Abstract:
An apparatus for delivering a compound includes a reservoir containing a compound to be delivered to the environment of use. The compound includes fragrances and insecticides. A compound permeable substrate includes a wick which extends from the substrate into the reservoir. A centrifugal fan is operatively associated with the compound permeable substrate to force air over the substrate when the fan is operational. A cover is disposed over the centrifugal fan in which the cover has at least one aperture on a top surface and provides for a side air passage from the centrifugal fan to the environment.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a centrifugal fan device and, in particular, a centrifugal fan device which is adapted for delivering a fragrance or an insecticide to an environment during use. 
     BACKGROUND OF INVENTION 
     Many devices and apparatuses have been developed for delivering a fragrance (such as an air freshener) or insecticide (for example, citronella) to an environment of use. Some devices disseminate the fragrance or insecticide (collectively referred to as a compound) using passive means. Examples of devices with passive means include devices having a compound evaporate from a substrate or membrane which disseminate the compound into the environment. Other passive devices have a reservoir which contains a compound which is released into the environment as the compound evaporates. 
     In addition to the aforementioned passive devices, active devices have been developed to aid in the dissemination of the compound. Some active devices have fans which enhance the dissemination of a compound from either a substrate, membrane or reservoir. Still other devices have a heat source, separately or in combination with a fan, to disseminate the compound into the environment. 
     There is a need in the art for an improved apparatus for enhanced compound delivery. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a centrifugal fan device which is adapted for delivering a compound, such as a fragrance or insecticide, to an environment of use. Advantageously, the device has a reservoir for containing the compound and a compound permeable substrate. The substrate includes a series of legs or wicks which extend from a horizontal surface of the substrate to the reservoir, whereby the compound is wicked from the reservoir to the horizontal surface. 
     In one advantageous form, the horizontal surface of the substrate forms a top over the reservoir. In an alternative form, a cap or plug is disposed between the reservoir and the substrate, forming a cover over the reservoir. The cap or plug has holes of a sufficient size which allow the legs or wicks to extend through the holes, and into the reservoir, thereby allowing the compound to be wicked from the reservoir to the horizontal surface of the substrate. 
     A fan motor is disposed within a fan housing, and a centrifugal fan is connected to the motor. A cover having at least one aperture on a top surface is disposed over the centrifugal fan. The cover provides for a side passage from the centrifugal fan to the environment of use. 
     During operation, advantageously, the centrifugal fan draws in air from the environment of use through the aperture in the top of the cover, axially down to the centrifugal fan, radially across the compound permeable substrate, and out the side passage, back to the environment of use. In one specific embodiment, the side passage is defined by a gap formed between the cover and a base containing the reservoir. 
     The present invention, in one form thereof, comprises an apparatus for delivering a compound to an environment of use. The apparatus comprises a base having an exteriorly disposed reservoir defining a center cavity. The reservoir contains a compound. A compound permeable substrate has a substantially horizontal surface and at least one wick extending from the substrate into the reservoir. When a compound is disposed in the reservoir, the compound will be wicked from the reservoir onto the compound permeable substrate. A fan motor is disposed in the center cavity. A centrifugal fan is operatively associated with, and extends upward from, the fan motor. A cover is disposed over the centrifugal fan. The cover has at least one aperture through a top surface and provides a side air passage from the centrifugal fan to the environment of use. 
     In one embodiment, the cover comprises a plurality of apertures. In an alternative embodiment, the cover comprises a disc spaced from a main portion of the cover and is disposed over the at least one aperture. In a further specific form, the disc is attached to the main portion of the cover via a plurality of legs. 
     In accordance with another specific embodiment of the present invention, the base is annularly shaped, as is the reservoir defining the center cavity into which the fan housing is disposed. 
     The present invention, in another form thereof, is an apparatus for delivering a compound to an environment of use comprising a reservoir for containing a compound and a compound permeable substrate having a substantially horizontal surface. At least one wick extends from the substrate into the reservoir, wherein, when a compound is disposed in the reservoir, the compound will be wicked from the reservoir onto the compound permeable substrate. A centrifugal fan is at approximately a same level as a top surface of the compound permeable substrate. A cover is disposed over the centrifugal fan. The cover has at least one aperture on a top surface and provides for a side air passage from the centrifugal fan to the environment of use. During use, the centrifugal fan draws in air from the environment of use, through the aperture in the top of the cover, axially down to the centrifugal fan, radially across the compound permeable substrate, and out the side passage, back to the environment of use. 
     The above and other aspects of the present invention will be apparent from the following description of the preferred embodiments of the invention and from the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following detailed description of specific non-limiting embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structures are indicated with like reference numbers. 
         FIG. 1  is an elevational view of a centrifugal fan device, in accordance with one embodiment of the present invention. 
         FIG. 2  is a cross-sectional view of the centrifugal fan device of  FIG. 1 . 
         FIG. 3  is a perspective view of a centrifugal fan device, in accordance with another embodiment of the present invention, with a partial cutaway portion of a base thereof. 
         FIG. 4  is a cross-sectional view of the centrifugal fan device of  FIG. 3 . 
         FIG. 5  is a top plan view of a centrifugal fan of the respective devices in  FIGS. 1 and 3 . 
         FIG. 6  is a perspective view of the centrifugal fan of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described with regard to  FIGS. 1 ,  2 ,  5  and  6 , and, in particular,  FIGS. 1 and 2 . Centrifugal fan device  10  includes a base  20 , a compound permeable substrate  30 , a fan assembly  40  and a cover  50 . 
     The base  20  has an annularly shaped reservoir  22  into which a compound  24 , such as a fragrance or insecticide, is disposed. The annularly shaped reservoir  22  defines a cylindrically shaped center cavity  26  into which the fan assembly  40  is disposed. A cap, such as plug  28 , has a complementary annular shape to that of the reservoir  22 , which completely covers the reservoir  22 . Although the base  20  of device  10  is annularly shaped, the base can be triangular, rectangular, pentagonal, etc. 
     The compound permeable substrate  30  is advantageously annularly shaped, adapted to be disposed over the plug  28 . A plurality of wicks  32  extend from a horizontal surface  31  into the reservoir  22  and are, thus, in contact with the compound  24 . A series of bores  29  in the plug  28  are of a sufficient size to allow the wicks  32  to extend down from the horizontal surface  31 , through the plug  28 , to the reservoir  22  below. As a result, the compound  24  is able to be wicked from the reservoir  22  up the plurality of wicks  32  to the horizontal surface  31 . 
     The fan assembly  40  includes a housing  41  which contains an electric motor  42  and batteries  44 , although other means for powering the electric motor may be used. Further, the fan assembly  40  includes a centrifugal fan  46 . The centrifugal fan  46  further comprises a plurality of fan blades  48 . Advantageously, a base  49  of the centrifugal fan  46  is approximately at the same level as a horizontal surface  31  of the compound permeable substrate  30 . 
     Advantageously, the electric motor  42  propels the centrifugal fan  46  with RPMs between 100 and 4,000 and, preferably, between 200 and 600 RPMs. Further, advantageously, the centrifugal fan  46  has between 5 and 15 blades  48  and, preferably, between 10 and 14 blades. The centrifugal fan  46  has a fan blade outlet angle (β) between 30° and 150° and, preferably, between 90° and 145°. The centrifugal fan  46  has a fan blade inner height (Hi) between 5 mm and 15 mm and, preferably, between 9 mm and 12 mm, and has a fan blade outlet height (Ho) between 20% and 100% of the fan blade inlet height and, preferably, 50% of the inlet height. The centrifugal fan  46  has a fan blade inner radius (Ri) between 5 mm and 15 mm and a fan blade outer radius (Ro) of greater than or equal to (≧) 20 mm. 
     The cover  50  is disposed over the centrifugal fan  46 . The cover comprises a plurality of apertures  52 . The cover  50  provides for a side air passage from the centrifugal fan  46  to the outside environment, as identified by arrows  60 . In one advantageous form, the passage is provided by a gap between the cover  50  and the base  20 . The cover  50  is attached to the base  20  using a plurality of legs  54 . 
     During use of the centrifugal fan device  10 , the electric motor  42 , powered by batteries  44 , drives the centrifugal fan  46  to rotate, thereby drawing air in from the environment through the apertures  52  in the cover  50 , as indicated by arrow  62 . The air continues axially downward to the centrifugal fan  46 . Then, the centrifugal fan  46  forces the air over the horizontal surface  31  of the compound permeable substrate  30  and, finally, the air exits the device  10  through the gap between the cover  50  and base  20 , as identified by arrows  60 . 
     Since the centrifugal fan  46  is substantially at the same height as a horizontal surface  31 , and it directly forces air across the surface, the size of the horizontal surface  31  is minimized, as compared to the size it would have to be to achieve the same compound dispersement were the fan not at the same height as the substrate. 
     In addition, the centrifugal fan device  10  allows for a 360 degree dispersion of a compound  24  using the centrifugal fan  46 , which draws air axially downward, in towards a center of the device, and blows air radially 360 degrees over a compound permeable substrate  30 , which, as a result, becomes an evaporating surface. 
     Although the reservoir  22  is located below the centrifugal fan  46  in device  10 , a reservoir and compound permeable substrate can be located above the centrifugal fan, e.g., in the cover section of the device. 
     Referring now to  FIGS. 3 and 4 , where like elements to those in  FIGS. 1 and 2  have been increased by 100, centrifugal fan device  110  represents an alternative embodiment which is essentially the same as that of centrifugal fan device  10 , except for having a different cover. Accordingly, various elements, which are the same as those in centrifugal fan device  10 , are not specifically repeated here, as they are essentially the same as those in centrifugal fan device  10 . 
     Cover  150  comprises a disc  157  which is disposed over aperture  156 . A plurality of legs  158  attach the disc  157  to a main portion  159  of the cover. During use of the centrifugal fan device  110 , when the centrifugal fan motor  142  is energized, thereby causing the centrifugal fan  146  to spin, air is drawn in from the environment between the disc  157  and a main portion of the cover  159 , as indicated by arrow  161 . Air continues through the aperture  156 , as indicated by arrow  162 , and is then blown radially 360 degrees over the horizontal surface  131  of the compound permeable substrate  130 , which thereby acts as an evaporating surface for the compound  124 . 
     It will now be apparent that the present centrifugal fan device provides features and advantages not found in prior devices for delivering a fragrance or insecticide. For example, the combination of the centrifugal fan  46 , 146 , and its location adjacent the compound permeable substrate  30 , 130 , allows for better compound delivery, as compared to other known passive and/or heated devices. 
     A further advantage of the present centrifugal fan device is that it allows for a small, more compact device, due to better air flow across the compound permeable substrate  30 , 130 . As a result, the present centrifugal fan device  10 , 110  allows the compound permeable substrate  30 , 130  to have a smaller surface area and requires fewer wicks  32 , 132  and/or allows for a reduction in the size of wicks  32 , 132 , as compared with prior devices, in order to achieve the same compound  24 , 124  delivery to the environment of use. 
     An additional advantage of the present centrifugal fan device is that it has less resistance to air flow, as a result of the present configuration, thus requiring a minimal amount of energy and, thus, prolonging battery life, as compared with prior devices. 
     The exemplary embodiments herein disclosed are not intended to be exhaustive or to unnecessarily limit the scope of the invention. The exemplary embodiments were chosen and described in order to explain the principles of the present invention so that others skilled in the art may practice the invention. As will be apparent to one skilled in the art, various modifications can be made within the scope of the aforesaid description. Such modifications being within the ability of one skilled in the art form a part of the present invention and are embraced by the appended claims.