Abstract:
An apparatus for cooling air that utilizes a reservoir that may be filled with low temperature substances or other cooled liquid or solid material. The reservoir is thoroughly insulated and contains a vertical air duct where the air duct utilizes a battery powered fan capable of drawing in warm air from outside of the base unit and cooling it by passing it over thermally conductive fins embedded within the duct in a turbulent fashion and expelling it back into the surrounding environment. The entire unit may be secured to the rear of a seat or chair to allow the person sitting to rest in comfort despite being surrounded by uncomfortable environment with a high ambient temperature.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to portable air conditioning units and specifically for use as attachments to the rear of chairs or seats. Specifically, the air conditioning unit cools the surrounding air by ingesting ambient air, and cooling it by fanning the air across a surface area of a thermally conductive material. The thermally conductive material is in direct contact with a cooled substance having a temperature that is much lower than the surrounding air. By doing so, that the surface area temperature approaches that of the liquid.  
       BACKGROUND OF THE INVENTION  
       [0002]     Outdoors seating, whether in an open-air stadium, at a park, or on a patio is often subject to extreme temperatures during the summer months. It is desirable to be seated in air-conditioned comfort regardless of the temperature. One approach to address the problem would be to install a portable air conditioner on the rear of the seat capable of providing a personal cooling system.  
         [0003]     The main problem with manufacturing a portable air conditioning unit is cost. Most air conditioning units are very expensive, bulky, contain elements that are potentially harmful to the environment, and often require an AC external power source to operate. An air conditioning unit that is small and efficient enough to operate on its own power source and be secured to a seat would be highly desirable. The present invention addresses each of those obstacles using a device that ingests ambient air into a thermally conductive path containing fins that are cooled by a reservoir containing substances cooled to a low temperature. It is desirable that ice is used, but any chilled substance would be permissible.  
         [0004]     It is known in the prior art that the use of frozen liquids, namely ice, can be used to cool ambient air when the air is fanned across the surface area of the ice or other conducting surface areas that come in contact with the frozen liquids. When the ambient air contacts a low-temperature surface area, the air is instantly cooled several degrees. However, many of these prior art systems do not efficiently lower the temperature of the air as the present invention is capable of doing.  
         [0005]     The present invention addresses the efficiency concerns by providing a portable air conditioning unit that cools the surrounding air near a seat for use in warm environments. The present invention makes use of a portable apparatus that includes a reservoir for cooled liquid or ice that surrounds an air duct. The air duct receives ambient air on one end and expels it into the general area at the top of the seat. The reservoir should be insulated as much as possible from the ambient air temperature.  
         [0006]     The air duct contains a series of fins that are assembled so they are in contact with other thermally conducting fins outside of the air duct and exposed to the contents of the reservoir. This creates a heat exchange system designed to maximize the exposure of the air to the exposed surface area of the fins in the air duct. The only air that is cooled is the air that comes in direct contact with the fins in the air duct.  
         [0007]     The entire external surface of the unit should be heavily insulated in order to prevent unwanted heat from coming into contact with the reservoir&#39;s contents. When the reservoir is filled with cold liquid or ice, the exposed surface area of the fins is cooled to the temperature of the reservoir&#39;s contents. The air duct is connected on one side by an air intake chamber and by an air exhaust chamber on the other. Warm air is drawn into the intake chamber from a battery-powered variable-speed motorized fan that creates a vacuum in the chamber. The fan then pushes the warm air through the air duct and is dehumidified and cooled when it contacts the exposed surface area of the fins that extrude either in a louvre or coil style relative to the surface of the air duct. The fins provide resistance and vary the direction of the air thereby creating turbulence. The temperature from within the reservoir is transferred down through the outer fins which indirectly come in contact with the fins inside the air duct. The turbulence greatly enhances the thermal conductive capacity of the system so that the heat transfer can occur at an efficient rate and maximizes the time that the temperature of the exposed surface of the reservoir remains cold. The turbulent air molecules bounce off of the adjacent surface areas of the inner fins as they move up the air duct. The cooled air is then propelled into an exhaust chamber where it is thrust into the external environment and may be used to generally cool a surrounding area of the seat.  
         [0008]     Over a period of time while low temperature substances come in contact with the surface of the fins that are exposed to the interior of the reservoir or container, a narrow region next to the surface of the heat exchanger exists where the velocity of the fluid is zero and rapidly changes to a finite number as the distance from the surface increases. This is known as the boundary layer. The fluid&#39;s velocity is zero due to a variety of factors ranging from molecular attraction to surface tension to friction. When a boundary layer forms, it may prevent the surface area of the fins from efficient thermal conductivity between the inner reservoir to the surface area of the fins. This lack of conduction is due to the layer of insulation the boundary layer creates from the fluid directly adjacent to the exposed surface of the heat exchanger. The present invention helps reduce the negative affects of the boundary layer on the efficiency of the system.  
         [0009]     Another feature of the apparatus is that the airflow may be directed by means of a nozzle, which is attached to the exhaust valve of the unit. It is also understood that to a person of reasonable skill in the art that the underlying claimed invention for a portable air conditioner can be utilized in other applications such as seating for automobiles, boats, RVs, trucks, or any similar application.  
       Discussion of the Prior Art  
       [0010]     The use of air conditioners is known in the prior art. More specifically, air conditioners that cool the surrounding air that exchange heat while passing outside air over cooled surfaces is discussed in the prior art. Other similar portable air conditioning devices are disclosed in U.S. Pat. Nos. 6,427,476; 6,227,004; 6,119,477; 5,953,933; 5,062,281; 5,046,329; and 4,841,742 and 5,724,824.  
         [0011]     While these devices aim to function as air conditioners, and while each invention disclosed in the respective patents may disclose a feature of the present invention, none of the above-listed patents disclose the combination of features in the present invention either individually or in combination with each other in such a way that it would have been obvious to do so at the time the present invention was conceived.  
         [0012]     In addition, there is a need in the art for a device which can function as a portable air conditioner when secured to the rear of a seat that maximizes the time that ambient air may be cooled to a temperature much lower than the ambient air temperature. Furthermore, there is a need to acomplish these tasks utilizing a removable cooling source in combination with a directed application of the cooled air. A device of this type is disclosed by the present invention.  
       SUMMARY OF THE INVENTION  
       [0013]     Broadly, it is an object of the present invention to provide a portable air conditioner that utilizes a motorized fan to ingest outside air and cool it by passing the air over the surface area of thermally-conductive fins in an air duct before propelling the cooled-air back into the environment.  
         [0014]     It is a further object of the present invention to minimize the temperature of cooled air by passing the air through a turbulent environment with an air duct.  
         [0015]     It is a further object of the present invention to provide a method of cooling outside air that efficiently ingests outside air, and cools it by passing the outside air in a turbulent manner over and through a cooled surface area within an air duct and expelling the cooled air into the environment.  
         [0016]     It is a further object of the present invention to utilize a series of fins secured generally perpendicular to an air duct capable of transferring the temperature inside a reservoir to additional conducting fins inside the air duct.  
         [0017]     It is a further object of the present invention to maximize the efficiency of heat exchange by minimizing the effects of the formation of a boundary layer on the thermally-conductive material.  
         [0018]     It is a further object of the present invention to use the portable air conditioner in conjunction with a chair or seat such that the air conditioner can be switched on whenever a person is seated in the chair.  
         [0019]     The description of the invention which follows, together with the accompanying drawings should not be construed as limiting the invention to the example shown and described, because those skilled in the art to which this invention appertains will be able to devise other forms thereof within the ambit of the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a perspective view of the air conditioner apparatus attached to the rear portion of a chair;  
         [0021]      FIG. 1A  is a perspective view of the air conditioner apparatus attached to the rear portion of a chair with a cross-sectional view of the air conditioner;  
         [0022]      FIG. 2  is an exploded view of the air conditioning apparatus;  
         [0023]      FIG. 3  is a side view showing the exploded view of the air conditioning apparatus;  
         [0024]      FIG. 4  is a top view showing the exploded view of the air conditioning apparatus.  
         [0025]      FIG. 5A  is a top view of the air duct unit showing the inner duct using coil style fins;  
         [0026]      FIG. 5B  is a top view of the air duct unit showing the inner duct using Louvre style fins;  
         [0027]      FIG. 6  is an alternate embodiment of the air conditioning unit showing a solid wall separating a vertical series of fins in a rectangular shaped air duct.  
         [0028]      FIG. 7  is an exploded view of the inner portion of the air conditioning unit demonstrating how the air flows through the unit from bottom to top.  
         [0029]      FIG. 8  is a cross-sectional view of the device showing while filled with a chilled substance. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0030]     By way of one example of many to serve as background in understanding the present invention,  FIG. 1  shows a portable air conditioner  200  secured to the rear of a chair  200 . The air conditioner  200  is secured to the rear of a chair  210 . When an individual sits in the chair  210 , the air conditioner  200  ingests ambient air  390  into the air conditioner  200 , cools it, and expels it from nozzle  205  in the general vicinity of the person seated in the chair  210 .  Fig. 1A  shows a cross section of the air conditioner  200  where the ambient air flow  390  is drawn into the air conditioner  200  by means of an electric powered fan  217  within the lower portion of the air conditioner  200 .  
         [0031]      FIGS. 2 and 3  show an exploded view of the air conditioner  200 . An air duct  350  is shown. The air duct  350  is generally in the shape of an elongated cylinder. However, the air duct  350  is not limited to cylinders and can be formed in any suitable shape that allows air to flow from a lower portion to an upper portion of the air conditioner  200 . The air duct  350  includes a tubular wall  380  that spans the entire length of the air duct  350 . The wall  380  is generally hollow to allow air to flow from the lower end to the upper end of the wall  380 . The wall  380  is surrounded by a series of fins  360  formed perpendicular to the wall  380  such that the fins  360  penetrate the wall  380  and make direct contact with a series of inner fins  370 . The inner fins  370  shown in  FIG. 2  are in a Louvre arrangement such that the inner fins  370  are all parallel to each other. The inner fins  370  are secured to the inner portion of the wall  380  along the entire length of the air duct  350 . An airflow intake valve  390  is secured to the lower end of the air duct  350  directly to the wall  380  so that the entire circumference of the wall  380  is surrounded by the valve  390 .  
         [0032]     A reservoir  305  consists of three parts: a rear bin  320 , a front bin  330 , and a cap  300 . These three parts when connected together form the reservoir  305  that will hold frozen liquid as shown in  FIG. 8 . The front ice bin  330  includes a hole  332  for receiving the valve  390 . The cap  300  is secured to the top of the two bins  320  and  330  so that an expulsion valve  310  is located directly over the circumference of the wall  380  on the top portion of the duct  350 . Air that is ingested into the duct  350  through the valve  340  travels up the duct  350  while coming into direct contact with the surface area of the inner fins  370  and then is expelled through the expulsion valve  310  as shown at  400 . As also shown in  FIG. 1A , an aromatic cartridge  206  can be secured within the nozzle  205  to provide a pleasant scent to the surrounding area. A switch may be used to direct the air through either an aromatic pathway in the nozzle  205  or an alternate pathway to prevent the scent from being added to the airflow  390 .  
         [0033]      FIG. 4  shows a top exploded view of the reservoir  305 . The inner fins  370  are shown in an alternate coiled arrangement. The outer fins  360  come into contact with the inner fins  370  on the outer ring of the coil. The coil then wraps around to a center point at  372 . As shown in  FIGS. 2 and 3 , the ambient air  390  is ingested into the valve  340  and then travels from the lower end of the duct  350  along the surface area of the coiled fins  370  and is then expelled through the top portion of the coils at  400 .  FIGS. 5A and 5B  show the alternate arrangement of the inner fins  370 .  
         [0034]     As shown in  FIG. 8 , the air conditioner works using the reservoir  305  as a container for storing a liquid or solid whose temperature is substantially colder than the air temperature outside of the air conditioner  200  such as ice. The reservoir  305  is highly insulated on all sides. It is a primary goal for the outer fins  360  to obtain, and subsequently retain, the same temperature of the liquid or solid inside of the reservoir  305  for as long as possible, and to remain in constant contact with the inner fins  370  thereby cooling the inner fins  370  to the temperature of the contents  375  inside the reservoir  220 . The surface area of the inner fins  370  is used to cool any air that comes into contact with the surface area.  
         [0035]     As shown in  FIG. 7 , air flow  390  from outside of the air conditioner  200  is drawn into the air intake valve  340  by means of a high-speed electric motor  217  that may be powered by a battery or an AC/DC power source. The motor  217  turns a rotating fan  218  in a manner that creates the airflow  390  that pulls in warmer air from outside of the air conditioner  200 . It is desirable to minimize the volume of the air intake valve  340  while maximizing the amount of airflow  390 . The airflow  390  follows the general direction from the air intake valve  340  through the fan  218  and into the cylindrical wall  380 . It is desirable to maximize the volume of the cylindrical wall  380  while creating turbulence in the air through the use of the inner fins  370 . The inner fins  370  are in direct contact with the outer fins  360  and create an environment such that the air molecules would maximize the time that they come in contact with the conductive surface area of the inner fins  370  thereby allowing the temperature of the airflow  390  to be minimized so that it may approach the temperature of the contents  375  inside of the reservoir  305 . Because the inner fins  370  are in direct contact with the outer fins  360  located in the reservoir  305 , the outer fins  360  are able to continually cool the surface area of the inner fins  370  for as long as the temperature of the contents  375  remains in the reservoir  305  and maintains a temperature lower than the ambient air flow  390 .  
         [0036]     The outer fins  360  and inner fins  370  are comprised of an efficient thermally conductive material such as aluminum or copper. It is understood that the outer fins  360  are not required to be positioned exactly perpendicular to the wall  380 . As stated above, because the inner fins  370  are directly connected to the outer fins  360  and the outer fins  360  are located within the reservoir  305 , the temperature of the surface areas of all fins  360  and  370  will drop to the temperature of the outer and inner fins  360  and  370  to the temperature of the contents  375  of the reservoir  305 . As the airflow  390  passes between the inner fins  370 , the airflow  390  will have a maximum amount of cooled surface area in which it will come in contact thereby minimizing the temperature of the airflow  390 . The airflow  390  will also change directions between each of the inner fins  370  thereby creating air turbulence. This would be true whether the Louvre or Coiled arrangement is used as shown in  FIGS. 5A and 5B .  
         [0037]     In an alternate embodiment as shown in  FIG. 6 , instead of utilizing a tube shaped air duct  350 , the reservoir  305  consists of a rectangular wall  385  located substantially near the front portion of the rear bin  320 . The wall  385  creates a rectangular-shaped air duct  367 . The air intake valve  340  is located at the lower portion of the rear bin  320 . The front bin  330  is completely insulated and unlike the previous embodiment, contains no air inlet. The rear bin  320  further consists of a series of outer fins  365  all arranged and secured perpendicular to the wall  385 . The outer fins  365  penetrate the wall  385  and create inner fins  366  within the rectangular-shaped air duct  367 . As described above, some type of frozen material is placed in the reservoir  305 . The frozen material  375  as shown in  FIG. 8  comes into direct contact with the outer fins  365 . Because the outer and inner fins  365  and  366  are made of a thermally conductive material such as aluminum or copper, the temperature of the inner fins  366  will eventually become approximately the same as the contents of the reservoir  305 . When the airflow  395  is ingested into the valve  340 , the motorized fan  218  pulls the ambient air into the rectangular-shaped air duct. The airflow  395  then comes into direct contact with the surface area of the inner fins  366  and becomes cooled substantially below the ambient air temperature. The airflow  405  then enters the cap  300  as shown in  FIGS. 2 and 3  and is expelled out of the upper valve  310  into the nozzle  205  and into the surrounding area.  
         [0038]     While the inventive apparatus, as well as a method of cooling ambient air as described and claimed herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiment of the invention and that no limitations are intended to the detail of construction or design herein shown other than as defined in the appended claims.  
         [0039]     Although the invention has been described in detail with reference to one or more particular preferred embodiments, persons possessing ordinary skill in the art to which this invention pertains will appreciate that various modifications and enhancements may be made without departing from the spirit and scope of the claims that follow.