Abstract:
A steam generator for a surface cleaning apparatus is described. The steam generator includes: a first chamber for generating steam and collecting scale; a water inlet disposed proximate a first end of the first chamber; a heater in thermal contact with the first chamber; a second chamber housed within the first chamber and in fluid communication with the first chamber; and a steam outlet for releasing steam and in fluid communication with the second chamber, wherein the steam outlet is disposed distal to the first end of the first chamber.

Description:
TECHNICAL FIELD 
       [0001]    The present teachings are directed toward the improved cleaning and durability capabilities of steam generating surface cleaners. 
       BACKGROUND 
       [0002]    A need has been recognized in the surface cleaning industry for steam generating surface cleaner that has increased longevity. A requirement for many steam generating appliances is the use of distilled water in order to prevent scale buildup within a boiler. Prior art boilers and steam generators have a single internal chamber for generating steam. Distilled water is free of any contaminates or particulates, and thus does not produce scale within the boiler. Failure to use distilled water in prior art boilers produces scale within the boiler, eventually leading to clogged outlets, and reduced efficiency and performance. Because a consumer must purchase and store distilled water in order to properly utilize a steam generating vacuum cleaner, such units have increased expense and inconvenience associated with their use. As such, there exists a need for a steam generating surface cleaner that can reduce scale buildup thereby increasing the longevity of the steam cleaning appliance while reducing the operational costs associated with use of the surface cleaner. 
         [0003]    Other deficiencies in the prior art can be inferred by the disclosure herein. 
       SUMMARY 
       [0004]    According to one embodiment, a steam generator for a surface cleaning apparatus is described. In some embodiments, the steam generator comprises a first chamber for generating steam and collecting scale, a water inlet disposed proximate a first end of the first chamber, a second chamber housed within the first chamber and in fluid communication with the first chamber, and a steam outlet for releasing steam and in fluid communication with the second chamber, wherein the steam outlet is disposed distal to the first end of the first chamber. 
         [0005]    In some embodiments, the water inlet is substantially orthogonal to the first chamber. In some embodiments, the first chamber is substantially cylindrical in shape. In some embodiments, the second chamber is substantially cylindrical in shape. In some embodiments, the first chamber comprises a non-corrosive heat conductor. In some embodiments, the second chamber comprises a non-corrosive heat conductor. 
         [0006]    In some embodiments, the steam generator further comprises a heating element disposed in contact with the first chamber. In some embodiments, the steam generator further comprises a temperature sensor to sense the operating temperature of the first chamber, wherein power is removed from the heating element when the operating temperature exceeds a threshold. 
         [0007]    In some embodiments, the steam generator further comprises a water pump, and a temperature sensor to sense the operating temperature of the first chamber, wherein power is supplied to the water pump when the operating temperature exceeds a threshold. 
         [0008]    In some embodiments, the steam generator further comprises a thermal insulator disposed around the first chamber. 
         [0009]    According to various embodiments, a steam generator for a surface cleaning apparatus is described. In some embodiments, the steam generator comprises a first chamber for generating steam and collecting scale, a water inlet disposed proximate a first end of the first chamber, and a conduit disposed within the first chamber and including a steam inlet disposed proximate a first end of the conduit, and a steam outlet disposed proximate a second end distal from the first end, wherein the steam outlet is disposed outside the first chamber, and the first end of the conduit is disposed proximate the water inlet. 
         [0010]    In some embodiments, the steam generator is disposed vertical to a cleaning surface. In some embodiments, the multi-chamber steam generator is horizontal to a cleaning surface. In some embodiments, the multi-chamber steam generator further comprises a water inlet and a steam outlet. In some embodiments, the steam generator further comprises a water pump, wherein a water pump outlet of the water pump is fluidly connected to a water inlet of the multi-chamber steam generator. 
         [0011]    In some embodiments, the water pump outlet is vertically below the water inlet. In some embodiments, the cleaning apparatus further comprises a water reservoir. In some embodiments, the water reservoir is vertically above the water pump. In some embodiments, the pump is a self-priming pump. In some embodiments, the pump is a metered pump. In some embodiments, the surface cleaning apparatus further comprises a beater bar housing, a beater bar for agitating a cleaning surface, and a debris collection unit for collecting debris from the cleaning surface, wherein the debris collection unit is fluidly connected to the beater bar housing. 
         [0012]    In some embodiments, the beater bar is driven by a motor. In some embodiments, the surface cleaning apparatus further comprises wheels, wherein the beater bar is driven by the frictional force of the wheels on the cleaning surface. In some embodiments, the surface cleaning apparatus further comprises a temperature sensor. In some embodiments, the temperature sensor turns on a pump when a minimum temperature within the multi-chamber steam generator is reached. In some embodiments, the temperature sensor shuts of power to a heating element when a maximum temperature within the multi-chamber steam generator is reached. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The same reference number represents the same element on all drawings. It should be noted that the drawings are not necessarily to scale. The foregoing and other objects, aspects, and advantages are better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which: 
           [0014]      FIG. 1  illustrates a cross section of one embodiment of a steam generator; 
           [0015]      FIG. 2  illustrates the interior of the body of an upright vacuum cleaner having a steam generator according to one embodiment; and 
           [0016]      FIG. 3  illustrates the interior of the base of an upright vacuum cleaner having a steam generator according to one embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The present teachings provide a steam generator for a surface cleaner capable of providing improved cleaning features and longevity. The structure of a steam generator can comprise an inlet, a body with an internal chamber, and an outlet. A second chamber, housed within the first chamber, prevents the accumulation of scale within the outlet, thereby increasing the longevity of the steam cleaner, reducing costs associated with use and maintenance for a consumer. 
         [0018]      FIG. 1  illustrates an exemplary embodiment of a steam generator  100 . A steam generator housing  102  may contain a first chamber  108  and a second chamber  110 . Water may flow into steam generator  100  via water inlet  104 , where the water flows into first chamber  108  and is heated into steam. As the steam rises within chamber  108 , pressure builds in chamber  108 . Eventually the steam is forced into second chamber  110  at second chamber steam inlet  112 . Steam may exit steam generator  100  by passing through second chamber outlet passage  118 . Second chamber outlet passage  118  can include a tip that is narrow in diameter at outlet  106 . During the evaporation of water into steam within first chamber  108 , any contaminants, particulates, or mineral deposits may be released from the water to form a scale  116 . The scale  116  falls out of the water and may accumulate at the bottom and along the side walls of first chamber  108 . Thus, steam, free from any contaminants, enter second chamber steam inlet  112  and exits outlet  106 . As such, the scale  116  is generally disposed off in chamber  108  and scale  116  does not clog outlet  106 . Contaminant free steam may be delivered to a mop head or a steam nozzle where it can used to clean a surface of interest. In some embodiments, the mass or surface area of a heated surface can be increased within first chamber  108 . This can be accomplished by disposing a spring  130  around second chamber  110 , or by disposing other non-corrosive heat conductive materials shaped as spheres, rings, powders etc. within first chamber  108 . The increased surfaces, thereby allowing more efficient steam generation and increasing the efficiency of the removal of contaminants from the water. 
         [0019]    Water, flowing into steam generator  100 , may be transformed into steam by heat generated by heater  122  embedded within a heater block  128 . Electrical power may be supplied to heater  122 . In some embodiments, heater  122  may include a resistance heating element, such as a wire, coil, ribbon, screen, foil, heat lamp or ceramic element. The heating element may comprise kanthal, nichrome, cupronickel, molybdenum dicilide, ceramic insulated metal, of PTC ceramic, or mixtures thereof. 
         [0020]    Temperature sensors  124  may detect temperatures of first chamber  108  and second chamber  110 . Temperature sensors  124  may be connected to a monitoring circuit (not shown) such that if an internal temperature of first chamber  108  and/or second chamber  110  is exceeded, power to a heater, pump, or other component of surface cleaner is turned off. In some embodiments, temperature sensors  124  may be connected to a monitoring circuit (not shown) such that if a minimum temperature is reached, power to a pump, beater bar, or other component of the surface cleaner is turned on. Temperature sensors  124  can be in thermal contact with heater block  128 . 
         [0021]    Housing  102  may be a single integrated unit or may contain multiple parts pieced together to form housing  102 . For example, housing  102  may include an inlet receiving portion to receive threads  126  on inlet  104 . As such, a conduit, for example, from a water reservoir, can be secured to inlet  104 . In some embodiments, outlet  106  may include threads  114  which allows second chamber  110  and second chamber outlet passage  118  to be secured into housing  102  within first chamber  108 . In some embodiments, housing  102  may comprise two halves. The two halves may be secured together via fasteners (not shown) which may be received in fastener receivers  120 . In some embodiments, fastener receivers  120  receive fasteners which secure steam generator into a surface cleaner. In some embodiments, the whole unit may be die cast. In some embodiments, housing  102  comprises a heat conducting material. For example, in some embodiments, housing  102  can comprise aluminum, steel, or other suitable materials, or combinations thereof. 
         [0022]    In some embodiments, first chamber  108  and second chamber  110  comprise heat conductive material that is resistant to rust. In some embodiments, first chamber  108  and second chamber  110  are made from the same materials. In some embodiments, first chamber  108  is a different material than second chamber  110 . In some embodiments, first chamber  108  and/or second chamber  110  comprise brass, copper, stainless steel, polytetrafluoroethylene (i.e., Teflon), or other suitable materials, and mixtures thereof. In a preferred embodiment, second chamber  110  comprises Teflon. 
         [0023]      FIG. 2  illustrates an embodiment of a steam generator in a surface cleaner. In this embodiment, steam generator  200  is secured within the body portion of an upright floor cleaner  202 . A water reservoir (not shown) supplies water to a pump  224 . Hose  226  may allow water to travel from pump to steam generator inlet  206 . Water enters first chamber  212 , where the water becomes steam, the steam travels to second chamber steam inlet  216 . Steam then travels through second chamber  214 , through second chamber outlet passage  210 , and out of steam generator  200  via outlet  208 . Hose  228  conducts steam from steam generator to a steam applicator, for example, a cloth mop or a nozzle. Hose  228  and/or hose  226  may be secured to various inlets or outlets via locking pins  236  or other fasteners as known in the art. 
         [0024]    Water, flowing into steam generator  200 , may be transformed into steam by heat generated by heating elements  222  embedded within steam generator interior portion. Power may be supplied to heating elements  222  via connectors  218 . In some embodiments, heating elements  222  may include a resistance heating element, such as a wire, coil, ribbon, screen, foil, heat lamp, or ceramic element. The heating elements  222  may comprise kanthal, nichrome, cupronickel, molybdenum dicilide, ceramic insulated metal, of PTC ceramic, or mixtures thereof. 
         [0025]    Temperature sensors  220  may detect temperatures of first chamber  212  and second chamber  214 . Temperature sensors  220  may be connected to a monitoring circuit (not shown) such that if an internal temperature of first chamber  212  and/or second chamber  214  is exceeded, power to heating element  222  is turned off. In some embodiments, temperature sensors  220  may be connected to a monitoring circuit (not shown) such that if a minimum temperature is reached, power to pump  224  is turned on. 
         [0026]    In this embodiment, steam generator  200  is located within a floor surface cleaning machine  202 . Floor surface cleaning machine  202  may have a surface cleaner housing and a base portion  232  which are connected at pivot point  234 . Although not shown, floor surface cleaning machine may include a handle, power cords, circuit boards, a water reservoir, motors, dust collecting chambers (or bags), beater bars, brushes, hand held attachments, etc. In some embodiments, floor surface cleaning machine utilized removable cloth pads to clean the surface. 
         [0027]    In this embodiment, pump  224  is located below steam generator  200  along axis A. In some embodiments, pump  224  is located below a water reservoir. In such embodiments, gravity may prime pump  224  with water from the water reservoir. In some embodiments, pump  224  is a self priming pump. In some embodiments, pump  224  is a metered pump. In some embodiments, first chamber  212  and/or second chamber  214  of steam generator  200  are disposed along axis A. As such, first chamber  212  and/or second chamber  214  of steam generator  200  are substantially orthogonal to the surface to be cleaned as depicted by axis B. 
         [0028]      FIG. 3  illustrates steam generator  300  within the housing  342  of a floor cleaner base  302 . In this embodiment, water flows from a water reservoir (not shown) and into pump inlet  330 , through pump  328 , through water hose  334 , and into steam generator. Steam generated in steam generator  300  travels through a conduit and out of the floor cleaner base  302  at nipple  338 . In some embodiments, floor cleaner base includes motor assembly  324  and motor shaft  326 , which drives beater bar  320  via flexible belt  322 . In some embodiments, floor cleaner base  302  includes wheels  336 . For example, in some embodiments, the floor cleaner includes a beater bar housing, beater bar  320  for agitating a cleaning surface, and a debris collection unit for collecting debris from the cleaning surface, wherein the debris collection unit is fluidly connected to the beater bar housing. 
         [0029]    In some embodiments, the steam generators are in any shape suitable for generating steam. In some embodiments, the steam generator may be substantially cylindrical, cuboidal, conical, rectangular, or spherical in shape. In some embodiments, the first chamber is substantially the same shape as the second chamber. In some embodiments, the first chamber has a different shape than the second chamber. For example, the first chamber may be substantially conical while the second chamber is substantially cylindrical in shape. 
         [0030]    Combinations of different features illustratively described in connection with the embodiments are also contemplated. Although the embodiments illustrated herein relate steam generators in a floor cleaner, alternative surface cleaner configurations (e.g., hand held, canister, etc.) are also contemplated. 
         [0031]    The various embodiments described above are provided by way of illustration only and should not be constructed to limit the invention. Those skilled in the art will readily recognize the various modifications and changes which may be made to the present invention without strictly following the exemplary embodiments illustrated and described herein, and without departing from the true spirit and scope of the present invention, which are set forth in the following claims.