Abstract:
The present room heater includes a housing supporting internal electric heat sources. The housing surrounds the heat sources with an interconnected serial series of chambers made from heat-conducting material. Air is motivated by an electric fan through the series of chambers to effect stepped uniform heating, as well as optimal heating as the air moves through preheat chambers and then closely past the heat sources to an outlet opening. The chambers are made using modular and relatively simply-made components that interfit to form the chambers, such that multiple configurations are possible, including stacked and laterally-adjacent versions. The modular components include a flat part, hat-shaped part, and U-shaped part that interfit to define a first elongated chamber and a second elongated chamber that wraps onto three sides of the first elongated chamber, the hat-shaped part having end-located notches to permit flow of air between the chambers.

Description:
[0001]    This application claims benefit under 35 USC section 119(e) of provisional application Ser. No. 61/270,091, filed Jul. 6, 2009, entitled QUARTZ INFRARED HEATER WITH IMPROVED AIRFLOW DESIGN, the entire contents of which are incorporated herein in their entirety. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to fluid heaters, and more particularly relates to room heaters, space heaters, and fluid heaters. 
         [0003]    Known room heaters are capable of improvement. For example, many are complex and expensive to manufacture, and as a result overly expensive to consumers. Many are difficult and/or impossible to service and repair. Often they have poor air flow and/or do not provide a uniform heat in a good steady air flow. Many have a poor appearance that detracts from a room&#39;s décor. 
         [0004]    In addition to the above, known room heaters are not modular, and hence they are not easily modified to provide higher heat units. Still further, they do not use common components, which drive up expense and complicate production. In addition, the known room heaters are not flexibly designed. 
       SUMMARY OF THE PRESENT INVENTION 
       [0005]    The present invention concerns a heater having one or more central heat sources, such as an infrared heater powered by electricity. The heater includes a housing forming a series of chambers around the heater and made from metal or other heat conductive material. Air is motivated by a fan through the series of chambers to effect stepped uniform heating, as well as optimal and uniform heating as the air moves through preheat chambers and then closely past the heat sources to an outlet opening. The chambers are made using modular and relatively simple components that interfit to form the chambers. 
         [0006]    In one aspect of the present invention, a room heater includes a housing with walls dividing the housing into first and second preheat chambers both formed at least in part along different sides of a third chamber, such that heat generated in the third chamber preheats air in the first and second chambers. The first, second, and third chambers are serially interconnected to define a continuous air flow path with at least two switch backs. At least one heater is located in the third chamber and at least one blower is configured to motivate fluid along the air flow path. 
         [0007]    In another aspect of the present invention, a room heater comprises a housing assembly including top and bottom plates, a front plate, at least one side plate, at least one inner chamber plate and at least one outer chamber plate assembled to define first and second preheat chambers extending around a third chamber, with each of the first, second, and third chambers being serially interconnected to define a continuous air flow path in which air flows back and forth a majority of a length of the housing assembly at least twice during movement along the continuous air flow path. The room heater also includes at least one heating element and at least one air motivator for motivating air through the air flow path. 
         [0008]    In another aspect of the present invention, a heater includes a flat part and a hat-shaped part that combine to form an elongated heating chamber. A U-shaped part is assembled in a sandwiched arrangement around the hat-shaped part to define pre-heat chambers around and along the heating chamber. One of the flat part, the hat-shaped part, and the U-shaped part have an opening allowing flow from the pre-heat chambers to the heating chamber. 
         [0009]    In still another aspect of the present invention, a room heater comprises a housing assembly defining elongated chambers defining a continuous air-flow path that extends back and forth a length of the housing assembly at least three times; the air-flow path including a heating chamber section with at least one heating element therein. The room heater also includes a sleeve shaped to receive the housing assembly and having an aesthetically treated outer surface, with an inner surface of the sleeve forming with the housing assembly an outer portion of the continuous air-flow path. 
         [0010]    Objects of the invention include high performance, power and efficiency; a relatively small compact size; aesthetic appearance and one that can be easily modified for particular aesthetic considerations; ability to mount vertically or be floor mounted; easy to service; and modular in design. 
         [0011]    An object is to provide interchangeable shells and shell designs, thus allowing optimal aesthetics and consumer selection. 
         [0012]    An object is to provide modularity allowing components to be used in smaller and/or larger, higher-output designs. 
         [0013]    An object is to provide a room heater that can be mounted vertically or horizontally. 
         [0014]    An object is to provide a room heater that remains sufficiently cool to be touched on the outside, while also providing significant room heat. 
         [0015]    An object is to provide a room heater that puts out heat in an efficient, uniform, and powerful manner. 
         [0016]    An object of the present invention includes providing methods of operation expressed by using the arrangement as defined above. 
         [0017]    An object of the present invention is to provide an aesthetic design that, in addition to being useful, is also novel, ornamental, and unobvious over known designs, including providing surprising and unexpected benefits of appearance and ornamental value. 
         [0018]    These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0019]      FIG. 1  is a front perspective view of a side-by-side-chamber single-fan room heater embodying the present invention, and  FIG. 1A  is a similar view with the outer shell eliminated to better show the inner housing assembly. 
           [0020]      FIGS. 2 and 2A  are rear perspective views of  FIGS. 1-1A  respectively. 
           [0021]      FIGS. 3-5  are top, rear, and side orthogonal views of  FIG. 1 ,  FIG. 4  being a cross section along line IV-IV in  FIG. 3 . 
           [0022]      FIGS. 6-8  are front perspective, rear perspective, and rear views of a modified single-side-chamber single-fan room heater assembly not unlike that shown in  FIGS. 1A ,  2 A and  4 . 
           [0023]      FIG. 9  is an exploded view of  FIG. 2 . 
           [0024]      FIG. 10  is a partially assembled view of  FIG. 9 , and showing air flow through preheat and final heat chambers. 
           [0025]      FIG. 11  is a front perspective view of a modified stacked-chamber heater including its outer shell, and  FIG. 12  is an exploded front perspective view of  FIG. 11 . 
           [0026]      FIGS. 13-14  are front and rear perspective views of the modified heater of  FIG. 11 . 
           [0027]      FIGS. 15-17  are top, rear, and side views of  FIG. 13 . 
           [0028]      FIG. 18  is a perspective view showing air flow through the room heater of  FIG. 11 . 
           [0029]      FIG. 19  is an exploded view of  FIG. 14 . 
           [0030]      FIG. 20  is an exploded perspective view of a modified room heater similar to the heater of  FIG. 19  but including three heating elements instead of only two. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0031]    The illustrated room heater  20  ( FIGS. 1-5 ,  9 - 10 ) (also called “space heater” or “heater apparatus”) is a side-by-side double-sided chamber, single-fan room heater embodying the present invention.  FIGS. 1 and 2  show a housing assembly  20 ′ covered by an outer shell  12  and by face and back end covers  12 ′ and  12 ″, each having an aesthetic shape and aesthetic outer surface. The room heater  20  includes multiple wall-forming metal members  1 ,  3 ,  4 ,  5 ,  6 , and  7  ( FIG. 9 ) (also called “plates”) that when assembled form the housing assembly  20 ′ defining multiple back-and-forth tortuous paths for air. The paths ( FIG. 10 ) include a first path  13 ′, along a first outermost preheat chamber(s)  13  (inside the shell  12  but outside the outer walls of the plates  3 ,  4  and  7  of the housing assembly  20 ′), a second path  14 ′ along second outer preheat chamber(s)  14  (centered and between plates  1 ,  1 ,  3 ,  4  of the housing assembly  20 ′), a third path  15 ′ along intermediate preheat chamber(s)  15  (between right side plates  6 ,  7  and between left side plates  6 ,  7 ), and a fourth path  16 ′ along a final heating chamber(s)  16  (inside the channel defined by plate  6 ). The heater elements  8  are positioned in the final heating chamber  16 , and heat from this chamber  16  preheats the other chambers  13 - 15  due to its location and relative position. The uniformly heated air exits the heater  20  at outlet opening(s)  17  in plate  5  and opening  17 ′ in the end cover  12 ″. 
         [0032]    It is noted that the term “plates” is sometimes used herein, but the term is not intended to be unnecessarily limiting. Specifically, the term “plates” is intended to include parts made from sheet stock and/or that are formed into sheet-like components, such as a stamping, a formed sheet metal part, a bracket-like stamped part, a break-formed component made from sheet metal, and/or a part molded from polymer (e.g., injection molding, thermoforming, compression molding, etc). 
         [0033]    The illustrated heater  20  includes one (or more) disk thermometer  2  ( FIG. 9 ) along with electrical circuitry to control temperature and air flow, and fuse clips  9  that support the heater elements  8  (also called “heaters”). This circuitry and control technology does not require detailed explanation for an understanding by persons skilled in this art. The illustrated heater elements  8  are preferably electric infrared emitters, but it is contemplated that they can include other heaters, such as kerosene or gas. The illustrated heater  20  also includes curved baffles  10  at the end of chambers  15 - 16  to cause a more laminar and efficient air flow from chamber  15  into the chamber  16  during a last one of the air switch backs. A fan  11  is positioned to draw air thru inlet openings  17 ″ along the outermost chamber  13  and then motivate the air into and through the chamber  14  (and subsequently serially through the chambers  15 - 16  in series) of the heater  20 . 
         [0034]    The side plates  1  are generally flat rectangular sheet metal panels with notches  19  cut out at one end and including holes for fuse clips  9  and for thermometer  2  and for attachment screws. The side plates  1  include tabs  19 ′ between notches  19  that close the chamber  16  at the front end so that air flow is forced from chamber  14  through notch  19  reversely into chambers  15 . Top and bottom plates  3  and  4  are mirror images and generally flat and rectangular sheet metal panels, with attachment flanges along each side edge. Front end exit plate  5  has openings  17  for outlet of heated air and a perimeter flange for attachment to the end edges of the plates  3 ,  4 ,  7 . Front cover  20 ″ has matching grill-covered openings  17 ′ for output of heated air, and further has grill-covered openings  17 ″ for input of ambient air into the chamber  13 . Inner chamber plate  6  has a hat-shaped cross section that extends its length, with its side flanges  6 ′ cut short to align with notches  19  (or holes). Outer chamber plate  7  is U-shaped and matably receives the inner chamber plate  6 . Notably, inner chamber plate  6  is slightly shorter than outer chamber plate  7  and side plate  1 , such that air can flow around the un-notched rear end of the inner chamber plate  6  from chamber  15  into chamber  16 . The infrared emitter electrical heater  8  are designed to electrically connect between the clips  9 . Curved baffles  10  and fan  11  are selected and sized to fit into their respective spaces. The curved baffles  10  are flexible sheets that can be resiliently bent and fit into their space, with their resiliency creating friction to hold them in place. 
         [0035]    Alternative embodiments and modifications are contemplated to be within a scope of the present invention. For example, the present inventive heater can be constructed using different shaped chamber walls (e.g., cylindrical). Also, it can be built with different heating elements (e.g., round bulbs) or with a different heat source other than infrared (e.g., gas or kerosene). It also includes different preheat chamber layouts and airflow directions. For example, more or less preheat chambers can be constructed (e.g., eliminating a shell where those aesthetics and function are not required), as well as different decorative shells can be used (e.g., different shapes and/or ornamentation). A wide variety of different materials can be used, including high temperature plastics, metals, or composites, and with differently coated surfaces. For example, see heaters  20 A- 20 C described below. Still further, the air flow direction and preheat designs could also be used to heat substances other than air (e.g., water, gaseous fluids other than air or water, etc). 
         [0036]    Operation: The air flow pattern for heater  20  is shown in  FIG. 10 . (Compare that shown in  FIG. 18 .) The heater  20  is plugged in and its thermostat adjusted to a desired temperature and/or the fan  11  is adjusted to a desired air flow rate. As the heating elements warm up, the fan  11  draws air inside the shell around all sides of the housing  20 ′, flowing along chamber  13  and reversing direction at locations  35  on each side into the fan  11  and into the chamber  14 . The air then flows along the chamber  14  until it is forced to switch back and move laterally through notches  19  and flow in a 180 degree reverse direction along chamber  15 . At the end of chamber  15 , the air again reverses with the assistance of baffles  10  and flows into and along chamber  16  along the heater  8  where the air is heated. The fully heated air then exits openings  17  and  17 ′ in the front cover  20 ″. Due to shared walls, air flowing along chamber  16  preheats the air flowing along chamber  15 . Similarly, air flowing along chamber  15  preheats air flowing along chamber  14 . Also, air flowing along chamber  14  preheats the air flowing along chamber  13 . This leads to a very efficient and uniform heating process. The effect is heated air that is exceptionally uniform and well-heated, and that is very quickly evenly heated during start up of the heater(s)  20 . 
         [0037]    Our test data suggests to us that the present room heater  20  has a substantially improved efficiency and uniformity of heated air flow over another well known stand-alone heated/forced-air room heater in generated air temperature by as much as 25% during constant operation. Specifically, we measured the present room heater  20  to provide a temperature of about 210 degree F. while one known prior art room heater was only able to provide a measured temperature of about 155 degree F. at a similar output location and time period. We are still trying to understand and explain this improvement, but believe it to be related at least in part to the efficient and uniform heating of air provided in the present room heater  20 , which is due in significant part from the preheat and air chamber arrangement(s) of the present room heater  20 . We believe our design leads to considerably more efficient and uniform heating of air over known prior art room heaters due to less turbulence and less “hot spots”, even when they have a heater element with similar btu/hour rating and heating capacity. 
         [0038]    The room heaters  20 A- 20 C use the same identification numbers as heater  20  but with an additional letter “A” or “B” or “C” for identical or similar components. This is done to reduce redundant discussion. 
         [0039]    The room heater  20 A ( FIGS. 6-8 ) is made using similar components, but with a single-side-chamber arrangement. Specifically, room heater  20 A ( FIGS. 6-8 ) includes an emitter  8 A (also called “heating element” or “heater”) mounted on a side plate  1 A by fuse clips  9 A. The fuse clips  9 A are wired to a power cord and control circuitry (such as an on-off switch and/or fuse and/or other heat and air flow controls, using well-known electrical components). The control circuitry can be located on the shell  12 A or in other locations on the unit  20 A. The illustrated side plate  1 A is rectangular and extends a full length of the unit, except for two square notches (or rectangular sections) cut out at the exit end of the unit  20 A above and below the emitter  8 A. When assembled, these two spaced notches allow air to flow from the outermost chamber  13 A to the preheat chambers  14 A. The thermometer  2 A is mounted on one side plate  1 A and wired in. 
         [0040]    The long rectangular top and bottom plates  3 A and  4 A are then attached to the sides  1 A creating a box with two open ends and with the emitter  8 A mounted on one side  1 A as shown. The inside of this box will be the fan chamber, chamber  14 A. The first inner chamber plate  6 A is then attached to the side plate  1 A fitting over and covering the emitter  8 A and creating the emitter chamber  15 A. Inner chamber plate  6 A has a hat-shaped profile, so that it defines the inner chamber  15 A, but also defines on its top, side, and bottom the chamber  14 A along with three-sided U-shaped out chamber housing  7 A (also called an outer wall-forming plate  7 A). The outer chamber housing  7 A is attached to the side plate  1 A, fitting over the inner plate  6 A. The spaces between these two outer plates now form the outer preheat chambers  13 A. 
         [0041]    Next, the fan  11 A is attached to the intake side of the fan chamber  13 A on the opposite side to the cutout sections of the side plate  1 A. A piece of thin resilient metal, curved baffle  10 A, is bent into a curve and inserted into the intake side opening of the emitter chamber  13 A, next to the fan. It is held in place by its own tension against the back of the emitter chamber  14 A, thereby sealing off the end of the chamber and creating a curved baffle. Next, a front plate  5 A (double model as shown) is attached to the exit end of the unit, which seals the other side of the preheat chambers except for the exit hole. The tubular sleeve shell  12 A is then assembled onto the unit to complete the assembly. Inlet air flows between the sleeve shell  12 A and the outer surfaces of the plate assembly, Air then reverses (“switches back”) to flow along the first pre-heat chamber, then reverses to flow along the second pre-heat chamber, then reverses to flow through the heating chamber and out into the room. 
         [0042]    The heater  20 A eliminates one of the plates  6  and eliminates one of the plates  7  found in heater  20 , but nonetheless uses a majority of the same components as heater  20 . 
         [0043]    A stacked two-element room heater  20 B ( FIGS. 11-19 ) and a stacked three-element room heater  20 C ( FIG. 20 ) are shown using components similar to those described above. They include similar components and similar switch-back air flow. Specifically, the heater  20 B includes two fans  11 B that draw air from an outer chamber  13 B into a top half of the top-located chamber  14 B. The air flows along a length of the top chamber  14 B, and then down through openings formed by notches  19 B at an end of the divider flat plate  3 B downwardly to the lower half of the assembly. The air then flows first into chambers  15 B formed around the outside of the hat-shaped members  6 B and then reverses to flow along chambers  16 B formed within the hat-shaped members  6 B, each of which contain a heater  8 B. 
         [0044]    The shell  12 B ( FIGS. 11-12 ) includes a tubular shape with flattened sides and rounded corners for receiving the assembly shown in  FIG. 13 . The rounded corners of the shell  12 B help cause the shell  12 B to form a space 360 degrees around the housing assembly  20 B′ and that extends a length of the housing assembly  20 B′. Rubber feet or standoffs  25 B are attached to a bottom of the shell  12 B such as by screws  26 B that engage embed (or weld-attached) nuts  27 B in a bottom of the shell  12 B. A front grill or cover  28 B and rear cover  29 B″ is attached to ends of the shell  12 B, the grill  28 B at the air outlet end including a grill area  31 B of openings for allowing air inlet and a grill area  32 B of openings allowing air exit, without undesired mixing of the inflowing and outflowing air. The mesh covering of the areas  31 B and  32 B help eliminate safety concerns of things being poked into the heater unit  20 B. Notably, the present room heater ( FIG. 11 ) can be set horizontally on a floor, including placement against a wall or furniture. It is also contemplated that the heater unit  20 B (and/or units  20 - 20 A and  20 C) also can be mounted vertically on a wall. 
         [0045]    The heater  20 C is similar to heater  20 B, but heater  20 C includes three hat-shaped plates  6 C (instead of two) and three heaters  8 C (instead of two). 
         [0046]    It is contemplated that the present inventive concepts can be used to heat any gas or fluid, and that they present concepts that are not limited to only air, nor to only room and space heaters. 
         [0047]    It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.