Abstract:
Wearable devices for dispensing insect repellents, fragrances, and/or other chemicals along the outside of the clothing of a human are disclosed. They are of the type that are clipped onto a belt or the like, and use a powered fan to dispense active. They are configured with fan rotor arrangements to minimize power use while still achieving acceptable air flow rates. These changes permit use of smaller batteries and more compact arrangements for battery positioning. This in turn permits a much more compact and lightweight construction to achieve the desired results. The devices are also provided with a rotatable clip structure to render use of the device more comfortable when the user is seated and to provide greater control over the direction of the dispensing. Further, they are provided with modified lids to facilitate active refill replacement.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     Not Applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to wearable devices that dispense chemicals such as insect repellents and/or fragrances. 
     Various techniques have been developed to provide humans with protection from insect bites. For insect control inside buildings a primary emphasis is placed on trying to keep insects from entering the building at all (e.g. placing screens over windows). This sometimes is supplemented with chemical treatment of room air and/or the use of traps. See e.g. U.S. Pat. Nos. 6,582,714 and 7,175,815, and also U.S. Patent Application Publication Nos. 2005/0079113, 2006/0039835, 2006/0137241 and 2007/0036688. 
     When the individual is outdoors where the area cannot be effectively screened, and the individual is mostly staying in a particular area (e.g. at a picnic, or on a patio near a building), traps and area-repellents are the primary focus. 
     Alternatively, when the individual is moving away from a single area that they control, individuals often apply a personal insect repellent to clothing or directly to their skin. However, some consumers have expressed a reluctance to apply insect repellents directly to their skin or to delicate clothing. 
     As a result, portable electrical devices having a fan and an insecticide source have been developed. These devices may have a clip so that they can easily be mounted on a belt, a purse, or even a pocket, and thus be “worn” by the consumer as they move outside. The device may draw air through, or blow air past, a substrate impregnated with an insect repellent or other air treatment chemical, thereby dispensing the active into the air, preferably (in the case of a repellent) downward along the outside of a human&#39;s clothing. See, for example, U.S. Pat. Nos. 6,926,902, 7,007,861, 7,152,809, and 7,168,630, and U.S. Patent Application Publication Nos. 2003/0044326, 2003/0175171, 2007/0183940, and 2009/0060799 (also ES 1063655). 
     However, some such devices may blow the active too far out away from the human body, causing too little of the active to reach locations of primary concern (e.g. near ankles). Other such devices do not provide a way of minimizing waste of the active, such as while blower operation is suspended between uses. Still other such devices are unduly costly, are too heavy, or have other deficiencies. 
     The deficiencies in the above noted devices have been addressed by the wearable chemical dispensers described in U.S. Patent Application Publication Nos. 2008/0141928 and 2009/0008411. However, it is still desirable to improve this type of product further, particularly with respect to making the device even more compact and lightweight, making the device easier to use when the consumer is seated, and making the refill unit for the air treatment chemical easier to replace when used up. 
     Hence, a need still exists to improve devices of this type in these areas. 
     SUMMARY OF THE INVENTION 
     In one aspect the invention provides a wearable device for dispensing an air treatment chemical, where the device has: 
     (a) a housing including an inlet for permitting air to enter into an interior space of the housing and including an outlet for permitting air mixed with air treatment chemical to exit the interior space; 
     (b) a substrate positioned in the housing, the substrate bearing an air treatment chemical; 
     (c) a power supply mounted to the housing; 
     (d) a motor mounted in the housing, the motor being powered by the power supply; and 
     (e) a fan mounted in the housing, the fan being capable of moving air from the inlet adjacent the substrate so as to mix air treatment chemical into the moving air, and then deliver a mixture of air and air treatment chemical through the outlet to outside of the housing, the fan including a rotor connected to the motor and a plurality of spaced apart blades connected to and extending away from the rotor. 
     In one form, the device can maintain an average volumetric flow rate of air of at least 1.5 cubic feet per minute (cfm) (0.042 m 3 /min.) over a twelve hour period with the device consuming from the power supply 0.35 watts or less of power for the twelve hour period. 
     In particularly preferred forms of this aspect of the invention the fan includes 12 to 18 blades (e.g. 13 to 15 blades, e.g. 14 blades), and each blade has a body extending from an inner edge to an outer edge, the inner edge of each blade being spaced a distance from a centerpoint of the rotor along a radial line from the centerpoint of the rotor, the body of a plurality of such blades: 
     (a) forming an included angle with its associated radial line in the range of 100 to 150 degrees; and/or 
     (b) having a length measuring 80% to 130% of a distance from a centerpoint of the rotor to the inner edge of the blade; and/or 
     (c) having a length measuring 45% to 75% of a distance from a centerpoint of the rotor to the outer edge of the blade; and/or 
     (d) having a length from a centerpoint of the rotor to an outer edge of the rotor of 10 to 50 millimeters. 
     The rotor can include a central wall spaced inward from a perimeter of the rotor and the wall defines a recess in the rotor. At least a portion of the motor is positioned in the recess, and the blades extend from the wall radially outward toward the perimeter of the rotor. 
     In other preferred forms the housing has a plurality of spaced apart openings, the openings being spaced around at least 180 degrees (more preferably at least 235 degrees) of a side structure of the housing, and a plurality of the blades are substantially perpendicular to a front wall of the housing, the front wall of the housing having an array of inlet apertures. The device can produce an average volumetric flow rate of air of at least 1.5 cubic feet per minute over a twelve hour period (preferably for an even longer period), yet is so efficient in energy use and power requirements more compact batteries (e.g. AAA rather than AA) can be used to power the device. This not only makes the device more compact from that factor, this permits the batteries to be positioned in an otherwise unavailable location, thereby further reducing the size and weight of the device. 
     In another aspect the invention provides a wearable device for dispensing an air treatment chemical, where the device has: 
     (a) a housing including an inlet for permitting air to enter into an interior space of the housing and including an outlet for permitting air mixed with air treatment chemical to exit the interior space; 
     (b) a substrate positioned in the housing, the substrate bearing an air treatment chemical; 
     (c) a power supply mounted to the housing; 
     (d) a motor mounted in the housing, the motor being powered by the power supply; 
     (e) a fan connected to the motor, the fan being capable of moving air from the inlet adjacent the substrate so as to mix air treatment chemical into the moving air, and then deliver a mixture of air and air treatment chemical through the outlet to outside of the housing; and 
     (f) a clip rotatably connected to an outer wall of the housing. 
     Preferred forms of this device are where one of the clip and the outer wall of the housing includes a projection, the other of the clip and the outer wall of the housing includes an arcuate well, and the projection moves in the well when rotating the clip. For example, the well can be dimensioned such that the clip can rotate at least 90 degrees, and there can be a means for indexed rotational positioning of the housing and the clip relative to each other. This latter feature can be a detent system where there is a flexible tab on one of the clip and housing, and a series of distinct rest positions for the tab on another of the clip and housing. For example, each such rest position can be in the form of a depression, and the tab can have a projection thereon. 
     In yet another aspect of the invention there is provided a wearable device for dispensing an air treatment chemical, the device having: 
     (a) a housing including a first main housing section and a second lid housing section, the first main housing section and the second lid housing section defining an interior space of the housing when the first main housing section and the second lid housing section are in a closed position, the housing having an inlet for permitting air to enter into an interior space of the housing, and an outlet for permitting air mixed with air treatment chemical to exit the interior space; 
     (b) a substrate positioned in the interior space of the housing, the substrate bearing an air treatment chemical; 
     (c) a power supply mounted to the housing; 
     (d) a motor mounted in the interior space of the housing, the motor being powered by the power supply; 
     (e) a fan connected to the motor, the fan being capable of moving air from the inlet adjacent the substrate so as to mix air treatment chemical into the moving air, and then deliver a mixture of air and air treatment chemical through the outlet to outside of the housing; and 
     (f) a hinge mechanism connecting the first main housing section and the second lid housing section for governing pivotal movement between a closed position and an open position of the second lid housing section relative to the first main housing section, the hinge mechanism comprising a pair of spaced apart hinge arms mounted on the second lid housing section, and a pair of spaced apart notches positioned on the first main housing section, each hinge arm including a pivot pin, each pivot pin capable of rotating within an associated one of the notches. 
     In preferred forms of this aspect of the invention the pivot pin of each hinge arm extends laterally adjacent an end of the hinge arm, each such pivot pin having an outer wall having a flat section, and the flat section of each such pivot pin is mounted in a notch to contact a flat surface of its associated notch when the second lid housing section is in the fully open position. 
     Each such pivot pin may also have on an outer wall a second flat section, and the second flat section of each pivot pin contacts a flat surface of its associated notch when the second lid housing section is in the fully open position. For example, the notches can be generally rectangular. These structures are most useful when their is a frame in the housing for supporting the substrate, the frame including a pair of slots, and each of the hinge arms moves within one of the slots during pivotal movement between the closed position and the fully open position of the second lid housing section. 
     Hence, it should be appreciated that the devices of the present invention have more efficient power usage, thereby permitting smaller power supplies and in any event a more compact and more lightweight assembly. Further, these devices make it more comfortable for the device to be operated even when the consumer is sitting and also provide greater control of the dispensing direction. Also, the special hinging and notch arrangement holds the lid open during replacement of the refill of active, but will cause the lid to snap to the closed once the lid is moved to a defined midpoint. This facilitates refill replacement. 
     These improvements lower the cost of production, permit the device to be operated at lower cost, and meets consumer preferences to minimize the weight of the device if a device like this is to be used. 
     These and other advantages of the present invention will become better understood upon consideration of the following detailed description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a left, top, frontal perspective view of a wearable chemical dispenser according to the invention; 
         FIG. 2  is a left side elevational view of the dispenser of  FIG. 1 ; 
         FIG. 3  is a right side elevational view of the dispenser of  FIG. 1 ; 
         FIG. 4  is a rear elevational view of the dispenser of  FIG. 1 ; 
         FIG. 5  is a right, bottom perspective view of the dispenser of  FIG. 1 , albeit with the lid in an open position; 
         FIG. 6  is an exploded perspective view of the dispenser of  FIG. 1 ; 
         FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 5 ; 
         FIG. 8  is an enlarged detailed perspective view focusing on the hinge supports of the dispenser of  FIG. 1 ; 
         FIG. 8A  is an enlarged detailed cross-sectional view of one arm of the hinge in one hinge support, with the lid in a fully open position; 
         FIG. 8B  is a view similar to  FIG. 8A , but with the lid instead in only a partially open position; 
         FIG. 8C  is a view similar to  FIG. 8A , but with the lid instead in the closed position; 
         FIG. 9  is a view taken along line  9 - 9  of  FIG. 7 , albeit with the clip added in phantom to show where its relative position would be if viewable in rear view; 
         FIG. 10  is an enlarged frontal view of the rotating clip of the dispenser of  FIG. 1  by itself; and 
         FIG. 11  is a top view of the rotor fan of the dispenser of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred example wearable chemical dispenser  18  is shown in  FIGS. 1-11 . The wearable chemical dispenser  18  includes a top housing section  20  having a generally oblong side wall  22  that extends from a top wall  23 . In use, the wall  23  is typically frontally disposed and acts as a lid. A plurality of spaced apart apertures  24  are radially arranged in the top wall  23  of the top housing section  20 . The apertures  24  provide an inlet for permitting air to enter into an interior space of the wearable chemical dispenser  18 . A tab  26  provides a means to grasp the top housing section  20  when opening the top housing section  20 . 
     The wearable chemical dispenser  18  also includes a slide cover  28  having an on-off button  29 , openings  31 , and a cam projection  32 . A fastener  34  (see  FIG. 6 ) mounts the slide cover  28  to the top housing section  20  such that the slide cover  28  may rotate with respect to the top housing section  20  when a user moves the on-off button  29  along the side wall  22  of the top housing section  20 . In the ‘off’ position, the slide cover  28  closes the apertures  24  that are radially arranged in the top wall  23  of the top housing section  20 . In the ‘on’ position, the openings  31  of the slide cover  28  align with the apertures  24  that are radially arranged in the top wall  23  of the top housing section  20 . 
     The wearable chemical dispenser  18  also includes a hinge bracket  36  that is mounted to an inner surface of the top housing section  20  as shown in  FIG. 5 . The hinge bracket  36  has a flat base plate  37  that mounts to the top housing section  20 , a generally L-shaped arm  38  having an inwardly directed pivot pin  39  at its end, and generally L-shaped arm  40  having an inwardly directed pivot pin  41  at its end. The arm  38  and the arm  40  are spaced apart on the plate  37  as shown in  FIGS. 5 and 6 . The hinge bracket  36  forms part of a hinge mechanism as described below. 
     A replaceable refill unit  44  is provided with the wearable chemical dispenser  18 . The refill unit  44  has a generally slab-like support structure  45 . In top plan view, the refill unit  44  has an essentially tear-drop shaped overall appearance, with a generally circular portion at one end and a generally triangular portion at another end. There is a spoke support  47  across a circular opening through the refill unit  44  (see  FIG. 5 ). Across the spoke support  47  is positioned a fabric substrate  48 . When air is drawn in, the air passes through the fabric substrate  48 . The choice of the fabric, and its porosity, the speed of the air flow, and the vapor pressure of the active, are the main factors in coordinating the speed of use up of the active with the speed of use up of a visual use-up cue  49  (see  FIG. 5 ) that can be viewed through the slot  25  of the top housing section  20 . An example refill unit has a twelve hour life, and the visual use-up cue  49  is designed to evaporate or change in appearance after twelve hours. A suitable visual use-up cue is described in U.S. Patent Application Publication No. 2008/0141928. 
     By impregnating the fabric substrate  48  with an appropriate air treatment chemical, air entering the device will pick up some of the volatile chemical, and dispense it out of the device. Active release rates of 0.2 milligrams per hour (mg./hr.) or higher are preferred. Particularly preferred actives are transfluthrin, prallethrin, vaporthrin, tefluthrin, and esbiothrin or other synthetic pyrethroids. For use in controlling mosquitoes, it is preferred to use metofluthrin from the Sumitomo Chemical Company (trade name SumiOne). The impregnation material can be pure active, or for ease of handling the material can be dissolved in a hydrocarbon or other solvent. Alternatively, or in addition, the fabric may also bear a fragrance, a deodorizer, or other air treatment chemical. It is preferred to have the fabric substrate  48  configured so that the pressure drop across the substrate is no more than 40 Pascals (Pa). Suitable fabrics can be made of woven or non-woven materials providing only minimal resistance to the airflow. 
     The fabric substrate  48  should also be capable of holding active ingredient dosed onto the material and also allow ready migration of the active to the surface so as to allow its evaporation in response to the airflow. For an active ingredient that is hydrophobic and migrateable at common environmental temperatures between about 10° C. and 40° C. (e.g., metofluthrin), suitable materials include, only by way of example, polyester, polypropylene, cotton, cellulose, poly-rayon, and other similar fabrics. These can be non-wovens with basis weights ranging from 10 grams per square meter (gsm) to 40 grams per square meter (gsm), fabricated from synthetic, natural, or combined synthetic and natural polymeric materials. 
     The ideal fabric substrate  48  should also allow for wicking of the active ingredient following dosing so as to ensure efficient distribution throughout the substrate, and thereafter allow migration of active ingredient to the substrate surface to replenish the active ingredient that is being evaporated by the passing airflow. Dosing may be by dropping, spraying, printing, or other conventional delivery of a liquid active ingredient to the substrate. A particularly desirable fabric is a non-woven felted material with a basis weight of 20-30 gsm fabricated from polyethylene terephthalate. 
     A frame  50  is located below the refill unit  44  in the wearable chemical dispenser  18 . The frame  50  has a generally oblong perimeter, and supports the refill unit  44  (see  FIGS. 5 and 6 ). Note that one side of the essentially triangular portion of the refill unit  44  is straight and the other is indented. This slight lack of symmetry is designed to accommodate a corresponding slight lack of symmetry along the top side of frame  50 , and to thereby prevent a consumer from installing the refill unit  44  inside-out on the frame  50 . One end of the frame  50  has a pair of slots  51  that form part of a hinge mechanism as described below. A circular opening  52  is provided at the other end of the frame  50 . Holes  54  in the frame  50  support a rotating activation button  56  that is biased by a rotary spring  57  into an off position. 
     Looking at  FIGS. 6 and 11 , there is shown a fan  60  of the wearable chemical dispenser  18 . The fan  60  has a rotor  61  having a central vertical wall  63  that joins a top central horizontal wall  64 . The central vertical wall  63  and the top horizontal wall  64  define a recess  65  in the bottom of the rotor  61  (see  FIG. 7 ). The top horizontal wall  64  of the rotor  61  includes a tubular mounting element  66  on the axis of the rotor  61 . 
     The preferred fan  60  includes fourteen fan blades  68   a  to  68   n  (see  FIG. 11 ). It has been discovered that a fan configuration, which results in an ideal balance of airflow and minimal power consumption for the wearable chemical dispenser  18 , includes twelve to eighteen fan blades. Preferably, the fan produces an average volumetric flow rate of air of 1.5 to 3 cubic feet per minute (with the refill unit  44  installed) over the life (e.g., at least eight, and most preferably at least twelve hours) of a refill unit  44 . Typically, the fan will operate at 3000-5000 rpm. In one example wearable chemical dispenser  18 , over the life (e.g., twelve hours) of a refill unit  44 , the consumed power from the power supply is 0.35 watts or less, preferably 0.30 watts or less, more preferably 0.25 watts or less, and even more preferably 0.20 watts or less. In one example embodiment, over a twelve hour life of a refill unit  44 , the consumed power from the power supply is about 0.17 watts while maintaining an average volumetric flow rate of air of at least 1.5 cubic feet per minute over the twelve hour period. When using one or more batteries for the power supply, the voltage will vary during discharge. However, the power consumed can be determined from the total energy consumed divided by the total time. 
     Each blade  68   a  to  68   n  has a generally rectangular body  69  defined by an inner edge  70 , an outer edge  71 , a top edge  72  extending from the inner edge  70  to the outer edge  71 , and top surface  73  of the rotor  61 . Looking at  FIG. 11 , a radial reference line R 1  can be extended from a centerpoint C of the rotor  61  to the inner edge  70  of each blade  68   a  to  68   n . Likewise, a radial reference line R 2  can be extended from a centerpoint C of the rotor  61  to the outer edge  71  of each blade  68   a  to  68   n . The body  69  of each blade  68   a  to  68   n  forms an included angle A with its associated radial reference line R 1 . 
     It has been discovered that a fan configuration, which results in an ideal balance of airflow and minimal power consumption for the wearable chemical dispenser  18 , includes a range of fan sizes and fan blade angles. Preferably, each blade  68   a  to  68   n  has a length extending from the inner edge  70  to the outer edge  71  in which the length measures 80% to 130% of the distance of radial reference line R 1 . Preferably, each blade  68   a  to  68   n  has a length extending from the inner edge  70  to the outer edge  71  in which the length measures 45% to 75% of the distance of radial reference line R 2 . Preferably, the included angle A in  FIG. 11 , which is formed between the body  69  of each blade  68   a  to  68   n  and its associated radial reference line R 1 , is in the range of 100 to 150 degrees. These example fan sizes and fan blade angles contribute to an ideal balance of airflow and minimal power consumption for the wearable chemical dispenser  18 . Thus, among other things, the average volumetric flow rate of air from the fan depends on the outer radius of the rotor, the inner radius of the rotor, the number of blades, the blade angles, and the fan revolutions per minutes. 
     One non-limiting example of the fan  60  has a length extending from the inner edge  70  to the outer edge  71  of about 15 millimeters, a radial reference line R 1  of about 14 millimeters, a radial reference line R 2  of about 25 millimeters, and an included angle A of about 120 degrees. In this non-limiting example, blade thicknesses can range from 0.3-1.0 millimeters, with 0.6 millimeters being preferred, and blade height (from the top surface  73  of the rotor  61  to the top edge  72  of the body  69 ) can range from 5-11 millimeters, with about 8 millimeters being preferred. 
     The wearable chemical dispenser  18  includes an electrical power supply. In the example embodiment shown, a microswitch  75  of the power supply is electrically connected to battery contacts  76 . Another battery contact  77  completes an electrical circuit with batteries  78  and the battery contacts  76  to provide electricity to the microswitch  75 . When a user rotates the slide cover  28  by rotating the on-off button  29  into the ‘on’ position, the cam projection  32  of the slide cover  28  is driven into the rotating activation button  56  which then contacts the microswitch  75  to turn on the power supply. 
     Looking at  FIGS. 6-8 , the wearable chemical dispenser  18  includes a chassis  80  for mounting various components of the wearable chemical dispenser  18 . When the top housing section  20  and the chassis  80  are in a closed position (see, e.g.,  FIG. 1 ), a housing having an interior space is formed. The chassis  80  engages the frame  50  in a snap fit. 
     The chassis  80  has a bottom wall  81  with a raised portion  82  that defines a upwardly directed space  83  in the chassis  80  (see  FIGS. 6 and 7 ). A battery compartment  84  is also provided in the bottom wall  81  of the chassis  80  (see  FIG. 7 ). The battery contacts  76 ,  77  are mounted at opposite ends of the battery compartment  84 . Extending upward from the bottom wall  81  of the chassis  80  there is a hinge support  85  having a notch  86  and a hinge support  87  having a notch  88  (see  FIGS. 6 and 8 ). The hinge support  85  and the hinge support  87  form part of a hinge mechanism as described below. 
     The chassis  80  also includes a side wall  90  having regularly spaced openings  91  that define an outlet for permitting air mixed with air treatment chemical to exit the interior space of the wearable chemical dispenser  18 . In the non-limiting example embodiment shown in  FIG. 5 , the openings  91  extend from point E to point F around the side wall  90  of the chassis  80 . In  FIG. 5 , the included angle between point E and point F and point D (which is on axis X shown in  FIG. 6 ) is about 270 degrees. Therefore, the openings  91  are regularly spaced around 270 degrees of the side wall  90  of the chassis  80 . Preferably, the openings  91  are regularly spaced around at least 180 degrees of the side wall  90  of the chassis  80 . More preferably, the openings  91  are spaced around at least 235 degrees of the side wall  90  of the chassis  80 . One non-limiting example of the total outlet area of the openings  91  is 8.5×10 −4  m 2 . Advantageously, the battery compartment  84  is isolated from the openings  91 . These example opening configurations contribute to an ideal balance of airflow and minimal power consumption for the wearable chemical dispenser  18 . 
     Preferably, a flow path from the fan to the openings  91  is unobstructed. Some other devices included a slide cover designed to shut off air flow by blocking the inlet vents and the exhaust vents. The intent was to minimize loss of actives while the unit is not in use by blocking off airflow across the dosed pad. The walls blocking the exhaust vents and the geometries supporting them occupied large space and caused the device to increase in size. These blocking walls are eliminated in the present invention without increased loss in actives ingredient. 
     A motor  93  is positioned in the space  83  in the chassis  80 , and a wire  94  connects the motor  93  to the microswitch  75  for powering the motor when the rotating activation button  56  contacts the microswitch  75  to turn on the power supply. The motor  93  includes a drive shaft  95  that is connected to the tubular mounting element  66  on the rotor  61 . As a result, the motor  93  can rotate the fan  60 . A battery door  96  covers the battery compartment  84  in the bottom wall  81  of the chassis  80 . The battery door  96  includes mounting tabs  97 . A bottom cover  102  is fastened to the chassis  80  by way of fasteners. 
     Looking now at  FIGS. 6, 9 and 10 , means for clipping the wearable chemical dispenser  18  to a user&#39;s clothing (e.g., a belt) are shown. The bottom cover  102  includes a throughhole  103  partially surrounded by an arcuate well  104  in a bottom surface  105  of the bottom cover  102 . The bottom surface  105  of the bottom cover  102  further includes five spaced apart oblong depressions  106   a ,  106   b ,  106   c ,  106   d ,  106   e  arranged in a semicircle around the throughhole  103 . The wearable chemical dispenser  18  also includes a clip  110  having a front section  112  that is spaced at its upper end from a rear section  113  by a top section  114  that connects the front section  112  and the rear section  113 . At the lower end of the clip  110 , the front section  112  and the rear section  113  are in contact until flexed apart by a user. The rear section  113  of the clip  110  has an arcuate projection  116 , a tubular mounting element  117 , and a movable tab  119  having a protrusion  120  on its end. The movable tab  119  is formed by a cutout  121  in the rear section  113  of the clip  110 . A fastener  122  (see  FIG. 6 ) is inserted through the throughhole  103  of the bottom cover  102  and into the tubular mounting element  117  of the clip  110  to connect the bottom cover  102  and the clip  110 . 
     Still looking at  FIGS. 6, 9 and 10 , a rotation feature of the clip  110  can be explained. When the clip  110  is connected to the bottom cover  102 , the clip  110  is positioned as in  FIG. 9 . The fastener  122  secures the tubular mounting element  117  of the clip  110  in the throughhole  103  of the bottom cover  102  such that the clip  110  can rotate with respect to the bottom cover  102 . When the clip  110  is rotated clockwise from its position shown in  FIG. 9 , the arcuate projection  116  moves in the arcuate well  104  in a clockwise direction thereby guiding rotation of the clip  110 . The protrusion  120  of the movable tab  119  moves out of the depression  106   c  by way of flexing of the movable tab  119 . The clip  110  rotates clockwise until the protrusion  120  of the movable tab  119  moves into the depression  106   b  of the bottom cover  102 . When the clip  110  is further rotated clockwise from the position in which the protrusion  120  is in the depression  106   b , the arcuate projection  116  moves further clockwise in the arcuate well  104 , and the protrusion  120  moves out of the depression  106   b  by way of flexing of the movable tab  119 . The clip  110  rotates clockwise until the protrusion  120  of the movable tab  119  moves into the depression  106   a  of the bottom cover  102 . When in this position, the arcuate projection  116  is prevented from moving further clockwise by wall  129  of the arcuate well  104 , and the housing of the wearable chemical dispenser  18  is at 90 degrees in relation to the clip  110 . 
     When the clip  110  is rotated counterclockwise from its position shown in  FIG. 9 , the arcuate projection  116  moves in the arcuate well  104  in a counterclockwise direction thereby guiding rotation of the clip  110 . The protrusion  120  of the movable tab  119  moves out of the depression  106   c  by way of flexing of the movable tab  119 . The clip  110  rotates counterclockwise until the protrusion  120  of the movable tab  119  moves into the depression  106   d  of the bottom cover  102 . When the clip  110  is further rotated counterclockwise from the position in which the protrusion  120  is in the depression  106   d , the arcuate projection  116  moves further counterclockwise in the arcuate well  104 , and the protrusion  120  moves out of the depression  106   d  by way of flexing of the movable tab  119 . The clip  110  rotates counterclockwise until the protrusion  120  of the movable tab  119  moves into the depression  106   e  of the bottom cover  102 . When in this position, the arcuate projection  116  is prevented from moving further counterclockwise by wall  127  of the arcuate well  104 , and the housing of the wearable chemical dispenser  18  is at 90 degrees in relation to the clip  110 . 
     Thus, the arcuate projection  116  and the arcuate well  104  provide a means for controlled rotation of the clip  110  with respect to the bottom cover  102 . Specifically, the projection  116  moves in the well  104  when rotating the clip  100 . In the example embodiment of  FIG. 9 , the well  104  and the projection  116  are dimensioned such that the clip  110  can rotate 180 degrees (i.e., 90 degrees clockwise and 90 degrees counterclockwise). Preferably, the clip  110  can rotate at least 90 degrees. 
     In addition, the movable tab  119  with the protrusion  120  and the spaced apart oblong depressions  106   a ,  106   b ,  106   c ,  106   d ,  106   e  arranged in a semicircle around the throughhole  103  provide a means for indexed rotational positioning of the clip  100  and the housing relative to each other. The depressions  106   a ,  106   b ,  106   c ,  106   d ,  106   e  provide a guide and the protrusion  120  of the movable tab  119  travels stepwise in the guide as explained above. 
     Often a user will clip the wearable chemical dispenser  18  to a belt with the clip  110  of the wearable chemical dispenser  18  in the position shown in  FIG. 9  wherein the outlet openings  91  face down from, to one side, and to the opposite side of the user. This directs a mixture of air and air treatment chemical down from, to one side, and to the opposite side of the user. If a user wishes to direct the mixture of air and air treatment chemical up, down, and to one side, the user can rotate the housing using the rotating clip  110  as described above. A user may also wish to rotate the housing in order to avoid any pinching against the body when sitting. Also, by locating a pivot point of the clip  110  in a section of the housing adjacent the outlet openings  91 , more precise control of the direction of the mixture of air and air treatment chemical is afforded when rotating the clip  110 . Thus, the housing of the wearable chemical dispenser  18  can be vertical or horizontal when in use. 
     Turning now to  FIGS. 5, 6, 8, 8A, 8B, and 8C , the hinge mechanism of the wearable chemical dispenser  18  can be described further. The hinge mechanism allows a user to open the top housing section  20  to the open position of  FIGS. 5, 7 and 8A  so that a new refill unit  44  can be installed on the frame  50  as shown in  FIG. 5 . 
     Looking at  FIGS. 8A, 8B and 8C , movement of the pivot pin  39  of the hinge arm  38  in the notch  86  of the hinge support  85  can be explained. The pivot pin  39  has an outer wall  131  having an arcuate section  132  that extends between a first flat section  133  and a second flat section  134 . An intermediate section  135  connects the first flat section  133  and the second flat section  134 . Although  FIGS. 8A, 8B and 8C  do not show the pivot pin  41 , the pivot pin  41  has an outer wall with the same shape as outer wall  131  of pivot pin  39 . 
     In  FIG. 8A , the top housing section  20  is in a fully open position. The second flat section  134  of the outer wall  131  of the pivot pin  39  rests on a bottom flat surface  137  (see  FIG. 8 ) of the notch  86  of the hinge support  85 . The mating of the bottom flat surface  137  of the notch  86  and the second flat section  134  of the outer wall  131  of the pivot pin  39  keeps the top housing section  20  in the fully open position. 
     In  FIG. 8C , the top housing section  20  is in a closed position. The first flat section  133  of the outer wall  131  of the pivot pin  39  rests on the bottom flat surface  137  of the notch  86  of the hinge support  85 . The mating of the bottom flat surface  137  of the notch  86  and the first flat section  133  of the outer wall  131  of the pivot pin  39  keeps the top housing section  20  in the closed position. Also, a catch  155  (see  FIG. 5 ) of the top housing section  20  engages a slot  157  (see  FIG. 5 ) to keep the housing closed. 
     In  FIG. 8B , the top housing section  20  is in a partially open position. The intermediate section  135  of the outer wall  131  of the pivot pin  39  rests on the bottom flat surface  137  of the notch  86  of the hinge support  85 . The mating of the bottom flat surface  137  of the notch  86  and the intermediate section  135  of the outer wall  131  of the pivot pin  39  tends to keep the top housing section  20  in the partially open position. However, movement of the top housing section  20  in direction Z will cause the top housing section  20  to quickly return to the fully open position shown in  FIG. 8A  as pivot pin  39  will rotate due to gravity until the second flat section  134  of the outer wall  131  of the pivot pin  39  rests on a bottom flat surface  137  of the notch  86 . In contrast, movement of the top housing section  20  in direction Y will cause the top housing section  20  to move to the closed position shown in  FIG. 8C  as pivot pin  39  will rotate due to gravity until the first flat section  133  of the outer wall  131  of the pivot pin  39  rests on a bottom flat surface  137  of the notch  86 . 
     The pivot pin  41  moves in the notch  88  in a similar manner with flat sections of the outer wall of the pivot pin  40  resting on the bottom flat surface  138  (see  FIG. 8 ) of the notch  88  of the hinge support  87  during opening of the top housing section  20 . During movement of the hinge, the arm  38  and the arm  40  of the hinge bracket  36  move in the slots  51  of the frame  50  (see  FIG. 5 ). 
     The configuration of the outer wall of the pivot pins  39 ,  41  of the arms  38 ,  40  of the hinge bracket  36  provides an advantageous hinging action when opening the top housing section  20 . When a user first begins to open the top housing section  20 , the user must overcome the tendency of the pivot pins  39 ,  41  to return to the closed position where the first flat section of the outer wall of the pivot pin rests on a bottom flat surface of the associated notch (see  FIG. 8C ). However, once the top housing section  20  has reached the partially open position of  FIG. 8B , a small amount of further movement in direction Z will cause the top housing section  20  to quickly move to the fully open position shown in  FIG. 8A  as pivot pin  39  will rotate due to gravity until the second flat section  134  of the outer wall  131  of the pivot pin  39  rests on a bottom flat surface  137  of the notch  86 . 
     Likewise, the configuration of the outer wall of the pivot pins  39 ,  41  of the arms  38 ,  40  of the hinge bracket  36  provides an advantageous hinging action when closing the top housing section  20 . When a user first begins to close the top housing section  20 , the user must overcome the tendency of the pivot pins  39 ,  41  to return to the fully open position where the second flat section of the outer wall of the pivot pin rests on a bottom flat surface of the associated notch (see  FIG. 8A ). However, once the top housing section  20  has reached the partially open position of  FIG. 8B , a small amount of further movement in direction Y will cause the top housing section  20  to quickly move to the closed position shown in  FIG. 8C  as pivot pin  39  will rotate due to gravity until the first flat section  133  of the outer wall  131  of the pivot pin  39  rests on a bottom flat surface  137  of the notch  86 . 
     Regarding component construction, the top housing section  20 , slide cover  28 , hinge bracket  36 , support structure  45  of the refill unit  44 , frame  50 , fan  60 , chassis  80 , battery door  96 , bottom cover  102 , and clip  110  may be formed from a suitable polymeric material such as polyethylene, polypropylene, or polyester. 
     In operation, the wearable chemical dispenser  18  will be clipped on a belt, purse or the like using clip  110  for that purpose. When a user moves the on-off button  29  along the side wall  22  of the top housing section  20  into the ‘on’ position, the openings  31  of the slide cover  28  align with the apertures  24  that are radially arranged in the top wall  23  of the top housing section  20 . The cam projection  32  of the slide cover  28  is driven into the rotating activation button  56  which then contacts the microswitch  75  to turn on the power supply to power the fan  60  by way of motor  93 . Air is sucked by the fan  60  of the wearable chemical dispenser  18  in through apertures  24  and the openings  31 . As the air passes through fabric substrate  48 , the air treatment chemical mixes into the air and a mixture of air and air treatment chemical is then blown radially out openings  91  (preferably down along pants or dresses). A user can rotate the clip  110  as described above. 
     While the present device is primarily intended to be used as a wearable item carried with a human when outdoors, it can also be laid flat, with the clip  110  downward and the top housing section  20  upward, on a picnic table or the like. When used in this manner it can provide protection to an area during a picnic or similar outdoor activity. 
     Hence, the device is much more compact and lightweight, yet still effective. Further, the cost of operation from a battery standpoint is reduced. The device can more comfortably be used when seated, and provides greater control over dispensing direction. Also, installing a replacement active refill is easier. These advantages are achieved at lowered cost, and provide a reliable construction. 
     In the wearable dispenser, the intake grill size is designed to work in concert with an improved fan which falls within a specific range of fan blades, size and blade angle. A low current draw motor is recessed into the axial hub of the fan design. The airflow exits through 270 of output vents. This combination of design features results in an ideal balance of airflow and minimal power consumption that results in a highly efficient system, which produces good insect repellency and usage duration in a relatively small, lightweight unit. 
     While an example embodiment has been described above, it should be appreciated that there are numerous other embodiments of the invention within the spirit and scope of this disclosure. For example, the device can be powered by a different source of energy (e.g. a solar power panel), other forms of actives can be dispensed along with or in substitution for the insect control ingredients (e.g. a fragrance or deodorizing chemical), and even when an insect control ingredient is dispensed it need not be one focused on controlling mosquitoes (e.g. chemicals for repelling other flying or crawling insects or pests can be used). Hence, the invention is not to be limited to just the specific embodiments shown or described. 
     INDUSTRIAL APPLICABILITY 
     Provided herein are wearable dispensing devices capable of dispensing insect control chemicals and/or other air treatment chemicals adjacent a human body.