FIELD OF THE INVENTION

This invention relates to a hair styling device, and in particular to an improvement upon the hair styling devices disclosed in our earlier applications WO2009/077747, WO2012/080751 and WO2013/186547.

For brevity, in the present application reference is made to the styling of a female's hair, but the invention is not limited thereby.

BACKGROUND TO THE INVENTION The hair styling devices described in WO2009/077747, WO2012/080751 and WO2013/186547 all have a rotatable element which captures or collects a section or length of hair to be styled, and winds the length of hair around a protrusion in the form of an elongate member. The preferred embodiments utilise a chamber surrounding at least part of the elongate member, the chamber being heated by way of heat applied to the walls of the chamber and/or to the elongate member. A hair treatment product may be applied to the hair within the chamber. The hair within the chamber becomes styled by the application of heat and/or by the application of the treatment product whilst it is located around the elongate member. The present invention shares many of the features of the preferred embodiments of the hair styling device described in WO2009/077747, WO2012/080751 and WO2013/186547, and so the disclosure of those documents is incorporated herein in order to avoid unnecessary repetition. In addition, it is believed that the hair styling devices described in WO2009/077747, WO2012/080751 and WO2013/186547 represent the closest prior art to the present invention. Less relevant hair styling devices are described in US patents 2,935,070 (Auz) and 4,177,824 (Gnaga).

SUMMARY OF THE INVENTION

Notwithstanding the practical and commercial attractiveness of the hair styling devices described in WO2009/077747, WO2012/080751 and WO2013/186547, the present inventors have conceived further improvements and modifications, and the present invention is directed to those improvements and modifications.

According to a first aspect of the present invention, there is provided a hair styling device having:

a body defining a chamber adapted to accommodate a length of hair, the chamber having an opening through which the length of hair may pass into the chamber; a rotatable element adapted to engage the length of hair adjacent to the opening;

a protrusion around which, in use, the length of hair is wound by the rotatable element;

at least one heating element to heat the length of hair; and

a controller adapted to control the rotation of the rotatable element, the controller being adapted to adjust the rate of rotation of the rotatable element between a first rate of rotation and a second rate of rotation.

For the avoidance of doubt, neither the first rate of rotation nor the second rate of rotation is zero.

Alternatively stated, the controller can set the rate of rotation of the rotatable element at the first rotational rate or at the second rotational rate.

The hair styling device may be operable at only two different rates of rotation, but preferably will be operable at three or more different rates of rotation. The first rate of rotation may be preset as the slowest available rate of rotation and the second rate of rotation may be preset as the fastest available rate of rotation, with the controller able to adjust the rotatable element to rotate at one or more additional rates of rotation between these extremes. Alternatively, the controller may be able to set the rate of rotation to any rate between the two extremes.

Known devices which are made according to WO2009/077747, WO2012/080751 and WO2013/186547 incorporate a controller and enable the user to adjust certain operating parameters and functions of the device. Specifically, the device has a number of switches, one of which permits the user to adjust the temperature of the heating element between a plurality of preset values. Another switch permits the user to adjust the period of operation of the device between a plurality of preset cycle times, the user being alerted to remove the styled length of hair from the chamber when the chosen time period has elapsed.

In some embodiments a further switch permits the user to alter the direction of rotation of the rotatable element, specifically between "clockwise", "anti-clockwise" and "alternating". In the first and second switch positions the hair styling device will form curls in a consistent direction, either clockwise or anti-clockwise as chosen, whereas in the third switch position the device will provide an alternating sequence of clockwise and anti-clockwise curls. The inventors have realised that most users will (deliberately or accidentally) introduce lengths of hair which vary in size (thickness), i.e. the number of individual hairs in a length of hair being styled will vary significantly between successive styling operations. For a given temperature and cycle time the thickness of the length of hair being styled will have a significant effect upon the curl which is produced, it being recognised that significantly more heat will usually be required to style a larger length of hair. It is desirable for the device to be able to accommodate differently-sized lengths of hair and for the operating parameters to be adjustable so that the device can produce consistent curls. In particular, the inventors wish the user to be able to style a very large length of hair, or a very small length of hair, as desired, whilst minimising the inconsistency between the formed curls.

The disclosure of WO2013/186547 is directed at least partly to a hair styling device having a relatively wide opening for the length of hair, permitting the user to style lengths of hair having significantly differing sizes (thicknesses). The first aspect of the present invention is directed to a hair styling device which seeks to enable the user more easily to provide consistent curls regardless of any inconsistencies in the size of the lengths of hair being styled.

Whilst the known devices which are made according to WO2009/077747, WO2012/080751 and WO2013/186547 permit some adjustment to the user, the user may not be able or willing to adjust the temperature and/or cycle time for each styling operation sufficiently accurately for successive lengths of hair to be styled consistently in the event that the lengths of hair have significantly different sizes. In common with WO2013/186547, there is preferably a panel to cover or close the opening, and the panel is heated. It will be understood that the free end of the length of hair is pulled past the panel by the rotatable element as it is drawn into the chamber. Adjusting the rate of rotation of the rotatable element between a first rate of rotation and a second rate of rotation varies the duration for which a particular portion of the length of hair is adjacent to the panel, and thereby adjusts the amount of heat applied to the length of hair. The controller will typically use a slower rate of rotation for a larger length of hair.

Also in common with WO2009/077747, WO2012/080751 and WO2013/186547, the rotatable element preferably lies between a first (or front) chamber and a second (or rear) chamber, the length of hair being retained within the first chamber for styling. The rotatable element causes a portion of the length of hair to be drawn directly into the first chamber and another portion of the length of hair initially to be drawn into the second chamber; continued rotation of the rotatable element causes the latter portion subsequently to be drawn from the second chamber into the first chamber.

Preferably, there is at least one heating element to heat the length of hair within the second chamber. Accordingly, that portion of the length of hair is pre-heated (perhaps to a temperature close to or equal to that of the first chamber) before it enters the first chamber. This can reduce the length of time for which the length of hair must remain within the first chamber in order to form the desired curl, and can reduce the overall cycle time.

Preferably, the controller is connected to the heating element(s) and can adjust the temperature of the heating element(s). It will be understood that increasing the temperature of a heating element will increase the rate at which heat is applied to the portion of the length of hair which is adjacent to that heating element. The controller may increase the temperature of the heating element(s) in the panel, and/or in the second chamber, and/or in the first chamber (ideally together with reducing the rate of rotation of the rotatable element), when the device is being used to style a larger length of hair. It will be understood that adjusting the rate of rotation of the rotatable element varies the duration for which a particular portion of the length of hair remains within the second chamber before it is pulled into the first chamber. The amount of heat applied to that portion of the length of hair before it enters the first chamber can thereby be varied, both by adjusting the temperature of the heating element(s) of the second chamber and by adjusting the period for which that portion of the length of hair remains within the second chamber.

Desirably, the controller has a timer and can adjust the cycle time of the device. It will typically be necessary to increase the cycle time together with reducing the rate of rotation of the rotatable element when the device is being used to style a larger length of hair. The controller may also increase the temperature of one or more of the heating elements together with increasing the cycle time (and vice versa). The controller will preferably be adapted to issue an audible signal to the user to alert the user to the end of a cycle; alternatively or additionally the heating element(s) may be switched off when the timer indicates that the cycle time has elapsed.

Preferably, the controller is also able to adjust the torque of the rotatable element, it being recognised that more torque will typically be required to draw a larger length of hair into the device. It is a feature of the devices made according to the Applicants' previous patent applications that the rotatable element will reverse its rotation and return to its start position if it slows or stalls due to entanglement of the length of hair. Adjusting the torque for the rotatable element (or alternatively by adjusting the threshold for the load or the measured speed reduction which is indicative of the rotatable element stalling) allows the device to be used to style lengths of hair of varying sizes, without avoiding the advantages of the automated reversing feature. In one embodiment the torque can be adjusted by varying the gearing ratio between the motor and the rotatable element, for example.

Desirably, there is at least one sensor within the device which can detect the presence of hair within the rear chamber. The use of sensors to detect misplaced hair is disclosed in WO2012/080751 . However, in the present invention sensors can be used also to detect the passage of the entire length of hair into the first chamber. The controller can thereby detect when there is no longer any hair within the second chamber, and can switch off any heater element(s) which act upon the second chamber, whereby to save energy. Also, in certain embodiments it may be desirable to stop the rotation of the rotatable element once all of the length of hair has passed into the first chamber. In the present invention, however, the rotatable element may continue to rotate in order to ensure that the length of hair is curled right to its tip. It will be understood from WO2009/077747, WO2012/080751 and WO2013/186547 that the rotatable element can continue to rotate without damage to the length of hair, and in practical embodiments the rotatable element continues to rotate until it reaches its start position with the rotatable element ready to receive another length of hair in the next styling operation. The inventors have appreciated that in some cases when the rotatable element stops rotating the free end of the length of hair lies adjacent to the aperture in the rotatable element, and in those cases the free end may pass back through the aperture and lie outside the first chamber. A few centimetres at the free end of the length of hair may therefore be substantially straight rather than curled, with the result that the formed curl does not extend all the way to the free end of the length of hair. If, however, the rotatable element continues to rotate throughout the styling operation the likelihood that the entire length of hair is curled as desired is maximised.

Also, it may be desirable to cool the length of hair before it leaves the chamber. It is recognised that cooling the length of hair helps to maintain the curl and whilst the length of hair will naturally cool once it is removed from the chamber it may be desirable to cool the length of hair whilst it is held in its curled form and thereby avoid any loss of the curl which might occur as soon as it leaves the chamber. The rotatable element can additionally act as a turbine or fan to drive ambient air into the chamber to cool the hair, or another turbine or fan could be provided for that dedicated purpose. In certain embodiments of the present invention the device has a control panel by which the user can input commands to the controller. For example, suitable operating parameters may be stored in a memory of the controller, the operating parameters comprising different rates of rotation of the rotatable element, plus ideally different temperature settings for each of the heating element(s), plus preferably various torque settings for the rotatable element, plus desirably different cycle times before the user is alerted to remove the styled length of hair. Several sets of parameters may be stored, suited to different sizes for the length of hair. In such embodiments the user will therefore be able to use the control panel to instruct the controller to use the stored parameters for a large length of hair, a small length of hair, or a medium length of hair, for example (more or fewer than three alternative sizes can be used, as desired). Asking the user to classify a length of hair into one of three ranges, and then to input the appropriate range to the controller for each styling operation, is not expected to be too onerous for the majority of users.

Alternatively, the controller may be connected to a sensor which is adapted to detect the size of a length of hair, the controller automatically determining the set of parameters for each styling operation dependent upon the detected size. In such embodiments no user input to the controller is necessary.

As above indicated, there may be a predetermined number of discrete rates of rotation of the rotatable element available for the user to select, or there may be a substantially continuous range of rotation rate available between a predetermined minimum and maximum. The same can be true for the temperature of each of the heating elements, and for the cycle time. Greater consistency in the styling of differently-sized lengths of hair can be obtained with a greater number of settings for each parameter, but the complexity of operation is also increased. If the operating parameters are adjustable by the user it is expected that a relatively small number of rates of rotation, a relatively small number of available temperatures, and a relatively small number of available cycle times are available (perhaps three to five settings in each case). If, on the other hand, the operating parameters are adjustable automatically by the controller, a greater number of settings for each parameter could be available, perhaps up to a continuous range of each parameter between a predefined minimum and maximum. In common with the disclosure of WO2012/080751 and WO2013/186547, a secondary opening preferably surrounds the free end of the elongate member. The elongate member may project beyond the secondary opening, or it may terminate in line with the secondary opening, or it may terminate within the chamber. The term "surrounds" is used for all of these alternatives because the relevant feature is that the secondary opening permits a formed curl to slide off the end of the elongate member without being forced to uncurl or deform. The term "surrounds" should therefore be considered from a viewpoint looking along the axis of the elongate member.

According to a second aspect of the invention, there is provided a hair styling device having: a body defining a chamber adapted to accommodate a length of hair, the chamber having an opening through which the length of hair may pass into the chamber;

a rotatable element adapted to engage the length of hair adjacent to the opening;

a protrusion around which, in use, the length of hair is wound by the rotatable element;

at least one insert locatable within the chamber to partially surround the protrusion. WO2009/077747 discloses that the diameter of the chamber can increase in order to accommodate longer lengths of hair. It will be recognised that varying the diameter of the chamber will vary the diameter of the curls which are formed. According to the second aspect of the invention the diameter of the chamber can be reduced by a predetermined amount by adding an insert of known thickness. Thus, it is desirable to allow the user to vary the diameter of the chamber by a chosen amount, i.e. other than automatically.

Desirably, the insert(s) has electrical contacts which can engage electrical contacts within the chamber, whereby the controller can detect the presence of the insert. The controller can therefore automatically adjust chosen parameters of the device dependent upon the installed insert.

Preferably, a plurality of differently-sized inserts is provided (each having a different thickness) and the controller can distinguish between the inserts so as to adjust the parameters to suit each particular insert. The inserts can be distinguished by way of differently-positioned contacts, or by way of a different response to an electrical signal communicated from the controller. There is also provided a tool for the installation and removal of an insert, it being recognised that a dedicated tool is desirable for this purpose so as to reduce the likelihood that a user will touch a hot insert, and that a hot insert will engage and perhaps damage a work surface.

According to a third aspect of the invention, there is provided a hair styling device having: a body defining a chamber adapted to accommodate a length of hair, the chamber having an opening through which the length of hair may pass into the chamber;

a rotatable element adapted to engage the length of hair adjacent to the opening;

at least one pressing part to drive the length of hair towards the opening;

a capture region for misplaced hair, the capture region being spaced from the opening;

at least one holding part for holding the misplaced hair within the capture region;

a detector for detecting misplaced hair within the capture region.

The inventors' earlier patent applications describe the use of sensors to detect misplaced hair, optical sensors being appropriate to detect the presence of hair in unwanted locations. In an embodiment described in WO2012/080751 for example, the length of hair is guided into the chamber by way of two inclined surfaces. It is recognised that hair which is located at the top of an inclined surface may not be engaged by the rotatable element and one or more sensors are located adjacent to the top of the inclined surface to detect hair in that location. It can be arranged that the device cannot be actuated if misplaced hair is located.

The present invention seeks to make the detection of misplaced hair easier and more reliable, and also provides a mechanical means for detecting misplaced hair.

As with the earlier methods and apparatus for detecting misplaced hair, the present invention seeks in particular to make the device easier to use by a person styling her own hair, especially in areas where the user may be unsighted, and seeks to avoid situations in which entanglement is likely. The present invention differs from the earlier disclosures in providing a defined capture region for misplaced hair. Whilst it is desirable to avoid any misplaced hair (and the device will preferably include guides and the like to make misplacing of the hair less likely) the inventors appreciate that misplaced hair will sometimes occur, and it is advantageous to provide a defined capture region where the misplaced hair may be held and detected. The controller can prevent actuation of the rotatable element if misplaced hair is detected, so that entanglement may be prevented.

The capture region can be close to the opening, but is preferably far enough away from the opening for hair within the capture region not to be engaged by the rotatable element. Alternatively stated, the device is configured so that ideally all of the length of hair is driven towards the opening where it can be engaged by the rotatable element and drawn into the chamber. If, however, some of the length of hair is misplaced so that it will not be driven towards the opening, it is instead held within the capture region where it can be detected.

The capture region can have a defined first edge and a defined second edge, the first edge being closer to the opening than the second edge. The separation of the first edge from the opening is sufficient to ensure that misplaced hair (which will not be captured by the rotatable element) is readily distinguishable from correctly-positioned hair (which will be captured by the rotatable element).

The form of the holding part(s) will depend upon the structure of the device. For example, the capture region may include a surface which is inclined away from the opening, in which case misplaced hair will be pressed away from the opening as correctly-placed hair is pressed towards the opening. In such an embodiment a single component can provide the pressing part and the holding part and it will not usually be necessary to clamp the misplaced hair within the capture region in order for it to be detected.

Alternatively, if the capture region is not inclined away from the opening, or is perhaps inclined towards the opening, it is preferable to clamp the misplaced hair in the capture region so as to better ensure that it can be detected. In such an alternative embodiment it is preferable that the holding part(s) is a separate component to the pressing part(s). Also, preferably the at least one holding part is resiliently biased, so as to better hold or clamp the misplaced hair within the capture region.

Desirably the detector includes one or more movable elements, ideally one or more pivoting levers. The ends of the levers can define the first and second edges of the capture region.

Preferably, the capture region includes converging surfaces, the ends of the surfaces providing the first and second edges of the capture region. Converging surfaces can also act to collect the misplaced hair into a small portion of the capture region. It is recognised that the misplaced hair may comprise only a few individual hairs; it is desirable to collect or concentrate all of those hairs together so that they may more easily be detected. The capture region can for example comprise a V-shaped groove. It will be understood that it is easier to detect a small number of individual hairs if they are concentrated into a small bundle.

There may be a single holding part and a single pressing part (which may comprise a single component) or there may be two (or perhaps more than two) holding parts and/or pressing parts. If there are two holding parts they are preferably spaced apart along the length of the opening, and ideally lie to opposed sides of the rotatable element.

The detector can be an optical sensor as in the previous disclosures, or it can be an electronic sensor such as a capacitive or inductive sensor, or it can be a mechanical sensor, for example including an electrical switch.

The different aspects of the present invention may be combined, individually or collectively, with any features of one or more of WO2009/077747, WO2012/080751 and WO2013/186547 with which they are compatible.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which:

Fig.1 shows a perspective view of a hair styling device according to the present invention, with the movable panel in its open position;

Fig.2 shows a sectional view through the device, with a length of hair positioned ready to be styled at the start of an operating cycle;

Figs.3-5 show two inserts for adjusting the diameter of the chamber so as to vary the diameter of the formed curls;

Fig.6 shows a view of the installation and removal tool carrying two inserts for installation into a hair styling device;

Fig.7 shows a view of the tool in a first stage of the procedure to install the inserts into the device;

Fig.8 shows a view similar to that of Fig.7 in a second stage of the procedure;

Fig.9 shows a view similar to that of Fig.8 in a third stage of the procedure;

Fig.10 shows a cross-sectional view of the tool and device immediately prior to the first stage of the procedure;

Fig.1 1 shows a view similar to that of Fig.10 during the second stage of the procedure;

Fig.12 shows a cut-away view of part of a hair styling device according to the third aspect of the invention, prior to operation of the device;

Fig.13 shows a view of the device of Fig.12 during operation, with no misplaced hair;

Fig.14 shows a view similar to Fig.12 with some misplaced hair;

Fig.15 shows a view similar to that of Fig.13 with some misplaced hair;

Fig.16 shows a perspective view of part of another hair styling device according to the third aspect of the invention;

Fig.17 shows an end view of the part of the device of Fig.16 during operation, with misplaced hair;

Fig.18 shows a side view of the device of Fig.17;

Fig.19 shows a side of the part of the device of Figs. 16-18 with no misplaced hair; and, Fig.20 shows a side view of part of an alternative deivce according to the third aspect of the invention.

DETAILED DESCRIPTION

Whilst WO2009/077747, WO2012/080751 and WO2013/186547 are included herein by reference, a brief description of the operation of the device is provided in relation to the embodiment of Figs. 1 and 2 so as to clarify the operation of the device and the distinctions over the previous disclosures.

The hair styling device 10 has a body 12 and a handle 14. Within the body 12 is a first or front chamber 16 and a second or rear chamber 18. A protrusion 20, in this embodiment in the form of an elongate member, is located within the front chamber 16. The body 12 has an opening 22 through which a length of hair 24 (Fig.2) may be introduced into the chambers 16, 18. In this embodiment, the introduction of the length of hair 24 through the opening 22 is facilitated firstly by a fixed inclined surface 26 which is mounted upon the body 12 and lies behind the opening 22, secondly by a pair of guide parts 28 which are pivotably mounted upon the body 12 and move towards the opening 22 together with the movable panel 56, and thirdly by a pair of pressing parts 30 (Fig.2) which are fixedly mounted upon the movable panel 56 and also move towards the opening 22 as the movable panel 56 moves downwardly as drawn. It will be understood that in other embodiments the inclined surface 26 is omitted, and in further embodiments another inclined surface is provided in front of the opening 22 (see for example the alternative embodiment of Figs. 12-15). The device 10 has a rotatable element 32 which lies between the front chamber 16 and the rear chamber 18 and separates those chambers. The rotatable element 32 can be driven to rotate by a motor 34 by way of a shaft 36, the shaft 36 being rigidly connected to the motor 34 and to the rotatable element 32. In this embodiment the elongate member 20 is fixed to the body 12 adjacent to the motor 34, so that the shaft 36 surrounds an extension of the elongate member 20 and rotates around the (stationary) extension. In other embodiments the elongate member is a continuation of the shaft and rotates with the shaft and the rotatable element. The rotatable element 32 is able to project beyond the opening 22. As represented in Fig.2, during rotation of the rotatable element it projects (upwardly as drawn) sufficiently far beyond the opening 22 to capture the length of hair 24. It will be understood that Fig.2 represents an artificial situation in which the rotatable element has commenced its rotation whilst the movable panel 56 is still in its open position. In practice, the movable panel 56 will be moved to its closed position (in which it lies adjacent to the body 12) before the rotatable element 32 begins to rotate. As the movable panel is moved to its closed position the pressing parts 30 press the length of hair 24 downwardly as drawn, towards the opening 22, and in particular to within the path of rotation of the leading end 38 of the rotatable element. As the rotatable element 32 rotates (clockwise as drawn in Fig.1 ), its leading edge 38 moves towards the viewer in the orientation of Fig.2 and passes over the length of hair 24. The rotatable element 32 tapers towards its leading edge 38 such that its rotation acts to pull the length of hair 24 downwards as viewed in Fig.2, through the opening 22. Considering the length of hair 24 shown in Fig.2, the end 40 is the free end of the length of hair, and the part 42 is connected to the user's head (not shown). The hair styling device 10 is intended to impart curls to substantially all of the length of hair 24 lying between the part 42 and the free end 40, so that the numeral 42 represents the approximate "end" of the length of hair 24 which will be styled by the device. Each of the individual hairs in the length of hair 24 will be connected to the user's scalp (not shown), and in practice the length of hair will usually be considerably longer than that represented in Fig.2 (i.e. the length of hair will in practice normally extend a significant distance beyond the left edge of the page). As the rotatable element 32 rotates, the distal portion of the length of hair 24 (which lies between the rotatable element 32 and the free end 40), is pulled through the opening 22 into the rear chamber 18 which lies to the left-hand side of the rotatable element 32 as drawn in Fig.2. As shown in Fig .1 , the opening 22 has a closed end 44 which provides a relatively fixed surface and it is the relative rotation between the rotatable element 32 and the opening 22 (and in particular its closed end 44) which causes the distal portion of the length of hair 24 to be drawn into the device 10.

In this embodiment, the opening 22 is connected to a secondary opening 46. When the rotatable element 32 is rotated, the proximal portion of the length of hair (which lies between the rotatable element 32 and the part 42), will be pulled through the opening 22 and into the front chamber 16, to the right-hand side of the rotatable element 32 as viewed in Fig.2. In particular, the proximal portion is pulled through the opening 22 and into the secondary opening 46. The hair styling device 10 has an abutment 50 within the secondary opening 46 which provides a relatively fixed surface which prevents the part 42 rotating around the elongate member 20. It will be understood that it is the rotation of the rotatable element 32 relative to the abutment 50 which causes the length of hair to be drawn into the front chamber 16. In common with the disclosure of WO2012/080751 and WO2013/186547, the abutment 50 is movable whereby to permit a formed curl to slide off the end of the elongate member 20 through the secondary opening 46 at the end of a styling operation.

Also in common with the hair styling devices of WO2009/077747, WO2012/080751 and WO2013/186547, the hair is not clamped by any part of the device 10. The part 42 of the length of hair 24 is, however, substantially fixed in position relative to the device 10 by virtue of the device being held substantially stationary close to the user's head. Accordingly, as the rotatable element 32 continues to rotate, the distal portion of the length of hair 24 is gradually pulled from the rear chamber 18 into the front chamber 16, i.e. it is pulled from the left-hand side of the rotatable element 32 to the right-hand side, as drawn in Fig.2, until eventually all of the length of hair 24 is wound around the elongate member 20 to the right-hand side of the rotatable element 32.

The front chamber 16 and the rear chamber 18 are both heated, in this embodiment by way of discrete heating elements 52a and 52b in the walls of the body 12, by heating elements 54a and 54b in the movable panel 56, and by heating elements 58a and 58b in the shaft 36 and elongate member 20 respectively. In other embodiments one or more of these heating elements can be combined into a single heating element, or can be omitted. In particular, it may be preferable not to provide a heating element such as 58a in the rotating shaft 36, and if it is desired to heat that part of the device 10 it may be preferred to provide a heating element within a non-rotating sleeve surrounding the shaft.

A plurality of (interconnected or separate) heating elements can be used in place of any of the heating elements 52a,b, 54a,b and 58a,b, as desired to provide the optimum heating regime for a particular hair styling device.

The motor 34 and all of the heating elements 52a,b, 54a,b and 58a,b are connected by respective electrical wires (not shown) to a controller 60. In this embodiment the controller 60 is located in the body 12, but may in alternative embodiments be mounted in the handle 14. In this embodiment the controller 60 receives user inputs by way of a control panel 62 mounted on the handle 14.

The control panel 62 allows the user to select one of a chosen number of different sizes (thicknesses) for the length of hair 24 which is to be curled. In this embodiment the control panel 24 carries a three-position switch permitting the user to choose between three thickness ranges, such as "large", "medium" and "small" for example. More or fewer than three preset thicknesses can be provided as desired. The controller 60 has a memory in which are stored several predetermined values for the rate of rotation of the rotatable element 32 dependent upon the position of the switch upon the control panel 62, the motor 34 driving the rotatable element 32 to rotate at the rate determined by the controller 60. In this embodiment the controller 60 is able to determine other operating parameters in addition to the rate of rotation of the rotatable element 32, specifically the temperature of each of the heating elements 52a,b, 54a,b and 58a,b, the torque of the rotatable element 32, and the cycle time of the styling operation (i.e. the period of time before a signal is issued to the user to indicate that the styling operation has been completed).

The inventors have appreciated that a larger length of hair will require a larger amount of heat to form a desired curl than a smaller length of hair, and will also require more force to draw it into the device. Accordingly, if the user indicates that she is to style a large section of hair, the controller will typically set the speed of the rotatable element 32 to its slowest setting, will set the torque of the rotatable element 32 to its highest setting, will set the temperature of the heating elements 52a,b, 54a,b, and 58a,b to their highest setting, and will set the cycle time to its longest setting.

The different settings for each of the operating parameters which are stored by the controller 60, and the value of each of the parameters which are used together for each of the possible user commands, are determined by the device manufacturer and stored within the memory of the controller 60. The device manufacturer will therefore determine the number of size ranges which are available for the user to select, and will determine the setting of each of the variable parameters which are to be used for each of the different size ranges.

Reducing the rate of rotation of the rotatable element is advantageous as it reduces the rate at which the distal portion of the length of hair 24 is drawn past the heating element 54a on its way into the rear chamber 18, and it also increases the length of time for which the distal portion remains within the rear chamber 18 where it is heated by the heating elements 52a, 54a and 58a. The distal portion of the length of hair is therefore pre-heated (perhaps to a temperature close to or equal to that of the front chamber 16) before it enters the front chamber 16, thereby reducing the length of time for which the length of hair must remain within the front chamber in order to form the desired curl.

Pre-heating the length of hair in this way, especially for thicker sections of hair, is expected to reduce the overall cycle time, even with a reduced rate of rotation of the rotatable element 32.

It will be understood that the temperature of each of the heating elements can differ if desired. Thus, it may be determined that the most consistent curls are formed when the temperature of the heating elements 52a, 54a and 58a are lower than (or perhaps higher than) the temperature of the heating elements 52b, 54b, 58b. Also, it may be determined that the temperature of the heating elements 58a and/or 58b should preferably be higher than (or lower than) the temperature of the respective heating elements 52a, 54a and 52b, 54b. The differing temperatures of the respective heating elements can be maintained for each of the available temperature settings.

In this embodiment a number of sensors 64 is located adjacent to the opening 22. As explained in the previous disclosures it is desirable to avoid the length of hair becoming tangled and the most likely cause of entanglement is that some of the length of hair 24 is captured by the rotatable element 32 and some is not captured. The sensors 64 detect hair which has become trapped between the body 12 and panel 56. The sensors 64 are connected to the controller 60 and the controller is configured so that it will not commence rotation of the rotatable element 32 if any hair is detected by the sensors 64.

In addition, a sensor 66 is provided upon the shaft 36. The sensor 66 also detects the presence of hair, and during each operating cycle the sensor 66 will detect the presence of hair and then the absence of hair, the absence of hair indicating that all of the distal portion of the length of hair 24 has passed from the rear chamber 18 into the front chamber 16. The controller 60 may then switch off the heating elements 52a, 54a and 58a if desired, so as to save energy. The controller 60 may also switch off the motor 34 once the rotatable element 32 has reached its start position, or the rotation of the rotatable element may be continued until the end of the cycle so as to ensure that all of the length of hair is retained within the front chamber.

If it is desired to cool the length of hair as a final stage of the styling operation, the controller 60 can switch off the heating elements 52b, 54b and 58b. Ambient air can be drawn into the chamber 16, either by configuring the rotatable element also to act as a turbine or fan, or by activating a dedicated turbine or fan within the device. The cooling part of the cycle can continue for a predetermined period of time before the user is alerted to the end of the cycle.

In an alternative embodiment the device may be able to detect the size of the length of hair 24 automatically. The size of the length of hair 24 may for example be detected by suitable sensors placed along the closed end 44, it being recognised that a part of the distal portion 24 of the length of hair is pressed against the closed end 44 when the panel 56 is moved to its closed position. A larger length of hair will be caused to spread farther across the closed end 44 and the distance over which the length of hair spreads is therefore indicative of the size of the length of hair 24. It will be appreciated that the size of the length of hair need not be determined precisely, but rather be determined to fall into one of a chosen number of predetermined ranges between zero and the largest length of hair which can pass through the opening 22, with each size range having its own operating parameter settings.

Alternatively, the size of the length of hair may be automatically determined by other means, for example by an optical sensor adapted to detect the width of the length of hair (perhaps in relation to a marked scale) lying upon the closed end 44 before the movable panel 56 is closed. Alternatively again, the initial resistance to rotation of the rotatable element (for example measured by the load on the motor 34 or by a reduction in the rate of rotation of the shaft 36) may be used to determine the size of the length of hair, it being recognised that a larger length of hair will require more force to bend it during the initial stage of drawing the length of hair into the device 10.

In addition to the variation in the rate of rotation and torque of the rotatable element, the present invention nevertheless retains the operation of the previous disclosures in stopping the rotation of the rotatable element if the measured load exceeds a predetermined threshold. Such an excess load indicates either that the length of hair has become entangled, or that too large a length of hair has been placed into the device. In accordance with the previous disclosures, in such an eventuality the rotation of the rotatable element is preferably reversed back to its start position, subsequent opening of the movable panel allowing the length of hair to be removed from the device 10.

In the prior art document WO2009/077747 it is disclosed that the diameter of the chamber can increase in order to accommodate longer lengths of hair. It will be recognised that varying the diameter of the chamber will vary the diameter of the curls which are formed. It is expected to be desirable to allow the use to vary the diameter of the chamber by a chosen amount, i.e. other than automatically. Such an arrangement is shown in Figs.3-5, which show a sleeve insert 62 adapted to slide into the front chamber 1 16, and a shim insert 64 adapted to fit to the movable panel 156. Fig.5 shows the fitted condition of the sleeve insert 62 and shim insert 64.

It will be understood that inserts of varying thickness can be provided to enable curls of several discrete diameters to be formed. The inserts are preferably thermally conducting so that they can communicate heat from the heaters in the body 1 12 and movable panel 156 to the length of hair within the front chamber.

The sleeve insert 62 can be retained by a friction fit within the body 1 12, but some method of temporarily securing the shim insert 64 to the movable panel 156 must be provided. One suitable method would be by way of one or more magnets, for example.

The diameter of the chamber may be varied by other means, in some cases continuously rather than discretely as is the case with inserts. In one embodiment the wall of the chamber is provided by a flexible sheet of metallic foil, the device including a motor adapted to feed a chosen amount of the sheet past a roller which lies adjacent to the opening (22). Feeding more of the sheet past the roller will increase the circumferential length of the chamber and thereby increase its diameter, and vice versa.

Figs. 6-1 1 show a tool 86 for installing and removing inserts from the device. The tool 86 has a manually-grippable shaft 88 connected to a shroud 90 of generally cylindrical form. The shroud 90 is open-ended so that the inserts (in the form of a sleeve insert 262 and a shim insert 264) are visible in Fig .1 .

The shroud 90 covers the inserts 262, 264 and is ideally made of a non-conductive material. Accordingly, if the tool 86 is used to remove inserts 262, 264 which are hot, they can be safely stored by the tool with only minimal likelihood that the user will touch the hot inserts, or that the hot inserts will damage a work surface of the like upon which the tool 86 is laid.

As seen in Fig.10, the insert 262 (which is ideally a good conductor of heat) has a pair of (electrically isolated) electrical contacts 92 interconnected by a (sheathed) conductive wire 94 (in another embodiment the contacts and wire are replaced by a single elongated electrical contact). Though not seen in these drawings, the hair styling device 210 has a corresponding pair of electrical contacts which engage the electrical contacts 92 when the insert has been installed within the device. By way of an electrical signal sent to the contacts 92, the controller of the hair styling device is able to detect the presence of the inserts 262, 264.

It is arranged that the inserts 262, 264 alter the diameter of the chamber 216 within which the length of hair is styled, i.e. they adjust the gap between the elongate member 220 and the periphery of the chamber 216. The controller is programmed to adjust certain operating parameters so that the length of hair is styled appropriately, depending upon whether or not the inserts 262, 264 are present. For example, since the length of hair within the (reduced diameter) chamber 216 is heated indirectly by way of the inserts 262, 264, it may be necessary for the controller to reduce the rate of rotation of the rotatable element so that the inserts 262, 264 have time to acquire the necessary operating temperature. Also, it may be desirable to increase (or in some cases decrease) the length of time for which the heat is applied before the signal indicating the end of the cycle is sent to the user. It may also be necessary or desirable to adjust the temperature of the heating element(s) around the chamber 216. It can be arranged that a number of differently-sized inserts are available, giving the user more freedom of choice in the size of the curls which are formed by the device 210. Thus, whilst the size (diameter) of the outer periphery of each set of the inserts is ideally the same so that they all fit into the chamber 216 of the device 210, the size of the inner periphery will vary so as to vary the size of the curl produced. In such circumstances it is expected that the parameters which the controller sets for the device 210 will vary depending upon the size of the inserts. It is therefore desirable that the controller is able to determine the particular inserts which have been installed.

Various methods for allowing the controller to determine the particular inserts which have been installed can be used. One method is for an electrical characteristic (such as electrical resistance for example) of the conductive wire 94 to differ between differently-sized inserts. Another method is to locate the electrical contacts in different positions for differently-sized inserts, the device 210 having a number of pairs of contacts, one pair of contacts being appropriately positioned to engage the contacts of each of the respective inserts.

Another method for allowing the controller to determine the particular inserts is to provide a projection upon the inserts, the projection locating into a recess within the device. A plurality of switches can be located within the recess and the size and location of the projection determines which of the switches is/are actuated. The switches which are actuated allow the device to identify the inserts, and also if desired allow the device to detect that an insert has been correctly installed.

The procedure for installing the set of inserts 262, 264 is described in relation to Figs. 7-1 1 . Firstly, the tool 86 containing the (chosen) inserts 262, 264 is placed against the device as shown in Fig.7. It will be seen from Fig.10 that the shroud 90 and periphery of the chamber 216 have cooperating chamfers to facilitate the correct positioning and alignment of the tool 86. As represented in Figs. 10 and 1 1 , the shroud 90 can slide along the shaft 88, and is biased by a (relatively weak) compression spring 92 to the extended position shown in Fig.10. A plate 96 is carried by the shaft 88 and engages the inserts 262, 264.

As the shaft 88 is pushed from its position of Fig.7 to its position of Fig.8 (which corresponds to its movement from the position of Fig.10 to the position of Fig.1 1 ), the plate 96 pushes the inserts 262, 264 into the chamber 216. As described in the previous application, the inserts 262, 264 are preferably temporarily secured within the chamber 216, for example by magnets (not shown). The engagement between the shaft 88 and/or plate 96 and the inserts 262, 264 is not shown in detail in Figs. 10 and 1 1 but is a temporary connection which is sufficiently strong to overcome the temporary securement of the inserts 262, 264 within the chamber 216. In this embodiment there is a partial screw thread carried by the shaft 88 immediately adjacent to the plate 96, and the inserts 262, 264 have a cooperating partial screw thread. In order to release the inserts it is therefore necessary to rotate the shaft 88 and shroud 90 as shown in Fig.9, in this embodiment through approximately a quarter rotation.

It will be understood that the sequence of operations to remove the inserts 262, 264 is substantially a reverse of the installation sequence described above. The inserts 262, 264 are first secured to the shaft 88 by way of the cooperating screw threads, whereby they can be pulled from the chamber 216 and into the shroud 90. Even if the inserts are very hot the user and any work surface upon which the tool 86 is laid are protected from harm by the shroud 90.

It will be understood that other methods of securing the inserts 262, 264 to the shaft 88 and/or plate 96 may be used as desired. The methods of securement are preferably mechanical, however, so that they may readily be arranged to transmit sufficient force to remove the inserts 262, 264 from the chamber 216.

It will also be understood that the inserts 262, 264 shown in this embodiment are relative thick, i.e. the remaining gap between the installed inserts 262, 264 and the elongate member 220 within which a length of hair will be styled is relatively small. Other inserts which can be installed and removed, ideally by way of the same tool 86, may be of thinner section so that they occupy a smaller proportion of the chamber 216. Figs. 12-15 show a part of a hair styling device 310 according to the third aspect of the invention, and Figs 16-19 show the capture region another hair styling device according to this aspect. The hair styling device 310 has a body 312 and a handle 314 (only parts of which can be seen in these views). Within the body 312 is a chamber 316. A protrusion 320 in the form of an elongate member is located within the chamber 316. The body 312 has an opening 322 through which a length of hair (not shown in these figures) may be introduced into the chamber 316. In this embodiment, the introduction of the length of hair into the opening 322 is facilitated by inclined guide surfaces 326 and 362 which are mounted upon the body 312 and which lie adjacent to the opening 322.

The movable panel 356 has a pair of pressing parts 330 (only one of which can be seen in these cut-away views) which move towards the opening 322 and in use drive a (correctly- positioned) length of hair towards the opening 322 as the movable panel 356 moves towards the body 312. It will be understood that the pressing parts 330 lie to either side of the inclined guide surfaces 326 and 362 and act to drive the length of hair along the guide surfaces 326 and 362 and towards the opening 322 as the movable panel 356 moves from the (open) position of Fig.12 to the (closed) position of Fig.13.

If desired, the device 310 may also have movable guide parts (ideally similar to the guide parts 28 shown in Fig.1 ) which move towards the opening 322 as the movable panel 356 is moved from the position of Fig.12 to the position of Fig.13, to further guide and press the length of hair towards the opening 322.

It will be understood that the device 310 has a rotatable element (not shown) which can be driven to rotate and which can engage the length of hair adjacent to the opening 322 and wind the length of hair around the elongate member 320.

The device 310 has a capture region 364 for misplaced hair. The capture region 364 is spaced from the opening 322, and in this embodiment the inclined guide surface 362 lies between the opening 322 and the capture region 364. It will be understood that in this embodiment the top edge 366 of the inclined guide surface 362 defines one edge of the capture region, and separates the capture region from the guide surface 362. In use, any portion of the length of hair which lies to the right of the top edge 366 as drawn will be pressed along the inclined surface 362 and towards the opening 322, whereas any misplaced hair which lies to the left of the top edge 366 will be pressed into the capture region 364. The top edge 366 is preferably relatively sharp so as to ensure that individual hairs within the length of hair are pressed either towards the opening 322 or into the capture region 364.

In the embodiment shown the other edge of the capture region is provided by the top edge of a second upstanding formation 370, and the capture region 364 comprises two converging surfaces. In this embodiment the converging surfaces are both substantially planar so that the capture region is of V-shape, but it will be understood that curved surfaces (concave, convex or both) would function similarly. The capture region 364 includes a slot 380 which can accommodate an articulating lever or finger 382 which is mounted upon the movable panel 356.

Figs. 12 and 13 represent the operation of the device 310 when there is no misplaced hair. As the panel 356 is moved downwardly from the open position of Fig. 12 towards the closed position of Fig.13, the pressing parts 330 engage the length of hair (not shown) and because in this case all of the length of hair has been positioned to the right of the top edge 366 as drawn, all of the length of hair is pressed towards the opening 322 where it can be captured by the rotatable element. Also, the articulating finger 382 enters the slot 380. Figs. 14 and 15 show the alternative situation in which there is misplaced hair 384. Specifically, the length of hair has been positioned so that some individual hairs within the length of hair to be styled lie to the left as viewed of the top edge 366. The user may herself press the length of hair downwardly as viewed before moving the movable panel 356 towards the body 312, in which case the misplaced hair 384 may be moved into the capture region 364 before the movable panel 356 is moved (as represented by Fig.14). More typically, however, the length of hair is inserted into the device by the user and held close to or against the movable panel 356 as this is moved downwards to the position of Fig.15. As the movable panel 356 is moved downwardly the pressing parts 330 engage the length of hair and press some of the individual hairs towards the opening 322 and other individual hairs (i.e. the misplaced hair 384) into the capture region 364. Continued movement of the pressing parts 330, combined with the converging form of the capture region 364, cause the misplaced hair 384 to be collected and concentrated where the sides of the capture region meet. Since the misplaced hair 384 lies across the slot 380, the finger 382 is caused to articulate as the movable panel 356 moves downwardly. The articulation of the finger can be detected directly, for example by a microswitch located adjacent to the mounting of the finger, or indirectly by a microswitch within the slot 380. It will be understood that the finger 382 is spring-biased to the position shown in Figs. 12-14, and the spring force needs to be sufficient to overcome any friction experienced by the finger 382 as it enters the slot 380 during normal operation. The spring force is not large, however, and even if the misplaced hair 384 comprises only a few individual hairs, the spring force can be overcome and the finger 382 prevented from fully entering the slot 380, as is drawn in Fig.15.

In addition to pressing the misplaced hair into the capture region 364, the pressing parts 330 in this embodiment act also to hold the misplaced hair 364 within the capture region, i.e. the pressing parts 330 close off the top of the capture region 364 to retain the misplaced hair 384 within the capture region. Ideally the pressing parts 330 clamp the misplaced hair at the bottom of the capture region so that the misplaced hair is forcibly concentrated in the position shown in Fig.15 which makes it easier to detect the misplaced hair. Also, by clamping the misplaced hair the pressing parts reduce the likelihood that the misplaced hair will be forced into the slot 380 by the articulating finger 382. Importantly, however, because the capture region includes a surface 300 which is inclined away from the opening 322 (and in particular inclined away from the top edge 366, clamping of the misplaced hair is not necessary, and as the pressing parts 330 move downwardly past the top edge 366 they will press the misplaced hair away from the top edge 366 and away from the opening 322 so that the misplaced hair is clearly separated from the correctly-placed hair and can be detected.

It is not necessary that the pressing parts also act as the holding parts, and in other embodiments separate components can be provided to hold (or clamp) the misplaced hair within the capture region. The articulation of the finger 382 can be detected by the device 310, and the controller can ensure that rotation of the rotatable element does not occur whilst misplaced hair is present within the capture region 364. The controller can cause a warning signal to be issued to the user indicating that misplaced hair has been detected. In an alternative arrangement, the finger 382 is replaced by a movable lever or panel mounted within the capture region, above the junction of the sides of the capture region. As misplaced hair is pressed into the capture region the lever or panel is caused to move indicating the presence of misplaced hair within the capture region.

The form of the capture region 364 which acts to concentrate the misplaced hair 384 is suitable also for other forms of detector. Thus, an optical or electronic sensor might not be able to detect individual hairs which are spread across a surface, but might be able to detect the same number of individual hairs when they are collected together within a capture region such as 364.

Whilst a capture region which acts to collect or concentrate the misplaced hair has certain benefits, it will be understood that the invention would work without the misplaced hair being concentrated or collected together. For example, in the alternative embodiment of Figs. 16-19 the capture region 464 comprises a substantially flat region between the body 412 and the movable panel 456.

Only the capture region of the device is shown in Figs. 16-19 and it will be understood that the device retains the rotatable element, the opening, the protrusion and the other components as in the other embodiments. In one modification of the embodiment of Fig.12 the inclined surface 362 and the second formation 370 are omitted and the capture region 464 of Figs. 16- 19 is located in the (approximate) position of those omitted elements, the capture region being spaced from the opening. Alternatively, the device can retain a formation providing inclined surfaces such as 362 and 300, if desired, in which case the capture region 464 of Figs. 16-19 could be located to one side of the inclined surface (e.g. in the area represented by the numeral 400 in Fig.12 - to the near side of the inclined surface 362 as drawn). Alternatively again, the capture region 464 could be located at the far side of the inclined surface 362 as drawn in Fig.12, or two capture regions 464 could be provided, one to each side of the inclined surface.

In the embodiment of Figs. 16-19 a set of interconnected articulating levers 482 are pivotably mounted upon the base 412 and can move into respective slot-shaped depressions 480 formed within the movable panel 456. In this embodiment there are three levers 482 but one, two, or four or more levers can be provided as desired.

The levers 482 are interconnected to move together, and each lever has its own slot 480. Accordingly, a misplaced hair which lies across only one of the levers 482 and slots 480 can be detected. Typically, the number (and length) of the levers will be determined according to the area of the capture region, with a larger area having a greater number of levers (and ideally with each lever being of greater length).

In this embodiment the surface 402 surrounding the levers 482 is substantially flat and smooth, but alternatively could be undulating, roughened or otherwise formed so as to resist unwanted movement of misplaced hair across the surface. In particular, the surface could comprise a series of small relatively sharp peaks or ridges.

Figs. 16-18 show a situation having misplaced hair 484 within the capture region 464. The misplaced hair can be one individual hair, or several hairs grouped together within (or alternatively spread across) the capture region. Fig.16 represents the situation in which the misplaced hair 484 has been moved by the user into engagement with the levers 482, but in an alternative situation the misplaced hair will be held by the user above the levers and will be driven downwardly as viewed as the movable panel 456 is moved towards the body 412. In common with the other embodiments of the invention, the movable panel 456 has pressing parts 430 (only one of which is shown) which are provided to press the length of hair towards the opening where it will be captured by the rotatable element. In this embodiment the movable panel has a surface 404 which is substantially a continuation of the pressing parts 430. The surface 404 provides additional pressing parts 406 (between adjacent slots 480) which engage misplaced hair and press it towards the capture region 464.

It will be understood that if a length of hair is correctly positioned within the device all of the individual hairs will be engaged by the pressing parts 430 and pressed towards the opening. If, on the other hand, the length of hair is incorrectly positioned the misplaced hair will be engaged by the additional pressing parts 406. As the movable panel 456 moves to the closed position of Figs. 17 and 18 the surface 404 and the additional pressing parts 406 press the misplaced hair 484 against the levers 482, causing the levers 482 to pivot, which pivoting can be detected (for example by a microswitch). It will be seen from Figs. 17 and 18 that the surface 404 and the additional pressing parts 406 also act to hold the misplaced hair 484 within the capture region, i.e. they can move to a position in which they engage the surface 402 effectively to clamp the misplaced hair against the surface 402. It can if desired be arranged that the holding (clamping) force is sufficient to hold the misplaced hair within the capture region even if the surfaces 402 and 404 are substantially flat and smooth.

It is desirable that the misplaced hair 484 be held within the capture region 464 so that it can be removed only by the user moving the movable panel back to the position of Fig.16, retrieving the length of hair and re-starting the procedure. In particular, it is not desirable that the user be able to slide the misplaced hair out of the capture region and towards the opening without moving the movable panel, as tangling of the length of hair is highly likely in such circumstances.

The levers 482 are resiliently-biased to the position of Fig. 16, ideally by a torsion spring at the pivot mounting. In the absence of misplaced hair the levers 482 remain projecting above the surface 402 and, when the movable panel is closed, they lie within the respective slots 480, as shown Fig.19. It will be seen that the slots 480 are significantly wider than the levers 482 in order to minimise the likelihood that a lever will be pivoted by the inadvertent engagement with the edge of a slot. The slots are not sufficiently wide, however, to allow misplaced hair to be pressed into the slots by the levers, and instead the misplaced hair 484 causes the levers 482 to pivot as shown in Figs. 17 and 18.

It will be seen from Fig.16 that the levers 482 are parallel and aligned substantially perpendicular to the misplaced hair 484. The preferred orientation of the length of hair in relation to the device will be advised to users, and so the likely alignment of the misplaced hair 484 in relation to the body 412 will be known. The levers 482 are ideally aligned substantially perpendicular to the expected alignment of the misplaced hair. It will be understood, however, that the perpendicular arrangement is not necessary (and in any event cannot be guaranteed). The levers 482 will nevertheless be caused to pivot by misplaced hair which crosses one or more of the levers, even at a relatively shallow angle. If desired the levers may be other than parallel in order to cater for all possible alignments of the misplaced hair.

Fig.20 shows a part of an alternative embodiment of hair styling device according to the third aspect of the invention. In embodiments having a handle part similar to that of Fig.1 , Fig.20 is a side view from a viewpoint looking towards the body with the handle parts behind the sheet of paper, and substantially aligned with the handle parts. The top edge 566 of the part of the body 512 which is visible in the drawing corresponds to the top edge 366 of the embodiment of Figs. 12-16. The inclined surface lies behind the top edge 566 as viewed, and the opening through which the length of hair can pass into the chamber lies behind the inclined surface, neither of which is visible in this drawing.

The rotatable element 532, which is shown in dotted outline in Fig.20, rotates relative to the body 512 within the section 500. The axis of rotation of the rotatable element is substantially parallel with the length of hair 542.

The movable panel 556 carries two pressing parts 530 which serve to press the length of hair 542 towards the primary opening, as in the earlier embodiments. The body 512 has two recesses 502 into which a respective pressing part 530 can move. The pressing parts 530 lie to either side of the rotatable element, and the recesses 502 therefore lie to either side of the section 500 which accommodates the rotatable element.

The body 512 has three sensors 564, one of the sensors being located upon the section 500 and the other two sensors being located upon the body 512 adjacent to the recesses 502. Each of the sensors 564 is adjacent to the top edge 566.

In operation of the device of Fig.20, the length of hair 542 is inserted between the body 512 and the movable panel 556 as in the other embodiments. The movable panel 556 is then moved downwardly as drawn, until the pressing parts 530 engage the length of hair. If all of the length of hair 542 is correctly positioned within the device the length of hair 542 will be pressed towards the primary opening by the pressing parts (including perhaps being pressed along the inclined surface). When the movable panel 556 has reached its final (closed) position all of the length of hair 542 will have been pressed sufficiently close to the opening to be engageable by the rotatable element, so that upon subsequent rotation of the rotatable element all of the length of hair is drawn into the chamber of the device and wound around the protrusion as intended.

If, however, some or all of the length of hair 542 is misplaced, in particular so that it lies closer to the viewer than the top edge 566, it will instead be pressed into the capture region 564. Initially, some of the misplaced length of hair is driven by the pressing parts 530 into the recesses 502. Subsequently, the misplaced hair is engaged by two holding parts 506, which are mounted upon the movable panel 556 by way of respective resilient mountings 508. The holding parts 506 in this embodiment each have a pad 598 of high friction material such as rubber or the like, which acts to grip any misplaced hair and hold or clamp it against the body 512.

Continued downwards movement of the movable panel 556 causes the resilient mountings 508 to deform and brings the additional pressing parts 606 into engagement with the misplaced length of hair. As with the pressing parts 530, the additional pressing parts 606 are substantially rigidly mounted upon the movable panel 556, and act to press the misplaced hair against the sensors 564. Any tendency of the misplaced hair to move away from the sensors as it is engaged by the additional pressing parts is resisted by the holding parts 506, so that the holding parts 506 and additional pressing parts 606 act together to retain the misplaced hair within the capture region where it can be detected.

In the embodiment of Fig.20 (as with the embodiment of Figs. 16-19) the holding parts engage the body 512 within the capture region. This is necessary because in this embodiment the capture region does not include a surface which is inclined away from the opening. The misplaced length of hair is therefore clamped within the capture region. The additional pressing parts 606 are also engageable with the body 512, for the same purpose. The capture region 564 of Fig.20 is defined by the holding parts 506 and the additional holding parts 606. As with the earlier embodiments, it is arranged that the rotatable element 532 cannot rotate if misplaced hair is detected. Since misplaced hair is detected before any part of it is wound around the protrusion, there is no likelihood of entanglement, and the misplaced hair can be retrieved and correctly repositioned by opening (raising) the movable panel 556. The sensors 564 are optical, capacitive or inductive sensors which do not need to move to detect the presence of misplaced hair. Alternatively, each of the sensors 564 can be replaced by a detector having one or more movable levers such as that of the embodiment of Figs. 16- 19 for example. In any event, the three sensors/detectors are preferably linked so that the detection of misplaced hair by any one of them is sufficient to prevent the actuation of the rotatable element.

It will be understood that the invention could operate with only a single holding part. In an alternative to Fig. 20 for example a single resiliently-mounted holding part could move into engagement with the section 500, and such an arrangement might avoid the requirement for any additional pressing parts. Alternatively, one of the two holding parts 506 shown in Fig.20 could be omitted.

Similarly, the various embodiments of the invention could operate with only a single pressing part, and with only a single additional pressing part (if present). If only a single holding part and/or a single pressing part and/or a single additional pressing part are provided, the single component preferably lies to the same side of the rotatable element as the free end 40 of the length of hair, thus taking advantage of the fact that the scalp end of the length of hair is less likely to move uncontrolledly because it is secured to the user's scalp. It will be understood that a capture region 464, 564 can be located in any desired position upon the device where misplaced hair might be found. Multiple capture regions can be provided, one for each of many suitable locations. For example, as indicated above separate capture regions may be located to either side of the inclined surface in front of the opening. Additional or alternative capture regions can be located behind the opening (i.e. adjacent to the inclined surface 326 of the embodiment of Fig.12). A capture region such as 464 can for example also be located upon one or both of the inclined surfaces to ensure that the rotatable element is not rotated unless the length of hair has been pressed sufficiently far along the inclined surface to be captured by the rotatable element. If the capture region is located upon an inclined surface the lever(s) are preferably directed towards the opening so that they do not hinder or prevent the movement of hair towards the opening. In any event, the capture region is spaced from the opening so that misplaced hair can be easily distinguished from hair which is correctly located adjacent to the opening. One particular alternative embodiment can utilise a capture region comprising a substantially flat surface spanning the region between the top edge of the formation 370 and the top edge 366 of the inclined surface shown in Fig.12. Thus, unlike the trough between those peaks as shown in Fig.12 the capture region can be a substantially flat surface between those peaks (perhaps similar to the surface 402 of Fig.16).

In an alternative embodiment to that of Fig.20, it can be arranged that the recesses 502 are not provided, and the pressing parts 530 are modified to conform to the shape of the body 512, be it linear, concave, convex or a combination of these. In such alternative embodiments it can be arranged that the (resiliently biased) holding part(s) engage the body before the pressing part(s) engage the length of hair.

In another alternative embodiment to that of Fig.20, friction pads similar to the pads 598 are located upon the body, and are perhaps spring-mounted upon the body, and are engageable by rigid parts of the movable panel.

The drawings show that the chamber 16, 216, 316 is almost fully enclosed, i.e. it is surrounded by a substantially continuous wall. This is preferred so as to maximise the control over the temperature within the chamber, and also to maximise the area of the chamber wall which can be heated. It will be appreciated, however, that in less preferred embodiments the panel 56 and the outer wall of the chamber may not be heated. In such embodiments the chamber can be relatively open, i.e. surrounded by a perforated wall or cage which serves simply to accommodate and retain the length of hair during the styling operation.