Abstract:
A range hood having an improved grease collecting motor housing and improved fan and motor connection. Housing openings are defined by circular walls projecting vertically into the housing acting to collect grease within the housing. A flange depends radially outwardly from, and at an angle to, the circular wall. Air entering the housing via the fan deflects off the flange and prevents turbulent air within the housing from exiting the housing in the space located between the circular wall and the fan. The fan connection is comprised of a threaded recess in a shaft of the motor and a fan cap having a threaded bolt. The shaft is inserted through an aperture in the fan and the fan cap threadingly connected to it. A tray attachable to the housing, and defining an air intake opening has an improved mating relationship with a lower panel of the range hood.

Description:
FIELD OF THE INVENTION 
   This invention relates to range hoods, and more particularly to an improved motor housing for use within a range hood and a connector for attaching a fan to the fan motor. 
   BACKGROUND OF THE INVENTION 
   Domestic range hoods having a pair of motors horizontally installed in a motor housing within the hood body are used above cooking surfaces to remove grease, common odors and hazardous gases created during the cooking process. A fan is connected to each of the motors. The fans suck air from the cooking area below and force it through the motor housing to ventilation piping. 
   Efforts have been made to produce a thinner range hood. Generally, the extent to which the size of the range hood can be reduced has been limited by the size of the motor housing within the range hood and the size of the grease tray connected below the housing. A prior art design for a range hood  10  is shown in FIG.  1 . The motor housing  12  is divided into two substantially similar chambers and has a pair of circular walls  14  extending into the interior of the motor housing  12  (one for each chamber, only one of which is shown). The openings defined by walls  14  are dimensioned to allow the fans  16  to be removable from the motor housing interior. 
   The presence of the circular walls  14  prevents grease within the motor housing from draining back out through the opening. Instead, grease within the motor housing is directed to drainage hole located in the general area marked with reference numeral  18  where it travels to an external grease cup  20 . Because most of the grease collects in and drains from the motor housing, very little grease collects in tray  22 . Tray  22  acts mainly to control the airflow into the fan. While the combination of wall  14  and tray  22  does restrict most of the air drawn into fan  16  to that from outside of the range hood, some air from within the motor housing is able to pass from within the motor housing back to the fan as illustrated by arrow  24 . This reduces the overall suction power and efficiency of the range hood. 
   In addition, as best shown in  FIGS. 2 and 3 , fan  16  is attached to motor  11  and secured in place by way of fan cap  26 . The shaft  28  of the motor  11  fits within a channel  30  passing through the fan  16 . The threaded portion  29  of shaft  28  extends below the channel  30  such that fan cap  26  may be screwed on. A torsional member  32  fits within a recess in the fan so that rotational force may be transferred from the motor  11  to the fan  16 . However, because the shaft  28  and fan cap  26  extend below the level of the motor housing, the fan grill  34  must be conical in shape in order to allow sufficient space. As the vaporized grease contained in the entrained air passes by the fan grill  34  some of the grease condenses on the bars of the grill. Grease collecting on the grill drains along the bars of the grill to the lowest point until there is sufficient grease to form a drop. In order to prevent grease from dripping off the grill, an additional grill tray  36  is required. This must be removed and cleaned periodically and adds to the manufacturing costs. 
   It is therefore an object of an embodiment of the invention to provide a range hood that does not require a grill tray. 
   It is a further object of an embodiment of the present invention to provide a range hood, which has increased suction power over prior art range hoods of the same size. 
   It is a further object of an embodiment of the invention to provide a thinner range hood as compared to similar prior art range hoods. 
   Various aspects of the invention address these objects, but not all aspects of the invention necessarily address all such objects simultaneously. Other objects of the invention will be apparent from the description that follows. 
   SUMMARY OF THE INVENTION 
   The invention is directed to an improved motor housing for use within a range hood and a connector for attaching a fan to the fan motor. 
   In one aspect, the invention comprises a range hood for drawing air from below the range hood and venting it to another location comprising a motor housing, a motor, a fan, and a tray. The motor housing generally defines an enclosure and has an upper surface and a lower surface. The lower surface has at least one opening and at least one drain hole. The motor has a rotatable shaft with a torsional member and is mounted within the motor housing enclosure. The fan has a top fan surface and a bottom fan surface and a plurality of fan blades connected therebetween. The bottom fan surface has top and bottom edges and the fan is releasably connectable to the motor. The tray comprises an air intake opening, first and second tray walls extending around the intake opening, and a floor between the first and second tray walls. The tray is releasably connectable to the motor housing opening. The motor housing opening is defined by a wall depending from the lower surface and projecting into the interior of the enclosure, the wall having an angular flange depending from the wall radially outwardly from the motor housing opening. 
   In another aspect, a portion of the angular flange is located above the level of the top edge of the bottom fan surface such that when the fan draws air into the motor housing, a portion of air travelling immediately adjacent the bottom fan surface is deflected by the flange. 
   In a further aspect, the shaft has a threaded recess, the fan has an aperture through which the shaft may be inserted and a fan cap having a threaded bolt is threadingly engaged with the threaded recess of the shaft. 
   In yet another aspect a flat fan grill is connected to the first tray wall and when the fan is connected to the motor by the fan cap, the fan cap is above the level of a portion of the bottom fan surface. 
   In yet another aspect the motor housing is sized such that only a portion of the fan is located within the motor housing. The floor of the tray has a notch and a lowermost surface. 
   In yet another aspect the range hood has a range hood body having a releasably connectable lower panel. The lower panel has a bottom surface and an opening corresponding to the tray. When the lower surface is connected to the range hood body, the lower panel and the tray are in abutment and the lowermost surface and the bottom surface of the lower panel lie substantially in a plane. 
   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 
     The invention will be described by reference to the detailed description of the preferred embodiment and to the drawings in which: 
       FIG. 1  is a cross sectional view of a range hood according to the prior art; 
       FIG. 2  is a cross sectional view of the motor, fan and fan cap shown in  FIG. 1 ; 
       FIG. 3  is an exploded view of the motor, fan and fan cap shown in  FIG. 2 , with the right half of the fan shown in cross section; 
       FIG. 4  is a cross sectional view of a motor, fan and fan cap according to the preferred embodiment of the invention; 
       FIG. 5  is an exploded view of the motor, fan and fan cap shown in  FIG. 4 , with the right half of the fan shown in cross section; 
       FIG. 6  is a cross sectional view of a range hood according to the preferred embodiment of the invention; 
       FIG. 7  is a cross sectional view of an alternative embodiment of a range hood; 
       FIG. 8  is a perspective view of the range hood body, tray and fan grill shown in FIG.  6 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The preferred embodiment of a range hood  100  with a motor housing and fan connection according to the invention is illustrated in FIG.  6 . The motor housing  110  itself doubles as a grease catcher. Tray  140 , which has a fan grill  138  (shown best in  FIG. 8 ) attached to it, is releasably connectable to the motor housing  110 . Lower panel  108  of the hood body  102  abuts the tray  140  as discussed below. The housing  110 , tray  140  and fan connection will be described in greater detail below. 
   The housing  110  defines an enclosure and is mountable within the enclosure formed by the hood body  102 . The housing enclosure forms a pair of substantially similar chambers, only one of which is visible in the view provided in FIG.  6 . For simplicity, the contents of only one of the chambers will be described. A motor  125  is mounted within the motor housing  110 . Fan  120  is attached to the motor  125  and secured by fan cap  129 . This is illustrated best in  FIGS. 4 and 5 . The motor  125  has a shaft  106  having a threaded recess  107 . A torsional member  104  passes through shaft  106  just above the termination point of the threaded recess  107 . The fan  120  has torsional member receiving portion  127  projecting from its upper surface  121  within which the torsional member may be seated. A plurality of fan blades  123  are radially spaced along and connected between upper surface  121  and lower fan surface  122 . The fan  120  also has an aperture  128  through which shaft  106  may pass when the fan  120  is attached to the motor  125  (see FIGS.  4  and  5 ). The shaft  106  is dimensioned so as to extend just below the level of the radially inward portion of upper fan surface  121  when the motor and fan are connected. Fan cap  129  has an integral threaded bolt  131  that is dimensioned to engage with the threaded recess  107  and when so engaged acts to securely connect the fan and motor. Once secured, the fan cap remains above the level of, or approximately level with, lower fan edge  124  thereby allowing the use of a flat fan grill. 
   Fan grills  138 , shown best in  FIG. 8 , are preferably flat and made of metal and are designed to allow maximum airflow into motor housing  110 , while still preventing solid objects such as kitchen utensils or body parts from penetrating through the grill to fans  120 . Because the fan grills are flat, and are positioned horizontally, grease that collects on the grill surface does not pool in any one area and is less likely to form a drop that could fall to a surface below. This is different than the prior art grill  34 , which took the form of an inverted cone, from the bottom of which grease would drip into the fan grill tray  36 . No fan grill tray is needed with this new design. Instead, the grill may simply be wiped periodically in order to keep it clean. This also results in material and space savings, making the range hood less costly and more aesthetically pleasing to the eye. 
   As shown in  FIG. 6 , wall  130  depends and rises vertically from, and substantially perpendicular to, the lower surface  114  of the motor housing. The diameter of the opening in the motor housing  110  formed by wall  130  is larger than the maximum diameter of the fan  120 . A radially outwardly projecting flange  132  depends from wall  130  at an angle. Preferably the flange  132  is at an angle of 45 degrees to wall  130 , however other angles are suitable, provided that the flange is above the level of a top edge of the bottom fan surface  122  so that it is positioned in the path of air being forced into the motor housing by fan  120 . A portion of the air travelling immediately adjacent the bottom fan surface  122  is deflected by flange  132  as indicated by arrow  150 . Turbulent air, indicated by arrow  152 , that is circulating in the lower part of the motor housing is prevented from passing back between the fan and wall  130  into tray  140  where it could then reenter the fan as occurred with the range hood  10  of the prior art. Flange  132  acts to deflect the turbulent air  152  radially outward. In addition, any of the turbulent air travelling around the radially outer edge of the flange will come into contact with the deflected air  150  and will in turn be forced in that direction (radially outward). Preferably, wall  130  has a recessed portion  134  dimensioned for fitted engagement with tray  140 . However, it is also contemplated that wall  130  could be linear or could have an inward and downwardly extending lip projecting therefrom, forming a gap with wall  130  within which tray  140  may be wedged. 
   The tray  140  is circular and has inner wall  144 , concentric outer wall  142 , floor  146  and fan grill  138 , which is connected to inner wall  144 . Inner wall  144  is proximate to, and defines, an intake opening  112 . Outer wall  142  is distal from the opening in relation to the inner wall  144 . Outer wall  142  is shaped and dimensioned to fit within recessed portion  134  when tray  140  is connected with housing  110  so that a portion of outer wall  142  is in abutment with wall  130 . The diameter of inner wall  144  is smaller than the diameter of lower fan edge  124 . The tray  140  is dimensioned such that when connected with the motor housing  140 , the top of inner wall  144  is just above the level of lower fan edge  124 , thereby directing air through intake opening  112  into the housing  110  by way of the fan  120 . A clip or other form of suitable restraint (not shown) accessible on the outside surface of the motor housing may be used in conjunction with radial edge  148  in order to hold the tray in place. 
   The lower panel  108  is removable from the remainder of main hood body  102 . Lower panel  108  has a pair of openings corresponding to trays  140 . When connected to the remainder of the hood body  102 , the lower panel is in abutment with trays  140 . Preferably, floor  146  is a stepped surface with a step rising from the inner to outer walls  144 ,  142 . The stepped surface forms a notch against which lower panel  108  may be fitted in flush engagement with the tray  140  as shown in FIG.  6 . In this way, the bottom of tray  140  and the bottom of lower panel  108  are located substantially in the same plane. The size of the range hood may therefore be reduced by the amount of space in the prior art range hoods between the lower panel and the bottom of the tray (see FIG.  1 ). 
   Preferably, the motor housing is of reduced size such that only a portion of fan  120  is positioned inside the housing  110  as shown in FIG.  6 . When activated, motor  125  rotates fan  120 , which draws air through intake opening  112  and into motor housing  110 . Air drawn into the motor housing is then forced out of ventilation holes (not shown) in the upper surfaces of the housing  110  and hood body  102 . The reduction in size of the motor housing results in an increased air pressure within the motor housing when the range hood is operating. Without wall  130  and flange  132  a great deal of the air forced into the motor housing would escape as was the case with the prior art. The wall and flange thereby increase the suction power and efficiency of the range hood. 
   Motor housing  110  is shaped such that any accumulated grease or liquid that condenses on its inner surface is directed towards a drain hole  80 . Accumulated grease and liquids travel through hoses  84  by way of gravity to an external grease cup  126 . Wall  130  acts as a barrier to any condensed grease or other liquid that accumulates in the interior of the motor housing. Typically only a very small amount of grease drips from a fan  120  as most is dispersed by means of the centripetal force of the rotating fan. Any grease or liquid that does drip from the fan when it is no longer rotating tends to drip from lower fan edge  122  and is captured in tray  140 . As very little grease accumulates in tray  140 , it need only be cleaned periodically during regular maintenance of the range hood and need only have minimal depth. 
   An alternative embodiment of the invention is shown in FIG.  7 . Those aspects of the alternative embodiment that are identical to aspects of the preferred embodiment have identical reference numbers. As illustrated with the alternative embodiment the motor housing  210  in range hood  200  may also be sized so that fan  120  fits within its enclosure. In this embodiment, outer wall  242  of tray  240  is sized to fit within depression  234  in circular wall  230 . Circular wall  230  is of sufficient height such that flange  232  is positioned adjacent the entry point of air into the motor housing. Fan grill  238  is attached to inner tray wall  244 . The lower panel  208  and the tray  240  abut one another and the bottom surfaces of each lie substantially in the same plane. 
   The main difference between the preferred and alternative embodiments shown in  FIGS. 6 and 7  is in the sizing of the motor housings and trays. This is simply illustrative of the changes that may be made to aspects of the range hood while using the wall and flange. It is also contemplated that different fan types could be used. The fan connection system of the invention may also be used in association with the range hoods of the prior art. 
   By minimizing the space located between connecting parts, specifically the lower panel and tray, and by having a flat grill, the overall size of the range hood may be reduced. This more streamlined range hood is able to intake the same cubic feet per minute (cfm) of air of a larger range hood while taking up less space. Additionally, a smaller size translates into lower material costs in the construction of the range hood and additional savings in shipping and storing costs. 
   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.