Abstract:
A hair care appliance comprising a body having an outer wall, an inner wall and a gasket located between the outer wall and the inner wall, wherein the gasket comprises a seal extending between the outer wall and the inner wall and a centralising feature extending from the inner wall towards the outer wall. The centralising feature may comprise a convex surface extending from the inner wall towards the outer wall. The convex surface may be hemispherical. The outer wall comprises an inner surface and the inner surface may comprise a cooperating centralising feature which may be a number of discrete points of contact radially disposed around the inner surface. The gasket may comprise a further seal extending around an upstream end of the gasket.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of United Kingdom Application No. 1520870.5, filed Nov. 26, 2015, the entire contents of which are incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    This invention relates to a hand held appliance, in particular a hair care appliance and a fluid outlet from such an appliance. 
       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. In addition, hot air blowers such as hot styling brushes are used to style hair from a wet or dry condition. 
         [0004]    Generally, a motor and fan are provided which draw fluid into a body; the fluid may be heated prior to exiting the body. The motor is susceptible to damage from foreign objects such as dirt or hair so conventionally a filter is provided at the fluid intake end of the blower. Conventionally such appliances are provided with a nozzle which can be attached and detached from the appliance and changes the shape and velocity of fluid flow that exits the appliance. Such nozzles can be used to focus the outflow of the appliance or to diffuse the outflow depending on the requirements of the user at that time. 
       SUMMARY OF THE INVENTION 
       [0005]    According to a first aspect, the invention provides a hair care appliance comprising a body having an outer wall, an inner wall and a gasket located between the outer wall and the inner wall, wherein the gasket comprises a seal extending between the outer wall and the inner wall and a centralising feature extending from the inner wall towards the outer wall. 
         [0006]    Preferably, the centralising feature comprises a convex surface extending from the inner wall towards the outer wall. 
         [0007]    In a preferred embodiment the convex surface is hemispherical. 
         [0008]    Preferably, the outer wall comprises an inner surface and the inner surface comprises a cooperating centralising feature. 
         [0009]    In a preferred embodiment the cooperating centralising feature comprises a number of discrete points of contact radially disposed around the inner surface. 
         [0010]    Preferably, cooperating centralising feature comprises at least three ribs extending radially inwards of the inner surface towards the inner wall. 
         [0011]    In a preferred embodiment the at least three ribs comprises four ribs. 
         [0012]    Preferably, the centralising feature only engages with the cooperating centralising feature. 
         [0013]    In a preferred embodiment the seal extends continuously around the gasket. 
         [0014]    Preferably, the seal extends continuously between the outer wall and the inner wall. 
         [0015]    In a preferred embodiment the inner wall comprises a flange extending radially around a radially outer surface of the inner wall. 
         [0016]    Preferably, the gasket further comprises locating feature for locating the gasket with respect to the flange. 
         [0017]    In a preferred embodiment the locating feature comprises a recess extending radially around an inner surface of the gasket and wherein the recess is adapted to accommodate the flange. 
         [0018]    Preferably, the locating feature comprises a protrusion extending radially around an inner surface of the gasket wherein when the gasket is attached to the inner wall, the gasket deforms to enable the flange to pass over the protrusion into the recess. 
         [0019]    In a preferred embodiment the gasket comprises a further seal extending around an upstream end of the gasket. 
         [0020]    Preferably, the outer wall comprises an upstream end and the further seal engages with the upstream end of the outer wall. 
         [0021]    In a preferred embodiment the outer wall comprises first part and a second part, wherein the second part comprises the upstream end of the outer wall. 
         [0022]    Preferably, the first part engages with the seal and the centralising feature. 
         [0023]    In a preferred embodiment the second part comprises an annulus having a flange and the first part comprises a cooperating projection wherein the flange engages against a cooperating projection from the first part. 
         [0024]    Preferably, the further seal urges the flange against the cooperating projection. 
         [0025]    Preferably, the appliance is a hairdryer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The invention will now be described by example, with reference to the accompanying drawings, of which: 
           [0027]      FIG. 1  shows a side view of an appliance according to the invention; 
           [0028]      FIG. 2  shows a cross section through the appliance of  FIG. 1 ; 
           [0029]      FIG. 3  shows a cross section through a gasket according to the invention; 
           [0030]      FIG. 4 a    shows an enlarged cross-section through part of an appliance according to the invention; 
           [0031]      FIG. 4 b    shows a further enlarged cross-section through part of an appliance according to the invention; and 
           [0032]      FIG. 5  shows an internal view of the second end of the body of an appliance according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]      FIGS. 1 and 2  show a hairdryer  10  with a handle  20  and a body  30 . The handle has a first end  22  which is connected to the body  30  and a second end  24  distal from the body  30  and which includes a primary fluid inlet  40 . Power is supplied to the hairdryer  10  via a cable  50 . At a distal end of the cable  50  from the hairdryer  10  a plug (not shown) is provided, the plug may provide electrical connection to mains power or to a battery pack for example. 
         [0034]    The handle  20  has an outer wall  200  which extends from the body  30  towards a distal end  24  of the handle. At the distal end  24  of the handle an end wall  210  extends across the outer wall  200 . The cable  50  enters the hairdryer through this end wall  210 . The primary fluid inlet  40  in the handle  20  includes first apertures that extend around and along  42  the outer wall  200  of the handle in a series of rows and/or columns that extend from the distal end  24  of the handle  20  and second apertures that extend across  46  and through the end wall  210  of the handle  20 . The cable  50  is located approximately in the middle of the end wall  210  so extends from the centre of the handle  20 . The handle  20  has a longitudinal axis X-X along which the outer wall  200  extends from the body  30  towards the distal end  24 . 
         [0035]    It is preferred that the cable  50  extends centrally from the handle  20  as this means the hairdryer is balanced regardless of the orientation of the handle  20  in a users&#39; hand. Also, if the user moves the position of their hand on the handle  20  there will be no tugging from the cable  50  as it does not change position with respect to the hand when the hand is moved. If the cable were offset and nearer one side of the handle then the weight distribution of the hairdryer would change with orientation which is distracting for the user. 
         [0036]    Upstream of the primary fluid inlet  40 , a fan unit  70  is provided. The fan unit  70  includes a fan and a motor. The fan unit  70  draws fluid through the primary fluid inlet  40  towards the body  30  through a primary fluid flow path  400  that extends from the primary fluid inlet  40  and into the body  30  where the handle  20  and the body  30  are joined  90 . The body  30  has a first end  32  and a second end  34 , the primary fluid flow path  400  continues through the body  30  towards the second end  34  of the body, around a heater  80  and to a primary fluid outlet  440  where fluid that is drawn in by the fan unit exits the primary fluid flow path  400 . The primary fluid flow path  400  is non-linear and flows through the handle  20  in a first direction and through the body  30  in a second direction which is orthogonal to the first direction. 
         [0037]    The body  30  includes an outer wall  360  and an inner duct  310 . The primary fluid flow path  400  extends along the body from the junction  90  of the handle  20  and the body  30  between the outer wall  360  and the inner duct  310  towards the primary fluid outlet  440  at the second end  34  of the body  30 . 
         [0038]    An inner wall  260  extends within the outer wall  360 . The inner wall  260  at least partially defines the primary fluid outlet  440  and extends from the second end  34  of the body  30  between the inner duct  310  and the outer wall  360 . 
         [0039]    Another fluid flow path is provided within the body; this flow is not directly processed by the fan unit or the heater but is drawn into the hairdryer by the action of the fan unit producing the primary flow through the hairdryer. This fluid flow is entrained into the hairdryer by the fluid flowing through the primary fluid flow path  400 . 
         [0040]    The first end  32  of the body includes a fluid inlet  320  and the second end  34  of the body includes a fluid outlet  340 . Both the fluid inlet  320  and the fluid outlet  340  are at least partially defined by the inner duct  310  which is an inner wall of the body  30  and extends within and along the body. A fluid flow path  300  extends within the inner duct  310  from the fluid inlet  320  to the fluid outlet  340 . At the first end  32  of the body  30 , a side wall  350  extends between the outer wall  360  and the inner duct  310 . This side wall  350  at least partially defines the fluid inlet  320 . The primary fluid outlet  440  is annular and surrounds the fluid flow path. 
         [0041]    A printed circuit board (PCB)  75  including the control electronics for the hairdryer is located in the body  30  near the side wall  350  and fluid inlet  320 . The PCB  75  is ring shaped and extends round the inner duct  310  between the inner duct  310  and the outer wall  360 . The PCB  75  is in fluid communication with the primary fluid flow path  400 . The PCB  75  extends about the fluid flow path  300  and is isolated from the fluid flow path  300  by the inner duct  310 . 
         [0042]    The PCB  75  controls parameters such as the temperature of the heater  80  and the speed of rotation of the fan unit  70 . Internal wiring (not shown) electrically connects the PCB  75  to the heater  80  and the fan unit  70  and the cable  50 . Control buttons  62 ,  64  are provided and connected to the PCB  75  to enable a user to select from a range of temperature settings and flow rates for example. 
         [0043]    Downstream of the PCB  75 , is the heater  80  and a PCB baffle  700  is provided between the PCB  75  and the heater  80 . The PCB baffle provides thermal protection for the PCB  75  when the heater  80  switched on amongst other things. 
         [0044]    In use, fluid is drawn into the primary fluid flow path  400  by the action of the fan unit  70 , is optionally heated by the heater  80  and exits from the primary fluid outlet  440 . This processed flow causes fluid to be entrained into the fluid flow path  300  at the fluid inlet  320 . The fluid combines with the processed flow at the second end  34  of the body. In the example shown in  FIG. 2 , the processed flow exits the primary fluid outlet  440  and the hairdryer as an annular flow which surrounds the entrained flow that exits from the hairdryer via the fluid outlet  340 . Thus fluid that is processed by the fan unit and heater is augmented by the entrained flow. 
         [0045]    Referring in particular to  FIGS. 3, 4   a  and  4   b , the duct  310  is co-moulded with the inner wall  260  which are connected together with supporting ribs  130 . The inner wall  260  channels fluid flowing in the primary fluid flow path  400  towards the primary fluid outlet  440 . The body  30  includes, at the second end  34 , a front face  340  which extends parallel to the longitudinal axis X-X of the handle. 
         [0046]    The outer wall  360  is formed from two parts. A first part  330  extends from the first end  32  to the second end  34  in two sections. A first section  362  extends from the first end  32  and is generally tubular about a central longitudinal axis Y-Y of the body  30 . A second section  364  extends from the second end  34  and is angled with respect to the longitudinal axis Y-Y of the body  30  as the diameter of the body  30  decreases towards the second end  34 . The front face  340  is orthogonal to the longitudinal axis of the body  30 . A second part  342  forms an annulus that extends around the front face  340 . 
         [0047]    The inner wall  260  extends radially around the downstream end of the heater  80 . A radially inner surface  260   a  of the inner wall  260  directs the fluid that exits the heater  80  towards the fluid outlet  440 . A gasket  116  is provided between the inner wall  260  and the outer wall  360  of the body  30 . This gasket  116  provides a number of functions from different features of the gasket. 
         [0048]    Firstly, the gasket  116  provides a seal  120  between the outer wall  360  and the inner wall  260 . The seal  120  is, in this example a lip seal  122  that extends radially around an outer surface  116   b  of the gasket  116  extending from the gasket  116  towards an inner surface  360   a  of the outer wall  360 . This seal  120  is a fluid seal to prevent fluid that exits the heater  80  exiting from anywhere other than the primary fluid outlet  440 , for example between the first part  330  and the second part  342  of the outer wall  360 . 
         [0049]    A further seal  124  extends from an upstream end  118  of the gasket  116 ; this further seal  124  is, in this embodiment, a lip seal  126  that extends radially around the upstream end  118  of the gasket  116 . The further seal  124  is adapted to urge the second part  342  of the outer wall  360  against the first part  330  of the outer wall  360 . The first part  330  of the outer wall  360  is provided with a projection  332  at the front face  340  which extends radially inwards of the longitudinal axis Y-Y of the body  30 . The second part  342  is provided with a flange  344  which extends radially around the largest diameter of the second part  342 . The second part  342  is retained in position by the inner wall  260 , the projection  332  and the further seal  124 . 
         [0050]    In one embodiment the second part  342  is formed from a metallic material and forms a part of an attachment system for attaching nozzles, for example concentrating nozzles or diffusing nozzles to the appliance. The further seal  124  ensures correct positioning of the second part  342  and prevents movement of the second part  342  which may produce a noise. 
         [0051]    The gasket  116  additionally includes a centralising feature  130  which cooperates with the outer wall  360  to maintain concentricity of the inner wall  260  within the outer wall  360 . In this embodiment, the centralising feature  130  is curved to minimise the contact between the centralising feature  130  and the inner surface  360   a  of the outer wall  360 . The inner surface  360   a  of the outer wall  360  is provided with four ribs  370  which extend radially inwards of the inner surface  360   a  ( FIG. 5 ). The four ribs  370  are radially spaced around the inner surface  360   a.    
         [0052]    It will be apparent to the skilled person that three ribs could be used or, more than four; four is preferred as it provides a symmetrical system. 
         [0053]    In order that the gasket  116  is located in the correct place within the body  30  so that the different functions of the gasket  116  are realised, the gasket  116  is connected to the inner wall  260 . The inner wall  260  has a flange  264  that extends radially away from an outer surface  260   b  of the inner wall  260  towards the outer wall  360 . 
         [0054]    The gasket  116  includes a protrusion  132  and a recess  134  upstream of the protrusion  132  so that when the gasket  116  is mounted onto the inner wall  260 , the protrusion  132  must pass over the flange  264  to enable the flange  264  to be seated within the recess  134 . The flange  264  has an upstream face  266  and a downstream face  268  and these two faces mate with an upstream surface  136  and a downstream surface  138  of the recess  134  respectively. 
         [0055]    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. 
         [0056]    The appliance can be used with or without a heater; the action of the outflow of fluid at high velocity has a drying effect. 
         [0057]    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. 
         [0058]    The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art.