PATENT ABSTRACT
A portable oscillating space heater is provided, which comprises at least one opening therein, at least one heating assembly including an electric heating element disposed within the housing for producing radiant heat energy, at least one fan mounted within the housing and adapted to produce a directed air flow introducing from the opening in the rear portion of the housing and passing through the electric heating element and thereby producing a heated air flow, and an oscillation mechanism for providing oscillatory movement at least to the heating assembly thereby to continuously change the direction of the heated air flow produced by the fan.

PATENT DESCRIPTION
RELATED PRIOR APPLICATIONS  
       [0001]    This application claims priority from Provisional Patent Application Serial Nos. 60/296,382 and 60/318,429, respectively filed on Jun. 6, 2001 and Sep. 10, 2001, the entire contents of which are incorporated herein by reference. 
     
    
     
       BACKGROUND  
         [0002]    1. Technical Field  
           [0003]    The present disclosure relates generally to portable space heaters, and more specifically to a portable oscillating space heater having at least one heating assembly for distributing heated air in a continuously changing direction.  
           [0004]    2. Background of the Related Art  
           [0005]    Portable space heaters for heating air are well known in the art and are available in many different forms, and may incorporate various types of heating elements, including electric resistance-wire heaters and positive temperature coefficient (PTC) heaters. Typically, electric resistance-wire space heaters include a heating element which may reach temperatures exceeding 1600 degrees Fahrenheit. As such, electric resistance-wire space heaters may present a fire hazard and usually require some fire prevention structure. In contrast, electric space heaters incorporating PTC heating elements include a conductive grid supported on a ceramic material body, or heat conductive plastic body. Electric current supplied through the conductive grid heats the ceramic material and the heat is distributed from the ceramic material by an air flow generated by an electric fan. When a PTC heating element rises to a temperature of approximately 340 degrees Fahrenheit, the resistance in the ceramic material prevents further flow of current through the ceramic material to prevent further temperature rise of the ceramic material, thereby minimizing the risk of overheating and the potential for fire.  
           [0006]    One problem associated with space heaters employing PTC heating elements is that the heat generated is directed over a small area. U.S. Pat. No. 5,513,296 to Goldstein (“Goldstein”) attempts to correct this problem by providing space heater having a PTC heating element which distributes the heat over a larger area. Goldstein discloses a space heater including a pair of PTC heater assemblies disposed in side-by-side relationship. Each heating assembly is positioned at an angle of approximately 7.5 degrees from normal so as to produce a diverging column of heated air.  
           [0007]    However, continuing need still exists for a space heater which is compact and portable, does not present a fire hazard and can distribute heat over a large area.  
         SUMMARY OF THE INVENTION  
         [0008]    In accordance with the present disclosure, a portable oscillating space heater for distributing heated air in a changing direction is provided.  
           [0009]    Generally, the present invention discloses an oscillating space heater which includes a housing having a front portion and a rear portion, each having at least one opening therein, at least one heating assembly including an electric heating element disposed within the housing for producing radiant heat energy, at least one fan mounted within the housing and adapted to produce a directed air flow introducing from the opening in the rear portion of the housing and passing through the electric heating element and thereby producing a heated air flow, and an oscillation mechanism for providing oscillatory movement at least to the heating assembly thereby to continuously change the direction of the heated air flow produced by the fan. A positive temperature coefficient (PTC) heater element is preferably utilized as the electric heating element of the heating assembly. The oscillation mechanism is adapted to provide oscillatory movement at least to the heating assembly over an arc of between about 15 and about 360 degrees.  
           [0010]    In one preferred embodiment, the electric heater of the invention includes a single heating assembly disposed adjacent the front portion of the housing, wherein the single heating assembly is adapted to be subject to oscillatory movement for changing the direction of the heated air flow produced by the fan.  
           [0011]    In another preferred embodiment, the electric heater of the invention includes two heating assemblies, one located adjacent to the other in substantial vertical alignment, wherein the two heating assemblies is adapted to be subject to oscillatory movement in simultaneous opposite directions.  
           [0012]    The present invention further discloses a positive temperature coefficient (PTC) heater which includes a housing, a first and a second heater assemblies, one located above the other, each including a positive temperature coefficient (PTC) heater element for producing heat energy when connected to an electric source, at least one fan disposed within the housing and adapted to produce a directional air flow toward the PTC heater elements and thereby to generate a heated air flow, an air flow guide mechanism disposed within the housing for guiding the direction of the air flow toward the PTC heater elements, and an oscillation mechanism for providing oscillatory movement of the first and the second heater assemblies, each continuously moveable in opposite directions with respect to each other. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    Preferred embodiments of the present disclosure are described herein with reference to the drawings, wherein:  
         [0014]    [0014]FIG. 1 is a side view in partial cutaway of an oscillating heater constructed in accordance with the present invention;  
         [0015]    [0015]FIG. 2 is an exploded perspective view of the oscillating heater of FIG. 1;  
         [0016]    [0016]FIG. 3 is a perspective view illustrating another embodiment of the oscillating heater;  
         [0017]    [0017]FIG. 3A is a perspective view of the oscillating heater of FIG. 3 illustrating oscillation movement of the first and the second heater assemblies in opposite directions;  
         [0018]    [0018]FIG. 4 is a side sectional view of the oscillating heater of FIG. 3;  
         [0019]    [0019]FIG. 5 is a top sectional view of the oscillating heater of FIG. 3;  
         [0020]    [0020]FIGS. 6 and 7 are perspective views illustrating the oscillation mechanism of the oscillating heater of FIG. 3; and  
         [0021]    [0021]FIG. 8 is a schematic view illustrating mounting of the oscillation mechanism of FIGS. 6 and 7 to the oscillating heater of FIG. 3.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0022]    Preferred embodiments of the presently disclosed oscillating heater will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views.  
         [0023]    Referring to FIGS.  1 - 2 , oscillating heater  10  includes a housing having a front housing portion  12 , a rear housing portion  14 , a lower housing portion  16 , an upper housing portion  18 , and a housing cover  20 . Front housing portion  12  and rear housing portion  14  define a first housing cavity, lower housing portion  16  and rear housing portion  14  define a second housing cavity and upper housing portion  18  and housing cover  20  define a third housing cavity. Each of the housing cavities encloses internal components of oscillating heater  10  as will be described in further detail below. Each of the housing portions is connected to the others in a known manner, preferably with screws. Alternately, other known fastening techniques may be used to fasten the housing portions together including adhesives, welding, snap-fit connectors, etc. The housing portions are preferably molded from a polymeric material but may be formed from a variety of materials including metals, etc.  
         [0024]    The housing of heater  10  is supported on a base member including a base top portion  22  and a base bottom portion  24 . Base portions  22  and  24  define a fourth housing cavity which is dimensioned to receive a foot activated switch or oscillation activator  26 . Switch  26  includes a foot pedal  28  and switch components  30 . Switch  26  is actuable to effect oscillation of a heating assembly  32  as will be described in further detail below.  
         [0025]    Heating assembly  32  includes an outlet screen  34  which is preferably formed of steel mesh but may be formed of other materials including plastics having a plurality of openings or gratings disposed therein. Heating assembly  32  also includes a plurality of vertically oriented PTC heating elements  36 , an element holder  38 , a body  40 , a top portion  42 , and a bottom portion  44 . PTC elements  36  are supported on element holder  38  and the assembly is secured to body member  40  using screws or the like.  
         [0026]    Body  40  is substantially c-shaped and is configured to be slidably received on front housing portion  12 . Front housing portion  12  includes a pair of vertically spaced elongated transverse openings  46  and body  40  includes a pair of vertically spaced openings  48 . When body  40  is slidably positioned on front housing portion  12 , each opening  48  communicates with a respective elongated opening  46 , which is preferably wider than opening  48 . Openings  46  and  48  permit air from inside the first housing cavity to flow across the PTC elements  36  and exit heater  10  through outlet screen  34 . Accordingly, openings  46  and  48  constitute an air flow guide or baffle mechanism. Other guide structure are also contemplated.  
         [0027]    A blower assembly  50  is supported within the first housing cavity and includes a motor  52  and a pair of fans  54  and  56 . Each fan  54  and  56  is configured to direct air through a respective opening  46 . While a single motor is shown, separate motors for each fan may be provided. Likewise, a single fan/motor assembly may be provided, with ducts to direct air flow to each opening  46 . Rear housing portion  14  includes a grating  58  which allows air to be drawn into the first housing cavity. An inlet grille  60  is removably supported over grating  58  of rear housing portion  14  to act like a filter and to prevent debris from entering the first housing cavity.  
         [0028]    Heating assembly  32  is slidably positioned on base portion  22 . Base portion  22  is crescent shaped and includes a curved guide slot  62  formed in an upper surface thereof. Slot  62  is configured to receive a protrusion (not shown) formed on heating assembly  32  to confine heating assembly  32  to a predetermined path of oscillatory motion.  
         [0029]    An oscillatory drive motor  70  is supported within the second housing cavity defined between lower housing portion  16  and rear housing portion  14 . Lower housing portion  16  includes an elongated slot  72 . A drive arm  74  extends through slot  72  and interconnects drive motor  70  to heating assembly  32 . Upon actuation of motor  70  via foot pedal  28 , motor  70  drives heating assembly  32  in oscillation about front housing portion  12 . Alternately, it is envisioned that heating assembly  32  may be driven in continuous rotation about the heater or in oscillation over any desired arc.  
         [0030]    A thermostat  80  and a control switch  82  are supported in the third housing cavity. Switch  82  is electrically connected to the fan motor  52  and PTC elements  36  to control operation of heater  10  in a known manner. Thermostat  80  may be included to provide variable heat settings.  
         [0031]    In use, when switch  82  is actuated, power is supplied to PTC elements  36  and fan motor  52 . As PTC elements  36  heat up, fans  54  and  56  draw air into the first housing cavity through rear housing portion  14  and force the air through openings  46  and  48  into contact with PTC elements  36 . As the air flows across PTC elements  36 , the air is heated and is forced to flow from heating assembly  32  through outlet screen  34 . When switch  30  is actuated via foot pedal  28 , motor  70  via link  74  effects oscillation of heating assembly  32  to distribute heated air over a predetermined arc.  
         [0032]    It will be understood that various modifications may be made to the embodiments disclosed herein. For example, the heater assembly may be pivoted about a horizontal axis rather than a vertical axis. Moreover, the PTC heating elements may be replaced by other heating elements known in the art. It is also envisioned that the heater assembly may be rotated  360  degrees continually about a central axis of the heater.  
         [0033]    Referring now to FIGS.  3 - 5 , an alternate embodiment of the present invention is described hereafter in detail. Oscillating heater  100  includes a housing  112 , first and second heater assemblies  114  and  116 , a heater actuator  118  supported on an upper end of housing  112 , and an oscillation actuator  120  supported on a lower end of housing  112 . Housing  112  is preferably formed from molded plastic sections. Alternately, other materials may be used to form housing  112  including metals.  
         [0034]    Housing  112  includes a backside  112   a  including an opening dimensioned to allow airflow into housing  112 . A frontside  112   b  of housing  112  also includes an opening which communicates with an opening formed in the backside of first and second heater assemblies  114  and  116 . Each of the openings formed in backside  112   a  and frontside  112   b  of housing  112  maybe covered by a grating, which may or may not be integrally formed with housing  112 .  
         [0035]    A motor  122  is supported within housing  112  between first and second fans  124  and  126 . First and second fans  124  and  126  are positioned to draw air through the opening formed in backside  112   a  of housing  112  and force it through the opening formed in front side  112   b  of housing  112 . First fan  124  is positioned to force air into first heater assembly  114  and second fan  126  is positioned to force air into second heater assembly  116 .  
         [0036]    Each heater assembly  114  and  116  includes a PTC heating element  130  supported within a casing  132  in general vertical orientation. Each casing  132  is movably supported on housing  112 . Preferably, each casing  132  is configured to be slidably supported with respect to housing  112 , with heater assembly  114  positioned above heater assembly  116 , and both heater assemblies  114  and  116  being rotatable with respect to a vertical axis. Alternately, other assembly configurations are envisioned. The use of other known heating elements is also envisioned.  
         [0037]    Referring now to FIGS.  6 - 8 , a rack  140  is secured to each heater assembly  114  and  116 . In one preferred embodiment, racks  140  are formed integrally with the housing  1   14   a  and  116   a  of each of the heater assemblies  114  and  116 . Alternately, racks  140  can be formed separately from housing  114   a  and  116   a  and attached thereto using known fastening techniques, e.g., screws, adhesives, welding, etc. A drive shaft  142  driven by motor  143  includes a pinion  144 . Pinion  144  is positioned between teeth  146  of each rack  140  such that rotation of pinion  144  affects movement of heater assemblies  114  and  116  in opposite directions. Oscillation actuator  120  (FIG. 3) operates an electric switch to control operation of motor  143  and thus control oscillation of heater assemblies  114  and  116 .  
         [0038]    In operation, when heater  110  is connected to a power source, e.g., an electrical outlet, and heater actuator  118  is turned on, current is supplied to PTC elements  130  to generate heat. Motor  122  is actuated to concurrently drive fans  124  and  126  to draw air into the backside  112   a  of housing  112  and force it over PTC elements  130 . Preferably, heater actuator  118  includes multiple settings to control the current supplied to PTC elements  130  to control the heater temperature. Moreover, baffles or air flow guiding mechanisms may be provided to direct air from fans  124  and  126  to flow over PTC elements  130 . Heated air flowing from PTC elements  130  flows through a perforated cover or screen  150  supported on each heater assembly  114  and  116  and is directed outwardly therefrom. When oscillation actuator  120  is manually pressed to supply electrical current to motor  143 , heater assemblies  114  and  116  are oscillated in opposite directions (as indicated by arrows “a” and “b” in FIG. 3A) over an arc, preferably between about 15 and about 360 degrees. Preferably, each heater assembly is moved over an arc of between about 30 degrees to about 90 degrees, and most preferably, heater assemblies  114  and  116  are oscillated over an arc of about 60 degrees. Preferably, each heater assembly  114  and  116  includes a slot or groove which cooperates with a slot or groove formed in housing  112  to guide the heater assemblies over the arc of oscillation.  
         [0039]    It will be understood that various modifications may be made to the embodiments disclosed herein. For example, the heater assemblies may be pivoted about a horizontal axis rather than a vertical axis. Moreover, the PTC heater elements may be replaced by other heating elements known in the art. It is also envisioned that the heater assemblies may be rotated 360 degrees continually about a central axis of the heater.  
         [0040]    Therefore, the above description should not be construed as limiting, but merely as an exemplification of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of this disclosure as defined by the claims appended hereto.