helmet to the next. These materials include but are not limited to EPS, vinyl nitrile, expanded polypropylene, polyurethane, polyethylene and engineered plastic structures. The combination of impact attenuation liner and material selection is critical to achieving a system that meets the protective requirements of the helmet as well as the fit and comfort required for prolonged use. Impact attenuating materials found in certain helmets can cause discomfort when in contact with the head due to pressure points or heat/moisture retention.
Safety helmets typically employ an impact attenuation material such as an expanded bead polystyrene (EPS) liner as a primary system to absorb blunt impacts. As well, minor attenuation may be provided by foam rubber pads situated around the circumference of the headband. However, EPS has a low chemical resistance, becomes fragile with use, and the foam rubber pads are known to be an additional cause of discomfort.
While the spacing between the helmet and the head is important for impact protection, the orientation or position of the helmet on the head is also important for stability and proper suspension and retention of the helmet. The stability and positioning of the helmet may be further affected by additional devices worn on the head or helmet, such as goggles or other eyepieces and earphones, microphones or other communications devices. Thus, once adjusted, the helmet must remain in position under static or dynamic loads. Likewise, the helmet shell, suspension system and impact attenuation liner also must not interfere with other devices worn on the head. For example, existing helmets have been found to interfere with ear pieces worn under the helmet, causing the ear piece to be displaced from the helmet wearer's ear.
Existing helmets may be fitted with an impact attenuation liner to absorb forces upon impact as described above. One or more pieces of impact attenuation material may be affixed to the helmet shell to meet this safety performance requirement. It has been found, for helmet systems with removable materials or padding, that helmet wearers also may carry out unauthorized modifications to the impact attenuation system and alter or remove the pieces of the impact attenuation material to further improve the comfort of the helmet. Such unauthorized modifications may severely impair the impact protection performance of the helmet and result in injury to the helmet wearer. Thus, comfort and proper fit of the helmet is critical to ensure unauthorized modifications do not occur which compromise the wearer's safety.
The helmet shell, impact attenuation and suspension system also must operate in harsh environments and may be degraded by sand, water and other elements. The impact attenuation, webbing and strap material typically wear out or become excessive soiled more quickly than the helmet shell, thus limiting the usable life of the helmet. A simple means to retrofit or upgrade the impact attenuation, suspension and retention system components is thus needed to allow for longer use of the helmet shell.
A further example of a safety helmet for military use is described in U.S. Pat. No. 5,068,922, issued Dec. 3, 1991 and No. 4,987,609, issued Jan. 29, 1991, to Zahn. Zahn discloses a military safety helmet with an inner supporting band, fastening strips and bosses resting against the helmet shell to provide impact protection. However, Zahn does not disclose adjustment of the inner supporting band, a second headband adjusted to the wearer, the accommodation of a liner to provide impact protection or the design of a fitting and impact attenuation system that may be used to retrofit existing helmet shells.
Thus, there is a need to improve the comfort and fit of new and existing safety helmets to accommodate additional components worn on or near the helmet, prevent wearer modifications aimed at improving fit and comfort, and to continue to meet impact protection and safety requirements during normal use.
Embodiments of the present invention provide a helmet fitting and impact attenuation system for new helmet shells or to be used to retrofit existing helmet shells. In accordance with an embodiment of the present invention, there is provided a helmet fitting and impact attenuation system for use in a helmet. The fitting and impact attenuation system comprises a semi-rigid space frame comprising a plurality of arms extending from a central crown point wherein at least three of the arms are attachable to the helmet such that the space frame is releasably fixed to said helmet. There is also provided a headband for receiving the head of a wearer, in which the headband is releasably attachable to the space frame by one or more of the arms. There is also provided an impact attenuation layer, fixably mounted to an inside surface of the helmet. The space frame maintains the headband in a fixed vertical configuration relative to the helmet.
According to another aspect of the present invention, there is provided a helmet comprising a helmet shell; a semi-rigid space frame comprising a plurality of arms extending from a central crown point wherein at least three of the arms are attachable to the helmet such that the space frame is releasably fixed to the helmet. There is also provided a headband for receiving a head of a wearer, in which the headband is releasably attachable to the space frame by one or more of the arms. There is also provided an impact attenuation layer, fixably mounted to an inside surface of the helmet shell. The space frame maintains the headband in a fixed vertical configuration relative to the helmet.
These and other advantages of the invention will become apparent upon reading the following detailed description and upon referring to the drawings in which:
While the invention will be described in conjunction with the illustrated embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
In the following description, similar features in the drawings have been given identical reference numerals where appropriate. References to the left or right side and front or back of the helmet and system components are made with respect to the helmet and system situated on a wearer's head.
Arms of the space frame 14 extend from a central crown point 20 and may be mounted to an existing helmet shell 12 at the three permanent and pre-existing mounting points in a typical helmet configuration, namely, one mounting point 30 at the back of the helmet and two mounting points 32, 34 at the front sides of the helmet. For example, the back mounting arm 38 is attached to the mounting point 30 at the back of the helmet shell 12. Side mounting arms 40, 42 attach to the front side mounting points 32, 34. As seen in
As seen in
The space frame 14 is semi-permanently affixed to the helmet shell 12 using the existing mounting screws or any other suitable fastener and requires tools to detach from the helmet shell 12, thus deterring a wearer from removing or modifying the space frame component. The space frame 14 may be removed, however, for any necessary replacement, cleaning or repair.
As shown in
An additional front tab 60 may be provided at the front of the headband 16 and space frame 14 as shown in
The headband 16 may be removed from the space frame 14 and thus from the helmet to be cleaned, replaced and readjusted without the need for additional tools. The headband 16 typically is constructed of semi-rigid plastic and covered with a material such as a fabric backed with foam or other compliant layer. Since the space frame 14 is attached to the outer side of the headband 16, the headband 16 provides a comfortable fit for the wearer and the wearer is not irritated by other straps or gear, such as the multiple loops of the crown webbing layer in the prior art.
The semi-rigid space frame 14 provides an appropriate vertical displacement between the wearer's head and the helmet shell 12 and maintains the proper positioning of the wearer's head within the helmet shell 12. As well, as seen in
Thus, the space frame 14 provides for proper positioning of the headband and ultimately the wearer's head, within the helmet 10. The removal, readjustment and reattachment of the headband 16 do not interfere with this positioning. The space frame 14 also provides a degree of mechanical constraint between the headband 16 and the wearer's head. By attaching the headband 16 to the helmet shell 12 via the space frame 14, the headband 16 is prevented from moving vertically relative to the helmet shell 12, thus increasing the helmet's stability. The space frame 14 allows some lateral movement of the headband (and thus the wearer's head) relative to the helmet shell 12.
The space frame 14 allows for an impact attenuation liner layer 70 to be inserted between the helmet wearer and the helmet shell 12.
The impact attenuation material may comprise expanded polypropylene (EPP), EPS, Gecet™, vinyl nitrile (VN), polyurethane, polypropylene, viscoelastic and other foams or other impact attenuating materials such as Brock™, Skydex™, Zorbium™, or any other suitable material which meets the impact protection requirements. As shown in
As seen in
In another aspect of the present invention, a yoke 80 may be provided at the back of the helmet 12 near the back mounting point 30 to provide separation between the joining of the straps at the back of the helmet. The yoke 80 is shown in
Thus, it is apparent that there has been provided in accordance with the embodiments of the present invention a helmet fitting and impact attenuation system that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with illustrated embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the invention.
This application claims the benefit under Title 35, U.S.C., S. 119(e) of U.S. Provisional Application No. 61/014,239 filed on Dec. 17, 2007, which is herein incorporated by reference.
Number | Date | Country | |
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61014239 | Dec 2007 | US |