REFERENCE TO RELATED PATENT APPLICATION  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/630,165, filed on Nov. 22, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to automated devices for drying clothing and laundry. More specifically, the ambient air clothes dryer is a clothes dryer devoid of any dedicated heating elements or systems for heating the air.  
         [0004]     2. Description of the Related Art  
         [0005]     The development of the automatic clothes dryer has been a great labor saving device for most households and, along with the automatic washing machine, has served to facilitate the commercial laundry industry as well. Automatic clothes dryers were initially developed when energy costs were relatively low, and accordingly make use of gas or electrical heat to accelerate the drying process. As a byproduct of the heat developed, the home or other structure is also heated, even though most of the heat is ducted to the exterior of the structure during dryer operation. Still, the residual heat output into the structure was not considered to be particularly undesirable, even in warmer conditions, as the energy costs required to operate air conditioning systems were much lower in the past.  
         [0006]     However, with ever-increasing energy costs, the cost of operation of such conventional dryers has climbed considerably over the years, and even more so when the energy required to dissipate their heat output is considered. While conventional hot air clothes dryers have their place in very damp and/or cool climates, the heat they develop is an undesirable side effect of the drying operation in many parts of the country during much of the year. The alternative of the conventional clothes line is not suitable for many households due to the frequency of damp weather in many areas and seasons, and the time and labor required to tediously pin up each garment or article to the line and remove them, perhaps several hours later, when they are dry.  
         [0007]     While some clothes dryers have been developed in the past that do not provide a source of heat during the drying operation, such dryers have not been found entirely satisfactory. Thus, an ambient air clothes dryer solving the aforementioned problems is desired.  
       SUMMARY OF THE INVENTION  
       [0008]     The ambient air clothes dryer is an automated device including a motor-powered rotating drum having a fan providing axial airflow through the drum. No dedicated heating element is provided. Some embodiments include a fan motor and an additional motor to rotate the drum, while other embodiments utilize a belt or other drive from the fan output shaft to drive a jackshaft to rotate the drum, thereby saving weight, complexity, and energy. Yet another embodiment may be devoid of any fan or air circulation device, and may include only a motor to rotate the drum. This embodiment includes means for the removable and temporary installation of a conventional “box fan” therewith, to provide the air circulation required. Any or all of the embodiments may include a timer and/or humidity detector to provide for automatic shutoff of the fan and drum when the laundry is dry and/or a predetermined time has been reached.  
         [0009]     The portability of the device allows it to be used indoors or outdoors, as desired. The device may take advantage of ambient heating sources within the home or other structure if so desired, e.g., a heat register, radiator, Franklin stove, etc., to provide some heating of the air, which then passes through the dryer drum. This also provides the beneficial effect of humidifying the air within the structure in colder weather. The device may be constructed to utilize twelve-volt power, if so desired, for use in camping when an automotive electrical system is available.  
         [0010]     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a partially broken away perspective view of a first embodiment of an ambient air clothes dryer according to the present invention, showing various details thereof.  
         [0012]      FIG. 2  is a simplified side elevation view of an alternative embodiment of the present dryer, illustrating an alternative drum drive system.  
         [0013]      FIG. 3  is another simplified side elevation view showing another alternative embodiment of a drum drive system.  
         [0014]      FIG. 4  is an exploded perspective view of yet another alternative embodiment of the present dryer, in which a separate portable box fan is used to provide airflow through the drum.  
         [0015]      FIG. 5  is a simplified schematic diagram of an exemplary electrical and control system that may be incorporated with the present dryer. 
     
    
       [0016]     Similar reference characters denote corresponding features consistently throughout the attached drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     The present invention comprises various embodiments of an ambient air clothes or laundry dryer, in which unheated air at ambient temperature is blown through the dryer drum to dry clothing therein. While some slight amount of heat may be provided from the fan motor, the present ambient air dryer device does not include any form of dedicated, specific heating apparatus, as is found in conventional clothes dryers.  
         [0018]      FIG. 1  of the drawings illustrates a first embodiment of the present dryer  10 , in which a separate fan motor  12  and drum rotation motor  14  are employed. The dryer  10  includes a housing or shell  16  having a hollow dryer drum  18  therein. The drum  18  rotates within the housing  16 , and is supported by drum support wheels  20  or other mechanism installed internally within the housing  16 . The dryer drum  18  has an impervious, generally cylindrical wall  22  having a diameter D. A screened airflow inlet end  24  is positioned adjacent the fan motor  12  with its fan  26  and fan drive shaft  28 , with a screened airflow outlet end door  30  located opposite the inlet end  24  of the drum  18 . The two screened ends  24  and  30  are preferably of a sufficiently fine mesh or gauge as to preclude the passage of small articles (e.g., loose change, buttons, etc.) therethrough, and have diameters closely approaching the diameter D of the dryer drum  18 . The screen of the outlet door  30  may have a mesh or gauge sufficiently fine to serve as a lint trap for the dryer.  
         [0019]     The fan drive motor  12  with its fan drive shaft  28  and circular, rotary fan  26  are concentrically disposed externally to the airflow inlet end  24  of the dryer drum  18 , but within the housing  16 . The fan  26  preferably has a diameter closely approaching the diameter D of the dryer drum  18  and the inlet and outlet ends  24  and  30  of the drum  18 , in order to maximize airflow through the drum  18 . A fan guard  32  is preferably installed across the air inlet opening of the dryer housing  16 , with at least the blades of the fan  26  being captured between the guard  32  and the screened inlet opening  24  of the drum  18 .  
         [0020]     The separate drum drive motor  14  of the embodiment  10  of  FIG. 1  drives an output shaft  34 , which in turn causes the drum  18  to rotate when the drum drive motor  14  is in operation. A common switch may be used to simultaneously actuate and deactivate the fan motor  12  and drum drive motor  14 , if so desired. In the case of the embodiment  10  of  FIG. 1 , the output shaft  34  has a drum belt pulley  36  at its distal end, with a drum drive belt  38  extending around the pulley  36  and around a circumferential groove  40  in the dryer drum  18 .  
         [0021]     The configuration of the ambient air clothes dryer  10 , as well as the configurations of other embodiments disclosed herein, requires no heavy, stiff high voltage and/or high amperage electrical cable, as is universally required for the heating elements of conventional electric clothes dryers. Moreover, no gas line connection is required, as there is no use of a gas heater for the incoming air of the present dryer. Thus, the present dryer is relatively lightweight in comparison to conventional dryers with their heating systems, and requires no more power than is capable of being supplied by a conventional household electric cord. (In some embodiments, the motor(s) may be 12-volt DC, enabling them to be powered from a motor vehicle electrical system if so desired.) The light weight and simple power requirements of the present ambient air dryer allow it to be moved about readily to various locations as desired. Accordingly, external transport wheels  42  may be provided beneath one or both ends of the housing  16 , with a pair of support legs  44  being shown beneath the opposite end of the housing  16  in the embodiment of  FIG. 1 . A handle  46  may be provided across one side of the housing shell  16 , to facilitate lifting of that side for rolling the device  10  as desired by means of the wheels  42 .  
         [0022]      FIG. 2  provides a side elevation view of an alternative drum drive system, in which the fan drive is also used to rotate the drum. In  FIG. 2 , the fan motor  112  drives an output shaft  128  to which the fan  126  is connected, as in the corresponding components  12 ,  28 , and  26  of the embodiment  10  of  FIG. 1 . However, the fan motor output shaft  128  may include a drive belt pulley  129  thereon, with a jackshaft drive belt  131  extending from the fan motor shaft pulley  129  to a driven pulley  133  on a radially offset jackshaft or drum drive shaft  134 . The shaft  134  includes a drum drive belt pulley  136  at its distal end, with a drum drive belt  138  extending around the pulley  136  and riding in a circumferential groove  140  around the dryer drum  118 . It will be seen that the dryer drum  118  and drum drive belt  138  may be identical to the corresponding components  18  and  38  illustrated in  FIG. 1  and described further above. The distinction between the configuration of  FIG. 1  and that of  FIG. 2  is the use of a shaft and belt system driven from the concentric fan motor to rotate the dryer drum in the embodiment of  FIG. 2 .  
         [0023]      FIG. 3  provides a side elevation view of an embodiment similar to that of  FIG. 2 , differing in the means used to impart rotary motion directly to the drum. In  FIG. 3 , the fan motor  212  drives an output or fan drive shaft  228  and fan  226 , with the shaft  228  having a drive belt pulley  229  thereon, just as in the case of the equivalent components  112 ,  128 ,  126 , and  129  of the embodiment of  FIG. 2 . The pulley  229 , in turn, drives a jackshaft or drum drive shaft  234  by means of a jackshaft driven pulley  233  on one end of the shaft  234 , just as in the embodiment of  FIG. 2 . However, rather than driving the drum  218  by means of a belt extending around the drum, as shown in  FIGS. 1 and 2 , the jackshaft or drum drive shaft  234  has a friction wheel  236  (rubber-coated, etc.) at its distal end which bears against a circumferential friction band  238  surrounding the dryer drum  218 . Rotation of the friction wheel  236  imparts rotational motion to the dryer drum  218  by means of the friction between the wheel  236  and friction band  238  around the drum. It will be seen that such a drum drive system may also be incorporated in the embodiment of  FIG. 1 , with the drum drive shaft  34  having a friction wheel  236  at the distal end thereof in lieu of the pulley  36  shown, and the dryer  10  incorporating the drum  218  of  FIG. 3  with its friction band  238 .  
         [0024]      FIG. 4  provides an illustration of an additional embodiment of the present ambient air dryer, in which a portable fan is used to supply the air through the dryer drum. The dryer  310  of  FIG. 4  includes a housing  316  which contains the drum  18  and drum drive mechanism comprising motor  14 , drum drive shaft  34 , shaft output pulley  36 , and drum drive belt  38 , just as in the embodiment illustrated fully in  FIG. 1 . However, rather than incorporating a fan integrally therewith, as in the embodiments of  FIGS. 1 through 3 , the housing  316  of the dryer  310  includes a fan receptacle  317  in the rear wall thereof, i.e., adjacent the screened air inlet end  24  of the drum. The fan receptacle  317  is configured to fit a conventional portable fan F, commonly known as a “box fan,” therein. The fan receptacle  317  may be configured to accept other types of fans, as desired. A suitable electrical outlet  319  may be provided on the housing  316 , allowing the fan F to be plugged in for operation. Power to the outlet  319  may be provided through appropriate control circuitry on or in the dryer housing or cabinet  316 , as desired, to provide control of the fan F from the ambient air dryer controls.  
         [0025]      FIG. 5  provides a basic electrical schematic diagram of circuitry that may be incorporated with the present ambient air clothes dryer in its various embodiments. In  FIG. 5 , a conventional electrical power source  410 , e.g., 115-volt ac power from the power grid, or perhaps 12-volt dc power from an automotive or other electrical source when the ambient air dryer is manufactured to accept such power, provides electrical power to the dryer through a master switch  412 . The master switch provides power to the fan motor, e.g., motor  12  of  FIG. 1 , and the drum drive motor, e.g., motor  14  of  FIG. 1 , through a solenoid or other appropriate switch  414 . The switch  414  may incorporate the electrical outlet  319  for incorporation in the portable fan embodiment of  FIG. 3 , if so desired.  
         [0026]     The solenoid switch  414  is not required in the simplest embodiments of the present ambient air dryer. However, the dryer in any of its embodiments may include a timer and/or humidity sensor  416 , if so desired. These components are conventional in clothes and laundry dryers, and need not be described in detail herein. The timer may be incorporated in combination with a rotary on/off switch to serve the function of the master switch  412 , if so desired. In any event, the timer and/or humidity sensor  416  is normally closed when electrical power is applied for operation of the dryer, with the electrical contacts opening when a predetermined time is reached (for the timer) or when the air flow from the dryer reaches a predetermined low level of humidity (for the humidity sensor). If either of these conditions occurs, power to the solenoid switch  414  is interrupted, thereby interrupting power to the fan and drum drive motors  12  and  14  and shutting off the dryer. The opening of the solenoid switch  414  may also trigger the operation of a buzzer, bell, or other audible or visual signaling means to alert the user of the dryer that the drying operation is complete, much as in the case of conventional clothes dryers. Where the circuit of  FIG. 5  is incorporated with the portable fan embodiment of  FIG. 4 , the switch  414  may control power to the outlet  319  to shut off power to the outlet  319 , thereby shutting off the fan F plugged into the outlet  319 .  
         [0027]     In conclusion, the present ambient air laundry and clothes dryer in its various embodiments provides a significant advance in efficiency for such machines, particularly in relatively warm and/or dry environments where the device may take advantage of the ambient air conditions.  
         [0028]     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
The ambient air clothes dryer is an automated device providing axial flow of unheated ambient air through the dryer drum. The dryer may include different drum drive systems, timer and/or humidity detector controls, and a configuration utilizing a separate, portable fan for temporary, removable installation with the dryer housing to provide airflow through the drum. The ambient air dryer greatly reduces energy requirements for drying laundry when compared to conventional heated air dryers, and is quite effective in warm and/or dry climates. The ambient air dryer is portable and may be used indoors or outdoors. The device may be configured to use twelve-volt power from a motor vehicle for use in camping. When used indoors, the device may be placed with a heat source (heat register, etc.) to draw warm air through the drum while humidifying the air as it passes through damp laundry in the drum.