Abstract:
The disclosed mirror cleaning device attaches to a side-view mirror of an automobile. Using a front-facing inlet, the mirror cleaning device takes in air, passes the air through a constriction and deflector/diverter, ultimately discharging the air against the mirrored face of a side-view mirror. The constriction and deflector act to redirect and accelerate the air, allowing the air to more effectively clean the side-view mirror.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a non-provisional application claiming priority to U.S. provisional application Ser. No. 62/192,374, filed Jul. 14, 2015, the disclosure of which is hereby incorporated by reference. 
     
    
     FIELD 
       [0002]    This invention relates to the field of automotive parts and more particularly to a device for using airflow to clean a side-view mirror. 
       BACKGROUND 
       [0003]    Vehicle side-view mirrors are critical to safe driving. Such mirrors allow drivers to maintain awareness of surrounding vehicles, allowing for safer lane changes, merging, and awareness of cyclists. 
         [0004]    But side-view mirrors are on the outside of the vehicle, subjecting the mirrors to elements and making it difficult for a driver to clean. 
         [0005]    Side-view mirrors accumulate condensation when it is humid, water droplets with it is rainy, and dirt when it is dusty. The normal flow of air around a side-view mirror fails to clean the mirrored surface because the air flow separates around the mirror housing. The result is a region of low to no flow that coincides with the mirrored surface. The result is a mirror that cannot clean itself. 
         [0006]    It is an object of this invention to provide an inexpensive and reliable device that automatically cleans a side-view mirror using the air through which the vehicle is moving. 
       SUMMARY 
       [0007]    The disclosed mirror cleaning device attaches to a side-view mirror of an automobile. Using a front-facing inlet, the mirror cleaning device takes in air, passes the air through a constriction and deflector/diverter, ultimately discharging the air against the mirrored face of a side-view mirror. The constriction and deflector act to redirect and accelerate the air, allowing the air to more effectively clean the side-view mirror. 
         [0008]    The result is that the mirror cleaning device removes any condensation, mist, rain, or dirt that has accumulated on the mirrored surface. And the device prevents any further build up by continually moving air across the mirror. 
         [0009]    For peak effectiveness the vehicle on which the mirror-cleaning device is mounted must be moving at least 25 miles per hour. At this speed, or greater speeds, the mirror-cleaning device quickly removes water and debris. The greater the speed, the stronger the air flow, and thus the more effective the device. 
         [0010]    Turning now to the structure of the mirror-cleaning device—two specific features are key to its effectiveness. The first is the constriction that increases airspeed, and the second is the deflector/diverter that changes the direction of the flowing air. 
         [0011]    First, the constriction. The constriction within the air flow path of the mirror-cleaning device utilizes the venturi effect. The venturi effect is the reduction in pressure, and corresponding increase in velocity, caused by the flow of a fluid through a constriction within a flow channel. 
         [0012]    The velocity of a fluid, here air, increases as it flows through the area of reduced cross-sectional area. The relative sizes of the air inlet and air discharge determine the increase of the speed of the air based on their relative sizes. 
         [0013]    The air inlet of the disclosed device has a height and a width. The air discharge of the disclosed device further has a height and a width. 
         [0014]    Assuming a constant width, experimental testing has shown that an air intake height of at least three times greater than the air discharge height provides the required air speed to clean the mirrored surface. 
         [0015]    Area varies linearly with increases of either height or width. Thus, tripling the height also triples the area. The preferred embodiment includes an air intake with a cross sectional area three times that of the air intake. 
         [0016]    Mathematically, the relationship can be shown using equations for fluid flow. Volumetric fluid flow is Q, represented in the equation: 
         [0000]    
       
      
       Q=v*A  
      
     
         [0017]    Where v=flow velocity and A=cross-sectional area. Assuming a constant flow, with two areas, the equation becomes: 
         [0000]    
       
      
       Q=v 
       i 
       *A 
       i 
       =v 
       d 
       *A 
       d  
      
     
         [0018]    Thus, a decrease in area causes a corresponding increase in velocity, where i is the inlet and d is the discharge. 
         [0019]    The above discussion ignores the energy lost as a result of the constriction, and assumes that the speed of the air entering the device is equal to the vehicle speed. 
         [0020]    Second, the diverter. With the speed of the air increased, the change in angle of the discharge air is also important to operation of the device. 
         [0021]    It is helpful to define flow directions in order to discuss angles. The air inlet takes in air, which is flowing in a direction referred to here as zero degrees. Within the mirror-cleaning device the air is redirected by use of a deflector that changes the flow direction of the air on its way to the discharge. The flow direction of air leaving the discharge is between 70 and 85 degrees offset from the air intake angle, or between 95 and 110 degrees if the supplementary angle is measured. Thus, the diverter changes the direction of the flowing air by a turn more acute than 90 degrees. 
         [0022]    The result is that the air is discharged in a direction that is mostly across, but also slightly toward, the mirrored surface of the side-view mirror. 
         [0023]    This allows the majority of the velocity of the air to push across the mirrored surface, but with sufficient angle toward the surface to ensure that the air rides along the mirrored surface. 
         [0024]    There are additional optional features incorporated into the mirror-cleaning device. 
         [0025]    For example, to minimize the quantity of rain entering the air intake tunnel, the length of the upper side of the tunnel can be extended to protrude beyond the length of the lower edge. This forms an air inlet rain overhang. In some embodiments the air inlet rain overhang includes a downward angle to further reduce the amount of incoming rain. 
         [0026]    While the air inlet rain overhang will reduce the intake of water, some water will still enter the mirror-cleaning device. A small quantity of rain is of little issue because the velocity generated by the mirror-cleaning device is sufficient to carry the water out the air discharge and past the mirrored surface of the side-view mirror. 
         [0027]    Turning to the embodiments of the mirror-cleaning device, three embodiments are illustrated. 
         [0028]    The first embodiment is intended for placement on top of a side view mirror. This embodiment is anticipated to fit many types of side view mirrors because nearly all such mirrors include a top surface for mounting. The second embodiment is for bottom mounting. The third embodiment is for side-mounting, likely on the inner side of the side view mirror. The embodiments are discussed in additional detail below. 
         [0029]    The preferred embodiment of the disclosed device is an aftermarket product for sale as an add-on. But in other embodiments the device is incorporated into side view mirrors as an integral component. 
         [0030]    In order to avoid scratching the paint or plastic of the side view mirror housing, the preferred embodiment of the disclosed device is constructed from plastic. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
           [0032]      FIG. 1  illustrates a view of a first embodiment; 
           [0033]      FIG. 2  illustrates a second view of the first embodiment; 
           [0034]      FIG. 3A  illustrates a schematic view of a generic embodiment; 
           [0035]      FIG. 3B  illustrates a schematic view of an alternative generic embodiment; 
           [0036]      FIG. 4  illustrates a view of a second embodiment; 
           [0037]      FIG. 5  illustrates a second view of a second embodiment; 
           [0038]      FIG. 6  illustrates a third view of a second embodiment; and 
           [0039]      FIG. 7  illustrates a fourth view of a second embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
         [0041]    Referring to  FIG. 1 , a view of a first embodiment is shown with an emphasis on the air intake section of the device. The mirror cleaning device  1  is shown attached to mirror housing top  82  of mirror housing  80 . Mirror housing  80  further includes a mirror housing inner wall  84  and a mirror housing outer wall  86 . 
         [0042]    The mirror cleaning device  1  is comprised of an air inlet  10  for the intake of air that would otherwise pass around the mirror housing  80 . Air inlet  10  has a size defined by air inlet height  12  and air inlet width  14 , which are used to calculate air inlet area  16 . 
         [0043]    Also shown is optional air inlet rain overhang  11 , which decreases the quantity of water introduced into the air inlet  10 . 
         [0044]    Referring to  FIG. 2 , a second view of the first embodiment is shown with an emphasis on the air discharge section of the device. Air discharge  30  is shown, with discharged air  24  being forced against the mirror glass  88 . The outside of flow diverter  21  is shown, whereby the direction of the flowing air is altered. The result is the air blowing against and across the mirrored face  88  of the mirror housing  80 . 
         [0045]    Also shown is blind-spot mirror  89 , intended to help a driver see areas behind the car that may be missed by the side-view mirror. 
         [0046]    Referring to  FIG. 3A , a schematic view of a generic embodiment is shown whereby air flows in across the top of the mirror cleaning device  1 . 
         [0047]    Mirror cleaning device  1  takes incoming air  22  into air inlet  10 . Incoming air  22  flows along air inlet axis  18  defined as perpendicular to air inlet area  16 . 
         [0048]    As the incoming air  22  moves through the mirror cleaning device  1 , it reaches the constriction  20  and flow diverter  21 . Constriction  20  reduces the cross-sectional area of the flow path, resulting in an air discharge area  36  that is 33% or less of the air inlet area  16 . 
         [0049]    Flow diverter  21  changes the direction of the incoming air. Discharged air  24  leaves air discharge  30 , which is defined by air discharge height  32  and air discharge width  34 , which together are used to calculate air discharge area  36 . The flow direction of discharged air  24  is perpendicular to the air discharge area  36 , defining air discharge axis  38 . 
         [0050]    The angle between air inlet axis  18  and air discharge axis  38  is a measurement of the angle by which the incoming air  22  is diverted before becoming discharged air  24 . The discharged air  24  contacts the mirrored face  88 , removing any water droplets, debris, or other particulates. 
         [0051]    These measurements are shown as air inlet and discharge axes outside angle Θ 1  and air inlet and discharge axes inside angle Θ 2 . 
         [0052]    Air inlet and discharge axes inside angle Θ 1  is between 95 and 110 degrees, resulting in air inlet and discharge axes outside angle Θ 2  being between 70 and 85 degrees. 
         [0053]    Referring to  FIG. 3B , a schematic view of a generic embodiment is shown whereby air flows in across the bottom of the mirror cleaning device  1 . All reference numbers match that of  FIG. 3   a.    
         [0054]    Referring to  FIG. 4 , a view of a second embodiment is shown. The second embodiment of the mirror cleaning device  1  fits along the mirror housing inner wall  84 , avoiding the need for support braces. Air inlet  10  is shown, as well as air inlet height  12  and air inlet width  14 . 
         [0055]    Referring to  FIG. 5 , a second view of a second embodiment is shown. 
         [0056]    Mirror cleaning device  1  is shown with air inlet  10  and incoming air  22 . Optional air inlet rain overhang  11  is shown. 
         [0057]    Referring to  FIG. 6 , a third view of a second embodiment is shown. 
         [0058]    Mirror cleaning device  1  is shown with air discharge  30 , directing discharged air  24  against mirrored face  88 . 
         [0059]    Referring to  FIG. 7 , a fourth view of a second embodiment. 
         [0060]    Mirror cleaning device  1  is shown with air discharge  30 , directing discharged air  24  against mirrored face  88 . The location of flow diverter  21  is indicated, although this is best shown in the cross-sectional view of  FIG. 3 . 
         [0061]    Also shown is blind-spot mirror  89 , intended to help a driver see areas behind the car that may be missed by the side-view mirror. 
         [0062]    It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.