Abstract:
A system for ventilating and cooling the interior of a parked vehicle. The system can be used on many types of vehicles including, but not limited to, aircraft, cars, trucks and the like. In one specific implementation, the system is used to ventilate and cool the interior of the cockpit of a general aviation aircraft, for example a single engine Piper Archer, while the aircraft is parked during non-use.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/669,258 filed on Apr. 7, 2005 and entitled “SOLAR POWERED VENTILATION SYSTEM”, and which is incorporated herewith by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates generally to vehicle ventilation systems. In particular, the invention relates to a system for ventilating the interior of a vehicle, for example the cockpit of an aircraft.  
       BACKGROUND OF THE INVENTION  
       [0003]     A problem that is common to many types of parked vehicles, for example airplanes, cars, trucks, and the like, is excessive heating of the interior of the vehicle by the sun. Many vehicles are equipped with systems to keep the interior cool when the vehicle is moving. However, these systems may not be designed to function while the vehicle is parked and left out in sunlight. The sun&#39;s rays entering through windows of a stationary, parked vehicle can quickly heat the interior of the vehicle. The amount of heating that can occur can be significant, raising the interior temperature to a level that is uncomfortable for someone later entering the interior of the vehicle, and possibly to a level that can cause damage to systems and contents within the interior of the vehicle.  
         [0004]     The cockpit of a general aviation aircraft, for example a single engine Piper Archer or a twin engine Piper Seneca, is one example of a vehicle where excessive heating can be problematic. Many general aviation aircraft have a relatively large amount of window area when compared to the window area on larger aircraft such as passenger jets. However, for general aviation aircraft, the large window area means more of the sun&#39;s rays can enter the cockpit when the aircraft is parked, thereby heating the interior of the cockpit. This problem is increased due to the fact that many general aviation aircraft are parked outside and away from shade, thereby fully exposing the aircraft to the full force of the sun&#39;s rays for extended periods of time.  
         [0005]     As with a vehicle such as a car, heating of the interior of the cockpit can be uncomfortable for someone later entering the cockpit. Further, excessive heating within the cockpit of an aircraft can cause damage to mechanical and electrical components, for example sensitive avionics, of the aircraft, and cause damage to upholstery, plastics, and interior contents.  
         [0006]     There is a need for a system to ventilate and cool the interior of a vehicle, for example the cockpit of a general aviation aircraft, while the vehicle is parked.  
       SUMMARY OF THE INVENTION  
       [0007]     The invention relates to a system for ventilating and cooling the interior of a parked vehicle. The system can be used on many types of vehicles including, but not limited to, aircraft, cars, trucks and the like. In one specific implementation, the system is used to ventilate and cool the interior of the cockpit of a general aviation aircraft, for example a single engine Piper Archer, while the aircraft is parked during non-use.  
         [0008]     In one aspect of the invention, the system comprises an array of photovoltaic cells electrically connected to an exhaust fan. The photovoltaic cells convert sunlight energy into electrical energy for powering the exhaust fan. The exhaust fan is positioned to vent hot air from the interior of the vehicle to the exterior of the vehicle, thereby creating negative pressure in the interior to draw in cooler outside air into the interior, for example through the vehicle&#39;s vents.  
         [0009]     When used on general aviation aircraft, the exhaust fan can, for example, be mounted within the pilot window often found on such aircraft. The photovoltaic cells are mounted in a position to be exposed to the sun rays, either inside the interior of the aircraft, for example in the cockpit, or on the outside of the aircraft. The system must also be removable to permit flight of the aircraft, as well as be compact so that it takes up minimal storage space within the aircraft and be light in weight so that it does not substantially diminish the aircraft&#39;s useful load.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     Like reference numbers generally indicate corresponding elements in the Figures. The embodiments illustrated are exemplary only and are in accordance with the principles of the present invention.  
         [0011]      FIG. 1  is a view of one embodiment of an array of photovoltaic cells shown in a portion of a cockpit area of an aircraft and for a ventilation system according to the invention.  
         [0012]      FIG. 2  is a view of one embodiment of a ventilation system shown in the interior of the cockpit and showing one embodiment of an exhaust fan mounted in the pilot window of the cockpit.  
         [0013]      FIG. 3A  is a side view of the exhaust fan mounted in the pilot window and shown at the exterior of the cockpit area.  
         [0014]      FIG. 3B  is an elevational bottom view of the exhaust fan showing the air outlet.  
         [0015]      FIG. 4  is a side view of the cockpit area from the exterior of the aircraft with the exhaust fan removed and the pilot window closed.  
         [0016]      FIG. 5  illustrates an alternative embodiment of an exhaust fan mounted in the pilot window.  
         [0017]      FIG. 6  is a detailed view of an area adjacent a hinge of the pilot window and at the interior of the cockpit.  
         [0018]      FIGS. 7A, 7B , and  8  illustrate alternative locations for the photovoltaic cells.  
         [0019]      FIG. 9  is a schematic view of one embodiment of a thermostat incorporated into an electrical cord assembly.  
         [0020]      FIG. 10  is a schematic depiction of an electrical connection between the electrical cord assembly and the thermostat. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]     The invention relates to a system  10  for ventilating and cooling the interior space  12  of a vehicle  14 . For sake of convenience, the vehicle  14  will hereinafter be described as a general aviation aircraft, for example a single engine Piper Archer, and the interior space  12  will be described as the cockpit area of the aircraft. However, it is to be realized that the invention could be used to ventilate and cool the interiors of other vehicles, as well as ventilate and cool other interior spaces of an aircraft.  
         [0022]     With reference to  FIG. 1 , the aircraft  14  includes front and side windows  16  as well as a door  18  that provides access to the interior of the cockpit  12 . As shown in  FIG. 4 , the pilot side window  16  includes a smaller pilot window  20  (also called a call window or a vent window) that can be opened and closed. The pilot window  20  in  FIG. 4  is shown in the closed position. Pilot windows similar to the window  20  are found on many types of general aviation aircraft. The invention can be adapted to be used in connection with a pilot window on any type of aircraft.  
         [0023]     With reference to  FIGS. 1 and 2 , the system  10  comprises an array of photovoltaic cells  22  and an exhaust fan  24  that is mountable in the pilot window  20  when the pilot window is opened. The photovoltaic cells  22  are configured to generate electrical energy from sunlight, in order to operate the exhaust fan  24  by electric power. The exhaust fan  24  is configured to exhaust hot air from the interior of the cockpit  12  to the exterior. This creates negative pressure in the cockpit interior which draws in cooler outside air into the cockpit through the aircraft&#39;s vents (not shown) thereby cooling the interior of the cockpit.  
         [0024]     Any type of photovoltaic cells  22  that can produce electrical energy can be used. In the illustrated embodiment, the array of photovoltaic cells  22  comprises a PowerFilm® solar panel available from Iowa Thin Film Technologies of Ames, Iowa. A PowerFilm® solar panel is flexible and allows the array  22  to be rolled up when not in use to minimize storage space.  
         [0025]     The array  22  is illustrated as being disposed inside the cockpit  12  with the photocells facing outward to be exposed to sunlight.  FIG. 1  shows the array  22  disposed on the dashboard of the cockpit.  FIG. 7A  shows the array  22  disposed on the interior of one of the front windows of the aircraft.  FIG. 8  shows the array positioned on the interior side of a side window of the aircraft. The array  22  could alternatively be disposed outside the aircraft at a suitable location, for example on the windshield ( FIG. 7B ) or on the engine housing.  
         [0026]     It will be appreciated that the solar powered configuration and use of the array of photovoltaic cells is one preferred embodiment for generating electrical power. It will be appreciated that other sources of electrical power may be used that may also be suitable for powering the exhaust fan.  
         [0027]     Securement means are provided to mount the array  22  in position. For example, when mounted inside the cockpit, suction cups  26  can be located at the corners of the array  22  for mounting the array to the interior surface of a window. When mounted outside the aircraft, suction cups could be used to mount the array to the exterior surface of a window or the exterior surface of the plane, or, if a cover is disposed over the aircraft, hook and loop fasteners can be used to secure the array  22  to the cover.  
         [0028]     It will be appreciated that the securement means illustrated is exemplary only as other configurations of mounting the array  22  in position may be employed that are equally or more suitable.  
         [0029]     With reference to  FIGS. 2-4 , the exhaust fan  24  is removably mounted within the pilot window  20  when the window is opened.  FIG. 2  shows the pilot window  20  swung inwardly into the interior of the aircraft. The exhaust fan  24  comprises a fan unit  28  and a fan housing  30 . The fan unit  28  illustrated in  FIG. 2  is a centrifugal fan in which air enters the fan axially through inlet  32   a  and is discharged radially through an outlet  32   b  (shown in  FIG. 3B ) in the housing  30  at the exterior of the aircraft. With reference to  FIG. 3B , the outlet  32   b  is located at the bottom of the housing  30  which projects outwardly from the side of the aircraft to accommodate the size of the centrifugal fan. By locating the outlet  32   b  at the bottom of the housing, rain is prevented from entering the cockpit through the fan.  
         [0030]      FIG. 5  shows an alternative exhaust fan  24 ′ in the form of a fan unit  28 ′ having an axial flow fan in which air enters and exits the fan axially. As with the fan  24 , the outlet for the fan  24 ′ would be disposed at the bottom of the housing to prevent entry of rain. As a result, even though the air exits the fan unit  28 ′ axially, the air exits the fan  24 ′ radially through an outlet in the housing for the fan  24 ′.  
         [0031]     With reference to  FIGS. 2, 4 , and  6 , the pilot window  20  comprises a piece of glass that is mounted by a hinge  34  for pivoting movement inward into the interior of the aircraft between the closed position shown in  FIG. 4  and the open position shown in  FIGS. 2 and 6 . A pivoting latch mechanism  36  is provided inside the aircraft which can be pivoted from a first, release position to allow the pilot window  20  to be pivoted inward, and a second, latching position (shown in  FIG. 4 ) at which it is disposed behind the pilot window in order to retain the pilot window  20  at the closed position.  
         [0032]     The hinge  34  generally includes a first portion with an end that is hingedly connected with an end of a second portion. The first portion has another end connected to the window  16  and the second portion has another end connected to the pilot window  20 . With reference to specifically to  FIG. 6 , the hinge  34  includes a first, J-shaped portion  35   a  connected to the window  16 , a second portion  35   b  connected to the pilot window  20 , and a hinge shaft that connects the first and second portions  35   a ,  35   b . When the pilot window  20  is opened, a trough  38  is formed by the J-shaped portion  35   a  of the hinge  34 . The bottom edge of the fan housing  30  is configured and sized to rest within the trough  38 . This secures the bottom edge of the fan  24 ,  24 ′.  
         [0033]     The upper edge of the fan housing  30  is retained by the latch mechanism  36  as shown in  FIG. 2 . The remainder of the housing  30  is configured and sized to substantially fill-up the entire opening of the pilot window  20 . In the illustrated embodiment, the housing  30  is made larger than the actual opening, so that the housing  30  overlaps the edges of the opening. As one preferred example, the housing  30  includes an overlapping edge  39  resembling an outer flange or border, and that is sized and configured to overlap the edge of the opening of the pilot window  20 . The overlapping edge  39  overlaps the edge of the opening at an interior surface of the window. This helps to retain the housing  30  in position and prevent air from leaking between the edges of the housing  30  and the opening. A seal, for example a strip of foam or rubber, is provided on the overlapping portions of the housing  30  to seal between the overlapping edge of the housing and the interior surface of the window to prevent water from leaking into the cockpit.  
         [0034]     As a result of the mounting arrangement of the fan  24 ,  24 ′, the fan cannot be pushed outward due to the overlap between the housing  30  and the opening, and cannot be pushed inwards due to the trough  38  and the latch mechanism  36 .  
         [0035]     Electrical connection between the array  22  and the fan  24 ,  24 ′ is established by a suitable electrical cord assembly  40 . The assembly  40  comprises a first cord  41  that connects to the array and that terminates in a 12 volt power point in the form of a female connector  42 . A suitable cord  41  is available from Iowa Thin Film Technologies of Ames, Iowa. A second cord  44  is also provided that provides electrical connection between the cord  41  and the fan  24 ,  24 ′. The cord  44  is similar to a conventional fused 12 volt autoplug that is often used to plug into a vehicle cigarette lighter, where the cord  44  includes a male connector  46  and a right angle male plug  48  that connects into a jack provided in the fan  24 ,  24 ′. Because of the male connector  46 , the fan unit  24 ,  24 ′ can be plugged into the electrical system of the aircraft through the cigarette lighter found on many general aviation aircraft.  
         [0036]     It will be appreciated that the specific embodiment of the electrical connector assembly shown is exemplary only. Other electrical connector configurations may be employed that are equally or more suitable.  
         [0037]     The cord  44  differs from a standard fused 12 volt autoplug in that a thermostat  50  is incorporated into the cord  44 .  FIG. 9  shows the thermostat incorporated into the cord  44 , and  FIG. 10  schematically depicts the electrical connection between the cord and the thermostat. The thermostat  50  comprises a circular disk electrically connected to one electrical wire  52  within the cord  44  and acting as a switch on that wire. A suitable thermostat is available from EAW Relaistechnik GmbH of Berlin, Germany and Portage Electric Products, Inc. of North Canton, Ohio. The thermostat  50  is encased in rubber or plastic after electrical connection with the cord  44  is established.  
         [0038]     The thermostat in the cord  44  senses the air temperature inside the cockpit. If the temperature is below a predetermined set point, for example 80° F., electricity is prevented from flowing to the fan unit  24 ,  24 ′ thereby preventing the fan from turning on. Only when the cockpit temperature increases above the set point can the fan turn on. This prevents the fan from operating when the air temperature is at a level such that dew and other moisture may be pulled into the cockpit interior as a result of the creation of the negative pressure inside the cockpit. A thermostat can be incorporated at other locations of the system  10  other than the cord  44  if desired, for example in the fan housing, for performing a similar function.  
         [0039]     Other than the thermostat  50 , the fan unit  24 ,  24 ′ is turned off by unplugging the cord  44  from either the fan unit  24 ,  24 ′ or from the cord  40 . When the array  22  is used outside the aircraft, a suitable plug-in jack for the male connector  48  will be provided on the portion of the housing  30  that is disposed outside the aircraft. This will permit electrical connection between the array and the fan unit without having to run the cord(s) inside the cockpit.  
         [0040]     The system  10  is intended to be removed during flight. In this regard, the compact size of the array  22  and fan  24 ,  24 ′ allows the system  10  to be stored within the interior of the aircraft without taking up excessive space. Moreover, the system is light in weight so that it does not substantially diminish the aircraft&#39;s useful load. The removable mounting of the fan  24 ,  24 ′ allows the fan  24 ,  24 ′ to easily be inserted and removed in the pilot window.  
         [0041]     The above specification provides a complete description of the composition, manufacture and use of the solar powered ventilation system in accordance with the principles of the present invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.