Technical Field

[0001] The present invention relates to heating plates such as those used in hair straighteners

Background of the Invention

[0002] Hair straighteners typically include a pair of substantially flat heating plates attached to rotatably coupled frames whereby the heating plates are able to be firmly clamped around a section of hair to be straightened When the heating plates are slid along the length of hair, the heat transferred from the heating plates to the hair serves to break down the hydrogen bonds found in the cortex of each hair thereby alleviating each hair's tendency to curl

[0003] However, prior art heating plates of hair straighteners tend to be difficult to direct towards the roots of the hair section and this may result in an uneven application of heat transfer along a full length of the hair section Consequently, the full length of the hair section may not appear to be uniformly straightened

[0004] A further problem with existing prior art hair straighteners is that when applying the heating plates to a particular section of hair, parts of the heating plate which are not necessarily in use, tend to be oriented in close proximity to the head of the person such that a risk of inadvertent burning to the head may exist

[0005] Typically, during the process of hair straightening, a person's hair is separated into sections This is often achieved by running the hair straighter through the person's hair as a divider Unfortunately, certain prior art hair straighteners do not perform this function well due at least partially to the squared-shaped end of the heating plates which do not lend themselves well to penetrating through clumps of hair Summary of the Invention

[0006] The present invention seeks to alleviate at least one of the problems discussed above in relation to the prior art

[0007] The present invention may involve several broad forms Embodiments of the present invention may include one or any combination of the different broad forms herein described

[0008] In a first broad form, the present invention provides a heating plate for a hair straightener including a substantially planar hair engagement surface and at least a first and a second edge defining a periphery of a first end of the hair engagement surface, wherein at least one of the first and second edges includes a tapered-shape profile

[0009] Typically, the tapered-shape profile may include a least one of a concurve- shape profile, a convex-shape profile and a triangular-shape profile

[0010] Typically, the tapered-shape profile extends at least a third of a length of the hair engagement surface of the heating plate

[001 1] Typically, the second edge may include a shape profile which is substantially symmetrical with the shape profile of the first edge Accordingly, the first and second edges may cooperatively and substantially resemble at least one of a partial-ellipse shape profile, a dome-shape profile, a bullet-head shape profile and an isosceles triangle shape profile

[0012] Alternatively, the second edge may include a shape profile which is substantially asymmetrical with the shape profile of the first edge The first edge and the second edge may also include different tapered-shape profiles For instance, the first edge may include a concurve-shape profile whilst the second edge may include a triangular-shape profile, the first edge may include a concurve-shape profile whilst the second edge may include a concave-shape profile, yet alternatively, the first edge may include a triangular-shape profile whilst the second edge may include a concave-shape profile [0013] Typically, at least one of the first and second edges of the heating plate may be adapted for releasable attachment to a frame of a hair straightener

[0014] Preferably, the heating plate may include an aluminium material Other materials providing suitable heat conductivity may also be used

[0015] In a second broad form, the present invention provides a heating plate for a hair straightener including a substantially planar hair engagement surface and at least a first and a second edge defining a periphery of a first end of the hair engagement surface, wherein at least one of the first and second edges includes a curved profile

[0016] Typically, the curved profile includes at least one of a concurve profile and a concave profile

[0017] In a third broad form, the present invention provides a hair straightener including a heating plate as described in accordance with the first or second broad forms of the present invention

[0018] Typically, the hair straightener includes a frame having first and second rotatably coupled frame arms adapted for mounting a corresponding first and second heating plates thereon

[0019] Preferably, the first and second rotatably coupled frames include substantially similar tapered shape profiles as the first and second heating plates which are mounted thereon respectively

[0020] Typically, at least one of the first and second edges of the first or second heating plate may be releasably attachable to the frame

[0021] In a fourth broad form, the present invention provides a heating plate for a hair straightener, said heating plate being generally elongate and having a substantially planar hair engagement surface for engagement with and application of heat to the hair of a subject, and having a first end portion, an opposed second end, a longitudinal axis extending in a direction of from the second end towards the first end, and a transverse axis generally normal to the longitudinal axis and being generally parallel to the hair engagement surface, wherein the first end portion is of a reduced transverse taper in the longitudinal direction towards the first end, and wherein the first end portion has an external periphery and is tapered in a manner so as to allow hair adjacent the first end portion to be engaged with the engagement surface when the external periphery is adjacent the head of a subject whilst in use

[0022] In a fifth broad form, the present invention provides a hair straightener including at least one heating plate in accordance with the fourth broad form of the present invention

[0023] Preferably, the hair straightener includes a second heating plate according to the fourth broad form of the present invention, wherein said first and second heating plates are disposed such that their hair engagement surfaces are in an opposed relationship and moveable towards each other so as to allow hair of a subject to be abutted therebetween for straightening of said hair

[0024] Preferably, the hair straightener includes a frame having first and second rotatably coupled frame arms adapted for mounting the first and second heating plates thereon

[0025] Preferably, the first and second rotatably coupled frame arms include substantially similar tapered shape profiles as the first and second heating plates which are mounted thereon respectively

[0026] Preferably, at least one of the first and second edges of at least one of the first and second heating plates are releasably attachable to the frame

[0027] In a sixth broad form, the present invention provides a method of forming a heating plate as described in accordance with the first, second and fourth broad forms of the present invention, wherein the heating plate is formed by punching an outline of the heating plate from a sheet of metal such as aluminium

[0028] In a seventh broad form, the present invention includes a heating plate in accordance with any one of the first, second and fourth broad forms of the present invention wherein the heating plate is formed by sintered metal process

[0029] Preferably, the heating plate includes at least aluminium Brief Description of the Drawings

[0030] The present invention will become more fully understood from the following detailed description of a preferred but non-limiting embodiment thereof, described in connection with the accompanying drawings, wherein

• Figure 1 shows a perspective view of a first embodiment first and second heating plates fitted to a hair straightener

• Figure 2 shows a further embodiment of a heating plate wherein the heating plate is detached from a hair straightener, the heating plate including first and second releasably attachable edges to enable selectably interchangeable combinations of edge shape profiles to be provided,

• Figure 3 shows a prior art squared-edge heating plate engaging with a hair line of a section of hair to be straightened whereby it is unable to engage substantially uniformly with the bulk of roots of the hair section,

• Figure 4 shows the first embodiment heating plate engaging with the roots of a section of hair to be straightened whereby the tapered edge substantially complements a hair line contour of a hair section to be straightened

Detailed Description of Preferred Embodiments

[0031] Preferred embodiments of the present invention will now be described with reference to Figs 1-4

[0032] Turning firstly to Fig 1 , corresponding first embodiment heating plates (1a, 1b) are shown in perspective view fitted to upper and lower frames (2a, 2b) of a hair straightener (2)

[0033] The first embodiment will be described only in relation to the heating plate (1 b) fitted to the lower frame (2b), but, it should be appreciated that the following description is applicable to the substantially identical heating plate (1a) fitted to the upper frame (2a) of the hair straightener (2)

[0034] The heating plate (1 b) includes a substantially planar hair engagement surface (1c) and first and a second edges (1d,1e) defining a periphery of first end (1f) of the hair engagement surface (1c)

[0035] The upper and lower frames (2a, 2b) are rotatably coupled to each other around a hinge (2c) whereby the heating plates (1a, 1b) are able to be rotatably clamped together around a section of hair (3) during straightening Figure 1 shows the upper and lower frames (2a, 2b) arranged in the opened position prior to clamping upon the section of hair (3) Surfaces of the upper and lower frames (1a, 1b) upon which the corresponding first and second heating plates (1a, 1b) are fitted include substantially similar shape profiles such that the hair straighter is relatively streamlined Furthermore, outward-facing surfaces of the first and second frames (1a, 1b) include substantially curved contours which further provide the hair straightener with a relatively streamlined shape

[0036] The hair straightener (2) includes a power cord (2g) for connection with a mam power supply The power cord (2g) includes a ringlet (2b) to allow the hair straightener (2) to be suspended from a hook if desired The hair straightener (2) further includes a control switch (2d) for controlling the temperature of the heating plates (1a, 1b) and hence the amount of heat that may be transferred to the hair (3) in use The hair straightener (2) also includes an on/off button implemented by way of a sliding switch (2f) disposed on the upper frame (1a) of the hair straightener (2)

[0037] The first and second edges (1d,1e) of the hair engagement surface (1c) each include substantially concurve-shape profiles which cooperatively, and substantially, form a bullet-head shaped end profile of the periphery of the hair engagement surface (1c)

[0038] Advantageously, as shown in Fig 4, the tapered shape profile of at least one of the first and second edges (1d,1e) may assist a user in positioning the hair engagement surface (1c) in closer and more uniform contact with the roots (3) at the hair line (3c) of a section of hair (3) to be straightened Consequently, the hair engagement surface (1c) may then be applied more uniformly substantially along an entire length of the hair (3) from the roots (3) to the tips (3d) In contrast, the deficiency in the prior art is depicted in Fig 3 in which the squared-edge (4a) of the prior art heating plate (4) is unable to substantially engage in uniform fashion with the roots (3) at the hair line (3c)

[0039] Moreover, the tapered-shape profile allows a user to selectively angle only the first end (1f) of the hair engagement surface (1c) inwardly towards the roots (3) to enable closer proximity and more uniform contact with the roots (3) of the hair (3) to be straightened whilst at the same time enabling an unused region (1g) of the hair engagement surface (1c) to be positioned outwardly away from the person's head (not shown) in use in order to alleviate the risk of inadvertently burning the head In contrast, the relatively dangerous proximity of a substantially rectangular-shaped prior art heating plate (4), when engaging with the hair (3) - that is, the unused portion (4b) of the prior art heating plate (4) extends linearly in close proximity to the head where inadvertent burning may arise

[0040] Also advantageously, in use, the tapered-shape profile of at least one of the first and second edges (1e,1e) of the heat engagement surface (1c) may assist in sectioning or partitioning the hair (3) due to the relatively streamlined configuration of the tapered-shape profile which is relatively easier to penetrate through the hair (3) during sectioning In contrast, with prior art hair straighteners, the non-streamlined squared ends of the heating plates do not lend themselves towards ease of partitioning or penetrating through the person's hair

[0041] It should be readily appreciated by a person skilled in the art that the aforementioned advantages may be provided in alternative embodiments where only one of the shape profiles of the first and/or second edges include a tapered-shape profile

[0042] The bullet-head shape profile is substantially symmetrical relative to an elongate axis (1h) of the hair engagement surface (1c)

[0043] Referring now to Fig 2, a second embodiment heating plate (5) is shown in which a first edge (5b) of the heat engagement surface (5a) includes a shape profile which is substantially asymmetrical with a shape profile of a second edge (5c) Specifically, the first edge (5b) includes a triangular-shape profile whilst the second edge includes a concurve shape profile [0044] Alternative combinations of first and second edge shape profiles may be employed in other embodiments. For instance, the first edge may include a concurve-shape profile whilst the second edge may include a concave-shape profile, or, the first edge may include a triangular shape profile whilst the second edge may include a concave-shape profile.

[0045] The heating plates (1 ,5) described in relation to the first and second embodiments are made from aluminium which provides suitable heat conductivity from the heating plates (1 ,5) to the hair (3) in use. More specifically, the heating plates (1 ,5) are formed by punching the heating plates from a sheet of aluminium or other suitably heat conductive metal.

[0046] In certain embodiments of the present invention, the first and second edges of the heating plate are releasably attachable to a frame of the hair straightener using a suitable attachment means. For instance the attachment means may include screwing the heating plate into position upon a support surface of the lower frame.

[0047] Advantageously, by allowing the first and second edges to be releasably attachable, this may conveniently enable selectable interchanging of first and second edges having different shape profiles each of which may be particularly suitable for use with different head shape contours and/or different orientations of the person's hair to be straightened. Moreover, the selectable interchangeability of first and second edges may provide commercial advantages in that the hair straightener may be conveniently sold separately to the heating plates so as to enable more flexible user-choice in selecting first and second edges which are of specific use to the user. Moreover, if a first or second edge of the heating plate is damaged in use, a user may conveniently purchase a suitable replacement first or second edge for the hair straightener. Alternatively, the heating plate may have different shape contours formed into the heating plate at the point of manufacture. In this case, selectable interchangability may not be available, however, the different shape contours on each edge of the heating plate may still provide great flexibility in use when straightening the hair of different persons.

[0048] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described without departing from the scope of the invention. All such variations and modification which become apparent to persons skilled in the art, should be considered to fall within the spirit and scope of the invention as broadly hereinbefore described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps and features, referred or indicated in the specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

[0049] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge.