Abstract:
A portable heater providing both radiant and forced air heat a closed loop heating element positioned within a substantially oval shaped reflector, The reflector air vent allows air to pass in from a bottom of the reflector, over the closed loop heating element and the reflector. A housing surrounds the reflector and heating element. A blower is located at a lower end of the housing and draws air inward and up between the reflector and the heating element from which it emerges past the heating element. Control knobs for controlling a thermostat and output power level are located at the top surface of the housing.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to portable radiant heaters and more particularly to an electrically powered radiant heater incorporating a blower for forcing air across a profile reflector surface and out into a space. The air absorbs heat from the heating elements and surfaces of the reflector, and is discharged forward from the heater, thereby augmenting radiant heating. The reflector is shaped to direct the radiant heat outwardly from the front of the heater. 
       BACKGROUND OF THE INVENTION 
       [0002]    Supplementary heat for limited spaces may be provided by portable heaters. Typically electrical, portable heaters may distribute heat by convection, forced air, radiation, or a combination of these, Radiant heaters have become popular since they are capable of heating solid objects within reach of the radiant heat, but they do not heat ambient air surrounding these objects. Thus, a person in the room or space benefits from the heat, although the air temperature is not greatly increased. 
         [0003]    However, only surfaces exposed to the source of radiant heat experience heating. If, for example, a person standing by a radiant heat source turns, or if another person or object is interposed between the standing person and the heat source, the warmed part of the standing person will chill. To even the heating effect, it becomes desirable to both project radiant heat and to warm the air of the space or room. 
         [0004]    To provide this benefit, combination radiant and forced air heaters have been proposed in the prior art. U.S. Pat. No, 5,381,509, issued to Thomas H. Mills on Jan. 10, 1995, describes such a combination of forced air and radiant heater. The heater has a reflector plate for projecting radiated heat forwardly out from the heater, and a fan located behind the reflector plate for forcing air upwardly and out from the heater. 
         [0005]    U.S. Pat. No. 3,229,070, issued to Orville C. Wells on Jan. 11, 1966, incorporated herein by reference describes a portable forced air and radiant electric heater which illustrates typical features such as manual on-off switch, thermostatic switch for protection against overheating, heating element guard for preventing direct contact by an external object, and fins for directing airflow. The fan draws air down through the center and directs it out the sides over the circular heating rod. The Wells invention acts primarily as a conventional conductive heater where air is the conductive medium. 
         [0006]    An industrial convection and radiant heater is shown in U.S. Pat. No.  4 , 336 , 442 , issued to Eugene W. Starr on Jun.  22 ,  1982 . Due to its industrial application, the direction of radiation and egress of heated air differs from those of the present invention. Because it is handling pressurized heated gas, 
         [0007]    U.S. Pat. No. 1,900,956, issued to William W. Somersall on Mar. 14, 1933, sets forth an upright, portable electric heater with air forced out radially at the top. This device humidifies occupied space by heating water contained above the heat source. 
         [0008]    U.S. Pat. No. 3,775,590, issued to William Joseph Gartner on Nov. 27, 1973, describes a portable forced air heater which features a fan mounted toward the top of the heater, and which discharges air horizontally and radially from the top of the heater. Unlike the present invention, there is no significant degree of radiant heating provided by this device. Air flow is different in the present invention, passing through a reflector plate absent in the Gartner device. Also, Gartner locates a manual control near the bottom of the heater. 
         [0009]    in U.S. Pat. No. 5,092,518, issued to Mituharu Tomioka et al. on Mar. 3, 1992, there is presented a combustion heater which features forced ejection of heated air. The thrust of the invention is to make constant the reach of projected heated air regardless of the amount of heat being dispersed. 
         [0010]    A portable radiant heater is shown in U.S. Pat. No. 4,004,128, issued to Carlo Marchesi on Jan. 18, 1977. This heater surrounds a heating element with a thermal mass, which absorbs heat and radiates heat over a period of time extending beyond the period of time during which the heating element is energized. 
         [0011]    A radiant heater described in U.S. Pat. No. 4,164,642, issued to Edward A. Ebert, on Aug. 14, 1979, is employed to heat eyeglass frames. A perforated metallic sheet is interposed between the heating element and an eyeglass frame. The metallic sheet absorbs energy of a given wavelength, and retransmits energy of another wavelength. Energy passing unobstructed through the perforations combine with retransmitted energy to assure that radiant energy of different wavelengths strikes the eyeglass frame. 
       SUMMARY OF THE INVENTION 
       [0012]    The present disclosure provides a portable heater for providing radiant and convection heat. The heater includes a housing having an upper end, a lower end, a back portion and a front portion. An air intake is located at bottom of the back portion and a grill is located at the front portion forming an air outlet. 
         [0013]    A heating element and reflector are positioned within the housing. The reflector is disposed between the heating element and a back portion of the housing. The reflector has a substantially oval shape, with the heating element being positioned within the reflector, the reflector at least partially surrounding at least of portion of the heating element. The reflector has a front surface capable of projecting radiant heat out of the heater through the grill. The reflector further includes an air vent arranged along a bottom portion thereof. 
         [0014]    A blower is mounted within the lower end of the housing. The blower is interposed between the air intake of the back portion of the housing and the air vent in the reflector. The blower operates to propel air across the height of the reflector and the heating element. Electrical circuitry including blower controls is provided in the upper end of the housing. The electrical circuitry supplying power to the blower and the heating element. The heating element can be a closed loop heating element, including two “U” shaped heating elements. 
         [0015]    The reflector is substantially oval in shape, forming a race track, having a raised center portion and a curved outside wall. The raised center portion and curved outside wall form a channel into which the heating element is positioned. 
         [0016]    The heater provides a two-fold heating function, the heating element providing radiant heat and the blower causes air to pass in through the air vent, between the reflector and the heating element and between the heating element and the grill to expel heated air through the gill. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
           [0018]      FIG. 1  depicts a front perspective view of the portable heater of the present disclosure; 
           [0019]      FIG. 2  depicts a rear perspective view of the portable heater; 
           [0020]      FIG. 3  depicts a rear view of the portable heater with the base attached thereto 
           [0021]      FIG. 4  depicts a side view of the portable heater; 
           [0022]      FIG. 5  depicts a front perspective view of the portable heater showing the reflector and heating element; 
           [0023]      FIG. 6  depicts a front sectional view of the portable heater; 
           [0024]      FIG. 7  depicts a front perspective view of the reflector and heating element of the portable heater; 
           [0025]      FIG. 8  depicts a front view of the reflector and heating element of the portable heater 
           [0026]      FIG. 9  depicts a horizontal cross sectional view of the reflector and heating element; 
           [0027]      FIG. 10  depicts a vertical cross sectional view of the reflector and heating element; and 
           [0028]      FIG. 11  depicts an exemplary electrical diagram of a simplified electrical circuit for the portable heater. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    Referring now to the drawing figures in which like reference designators refer to like elements, there is shown in  FIGS. 1 and 2  a radiant heater  10  of the present disclosure. The radiant heater  10  includes a housing  12  have a front portion  14  and a back portion  16 . A control panel  18  is positioned on an upper end  20  of the housing  12 . The control panel  18  can include an “on/off” switch, blower power control, oscillation, and thermostat. A base  22  is removable affixed to a lower end  24  of the housing  12 . A power cord (not shown) fitted with a power plug extends from the housing  12 , supplying electrical power from a household electrical receptacle to the heater  10 . 
         [0030]    The back portion  16  of the housing includes an air intake  32 , though which air is drawn into the heater  10 , the air intake  32  being located at a bottom of the back portion  16 . A pair of attachment clips  25  and  27  are centrally located on the back portion  16 , such that the base  22  can be removeable attached to the attachment clips  25  and  27  for shipping. In this configuration, the footprint of the heater  10  is decreased, allowing for smaller packaging. In addition, the cord can be wrapped about clips  25  and  25  for storage. 
         [0031]    Referring to  FIG. 3 , in use, a user removes the heater  10  from the packaging, detaching the base  22  from the back portion  16  of the heater  10 . The base  22  is then removeably attached to the lower end  24  of the housing  12 . 
         [0032]    Referring also to  FIGS. 4 and 5 , the front portion  14  of the housing  12  includes a grill  26 , partially enclosing a reflector  28  and heating element  30 . The grill  26  is shaped to be offset a distance “d” from the front portion  14 , spacing the grill  26  a distance from the heating element  30 . In this manner, air can pass around an object covering at least a position of the grill  26 , reducing the radiant heat on the object. 
         [0033]    Referring to  FIG. 5 , a blower  40  is positioned in a bottom portion  24  of the heater  10 , below and adjacent to the reflector  28 . The reflector  28  includes air vents  44  in fluid communication with the blower  40 . In operation, the blower  40  draws air in from the air intake  32  in the back portion  16  of the housing and blows the air into reflector though the reflector air vents  44 . The air vents  44  are positioned on a bottom portion  42  of the reflector  28 , such that the air from the blower  40  travels between the reflector  28  and the heating element  30  as well as in front of the heating element  30 . The blown air can travel the height of the reflector  28  and heating elements  30 , the opposite end  48  of the reflector  28  thereby directing the heated air out from the heater  10  through the grill  26 . 
         [0034]    Referring to  FIGS. 6-8 , the reflector  28  is shaped is a substantially oval configuration  50  having a raised central potion  52 . In this configuration, the reflector  28  forms a “race track” prismatic reflector. Referring also to  FIG. 9 , a horizontal cross sectional view of the reflector  28 , and  FIG. 10 , a vertical cross sectional view of the reflector  28 , the cross sections  54 ,  56  of the reflector  28  each forms a substantially “W” shape. The cross sectional  54 ,  56  “W” shapes of the reflector  28  are configured for reflecting the light and transport the heat outwardly from the heater  10  in all directions, allowing the radiated heat energy to heat up a room. 
         [0035]    The outside walls  58  of the “W” shaped cross sections  54 ,  56  act like a “bowl”  60  where the combination of the “W” shaped cross sections  54 ,  56  and “bowl”  60  keep reflecting the light and heat produced by the heating element  30  until it passes beyond the grill  26 . Furthermore, the combination of the “W” shaped cross sections  54 ,  56  and “bowl”  60  form a channel  62  through which the blown air travels, directing the heat away from the heater  10 . The outside wall  58  of the reflector  28  can also be stepped  64 , where the stepped walls  64  aid in the distribution of the heated air away from the heater  10 . 
         [0036]    The combination of the prismatic reflector  28  and the blower  40  provide a two-fold heating function. The prismatic reflector  28  directed the radiated heat energy outwardly from the beater  10  in all directions. The blower  40  forces air across the length of the heating element  30 , both between the reflector  28  and the heat element  30 , and the heating element  30  and the grill  26 , where the shape of the reflector  29  directs the heated air outward from the heater  10 . 
         [0037]    The heating element  30  can be a closed loop heating element, or be formed from a pair of “U” shaped heating elements  66 ,  68  electrically connected. The heating element  30  is attached to the reflector  28  by support members  70 . The support member  70  space the heating element  30  apart from the reflector  28 , allowing the blower  40  to blow air between the reflector  28  and the heating element  30 . The support members  70  can be made of a resilient material, allowing the heating element  30  to move with respect to the reflector  28 . In this manner the resilient support members  70  can absorb impact energy during transport or a sudden dropping of the heater, thus helping isolate and prevent the damage to the heating element  30 . 
         [0038]    A reset button  27  is located on the back of the housing  16  and a thermal cut-out switch is mounted on the reflector  28 . The location of the cut-out switch aids in the safe functioning of the heater. By placing it on the reflector surface, it is able to detect heat build-up which typically arises from being turned towards a wall or drapery or from towels or articles of clothing hanging nearby. 
         [0039]      FIG. 11  shows an exemplary electrical circuitry fur heater  10 . Power supplied through cord and plug  80  is signaled by a lit indicator  82  merely indicating that heater  10  is connected to power, and that ordinary precautions pertaining to any energized appliance would be appropriate. Switch  84  offers the choice of levels of power output connected to heating element  30 , this being controlled by appropriate diodes  86 . The blower  49  is energized in a power level selected by switch  84 . 
         [0040]    Thermostatic reset switch  86  is an automatic safety device comprising, preferably, a thermally responsive, snap action switch subjected to the heat from the front of the reflector  28 . Switch  86  is located in series within the electrical circuitry so as to control all power. Switch  86  has a metallic element which flexes, or snaps, when subjected to a predetermined temperature. Flexure operates switch contacts (not shown), thus breaking electrical continuity at temperatures above the predetermined temperature. At temperatures below the predetermined temperature, the metallic element flexes back to its original position, and switch returns to a normally closed position. 
         [0041]    A second lit indicator  88  (caution light) can be included which is placed in parallel with switch  86 , and illuminates should switch  86  break contact. This signals that switch  86  has detected and responded to a potentially dangerous high temperature. 
         [0042]    Thermostat  90  is manually adjustable, and operates by controlling all power flowing in the electrical circuitry. Thermostat  90  provides the user with control over the temperature at which heater  10  will operate. This control function is separate from the level of power output selected by switch  84 . On-off control may be provided either by selecting an appropriate actuating temperature at thermostat  90 , or by incorporation of an “off” position in switch  84 . 
         [0043]    Thermostat  90  can also incorporate a tip-over switch  92 . Switch  92  is preferably a pendulum switch, which opens switch contacts when heater  10  is not in its normal, upright position. Switch  92  could comprise a mercury switch or any other suitable switch responsive to inclination of heater  10  from its normal, upright position. As a further safety feature, an over current device  94  is located in series within the electrical circuitry. Device  94  is a fuse or circuit breaker, as desired, selected to break all power responsive to detection of electrical current exceeding a predetermined magnitude. 
         [0044]    Thus, it will be seen that both manual controlled switches  84  and  90 , and automatic safety devices  86 ,  92 , and  94 , all are placed in series so as to control all power flowing within electrical circuitry. This arrangement effectively de-energizes all components, thus assuring safety regardless of the source of a potential fault. 
         [0045]    All references cited herein are expressly incorporated by reference in their entirety. 
         [0046]    It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.