Patent Publication Number: US-9883726-B2

Title: Hair dryer with improved outlet unit

Description:
(a) Technical Field of the Invention 
     The present invention relates to a hair dryer and, more particularly, to a hair dryer with an improved outlet unit. The outlet unit is provided therein with an air-guiding member which can convert a linearly ongoing air current into a rotationally ongoing air current, to increase air speed, uniformity and penetration and to reduce noise. 
     (b) Description of the Prior Art 
     Hair dryers, which are commonly used at home, have a simple structure. Typically, a hair dryer is provided therein with a fan unit and a heating unit. In use, the fan unit can draw outside air into its housing to generate an ongoing air current, which is then heated by the heating unit and which finally goes out of an exit which is generally a circular opening for delivering a large amount of air. However, the intensity of the air current provided by this type of hair dryer is somewhat weak. To alleviate this defect, an outlet unit having a straight channel for a hair dryer is provided, which allows the ongoing air current to move in a unique direction towards an object. In combing hair, the ongoing air current can only enter the top of the hair structure of a user, but is unable to enter the bottom of the hair structure. Therefore, the top of the hair structure of the user will become dry and hot, while the bottom of the hair structure still remains wet. 
     In view of the foregoing, the present invention provides a hair dryer with an improved outlet unit for solving the shortcomings of conventional hair dryers. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a hair dryer having an outlet unit at the exit of the main body of the hair dryer. The outlet unit is provided thereinwith an air-guiding member, which can convert a linearly ongoing air current into a rotationally ongoing air current, to increase air speed and penetration and to reduce noise. 
     According to one feature of the present invention, the outlet unit defines a plurality of air holes through which outside air can be drawn into the outlet unit to mix with the air current flowing out of the exit of the main body, to provide a uniform air current for a user. 
     Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exploded view of a hair dryer with an outlet unit according to one embodiment of the present invention. 
         FIG. 2  shows a 3-dimensional view of the hair dryer. 
         FIG. 3  shows a sectional view of the hair dryer. 
         FIG. 4  shows an exploded view of a first embodiment of the outlet unit, which is composed of a rear housing and a front housing. 
         FIG. 5  shows a 3-dimensional view of the rear housing of the first embodiment of the outlet unit. 
         FIG. 6  shows a plan view of the rear housing of the first embodiment of the outlet unit. 
         FIG. 7  shows a 3-dimensionally sectional view of the first embodiment of the outlet unit. 
         FIG. 8  shows an exploded view of a second embodiment of the outlet unit. 
         FIG. 9  shows a 3-dimensional view of the second embodiment of the outlet unit. 
         FIG. 10  shows a sectional view of the second embodiment of the outlet unit. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1 through 4 , a hair dryer according to one embodiment of the present invention is shown, which generally comprises a main body  1  and an outlet unit  5 . The main body  1  is essentially composed of a left shell  11 , a right shell  12 , and an inner case  15  sandwiched between the left shell  11  and the right shell  12 . The inner case  15  defines therein an inner space  10 , which has a circular cross section, for installing a fan unit  16  and a heating unit  17 . The fan unit  16  can draw outside air into the inner case  15  to generate an air current  91 , which is originally cold air. The heating unit  17  can heat up the cold air current generated by the fan unit  16  to form a linearly ongoing current of hot air flowing out of an exit  13  of the main body  1 . Since the fan unit  16  and the heating unit  17  are commonly used elements in hair dryers, they are shown only by blocks in  FIG. 3 . After combining the left and right shells  11 ,  12 , the main body  1  forms a connection portion  14  at its front end  18 , which defines the exit  13 . A rear cap  3 , with air holes (not shown), is provided at the rear end  19  of the main body  1 . The main body  1  is provided, between the front end  18  and the rear end  19 , with a handle  2 , which is composed of a left part  21  and a right part  22 . One primary feature of the present invention is that the main body  1  is provided with the outlet unit  5  at its exit  13 , so that the linearly ongoing current of hot air can be converted into a rotationally ongoing current of hot air. In addition, the outlet unit  5  allows the air current  91 , which has been heated by the heating unit  17 , to mix with a downstream cold air current  90  (cold air) from the ambient environment. As such, the hair dryer can increase air speed, penetration and uniformity, and can reduce noise. In tidying hair, since the airflow provided by the hair dryer of the present invention, which is a rotationally ongoing air current rather than a linearly ongoing air current, can penetrate the top of the hair structure of a user to reach the bottom of the hair structure more easily, the user&#39;s hair can be quickly dried. Furthermore, the air current  91 , which is heated and mixed with the downstream cold air current  90  drawn from the ambient environment, can obtain an air flow of warm temperature suitable for a user, which is not like the airflow provided by conventional hair dryers, which is both hot and dry. 
     In a first embodiment, the outlet unit  5  is composed of a rear housing  6  and a front housing  8 . As shown in  FIGS. 4 and 5 , the rear housing  6  has a round portion  61  and a conical shell  66 . The round portion  61  defines an entrance  62  at its rear end and is formed with an inwardly annular wall  69  at its front end (see  FIG. 3 ). The conical shell  66  extends from an inner edge of the inwardly annular wall  69  of the round portion  61  and defines an exit  67  at its front end. The conical shell  66  is gradually reduced in its cross section as it extends towards its front end. The inwardly annular wall  69  is provided with an annular projection  63  around the conical shell  66 , and the external diameter of the annular projection  63  is less than that of the round portion  61 , such that an annular surface  64  is formed to and around the annular projection  63 . A first annular space  65  is defined between the annular projection  63  and the conical shell  66 . The rear housing  6  defines therein an inner space  68 . The inwardly annular wall  69  is located between the round portion  61  and the conical shell  66 . The rear housing  6  can be connected to the main body  1  by its round portion  61  snugly fitting over the connection portion  14  of the main body  1 . Namely, the connection portion  14  of the main body  1  is inserted into the entrance  62  of the round portion  61 , and the connection portion  14  of the main body  1  abuts the inwardly annular wall  69  of the rear housing  6 . An air-guiding member  7  is provided at the inner space  68  of the rear housing  6 . The air-guiding member  7  has a number of blades which extend outwardly from a central common axis  70  to the conical shell  66 . Each blade has a lateral edge  72  which joins with the conical shell  66 . Each blade has a front edge  74  facing towards the exit  67  of the rear housing  6  and has a rear edge  73  opposite to the front edge  74  (i.e., the rear edge  73  facing towards the exit  13  of the main body  1 ). The central common axis  70  of the air-guiding member  7  is coaxial with a central axis (X) of the inner case  15  sandwiched between the left and right shells  11 ,  12  of the main body  1 . The lateral edge  72  and the rear edge  73  of each blade of the air-guiding member  7  intersect at a first point  731 , while the lateral edge  72  and the front edge  74  of each blade of the air-guiding member  7  intersect at a second point  741 . A first line (X 1 ) is connected between the first point  731  and the central common axis  70 , such that the firstline X 1  has a shortest distance between the first point  731  and the central common axis  70 . Namely, the first line (X 1 ) is perpendicular to the central common axis  70 . A second line (X 2 ) is connected between the second point  741  and the central common axis  70  such that the second line (X 2 ) has a shortest distance between the second point  741  and the central common axis  70 . Namely, the second line (X 2 ) is perpendicular to the central common axis  70 . The length of the first line (X 1  ) is greater than the length of the second line (X 2 ). As such, the central common axis  70  and the lateral edge  72  of each blade of the air-guiding member  7  define a twisted surface therebetween. Furthermore, the first line (X 1 ) and the second line (X 2 ) are offset by an angle (Θ) as they are viewed in the direction of the central common axis  70 . Namely, the front edge  74  are generally twisted from the rear edge  73  by an angle (Θ). 
     The front housing  8  has a connection portion  81  at its rear end and defines an exit  84  at its front end  83  and defines a plurality of air holes  85  at its circumferential wall. The connection portion  81  of the front housing  8  defines an opening  82 , and the front housing  8  is gradually reduced in its cross section as it extends from its rear end to its front end. The front housing  8 , which is greater than the conical shell  66  in diameter, can be fitted around the conical shell  66  of the rear housing  6  to have its connection portion  81  snugly fit over the annular projection  63  of the rear housing  6  and abut the annular surface  64  of the rear housing  6 . As shown in  FIG. 3 , the maximum distance between the air holes  85  and the opening  82  defined at the rear end of the front housing  8  is indicated by (L 1 ). The distance between the exit  67  of the rear housing  6  and the annular surface  64  of the rear housing  6  is indicated by (L 2 ), which is also the distance between the exit  67  and the opening  82  after the front housing  8  is connected to the rear housing  6 , with distance (L 2 ) being greater than distance (L 1 ). The diameter of the rear housing  6  is less than that of the front housing  8 , thus defining a second annular space  92  therebetween (see  FIGS. 3 and 7 ). As shown, the downstream air current  90  can be drawn into the second annular space  92  via the air holes  85 . The downstream cold air current  90  from the ambient environment can go past the front end of the conical shell  66  of the rear housing  6  to move towards the exit  84  of the front housing  8 . As shown in  FIGS. 3 and 7 . The space between the exit  67  of the rear housing  6  and the exit  84  of the fronthousing  8  can work as an air mixing zone  93 , in which the air current  91  which has been heated can mix with the downstream cold air current  90 , to obtain a warm flow, which is less hot than the air current  91  which has been heated, so that the air current provided by the hair dryer is more comfortable for a user. Furthermore, the twisted blades of the air-guiding member  7  can convert the linearly ongoing air current  91  to a rotationally ongoing air current flowing out of the exit  84  of the front housing  8  (see  FIGS. 2 and 3 ), so that the air current provided by the hair dryer can penetrate the hair structure of a user more easily to facilitate the user in tidying and drying hair. 
       FIGS. 8, 9 and 10  show a second embodiment of the outlet unit of the present invention. The rear housing  40  has a round portion  41  and a conical shell  42  extending from the round portion  41  and is provided with an air-guiding member  43  having a number of twisted blades within the conical shell  42 . The left and right shells  11 ,  12  of the main body  1  respectively define semicircular recesses  110 ,  120  at their inner surfaces, near the front end  18  of the main body  1 . The left and right shells  11 ,  12  of the main body  1  are respectively provided, at the front end  18  of the main body  1 , with semicircular projections  111 ,  121 , which have an external diameter less than the circumferential wall of the main body  1 , thereby respectively forming steps  112 ,  122  around the semicircular projections  111 ,  121 . The round portion  41  of the rear housing  40  can be fitted into the semicircular recesses  110 ,  120 , so that the rear housing  40  can be connected to the main body  1 . The front housing  44  is different from the front housing  8  in shape. However, both housings of the two embodiments generally have the same structural features. The front housing  44  has a connection portion  45  defining an opening  46  at its rear end and defines an exit  48  at its front end  47 . As similar to the first embodiment, the front housing  44  defines a plurality of air holes  49 , through which outside air can be drawn into theinterior of the front housing  44 . The front housing  44  can be snugly fit over the semicircular projections  111 ,  121  of the left and right shells  11 ,  12  of the main body  1  to be in contact with the steps  112 ,  122  of the left and right shells  11 ,  12  of the main body  1 . 
     As a summary, the outlet unit  5  of the present invention can increase air speed, uniformity and penetration, and can reduce noise. Since the air output provided by the present invention is a rotationally ongoing air current rather than a linearly ongoing air current or in other words, since the air current flowing out the outlet unit  5  can rotationally advance, it can penetrate the top of the hair structure of a user to enter the bottom of the hair structure more easily, the user&#39;s hair can be quickly dried. Additionally, the air current  91  which is heated can mix with the downstream, cold air current from the ambient environment, so that the air output of the present invention will not tend to be both dry and hot. The less hot air current provided by the present invention will be more suitable for a user.