Abstract:
A cooling apparatus for a helmet is provided for cooling air in an interior space of a helmet to cool a wearer&#39;s head. The cooling apparatus maximizes the volume of air moving across an evaporator and minimizes the speed at which the air passes through cooling fins of the evaporator, thereby achieving air temperatures substantially below the outside ambient temperature. A narrow opening is provided between a first chamber of intake air and a second chamber which houses the evaporator, such that air passing through the narrow opening increases in velocity and pressure. Upon entering the second chamber which is a large open space, the highly pressurized and high velocity air immediately slows down and expands into the large second chamber, where it then passes across a large surface area of the evaporator and outward through a collection chamber and a blower to the inside of the helmet.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of the priority of U.S. Provisional Application No. 61/663,474, filed Jun. 22, 2012. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a helmet cooling system, and more particularly to an air duct and evaporator configured to more effectively cool air by controlling the speed, pressure and density of air being directed into a helmet. 
       BACKGROUND 
       [0003]    A variety of helmets are equipped with air cooling systems which direct air into an interior of the helmet in order to cool the head of the wearer. In motorcycle, racing or flight helmets which have thick walls and substantially surround a human head, poor circulation of air within the helmet causes discomfort to the wearer and may also lead to condensation or fogging of a visor, obscuring a wearer&#39;s view. If a wearer&#39;s head heats up too much, the wearer&#39;s concentration and judgment may become impaired, or he or she may even lose consciousness, which may be catastrophic in military situations or on a racetrack. Cooling systems are therefore considered safety equipment in many helmets, as they ensure that the wearer is not distracted by the discomfort of the helmet and can therefore provide their full attention to the high risk operation in which they are engaged. 
         [0004]    Given the spatial limitations of designing an air-cooling system in a helmet, significant challenges arise in creating a helmet with a cooling system that is comfortable to the wearer and which fits within a small area in or around the helmet without obscuring the wearer&#39;s movement or view. One of the more difficult tasks in designing a cooling helmet is regulating the air temperature and pressure so that the air can be effectively cooled and also be directed into the interior of the helmet at a rate effective to keep the wearer cool. 
       SUMMARY 
       [0005]    In an exemplary embodiment, a cooling apparatus is provided for a helmet for cooling air in an interior space of a helmet in order to cool a wearer&#39;s head. The cooling apparatus maximizes the volume of air moving across an evaporator and minimizes the speed at which the air passes through cooling fins of the evaporator, thereby achieving air temperatures substantially below the outside ambient temperature of incoming air. A narrow opening is provided between a first chamber of intake air and a second chamber which houses the evaporator, such that air passing through the narrow opening increases in velocity and pressure. Upon entering the second chamber which is a large open space, the highly pressurized and high velocity air immediately expands and slows down into the large second chamber, where it then passes across a large surface area of the evaporator and outward through a collection chamber where it is accelerated by a blower and directed out of the cooling apparatus and into an interior space of the helmet. 
         [0006]    In one embodiment of the invention, an apparatus for cooling an interior portion of a helmet with air comprises a first air intake opening connected with a first chamber by an inlet air duct; a second chamber connected with the first chamber at an opening, wherein the size of the opening increases the pressure and decreases the velocity of air passing from the first chamber to the second chamber; an evaporator disposed within the second chamber which cools air as it passes through the second chamber to create cooled air; a third chamber which collects the cooled air; and a blower disposed within the third chamber which receives the cooled air from the third chamber and passes the cooled air to an interior portion of a helmet. 
         [0007]    In another embodiment of the invention, a method of cooling an interior portion of a helmet with air comprises receiving air at a first air intake opening connected with a first chamber by an inlet air duct; directing the air in the first chamber to a second chamber connected with the first chamber at an opening, wherein the opening increases the pressure and decreases the velocity of air passing from the first chamber to the second chamber; cooling the air in the second chamber with an evaporator to create cooled air; collecting the cooled air in a third chamber; and directing the cooled air to an interior portion of the helmet with a blower connected with the third chamber. 
         [0008]    From this description, in conjunction with other items, the advantages of the said invention will become clear and apparent more so based upon the hereinafter descriptions and claims, which are supported by drawings with numbers relating to parts, wherein are described in the following sections containing the relating numbers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the objects, advantages, and principles of the invention. In the drawings: 
           [0010]      FIG. 1  is a side perspective-view illustration of a helmet cooling apparatus enclosed by a housing, according to one embodiment of the invention; 
           [0011]      FIG. 2  is a cross-section side-view illustration of the helmet cooling apparatus, according to one embodiment of the invention; 
           [0012]      FIG. 3 . is a perspective cross-section view illustration of the helmet cooling apparatus, according to one embodiment of the invention; 
           [0013]      FIG. 4  is a perspective cross-section side view illustration of the helmet cooling apparatus, according to one embodiment of the invention; 
           [0014]      FIG. 5  is another perspective cross-section side view illustration of the helmet cooling apparatus, according to one embodiment of the invention; 
           [0015]      FIG. 6A  illustrates a top perspective view of the cooling apparatus depicting an air filter inlet opening and air filter outlet opening of a central portion which connect with an air filter cover, according to one embodiment of the invention; 
           [0016]      FIG. 6B  is a see-through illustration of the structures of the cooling apparatus which more clearly indicate the flow of air, according to one embodiment of the invention; 
           [0017]      FIG. 7A  is a reverse perspective view of a left portion of the cooling apparatus further indicating the location of the air inlet duct within the central portion of the cooling apparatus, according to one embodiment of the invention; 
           [0018]      FIG. 7B  is a top perspective view illustration of the cooling apparatus illustrating distinct shading of different structures within the cooling apparatus, according to one embodiment of the invention; 
           [0019]      FIG. 7C  is a rear perspective view of the cooling apparatus illustrating an area where the evaporator is positioned, according to one embodiment of the invention; and 
           [0020]      FIG. 8  is a block diagram of a method of cooling air using the cooling apparatus in a helmet, according to one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0021]    After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. However, all the various embodiments of the present invention will not be described herein. It is understood that the embodiments presented here are presented by way of an example only, and not limitation. As such, this detailed description of various alternative embodiments should not be construed to limit the scope or breadth of the present invention as set forth below. 
         [0022]    Embodiments herein describe a helmet cooling device which may be attached with or molded into a helmet to provide significant cooling of air inside the helmet through the manipulation of the volume, speed and density of the air passing through the device. 
         [0023]    In order to obtain a maximum change in temperature of air being drawn into to a helmet cooling system, it is necessary to control not only the volume of air but also the speed and density of the air going to the helmet. To achieve a substantial cooling of the air brought into a cooling system of the helmet, the volume of air moving across a cooling system evaporator should be maximized, and the rate, or velocity, of air moving across the cooling fins of the evaporator should be minimized. 
         [0024]    In one embodiment of the invention illustrated in  FIGS. 1-5 , a cooling apparatus  100  is provided with an air duct system which controls the flow of air both before and after the evaporator. Air is drawn into an inlet air duct  4  through an air intake opening  2  via suction from a blower  20  positioned within the cooling apparatus  100 . The air is first cooled by direct contact of an external surface of an evaporator  16  with a wall (not shown) of the intake air duct  4  as initial airflow passes along this wall. In one embodiment, the air temperature at this level is reduced by approximately five (5) degrees Fahrenheit (F) from the incoming ambient air temperature. The slightly cooled air then passes through a first opening  6  into a helmet air duct  7 . In one embodiment, the helmet air duct is configured with a wall disposed from the external surface of the evaporator in order to slightly cool the air. 
         [0025]    In one embodiment, the air then flows into a carbon dioxide (CO 2 ) filter housing  8  and is drawn through a CO 2  filter (not shown) and into a first chamber  10 . The CO 2  filter is not a required component of the cooling system, but if included, it has only minimal effect on the velocity of the air flow. Other types of filtration devices may also be used. 
         [0026]    At the first chamber  10 , the velocity of the air is reduced and the air pressure increases as the air approaches a narrow opening  12  (also known as the expansion port) connecting the first chamber with a second chamber  14  at a distal end  11  of the first chamber. The opening  12  has a diameter which is substantially smaller than the diameter of the first chamber  10  in order to sufficiently slow the air flow and increase the pressure in the first chamber  10 . The air then travels through this narrow, reduced-sized opening  12  (i.e. a valve) and into the large second chamber  14 , also known as the expansion chamber, which houses the evaporator  16 . The second chamber  14  has a diameter which is substantially larger than the diameter of the opening  12  and an overall volume which is also substantially larger than that of the first chamber  10 . As the high pressure air enters the large second chamber  14  through the narrow opening  12 , it rapidly expands, decreasing the velocity and pressure and thereby cooling the air even before the air interacts with the evaporator  16 . The cooled air also has a higher density. The passage of air across the evaporator fins is then maximized due to its lower velocity. The evaporator  16  is also configured to span a large surface area of the second chamber  14  in order to further maximize the amount of time the air spends passing over the evaporator fins and being further cooled. In one embodiment, the highly cooled air exiting the second chamber  14  is approximately 30 degrees Fahrenheit lower than the incoming ambient air temperature. 
         [0027]    The changes in pressure, density, velocity and temperature prior to the ambient air interacting with the evaporator are all used to improve the efficiency of the evaporator to cool the helmet air exiting into the helmet by maximizing the amount of time the air is in contact with the evaporator cooling fins in the second chamber. 
         [0028]    Once the air has passed over the cooling fins of the evaporator  16 , the air is drawn into a third chamber  18 —also known as a collection chamber—via the connected helmet blower  20 . In this third chamber  18 , the dense, highly cooled air experiences increased velocity as it passes through the helmet blower  20  and through a narrow adapter  22  to an air outtake opening  24 , or helmet air port, before entering the interior space of the helmet (not shown). It should be noted that the helmet blower  20  also operates to pull air into the cooling apparatus  100  in addition to pushing it out of the cooling apparatus  100  and into an interior space of the helmet. 
         [0029]    Although similar in principle to refrigeration systems which liquefy the refrigerant gas as part of a cooling loop, the cooling system described herein does not change the physical state of the gas back to a liquid. Without this control, the physical size of the evaporator would be much larger in order to achieve similar levels of temperature change. Instead, this system rapidly cools the air, a gas, by reducing the velocity and pressure at a step in the cooling process before the cooled air is then sped back up by the blower and directed to the interior of the helmet. 
         [0030]      FIG. 1  illustrates a perspective view of the cooling apparatus  100  when enclosed by a housing  26 , in accordance with one embodiment of the invention. The air inlet opening  2  and inlet air duct  4  are provided on a side portion of the cooling apparatus  100  for air to enter the unit from the ambient, or outside, environment. The filter cover  8  may also protrude from the housing  26 . On an upper right portion of the cooling apparatus  100  is the air outtake opening  24  where cooled air exits to the helmet. The housing  26  may provide a ventilated portion  28  to ventilate heat from the evaporator  16   
         [0031]      FIG. 2  illustrates a cross-sectional side view of the cooling apparatus  100  in accordance with one embodiment of the invention. The inlet air duct  4  is provided on the side portion of the cooling apparatus, and is in connection with the air inlet opening  2 . The incoming air passes through the air inlet opening  2  and into the inlet air duct  4 . The cross-sectional view in  FIG. 3  also illustrates a helmet air duct  7  situated in a central portion of the apparatus, as well as the air filter cover  8  disposed above the helmet air duct  7 , which serves as an inlet to the helmet air duct.  FIG. 2  also illustrates the location of a helmet blower  20  which drives air into the helmet through an adapter  22  connecting the collection chamber  18  and the helmet air port (outlet opening)  24 . 
         [0032]      FIG. 3  illustrates a perspective cross-sectional view of the cooling apparatus  100  with arrows indicating the direction of air flow through the apparatus, in accordance with one embodiment of the invention. The air enters through the air inlet  2  (Arrow A), where it then passes into the inlet air duct  2 , through a first opening  6  (Arrow B) into the helmet air duct  7  in a central portion of the unit (Arrow C) where it is first slightly cooled by the outer housing of the evaporator. The slightly-cooled air then passes into a filter cover  8  (Arrow D) which contains the air filter (not shown), after which the filtered air is accelerated in the first chamber  10  (Arrow E) to an expansion port (narrow opening)  12 . 
         [0033]      FIG. 4  illustrates a separate perspective cross-sectional view of the cooling apparatus showing the passage of air into the second chamber  14  of the cooling apparatus (Arrow F), particularly across the evaporator  16  (Arrows G) and into the collection chamber  18  (Arrow H). The accelerated air from the first chamber  10  passes through the narrow opening  12  and into the second chamber  14 , where it is expanded (Arrows G) and slowed, and after which it passes across the evaporator  16  where it is cooled again to a temperature significantly lower than the outside ambient air temperature brought in through the air intake. The cooled air then passes from the second chamber  14  to the third chamber  18 . 
         [0034]      FIG. 5  illustrates the pathway (Arrows I) of cooled air through the cooling apparatus from the third chamber  18  into the adapter  22  and out of the cooling apparatus through the air outtake opening  24  to the interior of the helmet. 
         [0035]      FIG. 6A  illustrates a top perspective view of the cooling apparatus  100  depicting an air filter inlet opening  30  and air filter outlet opening  32  of the helmet air duct  7  which connects with the air filter cover (not shown). The outlet opening  32  passes air from the air filter cover to a first chamber before it passes through the expansion valve (narrow opening  12 ).  FIG. 6B  is a see-through illustration of the structures of the cooling apparatus which more clearly indicates the flow of air through the air filter and into the first chamber  10 , after which it passes down (Arrow E) to the expansion valve  12  where the air then expands into the second chamber  14  (Arrow F), otherwise known as the expansion chamber. The evaporator  16  is outlined in its central position within the second chamber  14  such that the expanded air in the second chamber  14  passes across the evaporator  16   
         [0036]    (Arrows G) and into the third chamber  18  (Arrow H) before it passes through the helmet blower (not shown) (Arrow I) and into the interior space of the helmet. 
         [0037]      FIG. 7A  is a reverse perspective view of a left portion of the cooling apparatus  100  further indicating the location of the air inlet duct within the central portion of the cooling apparatus. The air inlet duct communicates with the air filter inlet opening  30  to pass air through the air filter and then out of the air filter outlet opening  32  to the first chamber  10  disposed along the left side portion of the cooling apparatus. Once the air reaches the end of the first chamber  10 , the air is passed through the Expansion valve and into the second chamber  14 , or the expansion chamber, where the air expands and is then cooled further by the evaporator (not shown). The cooled air then flows through the third chamber  18  and into the interior space of the helmet.  FIG. 7B  is a top perspective view illustration of the cooling apparatus  100  illustrating distinct shading of different structures within the cooling apparatus, including the first chamber  10 , second chamber  14  and third chamber  18 , and an outlet  24  to a helmet blower.  FIG. 7C  additionally illustrates an evaporator area  15  where the evaporator (not shown) is disposed in relation to the first chamber  10 , second chamber  14  and third chamber  18 . 
         [0038]      FIG. 8  illustrates one embodiment of a method of cooling air for a helmet. The method comprises receiving air at a first air intake opening (S 102 ) connected with a first chamber by an inlet air duct; directing the air in the first chamber to a second chamber (S 104 ) connected with the first chamber at a narrow opening, wherein the opening increases the pressure and decreases the velocity of air passing from the first chamber to the second chamber; cooling the air in the second chamber (S 106 ) with an evaporator to create cooled air; collecting the cooled air in a third chamber (S 108 ); and directing the cooled air to an interior portion of the helmet (S 110 ) with a blower connected with the third chamber. 
         [0039]    The above description of disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, the generic principals defined herein can be applied to other embodiments without departing from spirit or scope of the invention. Thus, the invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principals and novel features disclosed herein.