Abstract:
A motorsports helmet having an isolation mount defining a receptacle is provided. An adjustment plate is selectively disposed within the receptacle at different depths and includes an ear-cup. The ear-cup is secured relative to the adjustment plate and includes at least two degrees of freedom of movement.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates generally to a variety of motorsports helmets. More particularly, the invention relates to a motorcycle helmet with noise reduction elements. 
         [0003]    2. Description of the Related Art 
         [0004]    A motorcyclist&#39;s ability to hear while riding is a critical safety factor in the modern environment. Unfortunately, a motorcyclist&#39;s hearing may be impeded by engine noise, wind noise and helmet design, among other things. High noise levels, such as those experienced by motorcyclists, may increase fatigue, may impair reaction times and may impede attention, effectively reducing the safety of the motorcyclists and those around him or her. Moreover, high intensity noise over long periods of time may have long-term consequences on a motorcyclist&#39;s hearing ability. At highway speeds, noise levels may easily exceed 100 dB even when wearing a traditional helmet. This is particularly troublesome for daily motorcyclists as well as occupational motorcyclists, such as police officers. 
         [0005]    To combat the noise, some motorcycle helmets use sound deadening material around the area of the ears. Other motorcyclists may opt to use earplugs to reduce noise and prevent noise induced hearing loss. In both cases, the motorcyclist&#39;s hearing may be protected, but it is also impaired such that the motorcyclist may not be able to hear other cars, people, sirens, etc. around him or her. 
       SUMMARY OF THE INVENTION 
       [0006]    The systems and methods of the present invention have several features, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of this invention as expressed by the claims which follow, its more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description of the Preferred Embodiments” one will understand how the features of this invention provide several advantages over traditional helmets. 
         [0007]    One aspect of the present invention is a motorcycle helmet that has a shell, an isolation mount disposed in the shell and having a receptacle, and an adjustment plate disposed within the receptacle. The helmet further includes a coupling secured to the adjustment plate and an ear-cup secured to the coupling. 
         [0008]    Another aspect of the invention is a passive noise cancellation system. The system has an isolation mount having a receptacle, an adjustment plate at least partially disposed in the receptacle, and an engagement structure disposed so as to inhibit movement of the adjustment plate through the receptacle. 
         [0009]    Another aspect of the invention is a method of reducing noise in a motorcycle helmet. The method includes providing a shell having an isolation mount and an adjustment plate, the isolation mount defining a receptacle configured to receive at least a portion of the adjustment plate at a plurality of positions and engaging the adjustment plate with the isolation mount so as to select one of the plurality of positions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of a motorcycle helmet with a passive noise reduction system. 
           [0011]      FIG. 2  is a perspective view of a motorcycle helmet with a passive noise reduction system and an active audio system. 
           [0012]      FIG. 3A  is a perspective view of a passive noise reduction system for a helmet. 
           [0013]      FIG. 3B  is a perspective view of an alternate embodiment of an eccentric isolation mount for use with the passive noise reduction system of  FIG. 3A . 
           [0014]      FIG. 4  is a perspective view of a noise reducing ventilation system in a helmet. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    The preferred embodiments of the present invention will now be described with reference to the accompanying figures, wherein like numerals refer to like elements throughout. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner simply because it is being utilized in conjunction with a detailed description of certain specific preferred embodiments of the present invention. 
         [0016]    Noise affecting a motorcyclist may have many sources, such as engine noise, road noise, other vehicle noise and wind noise. As the speed of a motorcycle increases, typically the most prominent source of noise is wind noise. Common to all types of noise experienced by a rider are vibrations that make their way to a rider&#39;s ear. In some cases, a helmet may increase the perceived amplitude of noise by transmitting vibrations from the environment directly to a rider&#39;s ear. For example, as a motorcyclist travels faster, the wind impacting the shell of his or her helmet will in turn create more vibration that the motorcyclist perceives as noise. This effect increases dramatically as speed increases. As discussed above, several methods for reducing noise in a motorcycle helmet exist, but they are mostly limited to sound suppression, which can be dangerous for a rider. These previous solutions fail to address the primary driver of helmet noise, which is the coupling of noise related vibrations to a rider&#39;s ear. 
         [0017]    A typical helmet is comprised of several layers, including a shell, a shock-absorbing layer, and a comfort layer. A helmet&#39;s shell is the outermost layer and is typically made from resilient, water-resistant materials such as plastic and fiber composites. A helmet&#39;s shock-absorbing layer, which is its primary safety layer, may be made out of a rigid, but shock-absorbing material such as expandable polystyrene foam. Although not typical, a helmet&#39;s fire-proof layer may be integrated and made of a closed-cell material such as vinyl-nitrile, which is both fire and water resistant. Further, this layer may have sound and thermo-insulating qualities and may be alternatively referred to as an acoustic layer. Finally, a helmet&#39;s comfort layer may be made of a soft material meant to fit against a rider&#39;s skin, such as cotton or other fabric blends as are known in the art. Other layers may be present as well, and some of the aforementioned layers may be deleted or combined. 
         [0018]    Helmets usually include ear-cups, which are often molded into the rigid portions of the helmet, such as the foam layer. The ear-cups may be static and merely provide space for a rider&#39;s ears, or they may include electronics, such as headphones, so that a rider may listen to music or communicate over an electronic communication system. In some cases, the ear-cups may be mounted to the shell of the helmet so that they can articulate and provide better comfort to riders. In other cases, the helmet may have a recess where a rider may install aftermarket ear-cups that are not a part of the helmet. Many designs are known in the art. Common to most designs is the fact that a standard ear-cup is either formed in a rigid material that is vibrationally coupled to the helmet&#39;s shell, or the ear-cup is directly connected to the helmet&#39;s shell. In both cases, vibrations from wind and other noise sources are readily transmitted from the shell of the helmet to the ear-cup and then to the motorcyclist&#39;s ear. This vibrational coupling in-turn creates irritating noise for the motorcyclist. 
         [0019]      FIG. 1  is a perspective view of a motorcycle helmet  100 . The helmet  100  comprises an outer shell  102 , an acoustic layer  104 , a foam layer  106 , a comfort layer  108 , and a passive noise reduction system  118 . The passive noise reduction system  118  comprises an ear-cup  110 , a coupling  116 , an adjustment plate  114 , and isolation mount  112 . The ear-cup  110  is mounted to a coupling  116  on each side of the helmet  100 . The coupling  116  is mounted to the adjustment plate  114 . The coupling  116  allows the ear-cup  110  to articulate for better comfort. The adjustment plate  114  allows the position of the ear-cup  110  to be adjusted to best fit a user&#39;s ear position within the helmet  110 . The adjustment plate  114  is adjustably mounted to the isolation mount  112 . The isolation mount  112  may be made from a vibration dampening material so as to isolate the ear-cup  110  from the shell  102 . Further, the isolation mount  112  may be molded with the interior dimension offset in relation to the exterior, and ribbed to enable multiple adjustment plate  114  mounting locations in both radial and circumferential directions relative to the motorcyclist&#39;s head. Alternatively, the adjustment plate  114  may be mounted to the isolation mount  112  by means of a press or friction fit, or other methods as are known in the art. 
         [0020]    Note that in  FIG. 1  only one ear-cup  110  is visible. However, the same assembly, shown in broken lines, is also present on the opposite side of the helmet  100 . The passive noise reduction system  118  will be described in more detail below with reference to  FIG. 3 . 
         [0021]    As is shown in  FIG. 1 , the ear-cup  110  is isolated from the shell  102  of the helmet  100  by the isolation mount  112 . The isolation mount  112  is preferably made of a vibration dampening material. The vibration dampening material may prevent shell  102  vibrations from reaching a user&#39;s ear and thus may decrease the user&#39;s perception of those vibrations as noise. Thus, by mounting the ear-cup  110  to something other than the shell  102  of the helmet, and decoupling it from rigid materials that easily transmit vibrations, noise transmitted to the ear-cup  110  may be reduced. Notably, this noise reduction is accomplished without significantly reducing a motorcyclist&#39;s hearing ability through, for example, excess padding placed against the ear. 
         [0022]      FIG. 2  is a perspective view of a motorcycle helmet  200  which is the same as the helmet  100  described in connection with  FIG. 1  except that the helmet  200  further includes an audio system  208 . The audio system  208  comprises audio port  202 , which provides a connection for an audio signal from, for example, a radio, a stereo, or a communication system. The audio port  202  may connect to electronics in each ear-cup  110  via electric connection  206 . Each ear-cup  110  may render the audio using, for example, a speaker or other type of sound driver, built into the ear-cup  110 . 
         [0023]    Additionally, the audio system  208  may include electronics  210  that sense noise frequencies and actively cancel them in conjunction with speakers in each ear-cup  110 . In this way, the benefits of the passive noise reduction system  118  may be combined with an active noise reduction system. In some embodiments, the electronics  210  components are mounted within the shell  102  of helmet  200  and may be isolated from the shell  102  by vibration dampening material. Activation switch  204  may activate or deactivate the electronics  210  of the active noise reduction system. 
         [0024]      FIG. 3A  is an exploded perspective view of the passive noise reduction system  118  from  FIG. 1 . As described above, the passive noise reduction system  118  includes ear-cup  110 , coupling  116 , adjustment plate  114  and isolation mount  112 A. The ear-cup  110 , which interfaces with the motorcyclist&#39;s ear, is mounted to coupling  116 , which allows the ear-cup  110  to rotate up or down, i.e. about a horizontal axis. The coupling  116  mounts to the adjustment plate  114 , which allow the ear-cup  110  to rotate side-to-side, i.e. about a vertical axis. Accordingly, this arrangement allows two degrees of freedom of the ear-cup  110 , which increases comfort for the user. 
         [0025]    The isolation mount  112 A includes a receptacle  306  sized to receive the adjustment plate  114 . The inner surface of the receptacle  306  and/or the outer surface of the adjustment plate  114  may include one or more engagement structures  304 . In the illustrated embodiment, the engagement structures  304  are disposed on the isolation mount  112 A. The engagement structures  304  circumscribe the inner walls of the receptacle  306  to form a plurality of ribs. Of course the engagement structures  304  need not circumscribe the entire receptacle  306 . For example, the engagement structures  304  may be in the form of protrusions intermittently disposed across one or more inner walls of the receptacle  304  or other structures which are disposed so as to engage the outer perimeter of the adjustment plate  114 . In some embodiments, the engagement structure  304  is an interference fit between complementary surfaces on the isolation mount  112 A and the adjustment plate  114  which at least inhibits movement of the adjustment plate  114  through the receptacle  306 . In this way, the engagement structure  304  allows the user to selectively locate the adjustment plate  114  within the receptacle  306 . 
         [0026]    The engagement structure  304  allows the user to adjust the mounting depth of the adjustment plate  114  within the receptacle  306  in the isolation mount  112 A. In other words, the distance between the ear-cup  110  and the user&#39;s ear is adjustable to better fit the user&#39;s ears. As discussed above, the isolation mount  112 A is made of a vibration dampening material so that the ear-cup  110  is better isolated from vibrations traversing the shell or other rigid parts of the helmet  100 . The exterior shape of the isolation mount  112 A may be dimensioned to fit within a complementary space within the helmet  100 , such as shown in  FIG. 1 . The exterior shape of the isolation mount  112 A of  FIG. 3A  is just one example, and those skilled in the art will appreciate that it can take many shapes. For example, another embodiment of the isolation mount  112 A may have a rounded exterior shape. 
         [0027]      FIG. 3B  is a perspective view of an isolation mount  112 B which is similar to the isolation mount  112 A except that the receptacle  306  is offset from the center of the isolation mount  112 B. For example, in the embodiment illustrated in  FIG. 3B , the receptacle  306  is offset in a direction towards the upper left corner of the isolation mount  112 B. In so doing, the adjustment plate  114  would fit within the isolation mount  112 B at a position relatively higher and farther to the left. An advantage of this embodiment is that the isolation mount  112 B may be mounted within the same helmet  100  in four different orientations. The different orientations of the isolation mount  112 B results in the receptacle  306  being located at locations slightly offset from one another. For example, the isolation mount  112 B may be located in the helmet  100  with the receptacle  306  offset in a direction towards the upper left corner of the isolation mount  112 B. Alternatively, the isolation mount  112 B may be removed from the helmet  100 , rotated 180 degrees, and replaced in the helmet  100 . When replaced within the helmet  100 , the receptacle  306  will be slightly off set from its prior position within the helmet  100  in a direction towards the lower right corner of the isolation mount  112 B. Additionally, the isolation mount  112 B may be flipped over and installed into the helmet, which provides two more possible orientations. 
         [0028]    By offsetting the receptacle  306  in the isolation mount  112 B, the user can adjust the position of the ear-cup  110  within the helmet  100  to better fit a user&#39;s ear position. This adjustment can be in addition to the multi-axis swivel (up or down and side-to-side) of the ear-cup  110 . The illustrated shape of the receptacle  306  in the isolation mount  112 B is exemplary, and those skilled in the art will appreciate that it can take many shapes. For example, another embodiment of an isolation mount may have a rounded interior shape. 
         [0029]      FIG. 4  is a perspective view of a helmet  400  comprising a ventilation system  408 . The ventilation system  408  may be employed in a helmet that includes the passive noise reduction system  118  and/or the active noise reduction system described above. 
         [0030]    The ventilation system  408  includes high-pressure venturi intake vents  402 . The vents  402  are disposed on the front or wind-facing side of the helmet  400 . Once air enters vents  402 , it travels through laminar flow ducts  404  around the periphery of the helmet  400 . In some embodiments, the ducts  404  are separated from the interior of the helmet  400  by a porous material, such as a cotton fabric, so that the airflow may enter the helmet all along the ducts  404 . In other embodiments, the ducts  404  are completely closed off from the interior of the helmet  400 . Air flowing through the ducts  404  exits at low pressure exhaust nozzles  406  and ventilates the motorcyclist&#39;s head and neck area. By reducing the pressure of the air by way of the vents  402 , as it enters the helmet  400 , and routing it through ducts  404  and out nozzles  406 , the amount of turbulence-induced vibration (i.e. noise) is minimized while still providing adequate ventilation to the motorcyclist. 
         [0031]    Embodiments of the helmets described in  FIGS. 1-4  may include additional accessories such as visors, chin straps, buttons, eye screens, and others without departing from the scope of the invention. 
         [0032]    The various embodiments of the helmets with noise reduction elements and techniques described above thus provide a number of ways to provide a helmet with reduced noise while in use. Of course, it is to be understood that not necessarily all such objectives or advantages may be achieved in accordance with any particular embodiment using the helmet system described herein. Thus, for example, those skilled in the art will recognize that the systems may be developed in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objectives or advantages as may be taught or suggested herein. In addition, the techniques described may be broadly applied for use with a variety of helmet types. 
         [0033]    Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments. Although these techniques and systems have been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that these techniques and systems may be extended beyond the specifically disclosed embodiments to other embodiments and/or uses and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the systems disclosed herein disclosed should not be limited by the particular disclosed embodiments described above.