Abstract:
A hand held appliance comprising a body and a handle connected to the body, wherein the body comprises a tubular inner wall, an outer wall extending about the inner wall, a fluid flow path extending between the inner wall and the outlet wall, and a barrier extending at least partially across the inner wall. The barrier may be located at one end of the inner wall and may be formed from transparent material. A space defined by the inner wall of the body may provide line of sight through the body. A fan unit may be located between the inner wall and the outer wall and may be supported by a bearing mounted on the inner wall. The barrier may be connected to the fan unit for rotation therewith. A motor for driving the fan unit and a heater may be located between the inner wall and the outer wall.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a national stage application under 35 USC 371 of International Application No. PCT/GB2013/050701, filed Mar. 19, 2013, which claims the priority of United Kingdom Application No. 1205699.0, filed Mar. 30, 2012, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a blower and in particular a hot air blower such as a hairdryer. 
       BACKGROUND OF THE INVENTION 
       [0003]    Blowers and in particular hot air blowers are used for a variety of applications such as drying substances such as paint or hair and cleaning or stripping surface layers. Generally, a motor and fan are provided which draw fluid into a body; the fluid may be heated prior to exiting the body. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides a hairdryer comprising a body and a handle connected to the body, wherein the body comprises a tubular inner wall, an outer wall extending about the inner wall, a fluid flow path extending between the inner wall and the outer wall from a fluid inlet into the hairdryer. 
         [0005]    Preferably, the outer wall defines an axial length of the body, and the fluid flow path extends along the axial length of the body. 
         [0006]    Preferably, the body has an inlet and an outlet end, the inlet end preferably includes the fluid inlet into the hairdryer. The outlet end preferably includes a fluid outlet from the hairdryer. Thus, fluid flows from an inlet end of the hairdryer along a fluid flow path located between the inner and outer walls to a fluid outlet. 
         [0007]    Preferably, a space defined by the inner wall of the body provides a line of sight through the body. Thus, the space within or internal to the inner wall provides a line of sight through the hairdryer. 
         [0008]    It is preferred that a barrier is provided and the barrier extends at least partially across the inner wall. Preferably, the barrier is located at one end of the inner wall. It is preferred that the barrier is formed from transparent material. Preferably, the barrier is a filter. 
         [0009]    Also disclosed is a hairdryer comprising a body and a handle connected to the body, wherein the body comprises a tubular inner wall, an outer wall extending about the inner wall a fluid flow path extending between the inner wall and the outer wall from a fluid inlet into the hairdryer, wherein a barrier is provided and the barrier extends at least partially across the inner wall. 
         [0010]    It is preferred that a fan unit is located between the inner wall and the outer wall. 
         [0011]    Preferably, the fan unit is supported by a bearing mounted on the inner wall. 
         [0012]    It is preferred that the barrier is connected to the fan unit for rotation therewith. 
         [0013]    Preferably, a motor for driving the fan unit is located between the inner wall and the outer wall. 
         [0014]    Also disclosed is a hairdryer comprising a body and a handle connected to the body, wherein the body comprises a tubular inner wall, an outer wall extending about the inner wall a fluid flow path extending between the inner wall and the outer wall from a fluid inlet into the hairdryer, wherein a fan unit is located between the inner wall and the outer wall. 
         [0015]    It is preferred that the hairdryer comprise a heater located between the inner wall and the outer wall. Preferably, the heater is annular in shape. 
         [0016]    Also disclosed is a hairdryer comprising a body and a handle connected to the body, wherein the body comprises a tubular inner wall, an outer wall extending about the inner wall a fluid flow path extending between the inner wall and the outer wall from a fluid inlet into the hairdryer, comprising a heater located between the inner wall and the outer wall. 
         [0017]    It is preferred that the barrier closes one end of the inner wall. Alternatively, the barrier partially closes one end of the inner wall. It is preferred that the barrier comprises a central aperture. 
         [0018]    Preferably, fluid is drawn through the aperture by fluid emitted from the fluid flow path. 
         [0019]    Preferably, the inner wall is tubular and defines a space within the body. In one embodiment, one end of the inner wall is closed or sealed. In another embodiment fluid can flow through the space defined within the inner wall. Fluid flows from an upstream or inlet end of the body to a downstream or outlet end of the body. 
         [0020]    It is preferred that the space defined by the inner wall of the body provides a line of sight through the body of the appliance. In the case where one end of the inner wall is sealed, the seal is transparent or semi-transparent. The seal may provide a magnifying effect on whatever is visible through the distal end of the appliance. 
         [0021]    Preferably, the hairdryer comprises a processor for processing fluid in the fluid flow path. It is preferred that the processor comprises the fan assembly and/or a heater. 
         [0022]    The fan assembly comprises a motor and a fan which is driven by the motor. Preferably the fan is provided in the fluid flow path. The motor may be provided in the fluid flow path or in a handle or duct of the hairdryer. 
         [0023]    The provision of the motor and thus one of the weight contributors of the hairdryer spaced apart from the fan and perhaps the heater means that the hairdryer can be balanced for weight to provide a more comfortable experience for a user. 
         [0024]    Preferably, the seal is at the inlet end of the body. This is advantageous as it prevents access to the inner surface of the inner wall which will get hot in the event that a heater is used in the appliance. 
         [0025]    It is advantageous to have at least one open end to the inner wall as this provides a convenient method of storage for the appliance. The hole defined by the aperture of the inner wall can be hooked onto a hook or nail for example. 
         [0026]    The inner and outer walls are preferably substantially circular in shape; alternatively they are oval, rectangular or square. In fact each wall may be a different shape or configuration. 
         [0027]    A second aspect of the invention provides, a hand held appliance comprising a body and a handle connected to the body, wherein the body comprises a tubular inner wall, an outer wall extending about the inner wall, a fluid flow path extending between the inner wall and the outer wall from a fluid inlet into the hairdryer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
           [0029]      FIG. 1  shows a rear end perspective of a one handled appliance according to the invention; 
           [0030]      FIG. 2  shows a side view of the appliance of  FIG. 1 ; 
           [0031]      FIG. 3  shows a sectional view of another appliance; 
           [0032]      FIG. 4  shows a rear end perspective of the appliance of  FIG. 3 ; 
           [0033]      FIG. 5  shows a sectional view of a two handled appliance; 
           [0034]      FIG. 6  shows a sectional view of a one handled appliance; 
           [0035]      FIG. 7  shows a sectional view across line S-S of  FIG. 2 ; 
           [0036]      FIG. 8  shows a sectional view of the appliance of  FIG. 4 ; 
           [0037]      FIG. 9  shows a side view of a second appliance according to the invention; 
           [0038]      FIG. 10  shows a sectional view along line N-N of  FIG. 9 ; 
           [0039]      FIG. 11  shows a rear end perspective of a further appliance according to the invention; and 
           [0040]      FIG. 12  shows a sectional view along line L-L of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0041]      FIGS. 1 and 2  show a first appliance  10 , the appliance has a body  12  having a fluid inlet end  12   a  and a fluid outlet end  12   b  and a duct or handle  14  which is disposed substantially perpendicular to the body  12 . 
         [0042]    The body  12  has an outer wall  112  and an inner wall  18 . The inner wall  18  contains a space or region  20  which is central to the body  12 . The annular region  30  between the inner  18  and outer  112  walls defines a primary fluid flow path through the appliance  10 . The tubular housing  18  is a duct, pipe or conduit that is generally longer than it is wide and preferably has a substantially circular cross section, however, it may be oval, square, rectangular or another shape. 
         [0043]    Referring now to  FIGS. 3 and 4 , within annular region  30  are located a heater  46  and fan assembly  50 ,  60 . The fan  50  is mounted on a circular bearing  56  and powered by a motor  60 . Power from the motor  60  is provided to the fan using a magnetic coupling, gear or belt mechanism  54 . Power is provided to the motor  60  using an electric cable  62 , which has a standard plug attached to its&#39; distal end (not shown). In this example the cable  62  enters the appliance at the bottom of the handle  14  however, the entry point can be anywhere that would not cause excessive tugging on the cable during use. 
         [0044]    The bearing  56  need not be circular and can be a discontinuous bearing surface. 
         [0045]    As the motor is not concentric with the fan which is often the case with conventional appliances of this type, it can be located in a position that is advantageous to handling of the appliance. Therefore, the motor can be positioned so as to balance the weight of the appliance as the motor is not directly attached to the fan and can be remote thereto and also to the heater which is another weight source for the appliance, i.e., the motor can be housed within the fluid flow path  20  or alternatively the motor is located within a duct or handle  14 . 
         [0046]    In this example the fan  50  has a hub  52  which seals the inlet to the inner wall  18 , thus the space  20  defined by the inner wall  18  does not have any significant fluid flow through it. 
         [0047]    The fan blades are of reduced length as they are mounted around the tubular housing  18  rather than centrally to the body of the appliance. This results in a reduction in the amount of fluid that can be drawn in by the fan  50  however, as most of the work is done by the outer part of the fan blades the reduction is not significant. This reduced fan blade length has the advantage that weight of the appliance is reduced. 
         [0048]    The hub  52  is preferably transparent and made from a durable plastic material such as polycarbonate. The hub  52  can be shaped to provide a magnifying effect on an object that enters the line of sight at the other end of the body  12   b.    
         [0049]    When the appliance is switched on, the motor  60  provides power to the fan  50  and this draws fluid into the primary fluid flow path  30 . If the heater  40  is activated, the fluid that is drawn in is heated prior to exiting the body at the outflow end  12   b.    
         [0050]    Referring now to  FIGS. 5 ,  6  and  7 , a fan  150  is provided within the primary fluid flow path  130 . Fluid is drawn into the body  112  at an inlet end  112   a  by the action of the fan  150 . The fluid then flows straight along the body to the heater  46  before exiting at the fluid outlet end  112   b  of the body  112 .  FIG. 5  shows an appliance having two handles  114  and  114   b  whereas  FIGS. 6 and 7  only have one handle  114 . 
         [0051]    A hubless fan  150  is provided within the primary fluid flow path  130 . Fluid is drawn into the body  112  at an inlet end  112   a  by the action of the hubless fan  150 . The fluid then flows straight along the body to the heater  46  before exiting at the fluid outlet end  112   b  of the body  112 . Fluid is entrained through a central fluid flow path  120  and mixes with the heated fluid  130   b  at the outflow  112   b.    
         [0052]    The hubless fan  150  is mounted on a circular bearing  166  and powered by a motor  46  which, in this embodiment is housed within the primary fluid flow path  130 , but could alternatively be located within the duct  114 . Power from the motor  60  is provided to the fan using for example, a magnetic coupling or gear or belt mechanism  164 . A filter  160  may be provided at the fluid inlet end  112   a  to protect the fan and motor from ingress of hair and dirt. 
         [0053]    In this embodiment, there is line of sight through the first or central fluid flow and the fan could be provided in a transparent form. 
         [0054]    Referring now to  FIG. 8 , a fan  250  is provided within the primary fluid flow path  230 . Fluid is drawn into the body  212  at an inlet end  212   a  by the action of the fan  250 . The fluid then flows straight along the body to the heater  46  before exiting at the fluid outlet end  212   b  of the body  212 . In this embodiment the fan  250  has a hub  270  which fits over the tubular housing  118 . The hub  270  has a central aperture  280  through which fluid can flow in a fluid path  220 . Thus, in this embodiment when the motor is switched on the fan draws air into the primary fluid flow path  230  and fluid is entrained or induced within the fluid flow path  220 . 
         [0055]    The fan  250  is mounted on a circular bearing  56  and powered by a motor  60  which, in this embodiment is housed within the primary fluid flow path  230 , but could alternatively be located within a duct  14 . Thus, as the motor is not concentric with the fan which is generally the case with conventional appliances of this type, it can be located in a position that is advantageous to handling of the appliance. Therefore, the motor can be positioned so as to balance the weight of the appliance as the motor is not directly attached to the fan and can be remote thereto and also to the heater which is another weight source for the appliance. 
         [0056]    Power from the motor  60  is provided to the fan using a magnetic coupling, gear or belt mechanism  64 . A filter may be provided at the fluid inlet end  212   a  to protect the fan and motor from ingress of hair and dirt. 
         [0057]    A second embodiment is described with respect to  FIGS. 9 and 10 . In this embodiment, the appliance  300  has ducts  314  which are oval in cross-section. There are advantages to using oval instead of circular ducts, the first is that when the duct is used as a handle it can be easier for a user to grip as the oval shape mimics the shape made by curled figures more precisely than a circular grip, the second is that the oval shape can be used to impart directionality to the ducts or handles. This feature is shown in  FIG. 10  where a first duct/handle  314   a  is oriented at right angles to a second duct/handle  314   b.  This directionality can make the appliance easier to use. 
         [0058]    A third advantage is that for a grippable handle, the oval shape gives a larger cross-sectional area than the circular handle meaning that a greater flow of fluid can pass through the oval handle. This can reduce one or more of the noise produced by the appliance in operation, power consumed by the appliance and pressure or duct losses within the appliance. 
         [0059]      FIG. 11  shows an appliance  400  having a filter  450  which is a grill like filter which covers the primary fluid flow path  430 , leaving the majority if not all of the central fluid flow path  20  open and unfiltered. The filter  450  may additionally comprise a mesh of material which is disposed between the grills of the filter. 
         [0060]    Referring now to  FIG. 12 , in this embodiment the ducts  14  are generally circular in cross section and are preferably lined with a material  140 . This material  140  is for example a foam or felt that is used for one or more of the following: to mitigate noise from the second fluid flow; vibrations from the fan assembly; or as an insulator to retain heat within the fluid flow system of the appliance. 
         [0061]    The lining material  140  is preferably flared, rounded or chamfered at one or both of the upstream  140   a  and downstream  140   b  end of the lining. This can reduce pressure losses in the ducts and assist in reducing the noise generated as a less turbulent flow into/out of the lined portion is provided. 
         [0062]    For all the embodiments described, the inner opening at one or other end of the appliance can be used to store the appliance for example, by hooking the inner opening onto a retainer such as a hook or nail for convenient storage and retrieval as required. 
         [0063]    For the embodiment described with respect to  FIGS. 3 and 4 , the inner wall  18  is sealed; there is no access to this surface at the inlet end of the body  12   b.  For the embodiments described with respect to  FIGS. 5 to 8 , the inner wall  118  is not sealed, so this wall can be accessed from outside the body and is thus an external wall. There are different compliance rules for internal and external surfaces, for example relating to maximum allowed temperature. For this reason, the temperature of inner wall  18  can be hotter than external wall  118 . This enables a more compact appliance to be made as the heater can be located closer to the inner wall  118 . 
         [0064]    For all the embodiments described, the body is generally tubular and has a length that extends along an axial direction. The primary fluid flow path that is drawn into the annular region  30 ,  130 ,  230 ,  430  between the inner and outer walls extends axially along the body from an inlet to an outlet. The primary fluid flow path extends along the body from a hairdryer inlet where fluid enters the hairdryer. Alternatively, the primary fluid flow path extends from an upstream end of the inner wall for example, in the case that the inner wall is recessed within the outer wall. 
         [0065]    The invention has been described in detail with respect to a hairdryer however, it is applicable to any appliance that draws in a fluid and directs the outflow of that fluid from the appliance. 
         [0066]    The appliance can be used with or without a heater; the action of the outflow of fluid at high velocity has a drying effect. 
         [0067]    The fluid that flows through the appliance is generally air, but may be a different combination of gases or gas and can include additives to improve performance of the appliance or the impact the appliance has on an object the output is directed at for example, hair and the styling of that hair. 
         [0068]    The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art.