Abstract:
A hand held appliance comprises a body having an outer wall, a duct extending at least partially along the body within the outer wall, an interior passage extending about the duct for receiving a primary fluid flow, a primary fluid outlet for emitting the primary fluid flow from the body, wherein the primary fluid outlet is defined by the duct and an inner wall of the body. The inner wall may extend from the outer wall towards the duct and may extend radially around the duct. The inner wall may extend from the outer wall towards the primary fluid outlet. At least one spacer may be provided between the inner wall and the duct. The at least one spacer may be a supporting rib. The duct may be formed from two parts, a first part fixed to the inner wall and a second part connected to the first part.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of United Kingdom Application No. 1317171.5, filed Sep. 27, 2013, 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 hand held appliance comprising a body having an outer wall, a duct extending at least partially along the body within the outer wall, an interior passage extending about the duct for receiving a primary fluid flow, a primary fluid outlet for emitting the primary fluid flow from the body, wherein the primary fluid outlet is defined by the duct and an inner wall of the body. 
         [0006]    Thus, fluid flowing through the interior passage is directed towards the primary fluid outlet using internal walls of the appliance. This means that the appearance of the outer wall is unaffected by a change in shape and size of the interior passage so the external features of the appliance can be clean and simple and the internal workings of the appliance are kept hidden from the user. 
         [0007]    Preferably, the inner wall extends from the outer wall towards the duct. The inner wall thus converges fluid flow towards the duct. 
         [0008]    It is preferred that the inner wall extends radially around the duct. 
         [0009]    Preferably, the inner wall extends from the outer wall towards the fluid outlet. 
         [0010]    It is preferred that at least one spacer is provided between the inner wall and the duct. The spacer provides a support between the inner wall and the duct and maintains the relative locations of the inner wall with respect to the duct. 
         [0011]    Preferably, the at least one spacer comprises a plurality of spacers radially spaced from each other. It is preferred that at least one spacer is a supporting rib. 
         [0012]    Preferably, the duct is formed from two parts, a first part which is fixed to the inner wall and a second part which connects to the first part. It is preferred that the first part of the duct is fixed to the inner wall by at least one supporting rib. Preferably, the first part of the duct, the inner wall and the at least one supporting rib are moulded as a single unit. This single unit is an air exit for the appliance and moulding it as a single unit means that tolerances between each feature of the air exit is fixed both for a single air exit and for multiple copies of an air exit. Thus, reliability of the appliance is improved. 
         [0013]    Also disclosed is a hair care appliance comprising a body having an outer wall, a duct extending at least partially along the body within the outer wall, an interior passage extending about the duct for receiving a primary fluid flow, a primary fluid outlet for emitting the primary fluid flow from the body, wherein the primary fluid outlet is defined by the duct and an inner wall of the body, wherein the duct is formed from two parts, a first part which is fixed to the inner wall and a second part which connects to the first part. 
         [0014]    It is preferred that the first part of the duct connects to the second part of the duct in one orientation. This is useful for construction of the appliance particularly when the first part of the duct, supporting ribs and the inner wall are moulded as a single unit (the air exit) as the duct and therefore the inner wall have one single fixed orientation. 
         [0015]    Preferably, the connection between the first part of the duct and the second part of the duct includes a lap joint. It is preferred that one of the first and second parts of the duct includes a recess and the other one of the first and second parts includes a projection adapted to cooperate with the at least two recesses to provide the connection. 
         [0016]    It is preferred that three recesses and protrusions are provided. Preferably, the three recesses and protrusions are unequally angularly spaced. Alternatively or additionally, recesses and projections are of different configuration. The different configuration includes different size and/or shape of the recesses and projection pairs. This again ensures that there is only one way to connect the respective parts of the connection. 
         [0017]    It is preferred that the inner wall comprises a sealing portion and a flow directing portion. The sealing portion prevents leakage of primary flow and the flow directing portion directs the primary fluid flow towards the primary fluid outlet. 
         [0018]    Preferably, the sealing portion seals between the outer wall and the inner wall. 
         [0019]    It is preferred that the sealing portion is a flexible gasket that extends about the inner wall. 
         [0020]    It is preferred that the sealing portion is spaced from an end of the inner wall. Preferably, a region defined between the inner wall, sealing portion and the outer wall is a cooling path. 
         [0021]    It is preferred that the flow directing portion comprises a surface of the inner wall that together with the duct defines a part of the interior passage. Preferably, the surface of the inner wall is smooth. This minimises turbulence created as the primary flow is directed towards the primary fluid outlet as the interior passage reduces in cross section. 
         [0022]    In a preferred embodiment, the appliance comprises a heater extending about the duct. Preferably, the heater is annular. This provides more even heating of the primary fluid flowing through the primary fluid flow path. 
         [0023]    It is preferred that wherein the heater is housed within a sleeve. Preferably, the sleeve extends longitudinally beyond the heater at one end. It is preferred that the sleeve extension is adapted to cooperate with the inner wall to locate the heater longitudinally within the body. Preferably, the sleeve extension is adapted to cooperate with the inner wall to locate the heater radially within the body. This locates the position of the heater with respect to the inner wall and the duct. 
         [0024]    It is preferred that the inner wall includes a ledge and the ledge supports the sleeve extension. Preferably, the one of the inner wall and the sleeve extension includes a recess and the other one of the inner wall and sleeve extension includes a projection adapted to cooperate with the recess. Preferably, three recesses and protrusions are provided. It is preferred that the three recesses and protrusions are unequally angularly spaced. Alternatively or additionally, the recesses and the projections are of different configuration. 
         [0025]    Thus, it is preferred that the heater can only connect in one orientation to the inner wall and when this feature is used in combination with other preferred features of the invention the result is that there is only one way to assembly the different components that are housed within the body of the appliance. As the heater, for example requires connection to a power source, this means that those connectors will always be radially located with the body in the same place making assemble quicker, more efficient and cost effective. 
         [0026]    Preferably, the fluid outlet is at a downstream end of the body. It is preferred that the inner wall has a downstream end and an upstream end and the downstream end at least partially defines the fluid outlet. 
         [0027]    Preferably, the upstream end of the inner wall extends towards the outer wall. Preferably, the inner wall includes a sealing portion that extends to the outer wall. It is preferred that the sealing portion is between the upstream end and downstream end of the inner wall. 
         [0028]    Preferably, the upstream end of the inner wall includes a connector for connecting with a heater. It is preferred that the connector extends radially around the inner wall. Preferably, the connector includes a stop extending radially out from the inner wall. It is preferred that the stop extends radially out towards the outer wall. 
         [0029]    Preferably, the heater includes a housing which extends radially about the heater. It is preferred that the housing extends longitudinally away from the heater at a downstream end of the heater. Preferably, the extension of the heater housing is adapted to engage with the connector and the stop to locate the heater with respect to the inner wall, duct and outer wall of the appliance. 
         [0030]    It is preferred that the inner wall includes a flow directing portion for directing flow from the heater towards the fluid outlet. 
         [0031]    Preferably, the interior passage reduces in diameter along the inner wall from the upstream end of the inner wall to the fluid outlet at the downstream end of the inner wall. 
         [0032]    It is preferred that the flow directing portion is a smooth curved surface of the inner wall. 
         [0033]    According to a second aspect of the invention is a hair care appliance comprising a body having an outer wall, a duct extending at least partially along the body within the outer wall, an interior passage extending about the duct for receiving a primary fluid flow, a primary fluid outlet for emitting the primary fluid flow from the body, wherein the primary fluid outlet is defined by the duct and an inner wall of the body. 
         [0034]    Preferably, the primary fluid outlet is in a front end of the body and the front end of the body comprises an end wall extending radially inwards of the body and the end wall comprises at least one magnet. It is preferred that the end wall abuts a plurality of magnets or a ring of magnetic material. The plurality of magnets or ring of magnetic material preferably extends around the end wall. Preferably, the end wall comprises an outer face and an inner face, the outer face being an external surface of the appliance, wherein the plurality of magnets are adjacent the inner face. The plurality of magnets is preferably received in an inner wall of the body. Preferably the inner wall forms part of an air exit as previously described herein. Preferably, the inner wall includes an inner facing surface which is a flow directing surface which together with the duct defines part of the interior passage. In addition the inner wall preferably includes a plurality of receiving units disposed around an outer facing surface for receiving the plurality of magnets. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0035]    The invention will now be described by example, with reference to the accompanying drawings, of which: 
           [0036]      FIG. 1  shows a perspective view of an appliance according to the invention; 
           [0037]      FIG. 2  shows a cross section through the appliance of  FIG. 1 ; 
           [0038]      FIG. 3  shows an exploded side view of the appliance of  FIGS. 1 and 2 ; 
           [0039]      FIG. 4   a  shows a cross section through a body of an appliance according to the invention; 
           [0040]      FIG. 4   b  shows an isometric cross section through a part of the body of  FIG. 4   a;    
           [0041]      FIG. 5  shows an air exit according to the invention; 
           [0042]      FIG. 6  shows a cross section through the air exit of  FIG. 5 ; 
           [0043]      FIG. 7  shows region B of  FIG. 6  in more detail; 
           [0044]      FIG. 8  shows a rear perspective view of the air exit of  FIG. 5 ; 
           [0045]      FIG. 9  shows a front perspective view of the air exit of  FIG. 5 ; 
           [0046]      FIG. 10  shows region C of  FIG. 9  in more detail; 
           [0047]      FIG. 11  shows a front perspective view of a duct; 
           [0048]      FIG. 12  shows a front perspective view of a heater; 
           [0049]      FIG. 13  shows an exploded isometric view through a head of  FIG. 4 ; 
           [0050]      FIG. 14   a  shows an exploded side view of components of a body of a further appliance; 
           [0051]      FIG. 14   b  shows part of the gasket of  FIG. 14   a  in more detail; 
           [0052]      FIG. 15  shows a cross section through the body of the appliance of  FIG. 14 ; 
           [0053]      FIG. 16  shows an example of an attachment for a hairdryer; 
           [0054]      FIG. 17  shows a rear perspective explosion of the attachment shown in  FIG. 16 ; 
           [0055]      FIG. 18  shows a front perspective explosion of the attachment shown in  FIG. 16 ; and 
           [0056]      FIG. 19  shows an isometric view of a hairdryer with the attachment of  FIG. 16 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0057]      FIGS. 1 and 2  show an example of a hairdryer  10  which is suitable for use with the invention. The hairdryer  10  has 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 inlet  40 . Power is supplied to the hairdryer  10  via a cable  50 . 
         [0058]    The body  30  has a first end  32  and a second end  34  and can be considered to have two parts. A first part  36  which extends from the first end  32  which is generally tubular and a second part  38  which extends from the second end  34  to join the first part  36 . The second part  38  is cone shaped and varies in diameter along its length from the diameter of the first part  36  of the body  30  to a smaller diameter at the second end  34  of the body. In this example, the second part  38  has a constant gradient and the angle α subtended from the outer wall  360  of the first part  36  of the body  30  is around 40°. 
         [0059]    Referring now to  FIG. 2  in particular the handle  20  has an outer wall  200  which extends from the body  30  to 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 inlet  40  in the handle  20  includes first apertures that extend around and along  42  the outer wall  200  of the handle 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 end wall  210  is orthogonal to the outer wall  200  and inner wall  220  of the handle. 
         [0060]    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. 
         [0061]    Upstream of the primary 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 inlet  40  towards the body  30  through a primary fluid flow path  400  that extends from the primary inlet  40  and into the body  30  where the handle  20  and the body  30  are joined  90 . 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. 
         [0062]    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 duct  310  towards the primary fluid outlet  440  at the second end of the body  34 . 
         [0063]    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 . 
         [0064]    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 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 duct 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 duct  310 . This side wall  350  at least partially defines the fluid inlet  320 . At the second end  34  of the body a gap is provided between the outer wall  360  and the duct, this gap defines the primary fluid outlet  440 . The primary fluid outlet  440  is annular and surrounds the fluid flow path  300 . The primary fluid outlet  440  may be internal so the primary fluid flow path  400  merges with the fluid flow path  300  within the body  30 . Alternatively, the primary fluid outlet  440  is external and exits from the body  30  separately to the fluid from the fluid flow path  300  at the fluid outlet  340 . 
         [0065]    The outer wall  360  of the body converges towards the duct  310  and a centre line A-A of the body  30 . Having an outer wall  360  that converges towards the duct  310  has the advantage that the primary flow exiting the primary fluid outlet  440  is directed towards the centre line A-A of the body  30 . The fluid exiting the primary fluid outlet  440  will cause some external entrainment of fluid  490  from outside the hairdryer due to the movement of the fluid from the primary outlet  440 . This effect is increased by the outer wall  360  converging towards the duct  310 . Partly this is because the primary flow is focused rather than divergent and partly this is because of the slope of the outer wall  360  of the body  30  towards the second end  34  of the hairdryer. 
         [0066]    The duct  310  is an internal wall of the hairdryer that can be accessed from outside the hairdryer. Thus, the duct  310  is an external wall of the hairdryer. The duct  310  is recessed within the body  30  so the side wall  350  that connects between the outer wall  360  and the duct  310  is angled with respect to the outer wall  360 . The angle  13  is around 115° from a line subtended by the outer wall  360  of the body  30  ( FIG. 2 ). 
         [0067]    A 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 duct  310  between the 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 duct  310 . 
         [0068]    The PCB  75  controls such parameters 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. 
         [0069]    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, 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. 
         [0070]      FIG. 3  shows an exploded side view of a hairdryer  100  using an air exit  110  according to the invention.  FIGS. 4   a  and  4   b  show a cross section through a hairdryer  100  showing the air exit  110  in situ with the heater  80  and  FIGS. 5 to 9  show various views and cross sections through the air exit  110 . For features that are common between Figures, the same reference numerals will be used. 
         [0071]    The air exit  110  has been designed so that it can provide positive locking of various features within the appliance. In addition, it is preferred that the positive locking can only be achieved in one orientation so for every product manufactured it is guaranteed that connections between different features such as an electrical connection from the heater  80  to the PCB  75  will be in the same place and are repeatable. 
         [0072]    Referring in particular to  FIGS. 4   a  to  12 , the air exit  110  has a first duct  310   a  and an inner wall  120  which are connected together by supporting ribs  130 . The inner wall  120  channels fluid flowing in the primary fluid flow path  400  towards the primary fluid outlet  440 . The inner wall  120  includes a flow directing portion  132  which channels or directs flow exiting the heater  80  towards the primary fluid outlet  440  as the diameter of the body  30  decreases towards the second end  34  of the body  30 . The first duct  310   a  is adapted to connect with a second duct  310   b  to form a whole duct  310  which extends from the side wall  350  to the downstream end  34  of the body  30  where the fluid outlets  340  and  440  are located. The connection  322  is formed from two cooperating parts which form a lap joint between the first duct  310   a  and the second duct  310   b  ( FIG. 4 ). 
         [0073]    Referring now to  FIGS. 4   a ,  4   b ,  8  and  11  in particular, the air exit  110  includes a first part  322   a  of the connection  322  which has an outer lip  328  of the lap joint having with three spaced apart recesses  324 ,  326 ,  328 . The second duct  310   b  includes a second part  322   b  of the connection  322  which has an inner lip  330  with three spaced apart projections  332 ,  334 ,  336 . A first pair of recess and projection  324 , 336  respectively is smaller than the other two pairs of recess and projection  326 , 334  and  236 , 332  respectively so the first duct  310   a  can only be inserted into the second duct  310   b  in one orientation. 
         [0074]    Referring in particular to  FIGS. 4   a ,  4   b ,  8  and  12 , the air exit  110  has a second connection  140  to the heater  80 . This second connection  140  is formed from two cooperating parts which form a lap joint between the inner wall  120  and the heater  80 . The inner wall  120  includes a first part  140   a  of the second connection  140  which has an inner lip  122  of the lap joint having three spaced apart pips  124 ,  126 ,  128  which protruded radially outwardly from the inner lip  122 . The heater  80  includes a second part  140   b  of the connection  140 . The heater element  82  is surrounded by an outer sleeve  84  which is a ring of insulating material, such as Mica. This outer sleeve  84  extends along the length of the heater element  82  (which is for example, a coiled wire) and extends downstream of the heater element  82  towards the fluid outlets  340 ,  440  of the body  30 . Part of the extension downstream of the heater element  82  forms a second part  140   b  of the second connection  140 . The second part  140   b  of the connection  140  includes three holes  88 ,  92 ,  94  or recesses in the sleeve  84 . 
         [0075]    In the embodiment shown the three holes  88 ,  92 ,  94  are ‘L’ shaped so the connection  140  is properly made by a push and twist motion. This is a preferred feature and it provides a more secure connection than simply pushing the pips  124 ,  126 ,  128  into each hole  88 ,  92 ,  94 . 
         [0076]    Each pip  124 ,  126 ,  128  and holes  88 ,  92 ,  94  are the same diameter; however they are not equally angularly spaced around the lap joint. Thus, the heater  80  can only be connected to the air exit  110  by the second connection  140  in one orientation. This means that the heater  80 , air exit  110 , the duct  310  and the side wall  350  are all connectable together in one predetermined orientation. This is extremely useful. In the hairdryer shown in  FIG. 2 , the side wall  350  includes control buttons  64  which extend from the PCB and the heater will have wires (not shown) connecting to the PCB. In the arrangement described, that the heater  80  will always be in the same orientation with respect to the PCB making assembly and electrical connection of the heater to the PCB simpler. 
         [0077]    It is also advantageous, but not essential that the air exit  110  includes the inner lip of one of the first or second connections and the outer lip of the other connection as this constrains the heater  80 , the air exit  110  and the duct  310  radially with respect to each other. The lap joints  322 ,  140  can be reversed i.e. the inner and outer lips can be formed on the opposite parts of each respect lap joint  322 ,  140  as can the location of the protrusions and recesses. Indeed each of the first and second connections can use unequal angular spacing and/or a different configuration of protrusions and recesses. The configuration includes the shape or profile and the sizes of each pair of protrusion and recess. 
         [0078]    Referring to  FIGS. 4   a ,  4   b  and  13  in particular, towards the downstream end  110   a  of the air exit  110  a sealing gasket  116  is provided between the inner wall  120  of the air exit  110  and the outer wall  360  of the body  30 . This has a number of functions including sealing against fluid flowing along the primary fluid flow path  400  and then between the inner wall  120  and the outer wall  360  to the second end  34  of the body  30  and bypassing the primary fluid outlet  440 . A second function of the gasket  116  is to retain the position of the inner wall  120  with respect to the outer wall  360  and hence retains the air exit  110  in position with respect to the outer wall  360 . 
         [0079]    Referring to  FIGS. 5 to 7  in particular, the inner wall  120  has two sections; a first section  136  includes the first part  140   a  of the second connection  140  and is generally parallel to one or more of the outer wall  360 , the first duct  310   a  and the heater  80 . A second section  138  includes the flow directing portion  132 . This second section  138  has a curved profile and in the flow direction through the primary fluid flow path  400  the second section curves towards the centre line A-A of the duct and the fluid outlet  320 . The flow directing portion  132  is curved and has a smooth surface which is in contact with fluid flowing through the primary fluid flow path  400 . 
         [0080]    Constraining the relative radial locations of the inner components of the body  36  of the hairdryer is useful as it allows each component to be concentric within the body  36 . Referring to  FIGS. 13 and 14  in particular, the body  36  extends lengthwise from a first end  32  to a second end  34  and within the body a number of different components are housed each of which extend along the length of the body. Firstly, there is the inner duct  310 ; this is surrounded by the heater  80  for at least a part of the length of the inner duct  310  and the heater  80  is surrounded by the outer wall  360  of the body  36 . It is important that the heater  80  does not touch either of the inner duct  310  or the outer wall  360  as this will create a hot spot where heat from the heater  80  can transfer directly to an external surface of the appliance, it could also reduce the life of the heater  80 . There is very little space between each of the components within the body  36 , so a loss of concentricity could cause the heater to touch the inner duct  310  or the outer body  360 . 
         [0081]    The primary fluid flow path  400  that extends along the body  36  is annular and should have generally consistent inner and outer diameter along the length of the body  36  otherwise there will be uneven flow around the primary fluid flow path  400  and this would result in the heater  80  having thermal fluctuations radially around the heater  80 . The outer wall  360  and the duct  310  are generally parallel along the length of the body. If the heater  80  did contact one of the inner duct  310  and outer body  360  that define the space in which the heater  80  resides there would be a thermal fluctuation along the length of the heater  80 . Both of these outcomes would compromise the efficiency of the appliance and possible cause damage to some of the components. 
         [0082]    The inner duct  310  is connected to the body  36  at the first end  32  of the body  36  via a side wall and by fixing the inner duct  310  to the air exit  110  and the heater  80  near the second end  34  of the body  36 , the spacing and concentricity of these components is ensured along with the cross sectional profile of the primary fluid flow path  400 . 
         [0083]    Referring to  FIGS. 4   a  and  4   b , a first gap  112  is provided between the heater  80  and the outer wall  360  and a second gap  114  is provided between the heater  80  and the inner duct  310 . The first gap  112  and the second gap  114  provide cool walls between the heater  80  and a respective externally accessible surface. Some fluid flowing through the primary fluid flow path  400  flows along these gaps  112 ,  114  providing a fluid insulator along the length of the heater  80  to reduce the temperature of the outer wall  360  and the inner duct  310 . The fluid that flows through the second gap  114  rejoins the main primary fluid flow path (that flows directly through the heater  80 ) at the air exit  110 . The first gap  112  continues beyond the heater  80  towards the second end  34  of the body  30  and the sealing gasket  116  that seals between the inner wall  120  of the air exit  110  and the outer wall  360  of the body  36  providing a fluid insulator between the inner wall and the outer wall  360 . 
         [0084]    At the front or second end  34  of the body  30  a plurality of magnets  150  are disposed radially spaced around the primary fluid outlet  440 . These magnets  150  comprise one part of a magnetic coupling to an attachment (not shown) such as a concentrator or diffuser which includes corresponding magnets or magnetic material which are attracted to the magnets  150  to connect the attachment to the body  30  of the hairdryer  10 . The outer wall  360  of the body  30  has an end wall  362  which extends radially inwards of the outer wall  360  towards the centre line A-A of the body  30 . In this example, the magnets  150  are housed within the air exit  110  and abut or are adjacent the end wall  362  of the body  30 . The magnets  150  are cylinders which are push or interference fit into receiving units  152  located radially spaced around a front face of the air exit  110 . The inner wall  120  thus has a first inner facing surface which is a flow directing surface  132  and a second outer facing surface  134  which includes the receiving units  152  for the magnets  150 . 
         [0085]    Each receiving unit  152  includes a pair or arms  154 ,  156  between which a magnet  150  is pushed until the magnet  150  is flush with the front face  118  of the air exit. By having a flush surface, the air exit  110  is able to abut the end wall  362  of the body  30  maximising magnetic attraction produced by the array of magnets  150 . In addition, having a flush front face  118  to the air exit  110  helps to position the air exit  110  with respect to the outer wall  360  of the body  30 . 
         [0086]    The gasket  116  is located somewhere along the inner wall  120  of the air exit  110 . The exact positioning is not critical as long as the gasket  116  does not interfere with the lap joint  140  or the function of the magnets  150 . 
         [0087]    An alternative gasket  316  is shown in  FIGS. 14 and 15 . In this embodiment, the magnets  150  are radially spaced around the fluid outlet  440  as before, however the magnets  150  are housed within the gasket  316  rather than the air exit  410 . The gasket  316  comprises a plurality of receiving units  352  each one designed to receive one of the cylindrical magnets  150 . Each receiving unit  352  comprises a pair of arms  354 ,  356  between which a magnet  150  is pushed until the magnet  150  is flush with the front face  318  of the gasket  318 . Having a flush surface means the magnets  150  can abut the end wall  362  of the outer body  360  of the body  30  maximising magnetic attraction between the body and an attachment. 
         [0088]    The gaskets  116 ,  316  both have a sealing surface  116   a ,  316   a  respectively which, when the gasket  116 ,  316  is positioned with respect to the air exit  110 ,  410  and the outer wall  360  of the body  30  seals against the outer wall  360  preventing fluid from the primary fluid flow path  400  exiting the appliance anywhere other than the primary fluid outlet  440 . 
         [0089]      FIGS. 16 to 19  show various views of an attachment to which a hairdryer  10  may be removably attached via the magnets  150 . In this example, the attachment is a docking port  450  for the hairdryer  10  when not in use. The docking port  450  is conveniently attached to a surface  460  such as a wall, vanity unit, or wardrobe for example. 
         [0090]    The docking unit  450  has three parts, a base  452  for attachment to a surface  460 , a ring  454  of magnetic material or magnetised material and a cone  456  for engaging with the duct  310  of a hairdryer  10 . The base  452  includes a screw thread  458  onto which the cone  456  is screwed when the ring  454  is in position. The ring  454  of magnetic material or magnetised material can be made from one of iron, a steel, or flakes of magnetic material moulded into a resin such as epoxy, other examples will be apparent to the skilled person. 
         [0091]    The inner duct  310  is generally tubular and it is preferred that the wall  312  that defines first duct  310   a  tapers radially outwardly towards the downstream end or the fluid outlet  340  ( FIG. 4 ). Thus, the wall  312  thins towards the outlet  340  increasing the diameter of the fluid flow path  300  slightly at the outlet  340 . Fluid that flows through the fluid flow path  300  is thus angled towards the outer wall  360  and the primary fluid outlet  440 . 
         [0092]    The gasket  116 ,  316  seal the inner wall  110 ,  410  respectively against the outer wall  360 . The seal need not be a perfect seal as in some circumstances it may be desirable to allow some controlled leakage through the gasket  116 ,  316  to provide a cooling flow of the outer wall  360  downstream of the gasket  116 ,  316 . The gasket  116 ,  316  could comprise a number of radially disposed bleeds or recesses to achieve this. 
         [0093]    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. 
         [0094]    The appliance can be used with or without a heater; the action of the outflow of fluid at high velocity has a drying effect. 
         [0095]    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. 
         [0096]    The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art.