Abstract:
An improved air diffuser for shooting ranges and the like is both inexpensive, easy to transport, and easy to maintain. Flexible plastic is utilized for the diffuser plates providing easier manufacture and shipment of an unassembled diffuser.

Description:
RELATED APPLICATIONS  
       [0001]     The present application claims the benefit of U.S. Provisional Application Ser. No. 60/710,007, filed Aug. 19, 2005, which is incorporated herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. The Field of the Invention  
         [0003]     The present invention relates to an air diffuser. More specifically, the present invention relates to an improved air diffuser for use in shooting ranges and other environments.  
         [0004]     2. State of the Art  
         [0005]     In shooting ranges and other areas where bullets are fired, it is desirable to control the movement of air. Specifically, it is desirable to create movement which draws smoke and air-born particles away from the shooter and, typically, down range.  
         [0006]     In order to promote a uniform flow of air across all of the shooters and down the shooting range, diffusers have been utilized. A diffuser is an air box having an air inlet and a plurality of air outlets, and is designed to release air uniformly from the outlets, such that each outlet releases a similar amount of air as compared to the other air outlets. Thus, a diffuser which extends across the width of a shooting range and is disposed behind or above the shooters can release air evenly across the width of the shooting range. The even flow of the air is important because it prevents eddies or other turbulent current which might inhibit gasses and airborne particles from being carried down range with Suitable air vents can be made downstream in the shooting range so that air flows from behind the shooters and down the shooting range, carrying smoke and particles away from the shooters.  
         [0007]     Shooting range diffusers are typically formed from steel. The diffusers are formed with a steel air box which extends across the shooting range and is covered by parallel sheets of steel which have a plurality of small holes formed therein. When air is introduced into an inlet in the air box, the box becomes pressurized inside and air flows out of the holes formed in the sheets of steel to develop consistent airflow. These boxes are expensive as they require considerable labor to construct, and as steel is increasingly expensive. These air diffusers are also expensive to ship, as many of the parts for the diffuser are 3-dimensional in nature. Additionally, existing air diffusers can be somewhat difficult to clean and maintain, and can be damaged during shipping.  
         [0008]     There is thus a need for an range air diffuser which is less expensive to produce and transport, and which is easier to maintain.  
       SUMMARY OF THE INVENTION  
       [0009]     It is an object of the present invention to provide an air diffuser for shooting ranges and other environments which is less expensive and more convenient to use than existing diffusers.  
         [0010]     According to one aspect of the present invention, a diffuser is provided which utilizes a plastic diffuser surface instead of a metal surface. A plastic surface is less expensive than a metal surface as plastic is cheaper and easier to form than metal. Additionally, diffusers commonly have curved surfaces and a plastic diffuser front may be formed and shipped flat and bent as it is installed, making the diffuser easier to make and ship.  
         [0011]     According to another aspect of the invention, a diffuser is provided which is easier to clean and maintain. A diffuser according to the present invention may be formed with hinges so as to allow a person to open the diffuser from the top and the bottom.  
         [0012]     According to still another aspect of the present invention, the diffuser with plastic surfaces better prevents denting caused by impacts.  
         [0013]     These and other aspects of the present invention are realized in an air diffuser as shown and described in the following figures and related description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein:  
         [0015]      FIG. 1  shows a perspective view of a diffuser according to the present invention;  
         [0016]      FIG. 2  shows a partial view of a diffuser plate of the diffuser of  FIG. 1  and according to the present invention;  
         [0017]      FIG. 3A  shows an end view of the diffuser of  FIG. 1  and according to the present invention;  
         [0018]      FIG. 3B  shows an alternate end view of the diffuser of  FIG. 1  and according to the present invention; and  
         [0019]      FIG. 4  shows a partial perspective view of a section of the diffuser of  FIGS. 1-3B  and according to the present invention. 
     
    
       [0020]     It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The various embodiments shown accomplish various aspects and objects of the invention.  
       DETAILED DESCRIPTION  
       [0021]     The drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The drawings and descriptions are exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims.  
         [0022]     Turning to  FIG. 1 , a perspective view of a diffuser according to the present invention is shown. The diffuser  10  is often formed into a semi-cylindrical shape as shown. Thus, semi-circular or arcuate side pieces  14 , a back piece (not shown) and front plate  18  are used to form the diffuser  10 . The front plate  18  is formed from a sheet of flexible plastic, and may be attached to the sides  14  with a plurality of fasteners  22 , which may be bolts, screws, rivets, pop rivets, etc., with pop rivets being presently preferred. The flexible plastic is advantageous as a flat sheet may be easily bent around the curved sides  14  without pre-forming. Typically, air enters through the back or sides of the diffuser  10  and exits through uniform holes in the front plate  18 . The length and overall size of the diffuser may be adjusted to accommodate varying room sizes and air flow requirements.  
         [0023]     Turning now to  FIG. 2 , a partial front view of a front plate according to the present invention is shown. The diffuser plate or front plate  18  is formed from a sheet of plastic as mentioned earlier. Many plastics are suitable. It is desirable that the plastic be flexible so as to easily bend around the sides  14 , It is also desirable that the plastic is not brittle, as this will allow for easier machining or forming of the plastic and will inhibit cracking of the plastic during use. Additionally, the plastic should be sufficiently rigid to maintain the desired shape. Suitable plastics include ABS, polyethylene, polypropylene, styrene, polystyrene, acetate, etc.  
         [0024]     The front plate  18  is typically formed with attachment holes  34  whereby the front plate may be attached to the frame of the diffuser  10 . Additionally, the front plate  18  is formed with air holes  38  through which air exits the diff-user  10 . The holes  34 ,  38  may be formed in many ways, including drilling, punching, molding, etc. In a diffuser  10 , air is pushed into the diffuser body by a blower or fan. The air holes  38  are sized such that the air inside of the diffuser  10  is pressurized by the blower or fan and a pressure drop is generated as air moves through air holes  38 . The pressure drop across the front plate  18 , and the corresponding increased pressure inside of the diffuser  10 , generates a fairly uniform flow out of the air holes  38 , such that a similar amount of air flows out of each air hole  38 . Thus, the number and size of air holes  38  is adjusted according to the size of the diffuser  10 , the amount of air moving through the diffuser, the size of the blower or fan, etc. Additionally, multiple diffuser plates  18  may be used such that the air passes through a first diffuser plate  18  and a second diffuser plate  18 .  
         [0025]     Turning now to  FIG. 3A , a sectional view of a diffuser according to the present invention is shown. The diffuser  10  is formed with a diffuser box  46 , side plate  14 , first diffuser plate  18 , second diffuser plate  18 , and an air inlet  50 . Air inlet  50  allows the diffuser  10  to be connected to an air source such as a blower or fan. The diffuser plates  18  are configured so as to provide uniform air flow out of the diffuser  10 . It will be appreciated that, depending on the circumstances in which the diffuser  10  is used, it may be advantageous to use different numbers of diffuser plates  18 . A single plate may be more efficient in some situations, while two or more diffuser plates  18  may be advantageous in other situations, as they provide more uniform flow. It may be that diffuser plates may be formed with a single size hole  38  ( FIG. 2 ) and hole spacing, and that it is more convenient to use two diffuser plates  18  than to form diffuser plates with varying air hole  38  configurations. Thus, a machine such as a punch may be set up to form the diffuser plates and need not be readjusted for different sizes of diffusers  10 .  
         [0026]     The diffuser  10  may also be formed with a top hinge  54  and a bottom hinge  58 . While a single top hinge  54  and single bottom hinge  58  are shown in this side view, it will be appreciated that a number or top hinges  54  and bottom hinges  58  may be used along the top and bottom edges of the diffuser  10 . The hinges are mounted to the diffuser such that the sides  14  and diff-user plates  18  may be pivoted away from the back  46 . The hinges  54 ,  58  may be arranged such that a top hinge  54  is used with a bottom catch, allowing the sides  14  and diffuser plates  18  to be released and pivoted upwards for cleaning or maintenance, or such that a bottom hinge  58  and top catch is used, allowing the sides  14  and diffuser plates  18  to be pivoted downwardly.  
         [0027]     According to one aspect of the present invention, top and bottom hinges  54 ,  58  may be used, and formed such that the hinge pin  62  may be removed from the hinge  54 ,  58  allowing the hinge to separate. Thus, any or all of the top and bottom hinges  54 ,  58  may be released. Releasing the bottom hinge  58  allows the sides  14  and diffuser plates  18  to be pivoted upwardly. Releasing the top hinge  54  allows the sides  14  and diffuser plates  18  to be pivoted downwardly. Releasing both of the hinges  54 ,  58  allows the sides  14  and diffuser plates  18  to be removed completely. The hinges  54 ,  58  may be plates with holes formed therein, and having a pin or bolt passed through the holes to form a hinge. The hinges  54 ,  58  may also be formed from tubes with hinge pins placed inside of the tubes. Many types or hinges, including releasable hinges, are suitable.  
         [0028]     Turning now to  FIG. 3B , an alternate end view of the diffuser of the present invention is shown. The diffuser is the same as that of  FIG. 3A  and is numbered accordingly. As such, the differences will highlighted herein. The air inlet  50  of the diffuser  10  is mounted to the upper surface of the back  46 . The diffuser  10  also includes one or more baffles  52 . The baffles  52  aid in directing airflow from the inlet  50  to the diffuser plates  18 , and air in providing a more even air flow from the diffuser. The baffles  52  may be curved as shown, or may be straight.  
         [0029]     Turning now to  FIG. 4 , a partial perspective view of a side and a connecting rail of a diff-user according to the present invention is shown. A connecting rail  70  is attached to the side  14  so as to provide a stronger structure to receive the diffuser plates  18  and to provide mounting surfaces to attach the diffuser plates  18 . The side  14  is shown with brackets  74  which may easily be formed by bending a tab so as to be perpendicular to the side  14 . The brackets  74  are shown with holes  78  which correspond with holes  34  of  FIG. 2  and which allow the diffuser plate  18  to be attached to the side plate  14  with bolts, screws, rivets, etc.  
         [0030]     The edge of a diffuser plate  18  may be attached to the connecting rail  70  to further strengthen the diffuser  10  and to seal air leaks. Accordingly, the connecting rail  70  may have a flange  82  configured to receive a diffuser plate  18 . The flange  82  may typically be formed with holes  86  whereby the diffuser plate  18  may be attached. Flange  82  provides a location whereby an inner diffuser plate  18  may be attached. Thus, it will be appreciated that the connecting rails  70  and other parts of the diffuser may easily be designed to accommodate varying numbers and sizes of diffuser plates  18 .  
         [0031]     A channel  90  may also be formed whereby an edge of a diffuser plate  18  may be inserted. The channel  90  may be formed between two flanges  94 . The channel  90  may be designed such that once a diffuser plate is attached to brackets  74 , no attachment is necessary to secure the diffuser plate  18  into the channel  90  and to prevent excessive air leakage around the edge of the diffuser plate  18 . Alternatively, holes  98  may be formed through the flanges  94  so as to permit fastening of the diffuser plate  18 . A simple single flange, such as one of flange  94 , may be used in place of a channel. It will be appreciated that internal bracing may be used to strengthen the diffuser, such as corner braces or diagonal braces extending between connecting rail  70  and side  14  as may be necessary for a particular size or design of diffuser.  
         [0032]     It will be appreciated that a diffuser according to the present invention may be made in varying sizes according to the needs of a particular use. It will also be appreciated that a diffuser according to the present invention may be significantly less expensive than conventional shooting range diffusers. Conventional difflusers have been made from steel in order to provide a diffuser which is strong enough to withstand the abuse of a shooting range. Steel is expensive, and is more difficult to machine. Thus, available diffusers are somewhat expensive. Applicant has found that plastic diffuser plates are strong enough for a shooting range, and may even be more durable as they do not dent as a metal plate would when accidentally bumped. Applicant has also found that a diffuser with plastic diffusion plates is less expensive to ship, as the diffuser may be shipped unassembled, and all of the pieces are relatively flat. Existing diffusers have a steel diffusion plate which must be bent to the desired shape before shipping and assembly, requiring a larger object be shipped at additional cost. If a replacement diffuser plate is required, a replacement plate may be shipped flat to the customer. The diffuser plates are easily bent into the desired shape as they are installed.  
         [0033]     In all, the cost of the diffuser can be reduced by more that  80  percent while providing comparable performance. Additionally, the diffuser of the present invention can be readily cut down to size in the event measurements were not accurate. With a conventional steel diffuser, a new diffuser would have to be ordered.  
         [0034]     A diffuser according to the present invention is easier to service than existing diffusers. Existing diffusers may be sealed, or may have a piano hinge on the top of the diffuser. Shooting range operators have found existing diffuser designs difficult to clean and maintain. As previously discussed, applicant&#39;s design involving top and bottom releasable hinges allows easy access to the diffuser for cleaning and maintenance.  
         [0035]     Applicant has also found that the plastic diffuser plates provide another unique advantage. The diffuser plates can act as an air filter. As most plastics do not conduct electricity or effectively diffuse electrical charge, the constant air flow through the plastic diffuser plates creates an electrostatic charge on the plates. The electrostatic charge on the diffuser plates attracts dust particles from the air. The additional filtration provides an important benefit in a shooting range, where dust particles in the air may commonly include smoke or even metal particles such as from the lead bullets which are not desirable to inhale.  
         [0036]     There is thus disclosed an improved air diffuser. It will be appreciated that numerous changes may be made to the present invention without departing from the scope of the claims.