A haircare appliance

Abstract

A haircare appliance comprising first and second arms that are moveable towards one another to clamp a tress of hair therebetween. The first arm comprises a first clamping surface having a length and being flexible in a direction along the length so as to be moveable from a rest position to a flexed position when a tress of hair is clamped between the first and second arms. The haircare appliance also comprises a heater configured to heat hair in contact with the first clamping surface, and a support assembly configured to provide resistance to movement of the first clamping surface. The support assembly is configured such that when the first clamping surface is moved from the rest position to the flexed position: in a first portion of the movement, the first clamping surface moves according to a first spring rate; and in a second portion of the movement, the first clamping surface moves according to a second spring rate that is greater than the first spring rate.

Description

[0001] 1 P005267-W001

[0002] A HAIRCARE APPLIANCE

[0003] BACKGROUND

[0004] Haircare appliances are known for styling hair. Some haircare appliances (e.g. hair straighteners) include arms, between which hair to be styled can be clamped. In some cases, heat can be used to facilitate shaping of hair clamped between the arms.

[0005] SUMMARY

[0006] In a first aspect, there is provided a haircare appliance comprising first and second arms that are moveable towards one another to clamp a tress of hair therebetween. The first arm comprises a first clamping surface having a length and being flexible in a direction along the length so as to be moveable from a rest position to a flexed position when a tress of hair is clamped between the first and second arms. The haircare appliance comprises a heater configured to heat hair in contact with the first clamping surface, and a support assembly configured to provide resistance to movement of the first clamping surface. The support assembly is configured such that when the first clamping surface is moved from the rest position to the flexed position: in a first portion of the movement, the first clamping surface moves according to a first spring rate; and in a second portion of the movement, the first clamping surface moves according to a second spring rate that is greater than the first spring rate.

[0007] The provision of a clamping surface (i.e. the first clamping surface) that is flexible in a direction along a length of the clamping surface may aid in ensuring the clamped tress of hair remains between the first and second arms. When clamping a tress of hair between two clamping surfaces, there can be a tendency for some of the hairs of a clamped tress of hair to spread out across the clamping surfaces. This may result in uneven tension and heating across the tress of hair. Moreover, in some case, hairs of a tress of hair may move along the arms so as to be dislodged entirely from between the arms (i.e. so as to be free of the arms). This may be detrimental to application of a style to the tress of hair.

[0008] The provision of at least one clamping surface that is flexible along its length can help to retain a tress of hair from spreading out across the clamping surfaces, and also from being 2 P005267-W001 dislodged from between the arms. This is because the clamping surface is able to flex around the tress of hair so as to restrict movement of the tress of hair in a direction along the length of the clamping surface. This may be referred to as corralling the hair.

[0009] However, one issue that can sometimes arise as a result of flexing of a clamping surface in this way (especially when a user wishes to apply significant tension to the hair), is that at least some of the hairs of a tress of hair can be pinched or snagged between the clamping surfaces of the haircare appliance. Providing two different springs rates in two different portions of the movement of the first clamping surface (as described above with respect to the first aspect) may help to reduce this pinching or snagging.

[0010] For example, the first spring rate in the first portion of movement may be configured to allow for a gradual increase in clamping force (such clamping force translating to hair tension in use) as the clamping surfaces are moved towards one another. This may help to reduce pinching / snagging, while also allowing the hair to be corralled by flexing of one or both of the clamping surfaces.

[0011] Further, the second (greater) spring rate, in the second portion of movement, may be configured to provide a steeper increase in clamping force (translating to hair tension) as the clamping surfaces are moved towards one another. This may provide controllable hair tension, with such controllability helping a user to avoid pinching or snagging of their hair. By way of example, if the second portion of movement (and second spring rate) were instead omitted, instead the user would experience a hard stop at the end of the first portion of movement. Such a hard stop would immediately (and significantly) increase the clamping force, which could cause hair to be pinched.

[0012] The first portion of the movement may occur before the second portion of the movement when the first clamping surface is moved from the rest position to the flexed position. In other words, the support assembly may be configured such that when a tress of hair is clamped between the clamping surfaces, the first clamping surface moves according to the first spring rate and then subsequently moves according to the second spring rate (as additional force is applied). 3 P005267-W001

[0013] The difference between the first and second spring rates may be at least 10 N / mm, or e.g. at least 15 N / mm, or e.g. at least 20 N / mm. The difference between the first and second spring rates may be no more than 50 N / mm, or e.g. no more than 40 N / mm, or e.g. no more than 35 N / mm.

[0014] The first spring rate may be less than 15 N / mm, or e.g. less than 10 N / mm, or e.g. less than 7 N / mm. The second spring rate may be less than 100 N / mm, or e.g. less than 80 N / mm, or e.g. less than 50 N / mm.

[0015] In the first portion of movement, the first clamping surface may move by between 0.1 mm and 1.5 mm, or e.g. between 0.3 mm and 1.0 mm. The first clamping surface may move in a direction away from the second arm. The distance moved in the first portion of movement may be predetermined. In this way, in use, the first clamping surface may move away from the second arm (e.g. the second clamping surface) to preferentially provide a separation distance (e.g. between the first clamping surface and second clamping surface) similar to the thickness of human hair to provide further mitigation against hair snagging.

[0016] In the second portion of movement, the first clamping surface may move at least 0.3 mm, or e.g. at least 0.5 mm. The second portion of movement may provide enhanced control of the tension applied to the hair, in use.

[0017] The first spring rate may be substantially constant for the first portion of movement. The second spring rate may be substantially constant for the second portion of movement.

[0018] The spring rate in a given portion of movement can be determined by measuring the force required to move the relevant clamping surface a given distance in a direction away from the opposite clamping surface (i.e. the given distance representing the portion of the movement). It may be understood that a second clamping surface, which is the clamping surface of the second arm, may also be referred to as the opposite clamping surface. In general, the spring rate of the first clamping surface may be measured by applying a 4 P005267-W001 plurality of different predetermined forces to the clamping surface and measuring the deflection of the clamping surface in response to each application of force. The force and displacement may, for example, be measured by positioning a rigid (e.g. metal) rod of 10 mm diameter on the first clamping surface so as to extend across the width of the first clamping surface (e.g. centrally with respect to the length of the first clamping surface). A plurality of different predetermined forces may then be applied to the rod (in a direction towards the first clamping surface) and the deflection of the first clamping surface from the rest position may be measured.

[0019] The first clamping surface may be a surface of a clamping plate of the haircare appliance. That is, the haircare appliance may comprise a clamping plate defining the first clamping surface. The clamping plate may be of uniform thickness. The clamping plate may have a thickness of less than 1 mm, or e.g. less than 0.7 mm, or e.g. less than 0.5 mm (e.g. may be about 0.2 mm thick). The thickness may be in a direction between the first clamping surface and an opposite surface (e.g. a rear surface). The first clamping surface may be a major surface of the clamping plate. As may be appreciated, the clamping plate will contribute to resistance of the movement of the first clamping surface and will therefore contribute to each of the first and second spring rates. As such, the clamping plate may be considered to form part of the support assembly.

[0020] The heater may be arranged to heat the clamping plate. The heater may be flexible in a width and / or length direction of the first clamping surface. The heater may comprise a thick film heater. The heater may be in contact with the clamping plate. The clamping plate may overlie the heater. That is, the heater may extend across the rear surface of the clamping plate (opposite to the first clamping surface). The heater may extend only partway across the clamping plate. For example, the heater (e.g. thick film heater) may not fully extend to opposite edges of the clamping plate. For example, the heater may not extend across at least one edge regions of the clamping plate (such edge regions are discussed in more detail), which may permit flexing of the clamping plate in the edge regions. The heater may, in some examples, form part of the support assembly. 5 P005267-W001

[0021] The first arm may comprise a support structure, which may at least partly support the clamping plate and / or the heater. The support structure may be moveably mounted within the first arm. The support structure may be arranged to move in response to movement of the first clamping surface. The support structure may form part of the support assembly.

[0022] The first arm may comprise a housing. The housing may be elongate. The housing may have a C-shaped profile (e.g. taken in a plane that is perpendicular to the direction of elongation). The housing may comprise an outer wall, which may comprise a convex surface around which hair may be wrapped in use. The housing may comprise an outer wall and may comprise an inner structure (e.g. chassis) disposed inwardly of the outer wall.

[0023] The support assembly may comprise at least one resilient member. The support assembly may comprise first and second resilient members. The first resilient member may have a different spring rate to the second resilient member. Each resilient member may be configured to provide resistance to movement of the first clamping surface. In this way, the first and second resilient members may at least partly provide the different first and second spring rates.

[0024] The second resilient member may be arranged so as not to resist movement of the first clamping surface in the first portion of movement. The second resilient member may be arranged to directly or indirectly engage the first clamping surface when in the flexed position. The second resilient member may be arranged to be disengaged from the first clamping surface when in the rest position. In this way, the second resilient member may only contribute to the spring rate of the movement of first clamping surface after the first clamping surface has been moved away from the rest position.

[0025] For example, the second resilient member may only contribute to the spring rate in the second portion of the movement of the first clamping surface (and may not contribute to the spring rate in the first portion of the movement). That is, in the first portion of the movement, the second resilient member may be disengaged from the first clamping surface, and in the second portion of the movement, the second resilient member may be 6 P005267-W001 engaged with the first clamping surface. In this way, the arrangement of the second resilient member may at least partly provide the difference in spring rate between the first spring rate and the second spring rate.

[0026] For the avoidance of doubt, references to the engagement between a resilient member and the first clamping surface do not require direct engagement. The term engagement is intended to refer to the second resilient member resisting movement of the first clamping surface. That is, when disengaged, the second resilient member may provide no resistance to movement of the first clamping surface, and when engaged the second resilient member may provide some resistance to the movement of the clamping surface.

[0027] The first resilient member may be arranged to directly or indirectly engage the first clamping surface in both the rest position and the flexed position. Accordingly, in the first portion of the movement of the first clamping surface, only the first resilient member may engage (i.e. resist movement of) the first clamping surface, and in the second portion of the movement of the first clamping surface, both the first and second resilient members may engage (i.e. be resist movement) of the first clamping surface.

[0028] The support assembly may comprise a resilient rail arranged to support an edge region of the first clamping surface (e.g. an edge extending in the length direction of the first clamping surface). The resilient rail may be the first resilient member. The resilient rail may comprise an elastic material, such as e.g. silicone rubber. The resilient rail may have a hardness of between ShA 10 and ShA 30, or e.g. about ShA 20 (ShA referring to Shore A hardness).

[0029] The resilient rail may be arranged such that, when the edge region of the first clamping surface is moved from the rest position to the flexed position, the resilient rail is compressed.

[0030] The resilient rail may be positioned between the first clamping surface (e.g. clamping plate) and the housing. The resilient rail may form at least a portion of a sidewall of the first arm. 7 P005267-W001

[0031] The resilient rail may comprise a plurality of recesses formed therein to facilitate compression of the resilient rail. The plurality of recesses may comprise first and second groups of recesses. The first group of recess may be formed in a first portion of the resilient rail. The first group of recesses may be sized and shaped to provide the first portion of the resilient rail with a spring rate. The second group of recesses may be formed in a second portion of the resilient rail. The second group of recesses may be sized and shaped to provide the second portion of the resilient rail with a spring rate that is different to the spring rate of the first portion. In this way, the first and second portions of the resilient rail may provide different spring rates in response to movement of the first clamping surface. The first portion of the resilient rail (i.e. the portion in which the first group of recesses is formed) may be closer than the second portion (i.e. the portion in which the second group of recesses is formed) to the first clamping surface.

[0032] The resilient rail may be a first resilient rail and the edge region that is supported by the first resilient rail may be a first edge region. The haircare appliance may comprise a second resilient rail to support a second edge region of the first clamping surface that is opposite to the first edge region. The second resilient rail may be as described above with respect to the first resilient rail. In general, the first clamping surface may comprise opposite edges (which may extend in the length direction of the first clamping surface), each supported by a respective resilient rail.

[0033] The support assembly may comprise a resilient stop member. The stop member may be the second resilient member. The stop member may be formed of an elastic material, such as silicone rubber, or e.g. foam. The stop member may have a hardness of between ShA 30 and ShA 70, or e.g. between ShA 40 and ShA 60.

[0034] The stop member may be mounted to the housing, such as the inner structure (e.g. chassis) of the housing. The stop member may be disposed between the first clamping surface (e.g. clamping plate) and the housing, such as an inner surface of the housing. The stop member may be disposed between the support structure and the housing. 8 P005267-W001

[0035] In a third portion of the movement of the first clamping surface from the rest position to the flexed position, the first clamping surface may move according to a third spring rate. The third portion of the movement may occur before the first portion of the movement when the first clamping surface is moved from the rest position to the flexed position. The third spring rate may be greater than the first spring rate.

[0036] The third portion of movement may be associated with overcoming an initial pre-load provided by the clamping plate. In some arrangements it can take a given amount of force to overcome an initial pre-load of the clamping plate in order to initiate full movement of the first clamping surface (e.g. according to the first spring rate). Accordingly, this third portion of movement may be considered a pre-load movement. While some movement may occur in this pre-load movement, it may occur at a significantly higher spring rate than during the first portion of the movement (i.e. subsequent to the pre-load movement). Likewise, the pre-load movement may be significantly smaller than at least the first portion of movement (e.g. the pre-load movement may represent only a very small proportion of the overall movement of the first clamping surface between the rest position and the flexed position).

[0037] The first clamping surface may have a width that is perpendicular to the length. The length may be longer than the width. The first arm may be elongate. The length may be parallel to a direction of elongation of the first arm.

[0038] The first clamping surface may be flexible in a direction along the width of the first clamping surface. Providing flexibility in the width direction may further aid in reducing pinching or snagging of hair. For example, without such flexibility, when the end of a tress of hair is captured between the clamping surfaces (e.g. just prior to release of the tress of hair from between the clamping surfaces), the clamping surface could otherwise pinch the end of the tress of hair. This is because in such circumstances the clamping force (applied by the clamping surfaces) is applied to a smaller area of hair (when compared to a tress of hair extending fully across the clamping surfaces), which increases the pressure applied to the hair. Providing flexibility in the width direction helps to better manage this application of force. 9 P005267-W001

[0039] Such pinching could also otherwise occur when a tress of hair extends across the clamping surfaces obliquely as a result of flexing of at least the first clamping surface in the length direction. As may be appreciated, if flexing of the clamping surface(s) is limited to the length direction, then the clamping surface(s) can flex to readily accommodate a tress of hair that extends perpendicularly across the clamping surface (essentially, by flexing to form a perpendicularly extending passage in which the tress of hair locates). However, if the tress of hair instead extends on an angle to the perpendicular direction, the flexing of the clamping surface(s), when limited to the length direction, can be less effective at accommodating the tress of hair because when the flexibility is limited to the length direction, the clamping surface(s) are only able to form a perpendicular “passage” by flexing (and not an oblique passage).

[0040] Accordingly, as noted above, providing flexibility in the width direction may help to reduce such pinching.

[0041] The first clamping surface may comprise opposite edge regions extending along lengthwise edges of the first clamping surface (i.e. edges extending in the length direction of the first clamping surface). The first clamping surface may comprise an intermediate region interposed between the edge regions. At least one of the edge regions may be less resistant than the intermediate region to movement in a direction away from a second clamping surface provided on the second arm. In other words, in use, one or both of the edge regions may more readily flex compared to the intermediate region.

[0042] As discussed above, when the end of a tress of hair is drawn between the clamping surfaces, and just before it is released from between the clamping surfaces, only a small amount of hair will be clamped between the clamping surfaces (in one of the edge regions). In arrangements in which the first clamping surface does not have a varying spring rate in the width direction, this could otherwise cause pinching of the tress of hair. Configuring the haircare appliance such that at least one of the edge regions is less resistant to movement than the intermediate region may reduce this pinching issue. 10 P005267-W001

[0043] In some examples, the difference between the spring rate at the edge of the first clamping surface and at a centre (i.e. with respect to a width of) the first clamping surface may be at least 2 N / mm, or e.g. at least 4 N / mm (taken in the same plane along the length of the first clamping surface). Such a spring rate difference may be in at least the second portion of the movement of the first clamping surface.

[0044] The haircare appliance may comprise an edge biasing arrangement, which may be arranged to resist movement of at least one of the edge regions in a direction away from the second clamping surface. The edge biasing arrangement may comprise the first and / or second resilient rail described above. The haircare appliance may comprise an intermediate biasing arrangement, which may be arranged to resist movement of the intermediate region in a direction away from the second clamping surface. The intermediate biasing arrangement may have a greater spring rate than the edge biasing member.

[0045] The intermediate biasing arrangement may comprise one or more compression springs. The one or more compression springs may be mounted to the housing (e.g. to the inner structure of the housing). The one or more compression springs may be disposed between the first clamping surface and the housing. The one or more compression springs may be disposed between the support structure and the housing. The one or more compression springs may be configured to urge the support structure away from the housing.

[0046] In some examples, the second clamping surface may be as described above with respect to the first clamping surface. For completeness, in such arrangements, the second clamping surface may move from the rest position to the flexed position in a direction away from the first clamping surface. In some examples, the second arm may be as described with respect to the first arm. As may be appreciated, the second arm may be a mirror image of the first arm (or may simply be rotated 180 degrees).

[0047] BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A is a side view of a haircare appliance;

[0049] Figure IB is a section view of an arm of the haircare appliance of Figure 1A, the section taken in a plane parallel to a width of the arm; 11 P005267-W001

[0050] Figure 1C is a section view of an arm of the haircare appliance of Figure 1A, the section taken in a plane parallel to a length of the arm;

[0051] Figure 2 is a side view of a resilient rail of the haircare appliance of Figure 1 A;

[0052] Figure 3 is a schematic showing clamping surfaces that are flexible in a length direction of the clamping surfaces;

[0053] Figure 4 is a schematic view showing clamping surfaces that are flexible in a width direction of the clamping surfaces; and

[0054] Figure 5 is a force vs displacement chart illustrating behaviour of a clamping surface of the haircare appliance of Figure 1 A in use.

[0055] DETAILED DESCRIPTION

[0056] Figures 1A illustrates a haircare appliance 10, in the form of hair straighteners, comprising first 11 and second 12 elongate arms that are connected by a pivot 15 so as to be moveable towards one another from an open position (as shown in Figure 1 A) to a clamping position to clamp a tress of hair therebetween. The first arm 11 comprises a first clamping surface 13, and the second arm 12 comprises a second clamping surface 14 that faces the first clamping surface 13 (these are the surfaces 13, 14 between which hair is clamped in the clamping position).

[0057] Figures IB and 1C show the interior of the first arm 11. It should be appreciated that the second arm 12 is a mirror image of the first arm 11, so the description of Figures IB and 1C below applies equally to the second arm 12.

[0058] The first arm 11 includes a C-shaped housing 16 on an opposite side of the first arm 11 to the first clamping surface 13. The housing 16 comprises an outer wall 25 that defines a convex outer surface 18 (facing away from the interior of the first arm 11) around which hair may be wrapped in use. The housing 16 also comprises an inner structure in the form of an elongate chassis 17 positioned inwardly of, and mounted to, the outer wall 25 of the housing 16. The chassis 17 may be formed of a thermally insulative material so as to reduce heat transfer to the housing 16. 12 P005267-W001

[0059] The first clamping surface 13 has a length L, which is parallel to the direction of elongation of the first arm 11, and a width W that is perpendicular to the length L. The length L of the first clamping surface 13 is longer than the width W. The first clamping surface 13 forms a surface of a clamping plate 20 of the haircare appliance. The clamping plate 20 is formed of phosphor bronze and has a thickness of about 0.2 mm, which allows the clamping plate 20 (and thus the first clamping surface 13) to flex in use.

[0060] A heater 21 is provided on an underside (as illustrated) of the clamping plate 20 (i.e. on an opposite side of the clamping plate 20 to the first clamping surface 13). The heater 21 is configured to provide heat to the clamping plate 20 in use. The heater 21 does not extend across the entirety of the clamping plate 20. Instead, (as should be apparent from Figure IB), the heater 21 is positioned so as to be adjacent to an intermediate region 28 of the clamping plate 20, which is interposed between two edge regions 29 of the clamping plate 20 (the edge regions 29 extending along edges 30 of the clamping plate 20 that they are parallel to the length L of the first clamping surface 13).

[0061] The heater 21 is supported by a support structure 22, which is located between the heater 21 and the chassis 17. This support structure 22 is urged towards the heater 21 (and the clamping plate 20) by two resilient members in the form of two helical compression springs 24 (best seen in Figure 1 C), which are spaced apart in the length direction L of the first clamping surface 13. Each compression spring 24 is positioned between the heater 21 and an inner surface 19 of the chassis 17. In the illustrated example, each compression spring 24 is configured so as to have a spring rate of 0.33 N / mm and is retained in position by a frustoconical protrusion 26 that protrudes from the inner surface 19 of the chassis 17 and into the hollow interior of the compression spring 24.

[0062] The clamping plate 20 is further supported by two further resilient members in the form of resilient rails 23, which in the illustrated example are formed of silicone rubber and have a hardness of about SHA20. Each resilient rail 23 supports a respective edge region 29 of the clamping plate 20 (and first clamping surface 13). That is, each edge region 29 of the clamping plate 20 is adjacent an upper end of a respective resilient rail 23. Each resilient 13 P005267-W001 rail 23 is, in turn, supported on the housing 16 (i.e. such that each resilient rail 23 extends from the housing 16 to the clamping plate 20).

[0063] One such resilient rail 23 is shown in more detail in Figure 2. The resilient rail 23 is elongate and includes a plurality of recesses 31, 32 formed therein. In particular, a first group of recesses 31 is arranged in a row at an upper portion 33 of the resilient rail 23, and the second group of recesses 32 is arranged in a row at a lower portion 34 of the resilient rail 23. The recesses 31 of the first group are of a different size and shape to the recesses 32 of the second group (e.g. the recesses 32 of the second group are longer in the direction of elongation of the resilient rail 23 than recesses 31 of the first group). The difference in size and shape of the recesses 31, 32 alters the spring rate provided by the resilient rail 23 as it is compressed in use.

[0064] Also mounted to the chassis 17 are two further resilient members in the form of stop members 27, which in the illustrated example are formed of silicone rubber and have a hardness of about SHA50. These are also spaced apart in the length direction L of the first clamping surface 13 and, in particular, are positioned between the two compression springs 24. As may be appreciated, the stop members 27, resilient rails 23, compression springs 24, support structure 22 and the heater 21 provide a support assembly that supports the clamping plate 20 (and thus the first clamping surface 13) in use.

[0065] The clamping plate 20 (and thus the first clamping surface 13) is flexible in both a direction along the length L of the first clamping surface 13 and in a direction along the width W of the first clamping surface 13. This flexing of the clamping plate 20 (and the first clamping surface 13) is illustrated schematically in Figures 3 and 4.

[0066] Figure 3 schematically illustrates flexing of the first 13 and second 14 clamping surfaces in a direction along their respective lengths L when a tress of hair 35 is received between the first 13 and second 14 clamping surfaces (i.e. so as to extend in the width direction W of the clamping surfaces 13, 14). As should be appreciated from Figure 3, the presence of the tress of hair 35 causes the first clamping surface 13 to flex in a direction away from the second clamping surface 14, and the second clamping surface 14 to flex in a direction 14 P005267-W001 away from the first clamping surface 13 (i.e. at the location of the tress 35). This causes the first clamping surface 13 and second clamping surface 14 to curve around the tress 35, which aids in restricting movement of the tress 35 in a direction along the lengths L of the first 13 and second 14 clamping surfaces (i.e. in the horizontal direction on the page). This control of the positioning of the tress 35 may be referred to as corralling.

[0067] Figure 4 schematically illustrates flexing of the first 13 and second 14 clamping surfaces in a direction along their respective widths W. In Figure 4, the tress of hair 35 is in the process of being removed from the clamping surfaces 13, 14. That is, the tress 35 extends only partway across the clamping surfaces 13, 14 in the width direction W. This will typically occur when a user has moved the haircare appliance 10 to the end of the tress 35, at the end of a pass along the tress 35 (and will then continue to move the haircare appliance 10 along the tress 35 until the tress 35 is completely free of the haircare appliance 10). As may be appreciated from Figure 4, the flexing of the first 13 and second 14 clamping surfaces in the width direction W can aid in release of the end of the tress 35 from between the clamping surfaces 13, 14 (i.e. without pinching or snagging the tress of hair 35).

[0068] The arrangement of each of the arms 11, 12 is such that this flexing of the clamping surfaces 13, 14 occurs in a controlled manner, so as to manage the clamping forces applied to a tress of hair in use. This control is provided by the above mentioned support assembly of each arm (i.e. made up of the stop members 27, resilient rails 23, compression springs 24, support structure 22 and the heater 21), which is configured to provide resistance to movement of the first clamping surface 13 when it is moved from a rest position (as shown in Figures IB and 1C) to a flexed position (when a tress of hair is clamped by the first clamping surface 13).

[0069] When the first clamping surface 13 is moved from a rest position (such as shown in Figures IB and 1C) to a flexed position (as shown in Figure 3), the movement can be nominally split into at least two portions of movement (a first portion and a second portion). The components of the support assembly are configured such that in the first portion of the movement, the first clamping surface 13 moves according to a first spring 15 P005267-W001 rate. Likewise, the components of the support assembly are configured such that in the second portion of the movement (in this case occurring after the first portion of movement), the first clamping surface 13 moves according to a second spring rate that is greater than the first spring rate.

[0070] In addition to the first and second portions of movement, the movement of the first clamping surface 13 may have a third portion (associated with a third spring rate) that is an initial movement resulting from the need to overcome a pre-load of the first clamping surface 13 (or clamping plate 20). This portion of the movement is typically significantly smaller than the first and second portions (i.e. so as to have minimal significance when clamping a tress of hair).

[0071] These portions of the movement of the first clamping surface 13 and their associated spring rates are best understood from Figure 5. This figure provides a chart showing how resistance (force) changes with the distance the first clamping surface 13 is deflected from its rest position.

[0072] After the initial pre-load of the clamping plate 20 is overcome (referred to henceforth as portion A of the movement), the first clamping surface 13 enters portion B of the movement (this is the “first portion” mentioned above). This occurs at point 37 on the chart of Figure 5, which is at a displacement of about 0.2 mm and a force of about 2.5 N.

[0073] In portion B of the movement, the first clamping surfaces moves according to a reduced spring rate compared to portion A. That is, in portion B of the movement, the amount of force required to move the first clamping surface 13 a given distance is reduced compared to portion A. This is represented by a shallower line in the chart of Figure 5. In portion B, the spring rate is about 5 N / mm. This reduced spring rate may help to minimise snagging of hair while also allowing corralling of the hair (as previously described in relation to Figure 3).

[0074] The spring rate of portion B of the movement is provided predominantly by the combined resistance of the compression springs 24, clamping plate 20 and the resilient rails 23. In 16 P005267-W001 portion B of the movement, the stop members 27 are not in contact with the support structure 22, so are disengaged from the first clamping surface 13, and do not contribute to the resistance to movement of the first clamping surface. However, as the first clamping surface 13 continues to move (as a result of further clamping a tress of hair by movement of the clamping surfaces 13, 14 towards one another), the support structure 22 comes into contact with the stop members 27. This is represented by point 38 on the chart of Figure 5. At point 38, in the illustrated example, the first clamping surface 13 has moved about 1 mm and the force required to move the first clamping surface 13 that distance is about 6 N.

[0075] The contact with the stop members 27 means that the stop members 27 also provide resistance to further movement of the first clamping surface 13. As a result, the spring rate in portion C (referred to as the second spring rate above) increases significantly to about 35 N / mm.

[0076] Even though the spring rate increases significantly from portion B to portion C, the resilient nature of the stop members 27 means that the first clamping surface 13 is able to continue to move (i.e. the provision of resilient stop members 27 avoids a hard stop). By allowing such movement (rather than providing a hard stop), pinching and snagging of a user’s hair may be reduced. Portion C of the movement also allows a user to exert tension on the hair, and to control that tension by adjusting the clamping force applied by the first clamping surface 13. Likewise, due to the higher clamping forces that can be achieved in portion C of the movement, a better transfer of heat may be provided between the clamping plate 20 and clamped hair.

[0077] Accordingly, in general terms, the provision of at least two spring rates may provide the user with better control of the tension applied to their hair, which may reduce snagging of hair and provide increased comfort.

[0078] To further reduce snagging (especially in circumstances where the end of a tress of hair is being drawn between the first 13 and second 14 clamping surfaces as discussed with respect to Figure 4 above), the haircare appliance of Figures 1A, IB and 1C is configured 17 P005267-W001 so as to provide varying spring rate across the width W of each of the first 13 and second 14 clamping surfaces.

[0079] This is best explained with reference to Figure IB. As can be seen in this figure (and as explained above) opposite edge regions 29 of the clamping plate 20 (and thus the first clamping surface 13 of the clamping plate 20) are supported by resilient rails 23. On the other hand, the intermediate region 28 of the clamping plate 20 (and thus the first clamping surface 13) is supported by the two compression springs 24 via the support structure 22. The two compression springs 24 are configured to provide greater resistance to movement (via flexing) of the clamping plate 20 than each resilient rail 23 (i.e. each resilient rail 23 has a lower springs rate than is provided by the two compression springs 24). Consequently, the first clamping surface 13 will more readily deflect at the edge regions 29 than in the intermediate region 28. This will mean the end of a tress of hair being drawn across the first 13 and second 14 clamping surfaces will experience less of a compression force (translating to less tension in the hair) as it passes the centre of the clamping surfaces 13, 14 (i.e. as it passes from the intermediate region 28 to one of the edge regions 29). This may reduce snagging of the tress of hair.

[0080] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

[0081] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

Claims

18 P005267-W001CLAIMS1. A haircare appliance comprising: first and second arms that are moveable towards one another to clamp a tress of hair therebetween, the first arm comprising a first clamping surface having a length and being flexible in a direction along the length so as to be moveable from a rest position to a flexed position when a tress of hair is clamped between the first and second arms; a heater configured to heat hair in contact with the first clamping surface; and a support assembly configured to provide resistance to movement of the first clamping surface, the support assembly configured such that when the first clamping surface is moved from the rest position to the flexed position: in a first portion of the movement, the first clamping surface moves according to a first spring rate; and in a second portion of the movement, the first clamping surface moves according to a second spring rate that is greater than the first spring rate.

2. The haircare appliance according to claim 1, wherein the first portion of the movement occurs before the second portion of the movement when the first clamping surface is moved from the rest position to the flexed position.

3. The haircare appliance according to claim 1 or 2, wherein a difference between the first and second springs rates is at least 10 N / mm.

4. The haircare appliance according to any one of the preceding claims, wherein the first spring rate is less than 15 N / mm.

5. The haircare appliance according to any one of the preceding claims, wherein the second spring rate is less than 100 N / mm.19 P005267-W0016. The haircare appliance according to any one of the preceding claims, wherein the support assembly comprises first and second resilient members.

7. The haircare appliance according to claim 6, wherein the first resilient member has different spring rate to the second resilient member.

8. The haircare appliance according to claim 6 or 7, wherein the second resilient member is arranged so as not to resist movement of the first clamping surface in the first portion of movement.

9. The haircare appliance according to any one of claims 6 to 8, wherein the second resilient member is arranged to directly or indirectly engage the first clamping surface when in the flexed position, and to be disengaged from the first clamping surface when in the rest position.

10. The haircare appliance according to any one of claims 6 to 9, wherein the first resilient member is arranged to directly or indirectly engage the first clamping surface in both the rest position and the flexed position.

11. The haircare appliance according to any one of the preceding claims, wherein the support assembly comprises a resilient rail arranged to support an edge region of the first clamping surface.

12. The haircare appliance according to claim 11, wherein the resilient rail comprises a plurality of recesses formed therein to facilitate compression of the resilient rail.

13. The haircare appliance according to claim 12, wherein the plurality of recesses comprises: a first group of recesses formed in a first portion of the resilient rail, the first group of recesses sized and shaped to provide the first portion of the resilient rail with a spring rate; and20 P005267-W001 a second group of recesses formed in a second portion of the resilient rail, the second group of recesses sized and shaped to provide the second portion of the resilient rail with a spring rate that is different to the spring rate of the first portion.

14. The haircare appliance according to any one of the preceding claims, wherein the support assembly comprises a resilient stop member.

15. The haircare appliance according to any one of the preceding claims, wherein in a third portion of the movement of the first clamping surface from the rest position to the flexed position, the first clamping surface moves according to a third spring rate.

16. The haircare appliance according to claim 15, wherein the third portion of the movement occurs before the first portion of the movement when the first clamping surface is moved from the rest position to the flexed position.

17. The haircare appliance according to claim 16, wherein the third spring rate is greater than the first spring rate.

18. The haircare appliance according to any one of the preceding claims, wherein the first clamping surface has a width that is perpendicular to the length, and the first clamping surface is flexible in a direction along the width of the first clamping surface.

19. The haircare appliance according to claim 18, wherein the first clamping surface comprises opposite edge regions extending along lengthwise edges of the first clamping surface, and an intermediate region interposed between the edge regions, and wherein at least one of the edge regions is less resistant than the intermediate region to movement in a direction away from a second clamping surface provided on the second arm.

20. The haircare appliance according to claim 19, comprising: an edge biasing arrangement arranged to resist movement of at least one of the edge regions in a direction away from the second clamping surface; and21 P005267-W001 an intermediate biasing arrangement arranged to resist movement of the intermediate region in a direction away from the second clamping surface; wherein the intermediate biasing arrangement has a greater spring rate than the edge biasing member.

21. The haircare appliance according to claim 20, wherein the intermediate biasing arrangement comprises one or more compression springs.

22. The haircare appliance according to any one of the preceding claims, comprising a clamping plate defining the first clamping surface, and wherein the clamping plate is of uniform thickness.

23. The haircare appliance according to claim 22, wherein the clamping plate has a thickness of less than 0.5 mm.

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