Patent Publication Number: US-9888758-B2

Title: Nail dryer

Description:
FIELD OF THE INVENTION 
     The invention relates to the field of nail dryers. 
     BACKGROUND OF THE INVENTION 
     In the manicure industry, nail dryers are widely used. It is desirable for a nail dryer to be relatively quiet, to be relatively efficient to run in terms of power costs and to dry nails relatively quickly. 
     SUMMARY OF THE INVENTION 
     A nail dryer forms one aspect of the invention. The nail dryer comprises: a squirrel cage impeller, a housing and a motor. 
     The impeller has a central void, an axis passing through the central void and a plurality of blades extending outwardly from the central void. 
     The housing: has a planar terminus defined by three or more portions of the housing; and has the impeller operatively rotatably mounted thereto such that, when the housing is positioned with the terminus horizontal and defining the bottom of the housing, the axis extends vertically and the impeller is above the terminus. 
     The housing further has a tubular sidewall:
         through which the axis extends and in which the impeller is positioned in spaced-apart relation;   being shaped and dimensioned such that a gap is defined between the sidewall and a notional plane aligned with the terminus; and   being further shaped and dimensioned to direct air flow ejected from the impeller through the gap.       

     The housing further has a screen occluding the end of the sidewall distal to the terminus, the screen being adapted to allow the throughpassage of air and to restrict the throughpassage of fingers. 
     The housing is shaped and dimensioned such that the screen has a portion that lies in the central void of the impeller. 
     The motor is for rotating the impeller. 
     According to another aspect of the invention, the end of the sidewall distal to the terminus can extend beyond the impeller. 
     According to another aspect of the invention, the motor can be positioned axially displaced from the impeller such that, when the housing is positioned with the terminus horizontal and defining the bottom of the housing, the motor is beneath the impeller. 
     According to another aspect of the invention, the sidewall can have a concave interior surface. 
     According to another aspect of the invention, the screen can be a round dish having a concave exterior surface and a concave interior surface. 
     According to another aspect of the invention, the impeller can have forward-curved blades. According to another aspect of the invention, the impeller can have a closed base. 
     Advantages, features and characteristics of the present invention will become evident upon review of the detailed description that follows and the accompanying drawings, the latter being briefly described hereafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a nail dryer according to an exemplary embodiment of the invention; 
         FIG. 2  is a bottom perspective view of the nail dryer of  FIG. 1 ; 
         FIG. 3  is a top view of the nail dryer of  FIG. 1 ; 
         FIG. 4  is a view along arrow  4  of  FIG. 3 ; 
         FIG. 5  is a view along arrow  5  of  FIG. 3 ; 
         FIG. 6  is a bottom view of the nail dryer of  FIG. 1 ; 
         FIG. 7  is an exploded view of the nail dryer of  FIG. 1 ; 
         FIG. 8  is a view along section  8 - 8  of  FIG. 3 ; 
         FIG. 9  is a schematic view similar to  FIG. 8  showing the nail dryer in use; and 
         FIG. 10  is a dimensioned view of  FIG. 8 . 
         FIG. 11  is a view produced by computational fluid dynamics showing the airflow produced by the nail dryer of  FIG. 1   
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT 
     The exemplary nail dryer  20  shown in  FIGS. 1-8  will be seen to include an impeller  22 , a housing  24  and a motor  26 . 
     The impeller  22  is of the squirrel cage type and thus has a central void  28 , an axis X-X passing through the central void  28  and a plurality of blades  30  extending outwardly from the central void  28 . The blades  30  are curved and are connected to one another by an annular disc  32  that forms a base of the impeller  22 . 
     The housing  24  has a base  34 , a sidewall  36  and a screen  38 . 
     The base  34  has a central socket  40 , an annular screen  42  surrounding the socket  40  and four feet  44  extending from the screen  42 . The feet  44  collectively define a planar terminus of the housing, that is, the ends of the feet  44  lie in a common plane and all of the housing  24  lies on the same side of that plane. Plane T-T shown in  FIG. 4  shows such a plane. The base  34  is positioned relative to impeller  22  such that, as shown in  FIG. 8 , with the terminus  44 , 44 , 44 , 44  of the housing  24  orientated to lie in the horizontal plane and defining the bottom of the housing  24 , the impeller  22  is above the terminus  44 , 44 , 44 , 44  and the axis X-X extends vertically. 
     The sidewall  36 : is tubular; has a concave interior surface  46  and a convex exterior surface  48 ; is positioned such that the axis X-X extends therethrough; has ends  36 A, 36 B spaced-apart from one another along the axis X-X; is further positioned such that the impeller  22  is positioned therein, in spaced-apart relation; and is positioned, shaped and dimensioned:
         such that a gap  50  is defined between the end  36 B of the sidewall  34  proximal to the terminus  44 , 44 , 44 , 44  and a notional plane aligned with the terminus  44 , 44 , 44 , 44 , such as indicated by plane T-T;   such that the end  36 A of the sidewall  36  distal to the terminus  44 , 44 , 44 , 44  extends beyond the impeller  22 , as shown in  FIG. 8 ; and   to direct air flow ejected from the impeller  22  through the gap  50 .       

     The gap  50  is indicated in  FIG. 8  and will be understood to be defined in part, in the illustrated embodiment, by arcuate notches in the sidewall, which otherwise extends substantially entirely to the terminus  44 , 44 , 44 , 44 ; the fan is shown in use in  FIG. 9  and it will be seen that the sidewall  36  stops just short of the surface upon which the fan rests . 
     The screen  38 : is a round dish; has a concave exterior surface  52  and a convex interior surface  54 ; occludes the end  36 A of the sidewall  36  distal to the terminus  44 , 44 , 44 , 44 ; is adapted to allow the throughpassage of air and to restrict the throughpassage of fingers; and has a portion that lies in the central void  28  of the impeller  22 , again as shown in  FIG. 8 . 
     The motor  26  is mounted in the central socket  40 , is axially displaced from and beneath the impeller  22  and is adapted for rotating the impeller  22  in a direction such that the blades  30  are forward-curved. 
     The exemplary nail fan  20  has been tested for noise and throughput and has demonstrated substantial utility, producing between 125 and 145 CFM flow through the screen while producing relatively little noise: measured at 12″ and 24″ respectively from the fan, was 70 dba and 68 dba. 
     The draw of the fan is sufficiently great that a gauze pad  58  or the like, as shown in the drawings, can be used to support the fingers during drying, to collect nail and skin debris and also to protect the screen against polish. 
     Without intending to be bound by theory, it is believed that the relatively high draw and low noise may be a function of very smooth flow characteristics. In this regard, the CFD simulation in  FIG. 11  shows that ingress and egress flows are very uniform and smooth. This uniformity may be a result of the specific geometry of the sidewall  36 , screen  38  and impeller  22 . Accordingly,  FIG. 10  shows representatives dimensions and radii of curvature. 
     Whereas but a single embodiment has been herein shown and described, it will be evident that variations are possible. For example, whereas in the exemplary fan, the blades are forward curved, the blades could be straight or could be reverse-curved. As well, the base could have feet greater or lesser in number than four. Further, the screen could be flat bottomed and could bottom out just above the impeller. The size and shape of the fan and its various components could also be varied from the specific embodiment illustrated. Accordingly, the invention should be understood as limited only by the accompanying claims, purposively construed.