Patent Publication Number: US-6712068-B1

Title: Cleaning fluid heating reservoir and motor assembly for a range hood

Description:
FIELD OF THE INVENTION 
     The present invention relates to range hoods for use above a cooking surface, and more particularly to a cleaning fluid heating reservoir and motor assembly for a range hood wherein cleaning fluid used to remove grease from the fans and interior of a motor housing is heated. 
     BACKGROUND OF THE INVENTION 
     Range hoods are used above cooking surfaces to remove grease, common odors and hazardous gases created during the cooking process. Typically, range hoods for domestic use have a pair of motors horizontally installed in a motor housing within the hood body. Each motor drives a fan. The fans draw air from the cooking area below and force it through the motor housing to ventilation piping. 
     As the vaporized grease in the entrained air travels through the motor housing, some of it condenses on the inside walls of the housing and may accumulate. It is therefore known to provide a cleaning fluid under pressure in order to clean the interior of the exhaust system. 
     It is also known in the art to place a refillable reservoir within the interior of the range hood so as to provide an internal supply of washing fluid. The reservoir is typically constructed of plastic in order to remove any concerns with respect to rust and is attached to the upper surface of the range hood body, towards the front of the range hood and separate from the motor housing. Fluid delivery means connected to the reservoir deliver fluid under pressure from the reservoir to the interior surfaces of the motor housing. The reservoir may be filled through a coverable hole located in the range hood exterior. Once used, the washing fluid and any grease travelling therewith drains to an external grease receptacle. 
     Because the reservoir is spaced apart from the motor housing, the temperature of the fluid contained within it remains at approximately room temperature. However, cleaning fluid becomes more effective at removing grease as its temperature increases. In addition, there is limited space available to accommodate the reservoir within the range hood body so its size remains limited and it must be refilled regularly. 
     It is therefore an object of an embodiment of the present invention to provide a range hood having an increased capacity for cleaning fluid so that the cleaning fluid reservoir need be refilled less often than those range hoods of the prior art having only a reservoir located externally to the motor housing. 
     It is a further object of an embodiment of the present invention to provide a range hood in which the cleaning fluid is heated above room temperature. 
     Other objects of the invention will be apparent from the description that follows. 
     SUMMARY OF THE INVENTION 
     According to the present invention there is provided a cleaning fluid heating reservoir and motor assembly for use in a range hood having a hood body defining an enclosure and a motor housing having top, bottom and perimeter side surfaces defining a further enclosure mounted therein. The assembly comprises a motor and a heating reservoir for cleaning fluid. The motor has a top, bottom and perimeter and is equipped with a fan. The fan and a substantial portion of the motor are contained within the motor housing. The heating reservoir is shaped and positioned substantially in abutment with a portion of said motor and has an inlet and an outlet. 
     In a further aspect of the invention, a portion of the heating reservoir is positioned between the top of the motor and the hood body. Alternatively, a portion of the heating reservoir is positioned between the perimeter of the motor and the fan or between both the top of the motor and the hood body and the motor and the fan. 
     In a further aspect of the invention, the assembly further comprises an intermediate reservoir located within the range hood body exterior to the motor housing. The intermediate reservoir is adapted to deliver cleaning fluid to the heating reservoir via the inlet. 
     The assembly of may further comprise a pair of conduits passing through the perimeter side surface of the motor housing, a first of the pair of conduits connecting to the inlet and a second of the pair of conduits connecting to the outlet. A first is connected to the intermediate reservoir and to the first conduit for pumping fluid from the intermediate reservoir to the heating reservoir. A second pump is connected to the intermediate reservoir and to fluid delivery means for delivering cleaning fluid to the interior of the motor housing. 
     The heating reservoir of the assembly may comprise an outer shell defining a compartment or piping wrapped about the motor. 
     Other aspects of the invention will be appreciated by reference to the detailed description of the preferred embodiment and to the claims that follow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings and wherein: 
     FIG. 1 is a cross sectional view of a range hood equipped with the cleaning fluid heating reservoir and motor assembly according to the preferred embodiment of the invention; 
     FIG. 2 is a perspective view of the cleaning fluid heating reservoir and motor assembly shown in FIG. 1; 
     FIG. 3 is a cross sectional view of a range hood equipped with a cleaning fluid heating reservoir and motor assembly according to an alternative embodiment of the invention; 
     FIG. 4 is perspective view of the cleaning fluid heating reservoir and motor assembly shown in FIG. 3; 
     FIG. 5 is a perspective view of a further alternative embodiment of a cleaning fluid heating reservoir and motor assembly; 
     FIG. 6 is a perspective view of a further alternative embodiment of a cleaning fluid heating reservoir and motor assembly; and 
     FIG. 7 is a partial top view of the cleaning fluid heating reservoir and motor assembly shown in FIG. 6 showing the fastening means. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred embodiment of range hood having a cleaning fluid heating reservoir  20  according to the invention is shown in FIGS. 1 and 2. An alternative embodiment of a cleaning fluid heating reservoir  50  is shown in FIGS. 3 and 4. Further alternative embodiments are shown in FIGS. 5 and 6. 
     FIG. 1 shows a range hood for mounting above a cooking surface to remove unwanted gases generated during the cooking process. A motor housing  10  defines an enclosure and is mountable within a further enclosure formed by a range hood body  2 . The motor housing has a top surface  6 , a bottom surface  8  and a perimeter side wall  14 , which when viewed from the top of the motor housing generally defines a figure-eight. Preferably the motor housing is made of metal and is coated to prevent rust. The interior of the housing  10  may be coated with a non-stick material so as to facilitate grease removal and is separated into two substantially similar, separate chambers  4 , only one of which is visible in FIG.  1 . 
     Each respective chamber  4  has an air inlet defined in the bottom surface  8  of the motor housing  10  and a ventilation hole (not shown) defined in top surface  6 . Each chamber is designed to accommodate a motor  15  having a top, bottom and perimeter and a fan  12  which act to draw hot, grease laden air from above the cooking surface, into the chamber  4  of the motor housing  10  and out the ventilation hole. The fan  12  is connected to the motor  15  by way of fan cap  11 . A tray  40  may be connected to the motor housing in the area of the air inlet in order to direct air being drawn into the motor housing by the fan and to capture any grease dripping off the outer surface of the fan. A fan grill  42  prevents the insertion of objects into the fan. 
     The motor  15  is mounted to a bracket  3  that in turn is connected to the hood body  2 , preferably by welding. Preferably screws are used to mount the connectors  16  of the motor to bracket  3  as is known in the art. After the motor is mounted in place, the motor housing  10  is also attached, also by way of screw or the like, to bracket  3 . 
     The cleaning fluid heating reservoir  20  has a solid outer shell defining a compartment. Heating reservoir  20  is shaped so as to trace the outer contour of motor  15  as best shown in FIG. 2, with a top reservoir portion  25  and a perimeter reservoir portion  23 . Heating reservoir  20  is further shaped and dimensioned so as to occupy the available space between the top of the motor  15  and the hood body  2  and between the motor  15  and the fan  12  (without coming into contact with the fan). A fastening means  47  may be used in order to ensure that the perimeter reservoir portion  23  remains in abutment with the motor  15 . When the motor is mounted to the bracket  3 , the top reservoir portion  25  is sandwiched between the hood body  2  and the top of the motor  15 . Preferably the heating reservoir is made of a non-rusting, heat conducting metal such as copper. When the motor  15  is in operation heat is generated that is conducted through the heating reservoir  20  to the cleaning fluid contained within. In addition heated air from the cooking surface raises the temperature within the motor housing. The temperature of the heating fluid is thereby raised well above that of the normal room temperature, making it more effective at removing grease that it comes into contact with when used for cleaning purposes as discussed below. 
     A further intermediate reservoir  30  is located externally to the motor housing  10 . Intermediate reservoir  30  may be filled by pouring cleaning fluid through an opening in the range hood body (not shown), through conduit  38  and inlet  36  into the reservoir. A pump  32  may be activated to pump cleaning fluid from the intermediate reservoir  30  through conduit  34  and inlet  22  to the entry portion  18  of the heating reservoir  20 . The cleaning fluid pumped into heating reservoir  20  fills top portion  25  and perimeter portion  23  before exiting through outlet  24  and passing through conduit  26  back to intermediate reservoir  30  by way of inlet  27 . Preferably inlet  27  projects into the lower interior of the intermediate reservoir so as to place heated water from heating reservoir  20  in close proximity to the outlet to spray dispensing means, which will be discussed below. 
     Fluid delivery means connected to the intermediate chamber  30  deliver the cleaning fluid under pressure to the interior surfaces of the range hood, in particular the motor housing. In the preferred embodiment, a further pump  28  may be activated to pump cleaning fluid from the intermediate reservoir by way of an outlet, through conduit  29  to a spray dispenser such as nozzle  31 . While the spray dispenser  31  acts to spray cleaning fluid onto the fan and into the interior of the motor housing, other spray dispensers fed by pump  28  or other such pumps may be located to clean other parts of the motor housing. It is contemplated that other fluid delivery means could be used, the essential aspect being that the intermediate reservoir and heating reservoir be in fluid communication with cleaning fluid and that the heated cleaning fluid may be used for cleaning purposes. Used cleaning fluid, grease and other liquids within the motor housing chambers drain out through drainage hose  44  to external grease cup  46 . 
     Preferably, the conduits  26 ,  29 ,  34 ,  38  are formed of heat resistant flexible hose. Hoses  26  and  34  must pass through openings (not shown) in the side of the motor housing  10 . In order to prevent any air or grease within the motor housing from passing through these openings in the motor housing, some form of seal is used, such as a rubber gasket seal. Some form of retainer may also be present to retain the hoses  26  and  34  in contact with the hood body  2  so as to avoid coming into contact with fan  12  as shown in FIG. 1 
     In the alternative embodiment shown in FIGS. 3 and 4, the heating reservoir  50  is in the form of piping wrapped about the top and side of the motor  15 . Piping  50  is constructed of a heat conducting, non-rusting metal, preferably copper. However, any material meeting the necessary criteria (heat conducting and non-rusting) would be satisfactory. The conduit need not take the specific form of piping, but instead need only provide channels or the like within which cleaning fluid may be contained and which provides an increased surface area of heat conducting material in contact with the cleaning fluid. Components identical to those of the preferred embodiment have been identified with identical reference numbers. 
     Cleaning fluid from intermediate reservoir  30  is delivered by pump  32  through hose  34  and inlet  22  into piping entry  58 . The cleaning fluid then courses through the top piping  55  and side perimeter piping  53  to piping exit  59  where it passes through outlet  24  and hose  26  to inlet  27  and back into the intermediate reservoir  30 . Once in the piping, the cleaning fluid is heated via conduction in a similar fashion to the preferred embodiment. However, because there is more heat conducting material in relation to the volume of cleaning fluid, the cleaning fluid may be heated at a faster rate and to a higher overall temperature. 
     As with the preferred embodiment, the heating reservoir  50  is shaped and dimensioned to be in abutment with the motor while occupying the available space above and about the motor  15 , without coming into contact with the fan  12 . 
     The heating reservoir need not be positioned above the top and about the perimeter at the same time. As shown in the alternative embodiment in FIG. 5, the heating reservoir  60  may simply be located about the perimeter of the motor  15 . Alternatively, as shown in FIG. 6, the heating reservoir  70  may simply be located on top of the motor  15 . 
     The fastening means to retain the heating reservoir in position about the motor becomes more important when there is no top reservoir portion sandwiched between the top of the motor and the hood body to hold the perimeter portion in place. The fastening means  47  is best illustrated in FIG.  7 . Preferably a pair of spaced apart flanges  52  project radially from the perimeter heating reservoir  60 , one flange on the entry portion of the perimeter heating reservoir and the other located on the exit portion of the heating reservoir, the two portions being spaced apart as shown in FIGS. 6 and 7. A bolt  48  is inserted through an opening in each of the flanges  52  and connected to a nut. Preferably a spring  51  is positioned between the flange and the head of the bolt, or between the flange and the nut. The nut and bolt are tightened until the heating chamber is firmly tightened about the motor. Should the heating chamber expand as a result of heating, the spring will take up any give in the connection, thereby maintaining the heating reservoir in position about the motor. 
     It is contemplated that the pumps may be controlled automatically by a programmable system or manually. Preferably, pump  32  will be activated whenever the motor  15  is turned on. In that way, a constant flow of water will be coursing through the heating reservoir absorbing heat energy from the conducting surface. This will act to both heat the cleaning fluid and conversely to cool the motor (heat is drawn away from it). In addition to providing heated cleaning fluid that is more efficient at removing grease, is this has the added benefit of extending the useful life of the motor by reducing the temperature at which it operates. 
     The intermediate reservoir  30  may also be equipped to determine the temperature of the cleaning fluid contained therein. Pump  32  may also be equipped with a shut off valve so that once the cleaning fluid within the intermediate reservoir  30  reaches a specified temperature, the pump  32  shuts off. Once the temperature drops to a set temperature, pump  32  reactivates. Such a setup would help to extend the life of pump  32  by reducing the length of time that it is in operation. The pump  28  for directing fluid from the intermediate reservoir  30  to the fluid delivery means may also be activated automatically, for example after a specified number of days or range hood uses, or manually. 
     It is contemplated that there may be one or more intermediate reservoirs  30  and associated pumps for use in association with the two heating reservoir and motor assemblies of the range hood (one heating reservoir and motor assembly in each chamber of the motor housing). 
     The addition of the heating reservoirs provides additional storage area for cleaning fluid. When combined with the storage capacity of the intermediate reservoir  30 , the heating reservoirs allow a range hood to contain a greater volume of cleaning fluid than the prior art designs having only cleaning fluid reservoirs located externally to the motor housing. In addition, the heating reservoirs may utilize only existing space within the range hood body, so the overall size of the range hood need not be increased in order to accommodate it. 
     It is contemplated that other materials such as heat resistant plastic could be used to form the heating reservoirs. While the use of plastic would not provide the same amount of heat transfer from the motor to the cleaning fluid within the heating reservoir, it is more convenient and less costly to use. 
     It will be appreciated by those skilled in the art that the preferred and alternative embodiments have been described in some detail but that certain modifications may be practiced without departing from the principles of the invention.